阅读说明：本技术 用于处理设备的过滤器 (Filter for a treatment device ) 是由 加雷思·埃文·林恩·琼斯 于 2018-12-19 设计创作，主要内容包括：一种用于设备的离心过滤单元,其中所述设备用于使用处理制剂处理基材,所述离心过滤单元包括：a)壳体,其具有出口,所述出口被配置成允许滤液离开所述离心过滤单元；b)过滤器,可旋转地安装在所述壳体内,其中所述过滤器包括：第一端,靠近所述壳体的第一端；第二端,靠近所述壳体的第二端；和侧壁,连接所述过滤器的第一端和所述过滤器的第二端；其中所述过滤器的第一端、第二端和侧壁限定一过滤室,且其中所述侧壁包括穿孔,所述穿孔被配置成允许液体通过但防止固体材料通过；c)端盖,被配置成基本上密封所述壳体的第一端；d)入口,被配置成允许进料进入所述过滤室；e)盖体,位于所述过滤器的第一端,其中所述盖体包括与所述入口配合的孔,以允许进料进入所述过滤室；f)驱动装置,用于旋转所述过滤器；以及g)叶轮,所述叶轮包含在所述过滤室中；其中,所述离心过滤单元被配置成当所述叶轮旋转时,所述进料通过所述入口吸入所述过滤室,并且液体通过所述穿孔排出。(A centrifugal filtration unit for an apparatus for treating a substrate with a treatment formulation, the centrifugal filtration unit comprising: a) a housing having an outlet configured to allow filtrate to exit the centrifugal filtration unit; b) a filter rotatably mounted within the housing, wherein the filter comprises: a first end proximate the first end of the housing; a second end proximate the second end of the housing; and a sidewall connecting a first end of the filter and a second end of the filter; wherein the first end, second end, and sidewall of the filter define a filter chamber, and wherein the sidewall includes perforations configured to allow liquid to pass through but prevent solid material from passing through; c) an end cap configured to substantially seal a first end of the housing; d) an inlet configured to allow feed to enter the filtration chamber; e) a cover at a first end of the filter, wherein the cover includes an aperture that mates with the inlet to allow feed to enter the filter chamber; f) a drive means for rotating the filter; and g) an impeller contained in the filter chamber; wherein the centrifugal filter unit is configured such that when the impeller is rotated, the feed is drawn into the filter chamber through the inlet and liquid is discharged through the perforations.)

1. A centrifugal filtration unit for an apparatus for treating a substrate with a treatment formulation, the centrifugal filtration unit comprising;

a) a housing having an outlet configured to allow filtrate to exit the centrifugal filtration unit;

b) a filter rotatably mounted within the housing, wherein the filter comprises: a first end proximate the first end of the housing; a second end proximate the second end of the housing; and a sidewall connecting a first end of the filter and a second end of the filter; wherein the first end, second end, and sidewall of the filter define a filter chamber, and wherein the sidewall includes perforations configured to allow liquid to pass through but prevent solid material from passing through;

c) an end cap configured to substantially seal a first end of the housing;

d) an inlet configured to allow feed to enter the filtration chamber;

e) a cover at a first end of the filter, wherein the cover includes an aperture that mates with the inlet to allow the feed to enter the filtration chamber;

f) a drive means for rotating the filter; and

g) an impeller contained in the filter chamber;

wherein the centrifugal filter unit is configured such that when the impeller is rotated, the feed is drawn into the filter chamber through the inlet and liquid is expelled through the perforations.

2. A centrifugal filtration unit for an apparatus for treating a substrate with a treatment formulation, the centrifugal filtration unit comprising;

a) a housing having an outlet configured to allow filtrate to exit the centrifugal filtration unit;

b) a filter rotatably mounted within the housing, wherein the filter comprises: a first end proximate the first end of the housing; a second end proximate the second end of the housing; and a sidewall connecting a first end of the filter and a second end of the filter; wherein the first end, second end, and sidewall of the filter define a filter chamber, and wherein the sidewall includes perforations configured to allow liquid to pass through but prevent solid material from passing through;

c) an inlet configured to allow feed to enter the filtration chamber;

d) a cover at a first end of the filter, wherein the cover includes an aperture that mates with the inlet to allow the feed to enter the filtration chamber;

e) a drive means for rotating the filter; and

f) an impeller contained in the filter chamber.

3. A centrifugal filter unit as recited in claim 2, further comprising an end cap configured to substantially seal the first end of the housing.

4. A centrifugal filtration unit as claimed in claim 1, 2 or 3 wherein the impeller is coupled to the filter such that the impeller rotates at the same speed as the filter.

5. A centrifugal filter unit as claimed in claim 1 or 3, wherein the end cap is openable.

6. A centrifugal filtration unit for an apparatus for treating a substrate with a treatment formulation, the centrifugal filtration unit comprising;

a) a housing having an outlet configured to allow filtrate to exit the centrifugal filtration unit;

b) a filter rotatably mounted within the housing, wherein the filter comprises: a first end proximate the first end of the housing; a second end proximate the second end of the housing; and a sidewall connecting a first end of the filter and a second end of the filter; wherein the first end, the second end, and the sidewall of the filter define a filter chamber, the sidewall including perforations configured to allow passage of liquid but prevent passage of solid material;

c) an end cap configured to substantially seal a first end of the housing; wherein the end cap is openable;

d) an inlet configured to allow feed to enter the filtration chamber;

e) a cover at a first end of the filter, wherein the cover includes an aperture that mates with the inlet to allow feed to enter the filter chamber;

f) a drive means for rotating the filter; and

g) a detachable portion configured to be positioned in the filtration chamber during operation of the centrifugal filtration unit and to remove and carry the solid material at least partially prevented from passing through the perforations from the filtration chamber after operation of the centrifugal filtration unit.

7. A centrifugal filtration unit for an apparatus for treating a substrate with a treatment formulation, the centrifugal filtration unit comprising;

a) a housing having an outlet configured to allow filtrate to exit the centrifugal filtration unit;

b) a filter rotatably mounted within the housing, wherein the filter comprises: a first end proximate the first end of the housing; a second end proximate the second end of the housing; and a sidewall connecting a first end of the filter and a second end of the filter; wherein the first end, the second end, and the sidewall of the filter define a filter chamber, the sidewall including perforations configured to allow passage of liquid but prevent passage of solid material;

c) an inlet configured to allow feed to enter the filtration chamber;

d) a cover at a first end of the filter, wherein the cover includes an aperture that mates with the inlet to allow the feed to enter the filtration chamber;

e) a drive means for rotating the filter; and

f) a detachable portion configured to be positioned in the filtration chamber during operation of the centrifugal filtration unit and to remove and carry the solid material at least partially prevented from passing through the perforations from the filtration chamber after operation of the centrifugal filtration unit.

8. A centrifugal filter unit as recited in claim 7, further comprising an end cap, wherein the end cap is openable.

9. The centrifugal filtration unit of any one of claims 6-8, wherein the detachable portion is configured to rotate with the filter.

10. The centrifugal filter unit of any of claims 6-9, wherein the removable portion comprises a plunger.

11. A centrifugal filter unit as claimed in any one of claims 6 to 10, wherein said detachable portion has substantially the same shape as the cross-section through said filter chamber at the side wall of said filter.

12. A centrifugal filter unit as claimed in any one of claims 6 to 10 wherein at least a portion of the detachable portion has substantially the same shape as the cross-section of the filter chamber through the side wall of the filter.

13. A centrifugal filter unit as claimed in any one of claims 6 to 12 wherein said detachable portion is shaped to scrape against said side wall during removal of said detachable portion from said filter chamber.

14. A centrifugal filter unit as claimed in any one of claims 6 to 13 wherein said removable portion comprises a plurality of brushes disposed on said removable portion adjacent the side wall of said filter.

15. A centrifugal filter unit as claimed in any one of claims 6 to 14 wherein the removable portion comprises a cover.

16. The centrifugal filter unit of any of claims 6-15, further comprising an impeller contained in the filter chamber.

17. The centrifugal filter unit of claim 16, wherein the impeller is coupled to the filter such that the impeller rotates at the same speed as the filter.

18. A centrifugal filter unit as claimed in claim 16 or 17 wherein the centrifugal filter unit is configured such that when the impeller is rotated, the feed is drawn into the filter chamber through the inlet and liquid is expelled through the perforations.

19. The centrifugal filter unit of any of claims 16-18, wherein the removable portion comprises an impeller.

20. The centrifugal filter unit of claim 19, further comprising an impeller, wherein the removable portion comprises the impeller and the cover.

21. A centrifugal filtration unit according to any one of claims 6 to 20 wherein the removable portion is separated from the filter by a twist-lock mechanism.

22. A centrifugal filter unit as claimed in any one of the preceding claims wherein the housing and the filter are cylindrical.

23. The centrifugal filter unit of any of claims 1-21, wherein the housing is conical and the filter is cylindrical, or both the housing and the filter are conical.

24. The centrifugal filter unit of any one of the preceding claims, wherein the filter is removable from the housing.

25. A centrifugal filtration unit according to any preceding claim, further comprising a controller for the drive means, the controller being programmed to cause the drive means to drive the filter in rotation at a first speed to filter the solid material from the feed and a second speed to dewater the filtered solid material.

26. The centrifugal filter unit of any preceding claim, wherein the cover is configured to rotate with the filter.

27. A centrifugal filter unit as claimed in any one of the preceding claims when dependent on claim 1,3,5,6 or 8 wherein the cover forms a labyrinth seal with the end cap.

28. The centrifugal filter unit of claim 27, wherein the cover comprises a first plurality of concentric rings located on a side of the cover facing away from the filter chamber, and the end cap comprises a second plurality of concentric rings facing a side of the end cap of the filter chamber, wherein the first and second plurality of concentric rings are interspersed with respect to one another to form a labyrinth seal.

29. A centrifugal filter unit according to any one of the preceding claims further comprising an air release mechanism.

30. The centrifugal filter unit of claim 29, wherein said air release mechanism is contained in said cover.

31. The centrifugal filter unit of claim 30, wherein said air release mechanism comprises a channel having a first end, a second end, and a midpoint, wherein the first end of said channel is located on a side of said cover facing said filter chamber and the second end of said channel is located on a side of said cover facing away from said filter chamber, wherein the midpoint of said channel is positioned at a distance from the axis of rotation of said filter that is less than the distance between the first and second ends of said channel and the axis of rotation of said filter.

32. A centrifugal filter unit as claimed in claim 31 wherein the channel has a u-bend shape.

33. The centrifugal filter unit of claim 29, wherein the air release mechanism is contained within the housing.

34. A centrifugal filter unit as claimed in claim 29 when dependent on claim 1,3,5,6 or 8 wherein the air release mechanism is contained within the end cap.

35. The centrifugal filter unit of claim 34, wherein said air release mechanism includes a second outlet disposed in said end cap.

36. The centrifugal filter unit of claim 34, wherein the second outlet includes a closure movable between a closed position preventing air from flowing out of the second outlet and an open position allowing air to flow out of the second outlet.

37. A centrifugal filter unit according to any one of claims 1 to 26 when dependent on claim 1,3,5,6 or 8 wherein the cover is contained within the end cap.

38. A centrifugal filter unit as claimed in any one of the preceding claims when dependent on claim 1,3,5,6 or 8 further comprising attachment means to secure the end cap to the housing.

39. A centrifugal filter unit as claimed in any one of the preceding claims when dependent on claim 1,3,5,6 or 8 wherein the end cap includes the inlet.

40. A centrifugal filter unit as claimed in any one of the preceding claims wherein at least a portion of the housing is transparent.

41. The centrifugal filter unit of any one of the preceding claims, wherein the centrifugal filter unit is configured to operate in a substantially horizontal orientation.

42. The centrifugal filter unit of any of claims 1-40, wherein the centrifugal filter unit is configured to operate in a substantially vertical orientation.

43. A centrifugal filtration unit according to claim 42, further comprising an overflow mechanism.

44. The centrifugal filter unit of claim 43, wherein the overflow mechanism comprises an overflow aperture and an overflow collection chamber fluidly connected to the aperture.

45. A centrifugal filter unit as claimed in claim 44 wherein the overflow aperture is incorporated in the cover of the filter and/or in a side wall of the filter chamber.

46. A centrifugal filtration unit according to claim 44 or 45, wherein the overflow collection chamber comprises an overflow outlet.

47. A centrifugal filter unit as claimed in any one of claims 44 to 46 when dependent on claims 1,3,5,6 or 8 wherein the overflow collection chamber is contained within the end cap.

48. The centrifugal filter unit of claims 44-47, wherein the overflow mechanism further comprises an overflow sensor disposed in the overflow collection chamber.

49. A centrifugal filter unit as claimed in any one of the preceding claims, wherein the apparatus is a textile treatment apparatus.

50. A centrifugal filter unit as claimed in any one of the preceding claims wherein the apparatus is a washing machine.

51. An apparatus for treating a substrate with a treatment formulation, the apparatus comprising:

a) a tub rotatably mounting a drum having a plurality of sidewalls including one or more apertures configured to allow the treatment formulation to exit the drum;

b an access device movable between an open position for placing at least one substrate in the drum and a closed position for substantially sealing the apparatus;

c) a collector located below the drum and configured to collect the treatment formulation flowing from the drum;

d) a centrifugal filtration unit according to any one of claims 1-50; and

e) a first flow passage between the collector and the inlet of the centrifugal filter unit.

52. The apparatus of claim 51, wherein the outlet of the centrifugal filter unit is fluidly connected to the bowl.

53. The apparatus of claim 51, wherein said outlet of said centrifugal filter unit is fluidly connected to said drain.

54. An apparatus according to claim 51, further comprising a control valve configured such that filtrate flowing from the outlet of the centrifugal filter unit is selectively recirculated to the bowl or delivered to the drain.

55. An apparatus according to claim 51 or 52, further comprising recirculation means for recirculating the treatment formulation from the collector to the drum, wherein the centrifugal filtration unit is contained in the recirculation means.

56. The apparatus of any one of claims 51 to 55, wherein the apparatus is configured to enable treatment of a substrate with the treatment formulation in the presence of a solid particulate material.

57. An apparatus as claimed in claim 51, wherein said solid particulate material cannot exit said drum through said apertures.

58. An apparatus as claimed in any one of claims 51 to 57, characterized in that the apparatus is a textile treatment apparatus.

59. The apparatus of any one of claims 51 to 58, wherein the apparatus is a washing machine.

60. A method of filtering a treatment formulation in an apparatus as claimed in any one of claims 51 to 59, comprising operating drive means to rotate the filter of the centrifugal filtration unit at a first speed and transfer treatment formulation from the collector to the inlet of the centrifugal filtration unit, wherein at least a portion of liquid from the treatment formulation flows through the filter and at least a portion of solid material from the treatment formulation is prevented from passing through the filter.

61. A method as claimed in claim 60, wherein said centrifugal filter unit comprises an impeller disposed in a centrifugal filter chamber, wherein said impeller effects transfer of said treatment formulation from said collector to said inlet of said centrifugal filter unit.

62. A method as claimed in claim 60 or 61, further comprising the step of transferring filtrate flowing from the outlet of the housing of the centrifugal filtration unit into the bowl.

63. The method of claim 60 or 61, further comprising the step of diverting filtrate flowing from the outlet of the housing of the centrifugal filtration unit to the drain.

64. A method as claimed in any one of claims 60 to 63 further comprising the step of operating the drive means to increase the rotational speed of the filter from the first speed to a second speed higher than the first speed in order to dewater the solid material collected in the filter chamber.

65. A method as claimed in any one of claims 60 to 64, further comprising the step of opening the end cap of the centrifugal filtration unit and extracting the solid material collected in the filtration chamber.

66. A method of treating a substrate comprising treating the substrate with a treatment formulation using the apparatus of any one of claims 51 to 59.

67. The method of claim 66, comprising the steps of:

a) loading at least one of said substrates onto said drum and closing said entry means;

b) introducing the treatment formulation into the drum;

c) rotating the drum;

d) collecting the treatment formulation from the drum to the collector; and

e) operating a pumping device to pump the treatment formulation from the collector to the centrifugal filtration unit and to pump the filtrate from the centrifugal filtration unit back to the bowl or drain.

68. A method as claimed in claim 67, wherein said pumping means comprises an impeller disposed in said filtration chamber of said centrifugal filtration unit.

Technical Field

The present disclosure relates to a centrifugal filtration unit for a treatment apparatus for treating a substrate, in particular a textile substrate or a substrate comprising a textile, with a treatment formulation, and to a treatment apparatus comprising the filter. The disclosure also relates to methods of filtering treatment formulations and methods of treating substrates.

Background

Conventional methods of treating and cleaning textiles and fabrics typically involve water cleaning using large amounts of water. These methods typically involve water immersion of the fabric, followed by removal of the contaminants, suspension of the aqueous contaminants and rinsing with water. The use of solid particles to improve and optimize these conventional processes is known in the art. For example, PCT patent publication WO2007/128962 discloses a method of cleaning a soiled substrate using a variety of solid particles. Other PCT patent publications disclosing related cleaning methods include: WO 2012/056252; WO 2014/006424; WO 2015/004444; WO 2014/147391; WO 2014/006425; WO2012/035343 and WO 2012/167545. These disclosures disclose apparatus and methods for treating or cleaning substrates that have several advantages over conventional methods, including: improved treatment/cleaning performance, reduced water consumption, reduced consumption of detergents and other treatment agents, and better low temperature treatment/cleaning (and thus more energy efficient treatment/cleaning). Other patent publications, such as WO2014/167358, WO2014/167359, WO2016/051189, WO2016/055789, and WO2016/055788, etc., all disclose the advantages of solid particles in other areas of leather processing and leather making.

However, in the conventional methods using a large amount of water and the methods using solid particles, there is still a problem that solid waste fibers and particles such as lint from the substrate should be sufficiently removed before the discharge liquid of these methods enters the drain. In particular, the treatment (e.g., washing) of garments made of synthetic materials such as acrylic, nylon, and polyester results in the removal of fine particles or fibers from the garments and the carry-over of the effluent to the sewer. Microfibers made of synthetic material can reach waterways, negatively affecting rivers and marine life. With the growing awareness of the potential damage caused by waste plastic materials to rivers, lakes, oceans and oceans, there is an increasing demand for a substantial reduction or elimination of solid materials from entering drainage and sewage systems. The United Nations Goal 14(United Nations Goal 14) involves the prevention and substantial reduction of various marine pollutions, including marine waste and nutrient pollution, especially pollution caused by land activities.

US 6,820,446B 2 discloses a centrifugal force filtering device for filtering flocs from sewage, wherein the flocs are formed by flocculating chemical contaminants in water using a flocculating agent. The flocs are lighter than water and therefore concentrate in the central portion of the filter cartridge and become sparse in the peripheral portion. This is said to prevent flocs from adhering to the circumferential surface of the filter cartridge, thereby clogging the circumferential surface of the filter cartridge. However, US 6,820,446B 2 does not address the problem of removing solid waste fibers and particles from the substrate during substrate processing or in the presence of solid material build-up on the filter surface from the treatment formulation.

EP 0956133B 1 and EP 1101518 both disclose a drum filter and a cleaning assembly comprising a drum filter. However, there is still a need to provide an improved centrifugal filter unit, e.g. which can be more easily accommodated in a cleaning device, which has improved filtering properties and which can be emptied more easily of filtered solid material.

Disclosure of Invention

It is an object of the present invention to increase the removal of solid waste material from the effluent of a treatment plant, in particular from a substrate being treated, when the treatment plant is used to treat a substrate with a treatment formulation.

According to a first aspect of the present invention there is provided a centrifugal filtration unit for an apparatus for treating a substrate with a treatment formulation, the centrifugal filtration unit comprising:

a) a housing having an outlet configured to allow filtrate to exit the centrifugal filtration unit;

b) a filter rotatably mounted within the housing, wherein the filter comprises: a first end proximate the first end of the housing; a second end proximate the second end of the housing; and a sidewall connecting a first end of the filter and a second end of the filter; wherein the first end, second end, and sidewall of the filter define a filter chamber, and wherein the sidewall includes perforations configured to allow liquid to pass through but prevent solid material from passing through;

c) an end cap configured to substantially seal a first end of the housing;

d) an inlet configured to allow feed to enter the filtration chamber;

e) a cover at a first end of the filter, wherein the cover includes an aperture that mates with the inlet to allow feed to enter the filter chamber;

f) a drive means for rotating the filter; and

g) an impeller contained in the filter chamber;

wherein the centrifugal filter unit is configured such that when the impeller is rotated, the feed is drawn into the filter chamber through the inlet and liquid is discharged through the perforations.

According to a second aspect of the present invention there is provided a centrifugal filtration unit for an apparatus for treating a substrate with a treatment formulation, the centrifugal filtration unit comprising:

a) a housing having an outlet configured to allow filtrate to exit the centrifugal filtration unit;

b) a filter rotatably mounted within the housing, wherein the filter comprises: a first end proximate the first end of the housing; a second end proximate the second end of the housing; and a sidewall connecting a first end of the filter and a second end of the filter; wherein the first end, second end, and sidewall of the filter define a filter chamber, and wherein the sidewall includes perforations configured to allow liquid to pass through but prevent solid material from passing through;

c) an inlet configured to allow feed to enter the filtration chamber;

d) a cover at a first end of the filter, wherein the cover includes an aperture that mates with the inlet to allow the feed to enter the filtration chamber;

e) a drive means for rotating the filter; and

f) an impeller contained in the filter chamber.

In the second aspect of the present invention, preferably, the centrifugal filter unit further comprises an end cap configured to substantially seal the first end of the housing.

For both the first aspect of the invention and the second aspect of the invention, the presence of the rotatable filter affects centrifugal filtration of the feed. Furthermore, centrifugal filtration is improved by providing an impeller within the filtration chamber, since the impeller increases the force with which liquid exits the filter. In particular, the presence of the impeller improves filtration, since even if filtered solid material accumulates on the inner surface of the filter within the filter chamber, liquid drainage from the filter is improved. In this way, effective filtration of the treatment formulation can be sustained for a longer period of time without the need to clean the filter.

Another advantage of the centrifugal filter unit of the first aspect of the invention is that the impeller is contained in the centrifugal filter chamber, so that the centrifugal filter unit can function as a combination of a filter and a pump. In particular, the centrifugal filtration unit itself is capable of generating a feed flow without the need for a separate pump. Depending on the arrangement of the apparatus in which the centrifugal filter unit is used, the centrifugal filter unit may act as the only pump in the apparatus. For example, when the centrifugal filter unit is included in the recirculation means of the apparatus, the centrifugal filter unit may avoid the need for the recirculation means to comprise a separate pump. The ease of accommodating the centrifugal filter unit in the apparatus is improved by the possibility of omitting a separate pump. Preferably, the end cap is configured to completely seal the first end of the housing such that the first end of the housing is air-tight and water-tight. In this way, the pumping performance can be further improved.

The centrifugal filter unit of the second aspect of the invention comprises an end cap configured to substantially seal the first end of the housing, which also has the advantage of being able to function as a filter and pump combination. In particular, the centrifugal filter unit itself is capable of generating a feed flow without the need for a separate pump. Depending on the arrangement of the apparatus in which the centrifugal filter unit is used, the centrifugal filter unit may act as the only pump in the apparatus. For example, when the centrifugal filter unit is included in the recirculation means of the apparatus, the centrifugal filter unit may avoid the need for a separate pump for the recirculation means. Thereby enabling the elimination of a separate pump and improving the ease of installing the centrifugal filter unit in an apparatus. Preferably, the end cap is configured to completely seal the first end of the housing such that the first end of the housing is air-tight and water-tight. In this way, the pumping performance can be further improved.

The following features described in accordance with the first aspect of the invention also apply to each of the second to seventh aspects of the invention described herein:

the orientation of the centrifugal filter unit may depend on the configuration of the apparatus used. Typically, the centrifugal filter unit may be configured to operate in a substantially vertical orientation. Alternatively, the centrifugal filter unit may be configured to operate in a substantially horizontal direction. As used herein, "in a substantially vertical direction" means that the first end of the filter is disposed substantially vertically above the second end of the filter, and the axis of rotation of the filter is aligned substantially vertically. The substantially vertical orientation may allow the material to be filtered to be more easily fed into the filtering chamber by gravity feed. For example, if the centrifugal filter unit is in a vertical orientation, the centrifugal filter unit may not require a separate pump. The substantially vertical orientation may eliminate the need for sealing around the inlet or providing an end cap in the centrifugal filter unit. The substantially vertical orientation may also allow the centrifugal filter unit to be more easily self-priming. As used herein, "in a substantially horizontal direction" means that the first end of the filter is substantially horizontal relative to the second end of the filter. In this way, the axis of rotation of the filter is substantially horizontally aligned.

As used herein, "feed" refers to the material to be filtered by the centrifugal filter. Typically, the feed is a liquid comprising solid material. Typically, the feed comprises a treatment formulation that has been used to treat a substrate. The amount of solid material in the feed may vary depending on the substrate being treated, the type of treatment and the stage of the treatment. Thus, the concentration of solids in the feed may vary greatly. Preferably, the feed is a fluid. Preferably, the feed is not in the form of a paste or semi-solid.

Generally, if the centrifugal filter unit is used for treating a substrate such as a textile, for example, cleaning of textiles or treatment of denim, the concentration of solid material in the feed (as a percentage of the total mass of solid material and liquid) is less than about 30 wt%, preferably less than about 20 wt%, preferably less than about 10 wt%, more preferably less than about 5 wt% before entering the centrifugal filter unit. The concentration of solid material in the feed (as a percentage of the total mass of solid material and liquid) is typically at least about 0.001 wt%, or at least about 0.01 wt%, or at least about 0.1 wt%. Preferably, the feed comprises from about 0.01 wt% to about 5 wt% solid material, more preferably from about 0.1 wt% to about 3.5 wt% solid material. Typically, the concentration of solid material in the feed is related to the solid material having a maximum dimension of at least about 10 μm. Typically, the solid material has a maximum dimension of less than about 5mm, preferably less than about 2mm, more preferably less than about 1 mm.

Typically, the drive means comprises an electric motor. The power of the motor may be selected according to the apparatus in which the centrifugal filter unit is used. When the centrifugal filter unit is used in a household appliance, the power of the motor is typically about 30W to 60W, or about 40W to 50W. When centrifugal filter units are used in commercial or industrial settings, the power of the motor is typically much higher. Generally, the more substrates and treatment formulations a device can treat, the higher the power required by the motor of the centrifugal filtration unit.

Typically, the drive means comprises a drive shaft. The drive arrangement may further comprise a clutch mechanism for engaging and disengaging rotation of the drive shaft. The clutch mechanism can be advantageous for protecting the motor if there is a blockage in the filter chamber.

The centrifugal filter unit may comprise a controller for driving the device. Alternatively, the controller may be remote from the centrifugal filter unit, for example, the controller may be located elsewhere in the apparatus using the centrifugal filter, for example alongside or as part of another controller for controlling other functions of the apparatus. By having a controller for the drive means, the operation of the centrifugal filter unit can be controlled. For example, the rotational speed of the filter may be selected and/or varied. In addition, the duration of the rotation period of the filter may be controlled, for example, the filter may be allowed to rotate during the entire operation of the apparatus to process the substrate, or the filter may be rotated during certain individual or intermittent periods during operation of the apparatus.

Preferably, the controller is operated or programmed to cause the drive means to drive the filter in rotation at a first speed to filter solid material from the feed material and a second speed to dewater the filtered solid material. Prior to rotating the filter at the second speed, the feed is typically either stopped from entering the inlet, for example by a valve before the inlet, or the treatment formulation is substantially expelled from the apparatus using the centrifugal filtration unit, so that substantially no treatment liquid capable of constituting the feed remains in the apparatus. Typically, the second speed for dewatering the filtered solid material is higher than the first speed for filtering the solid material from the feed. Operating the centrifugal filter unit to rotate the filter at a second speed increases centrifugal force and can improve removal force of liquid contained in the filtered solid material in the filter. Dewatering in this manner compresses the solid material, for example forming a "filter cake," which improves the ease of removal of the solid material from the filtration chamber. The compressed solid material is easier and more hygienic to handle and can be disposed of together with ordinary waste. Compressing the solid material in this manner advantageously increases the time interval required to empty or clean the filter chamber. Dewatering also facilitates preservation of the liquid in the apparatus in which the centrifugal filtration unit is used.

The rotational speed of the filter in the centrifugal filter unit during filtration of the treatment formulation may be selected depending on various factors, such as the diameter of the filter, the type of filter material used, and/or the concentration of solid material in the feed. For example, in the case where the filter contained in the centrifugal filtration unit has a diameter of about 75mm, the rotational speed of the filter during filtration of the treatment formulation is typically from about 900rpm to about 1300rpm, preferably from about 1000rpm to about 1200rpm, more preferably about 1100 rpm. Alternatively, if the filter comprised in the centrifugal filter unit has a diameter of about 75mm, the rotational speed of the filter during filtration of the treatment preparation is typically at least about 2000rpm, preferably at least about 2500rpm, more preferably at least about 3000rpm, especially preferably at least about 3500 rpm. Surprisingly, higher rotation speeds can provide high filtration efficiency. Preferably, the rotational speed is no more than about 10000rpm, no more than about 15000rpm, no more than about 20000rpm, no more than about 25000rpm or no more than about 30000 rpm. Rotational speeds in excess of 30000rpm can be difficult to design and balance.

If the filter comprised in the centrifugal filtration unit has a diameter of about 75mm, the rotational speed of the filter during dewatering is typically about 1300rpm to about 1900rpm, preferably from about 1400rpm to about 1800rpm, more preferably about 1600 rpm. Alternatively, if the filter comprised in the centrifugal filter unit has a diameter of about 75mm, the rotational speed of the filter during dewatering is typically at least about 2000rpm, preferably at least about 2500rpm, more preferably at least about 3000rpm, especially preferably at least about 3500 rpm. Preferably, the rotational speed is no more than about 10000rpm, no more than about 15000rpm, no more than about 20000rpm, no more than about 25000rpm or no more than about 30000 rpm. Rotational speeds in excess of 30000rpm can be difficult to design and balance.

Typically, the rotation of the filter is such that a G force is provided at the inner wall of the filter furthest from the axis of rotation, from about 25G to about 150G, preferably from about 40G to about 100G. G is a function of filter size and filter rotation speed. G may be calculated as described in EP2663683B 1. Thus, for a filter having an inner diameter R (cm) and rotating at R (revolutions per minute (rpm)), g is taken to be 9.81m/s²The acceleration of gravity of (2), then:

G＝1.118x 10^-5rR²

alternatively, the rotation of the filter is such that a G force, typically at least about 100G, preferably at least about 200G, more preferably at least about 300G, more preferably at least about 400G, and especially preferably at least about 500G, is provided at the inner wall of the filter furthest from the axis of rotation. Higher G-forces can be beneficial to provide high filtration efficiency. Preferably, the G force is no more than about 10000G, no more than about 20000G, no more than 30000G or no more than about 40000G. G forces greater than 40000G can be difficult to design and balance.

The centrifugal filter unit of the first and second aspects of the invention comprises an impeller. The impeller is optional in third to seventh aspects described below. When the centrifugal filter unit comprises an impeller, the impeller typically comprises a plurality of blades (blades), which may also be referred to as vanes (vane). Preferably, the impeller has 3 to 10 blades, preferably 4 to 8 blades, preferably 6 blades. Preferably, the vanes of the impeller are located adjacent the second end of the filter. Preferably, the vanes of the impeller are not adjacent the first end of the filter. Typically, the vanes of the impeller are located in one half of the filter chamber, near the second end of the filter. In this way feed through the inlet of the housing can enter the filtration chamber before reaching the impeller vanes, with the advantage of reducing the build up of filtered solid material adjacent the inlet, thereby reducing the chance of blockage of the inlet.

Both the impeller and the filter may be driven in rotation by a drive means. The filter is adapted to engage with the drive means. Typically, the filter is shaped such that it engages with the drive shaft of the drive means. The impeller and the filter may each be adapted to engage with a drive means and be independent of each other. For example, the impeller and the filter may each have a mounting portion such that they directly engage the drive shaft of the drive device. Preferably, the impeller and the filter are engaged with the same drive shaft. When the drive means is operated, the drive shaft to which the impeller and/or filter are connected is rotated, thereby rotating the impeller and filter. The impeller and the filter may rotate at the same speed. Alternatively, the impeller may rotate at a different speed than the rotational speed of the filter, for example when the impeller and filter are engaged by different drive shafts of the drive means, or where there is a gear mechanism that allows differential rotation between the filter and impeller.

Typically, the drive means comprises a splined drive shaft, that is to say, the drive shaft comprises at least one spline. Typically, the drive shaft includes about 2 to 10 splines, or about 4 to 8 splines. The use of a splined traction shaft may improve ease of positioning of the filter and/or impeller and may also improve stability of the filter and/or impeller during rotation.

Preferably, the impeller is coupled (coupled) with the filter such that the impeller rotates at the same speed as the filter. In this way, the impeller does not directly engage the drive means, but rotates as the drive means drives the filter to rotate. This arrangement has the advantage that the impeller can be more easily removed from the centrifugal filter unit, i.e. without having to be detached from the drive shaft.

Typically, the impeller has grooves that engage with projections in the filter so that the relative position of the filter and the impeller is fixed. Alternatively, the impeller may have a projection which engages a groove in the filter. In these arrangements, the impeller rotates at the same speed as the filter rotates. Typically, the projections or grooves in the filter have a plurality of shaped features that securely engage the impeller, preferably the filter has splined projections for engaging the grooves in the impeller.

In a third aspect of the centrifugal filter unit described below, the end cap is openable. In the first, fifth and seventh aspects described herein, typically, the end cap is openable. In this way, access to the interior of the housing may be provided for removing solid material filtered from the feed material or for servicing the centrifugal filter unit. Alternatively, in the first, fifth and seventh aspects described herein, the end caps may be fixed in place and not openable, for example where the centrifugal filtration unit is disposable. In the arrangements of the second and sixth aspects the centrifugal filter unit comprises an end cap, preferably said end cap is openable. In this way, access to the interior of the housing may be provided for removing solid material filtered from the feed material or for servicing the centrifugal filter unit. Alternatively, the end cap may be fixed in place and not openable, for example in case the centrifugal filter unit is disposable.

The centrifugal filter unit may further comprise an attachment mechanism to secure the end cap to the housing. For example, the attachment mechanism may include a clip, such as a quick release clip, a threaded member, or a twist-lock mechanism. Preferably, the attachment mechanism comprises a quick release clip.

The end cap is configured to substantially seal the first end of the housing. Preferably, "substantially sealing the first end of the housing" means that the end cap renders the first end of the housing watertight so that the liquid (e.g., treatment formulation) enters and exits the centrifugal filter unit only through the inlet or outlet of the housing.

When the centrifugal filter unit is configured to operate in a substantially horizontal orientation, preferably the end caps do not include air release mechanisms, such as air holes, or if air release mechanisms, such as air holes, are present in the end caps, they may be closed during operation of the centrifugal filter unit. When the centrifugal filter unit is configured to operate in a substantially vertical orientation, the end cap may include an air release mechanism, such as an air vent, but the end cap still functions to substantially seal the first end of the housing, allowing only liquid to enter and exit the centrifugal filter unit through the inlet or outlet of the housing.

The end cap may be configured to completely seal the first end of the housing. By "completely sealing the first end of the housing" is meant that the end cap provides water and air tightness to the first end of the housing.

Preferably, the end cap includes an inlet. Typically, the inlet is located approximately in the center of the end cap. The end cap may include a handle or lever to assist in opening or removing the end cap.

Preferably, the cover is configured to cover the first end of the filter. Typically, the cover prevents all solid material from exiting the filter chamber from the first end of the filter. Typically, the cover prevents most of the treatment formulation from exiting the filter chamber through the first end of the filter. Preferably, the cover seals the first end of the filter such that the cover substantially prevents all of the treatment formulation from flowing out through the first end of the filter. In some arrangements, the cover is water tight, for example, the cover may include a seal, such as an O-ring or oil seal, preferably an O-ring, with the inlet.

The sidewall of the filter includes perforations configured to allow liquid to pass through but prevent solid material from passing through. The type of filter used, as well as the density and size of the perforations, may be selected according to the intended use of the centrifugal filter unit. In particular, the choice of filter depends on the amount, size and type of solid material that is desired to be prevented from passing through.

Typically, the perforations of the filter have an average largest dimension of at least about 1 μm, preferably at least about 2 μm, more preferably at least about 5 μm, especially preferably at least about 10 μm. Typically, the perforations of the filter have an average largest dimension of no more than about 2mm, preferably no more than about 1mm, preferably no more than about 500 μm, preferably no more than about 250 μm, more preferably no more than about 100 μm. Typically, the perforations have an average largest dimension of about 10 μm to about 100 μm.

Typically, the perforations in the filter have an average largest dimension of at least about 20 μm, preferably at least about 30 μm and more preferably at least about 40 μm. These dimensions may provide good flow rates, anti-clogging, and/or longer life cycles before the filter needs cleaning.

Typically, the perforations in the filter have an average largest dimension of no more than about 70 μm, preferably no more than about 50 μm, more preferably no more than about 40 μm and especially preferably no more than about 30 μm. These dimensions can provide good filtration efficiency. In particular, these perforation sizes provide advantageous filtration efficiencies for fibrous solid materials having longest linear dimensions greater than about 1 μm and typically not greater than about 5mm, typically not greater than about 1 mm. Fibrous solid materials having a longest linear dimension greater than about 1 μm and typically not more than about 5mm, typically not more than about 1mm, are commonly referred to as "microfibers".

Typically, at least about 50%, at least about 60%, at least about 70%, at least about 80%, at least about 90%, at least about 95%, or at least about 99% of the solid material in the feed is prevented from passing through the filter. The percentage of solid material that the filter is able to prevent passage can be readily measured, for example, by measuring the mass of the filter (together with the impeller, if any) removed from the centrifugal filtration unit and then mixing a known mass of solid material with a known volume of water as the feed. Feed is added to the centrifugal filtration unit through the inlet when the centrifugal filtration unit is operating at a first speed of rotation of the filter. Once the flow of liquid exiting the outlet is substantially stopped, the rotational speed of the filter is increased to a second speed to thoroughly dewater the collected solids. By removing the filter (if an impeller is present) and measuring its mass at the end of the filtration, the mass of the collected solids can be calculated, and thus the percentage of the mass of the collected solids to the mass of the solids and water mixed as feed can also be calculated.

Typically, materials having a largest dimension greater than about 2mm, greater than about 1mm, greater than about 500 μm, greater than about 200 μm, greater than about 100 μm, greater than about 50 μm, greater than about 32 μm, greater than about 10 μm, greater than about 5 μm, or greater than about 1 μm are prevented from passing through the filter. In certain applications, filters capable of preventing passage of submicron particles may be used.

Typically, fibrous solid material (i.e., comprising "microfibers") having a longest linear dimension greater than about 1 μm is prevented from passing through the filter.

Typically, the filter prevents passage of solid materials having a maximum dimension of greater than about 10 μm to greater than about 100 μm, preferably a maximum dimension of greater than about 10 μm to greater than about 50 μm. Although filters may be used to prevent solid material having a maximum dimension of less than about 10 μm from passing, the use of such filters has the disadvantage that, for example, bacteria may be prevented from passing through the filter, such that such bacteria are retained in the collected solid material, which may result in health hazards to the user when removing the collected solid.

Preferably, the term "prevent passage of solid material" means preventing at least about 50%, preferably at least about 60%, more preferably at least about 70%, more preferably at least about 80%, more preferably at least about 90%, more preferably at least about 95%, even more preferably at least about 99%, most preferably about 100% of solid material having a largest dimension greater than about 10 μm from passing through the filter. Particularly preferably, the centrifugal filtration unit is used in an apparatus for cleaning a substrate, for example in a domestic or commercial laundry appliance.

Preferably at least about 50%, preferably at least about 60%, more preferably at least about 70%, more preferably at least about 80%, more preferably at least about 90%, more preferably at least about 95%, even more preferably at least about 99%, most preferably about 100% of the solid material having a largest dimension greater than about 1 μm is prevented from passing through the filter. Particularly preferably, the centrifugal filtration unit is used in an apparatus for cleaning a substrate, for example in a domestic or commercial laundry appliance.

Although the filter material generally has inherent properties in terms of the size of the solid material that prevent it from passing through, the build-up of collected solid material on the filter during operation of the centrifugal filter unit can have the effect of improving the filtration performance of the filter. Thus, during operation of the centrifugal filter unit, the filtration performance of the filter material may be increased, thereby preventing passage of solid material of smaller maximum size and/or being able to prevent passage of a higher proportion of solid material of certain sizes. This increase in filtration performance is often accompanied by a final decrease in performance before reaching the point where cleaning of the filter is required.

The collected solid material typically includes fibers or particles derived from the substrate (also referred to as "lint"), contaminants, or combinations thereof.

The filter may comprise any suitable material that prevents the passage of solid materials but allows the passage of liquids. Typically, the filter comprises a mesh, preferably a metal or plastic woven mesh. Preferably, the filter comprises a woven nylon mesh. Preferably, the average perforation size of the woven mesh is less than about 40 μm, preferably less than about 30 μm, preferably about 25 μm, preferably less than 25 μm. Alternatively, the filter may comprise a non-woven fabric or mesh, a sintered material, paper, a pleated filter, a wire wedge or a chemically etched metal sheet, such as steel sheet. The filter may comprise a single layer of filter material. An advantage of having a single layer of filter material is that it provides a filter that is easy to clean. Alternatively, the filter may comprise more than one layer, typically two layers, typically three layers, of filter material. Filters having more than one layer of filter material may improve durability. When the filter comprises more than one layer of filter material, for example two layers, wherein the first layer is nested in the second layer relative to the filter chamber, typically the size of the perforations in the first layer is smaller than the size of the perforations in the second layer. Having a finer filtration layer within the coarse filtration layer helps reduce clogging of the two filters. The use of a coarser filter as the second layer can significantly improve the mechanical robustness of the two-layer filter.

Preferably, the filter comprises a filtration material combined with a rigid structure, such as a moulded thermoplastic structure, to provide strength.

Preferably, the filter is cylindrical and has a smooth inner surface. An advantage of this arrangement is that the filter chamber can be emptied more easily and also the inner surface of the filter can be cleaned more easily to remove any collected solid material.

Preferably, the filter is removable from the housing. In this way, the centrifugal filter unit can be maintained more easily. In particular, when the filter is detached from the housing, it can be more easily cleaned.

The filter may be constructed from multiple components. For example, the filter may include an outer holder and an inner holder, wherein the inner holder is nested within the outer holder and the inner holder includes filter material. The outer cage may provide additional structural support, particularly during filter rotation. The outer holder and the inner holder are preferably detachable from each other. For example, the inner holder may be removably connected to the outer holder by a spring release pin. The inner and outer holders are removable from the housing in sequence so that the inner holder can be removed first and then the outer holder can be removed in a separate step if desired. In this way, the inner holder can be removed from the centrifugal filter unit, while the outer holder part of the filter remains in the housing. The outer holder can be removed if desired, but can remain in the housing during routine maintenance of the centrifugal filter unit. Alternatively, the outer holder may be permanently connected to the drive means and only the inner holder of the filter may be removed. In this way, when the outer holder is reused, the inner holder part of the filter can be cleaned or replaced with a new inner holder.

The end cap and cover may be separate components. Alternatively, the cap may be incorporated into the end cap. In arrangements in which the cap is contained within the end cap, the end cap is configured to be able to rotate the filter without rotating the cap portion of the end cap. Preferably, the end cap and cover are separate components. When the end cap and cover are separate components, the cover is preferably configured to rotate with the filter.

The cover may form a non-contact seal with the end cap. Preferably, the non-contact seal between the cover and the end cap is configured to inhibit backflow of liquid that has passed through the filter during rotation of the filter and to prevent feed material from escaping from the filter chamber via the first end of the filter, thereby preventing contamination of the filtered liquid. The non-contact seal provides a tortuous path between the cover and the end cap.

Typically, the non-contact seal is formed by the outermost surface of the cap in cooperation with the innermost surface of the end cap, forming a tortuous path between the cap and the end cap. Preferably, the cover forms a labyrinth seal with the end cap. For example, the cover may include a first plurality of concentric rings disposed on a side of the cover away from the filter chamber, and the endcap may include a second plurality of concentric rings disposed on a side of the endcap facing the filter chamber, wherein the first plurality of concentric rings are relatively interleaved with the second plurality of concentric rings to form a labyrinth seal. Alternatively, the cover may comprise a first plurality of helical segments disposed on a side of the cover remote from the filter chamber; and the end cap may include a second plurality of spiral segments disposed on a side of the end cap facing the filter chamber, wherein the first plurality of spiral segments are interspersed with respect to the second plurality of spiral segments to form a labyrinth seal.

Alternatively or additionally, the outlet of the housing may comprise a one-way valve, for example a flap valve, to prevent backflow of liquid past the filter chamber when the filter stops rotating.

Alternatively or additionally, the filter may comprise a flange at the first end of the filter, the flange projecting from the first end of the filter towards the housing. The flange prevents feed escaping from the first end of the filtration chamber from contaminating the filtered liquid.

Preferably, in case the centrifugal filter unit is configured to operate in a substantially vertical direction, the centrifugal filter unit may further comprise an overflow mechanism. Preferably, the overflow mechanism comprises an overflow aperture and an overflow collection chamber fluidly connected to the aperture. Preferably, the overflow aperture is contained in the filter cover. Alternatively or further, the overflow aperture is contained in a side wall of the filter chamber. In this way, the overflow collection chamber can catch any feed escaping from the first end of the filter chamber. This is particularly useful when the filter is subject to reduced filter efficiency or clogging by build-up of collected solid material on the filter such that feed material escapes from the first end of the filter chamber. Preferably, when the filter is clogged, feed exits the first end of the filtering chamber through an aperture in the cover and enters the overflow collection chamber. Alternatively or further, the cover may comprise additional overflow apertures. Alternatively or additionally, the side wall of the filtering chamber may comprise an additional overflow aperture, wherein the overflow aperture is located near the first end of the filtering chamber. When the filter is clogged, feed can exit the first end of the filter chamber through the overflow aperture and enter the overflow collection chamber.

The overflow collection chamber can include an overflow outlet. In this way, feed that has entered or collected in the overflow collection chamber can be released. The overflow may discharge into the housing or a separate outlet. Preferably, feed that has entered or collected in the overflow collection chamber is released into the housing through the overflow outlet, entering the filtration chamber on the other side of the filter. Preferably, the separate outlet may be a pipe or a drain. In this way, feed that enters or is collected in the collection chamber can be released directly from the overflow collection chamber rather than through the housing. The overflow outlet may include a valve that may be opened to selectively drain the collected feed from the overflow collection chamber. The valve thus controls the release of the feed collected in the overflow collection chamber and in this way prevents the filtered liquid from being contaminated. Typically, the overflow collection chamber may be contained in an end cap.

Optionally, the overflow mechanism may further comprise an overflow sensor in the overflow collection chamber. The overflow sensor may be configured to detect when feed overflows the filtration chamber, when the collection chamber begins to fill, or when a predetermined feed level is reached. Further, the extravasation sensor may be configured to alert a user. In this way, when the filter becomes clogged, feed material passes through, flows into, or collects in the overflow collection chamber, the user may be alerted to enable the user to take action, such as cleaning or replacing the filter.

Preferably, the centrifugal filter unit may further comprise an air release mechanism. When feed is introduced through the inlet, particularly in case the centrifugal filter unit is in a substantially horizontal orientation, such that the first end of the filter is substantially horizontal with respect to the second end of the filter, air pockets may be formed within the filter chamber. Where air pockets are present, operation of the centrifugal filter unit causes water to be thrown to the outside of the filter by centrifugal effect, while air is drawn to the centre. In particular, in arrangements where the centrifugal filter unit includes an impeller, the presence of stagnant air in the filter chamber can have a significant adverse effect on the efficiency of the pump. Furthermore, the entrapped air causes turbulence within the filter chamber, thereby creating the effect of moving solid material. By having an air release mechanism, the adverse effects of air pockets in the filter chamber can be reduced.

Typically, the air release mechanism is contained in the cap. The air release mechanism may include a channel having a first end, a second end, and a midpoint, wherein the first end of the channel is located on a side of the cover facing the filter chamber and the second end of the channel is located on a side of the cover facing away from the filter chamber, wherein a distance between the midpoint of the channel and an axis of rotation of the filter is less than a distance between the first and second ends of the channel and the axis of rotation of the filter. Preferably, the channel has a U-bend shape. Preferably, the air release mechanism comprises a plurality of channels, preferably three to twelve channels, preferably six to nine channels, more preferably six channels. In an arrangement where the cover rotates with the filter, having multiple channels is advantageous because when the filter stops rotating, the filter chamber can release air regardless of the orientation of the cover.

The position of the filter with respect to its distance from the axis of rotation of the filter at the first end of the channel and the second end of the channel may be varied to produce an inflow or outflow through the cover. Preferably, the second end is closer to the axis of rotation than the first end, which provides an inflow that helps reduce potential contamination of the filtered liquid by the feed material. Alternatively or additionally, the air release mechanism may comprise a second outlet, the second outlet being located in the housing. The second outlet may be used to vent or bleed air from the centrifugal filter unit. As such, the air release mechanism may include a second outlet. Preferably, said second outlet is connected to a valve which can be opened to selectively release air from the centrifugal filter unit. For example, the valve may comprise a float valve.

Alternatively or further, the second outlet may be comprised in the end cap. Air pockets also form inside the centrifugal filter unit when the end cap is secured to the housing. Advantageously, the second outlet allows air to escape or be discharged from the centrifugal filter unit. Advantageously, the second outlet allows the centrifugal filter unit to be self-priming. Preferably, the end cap still functions to substantially seal the first end of the housing, allowing liquid to enter and exit the centrifugal filter unit only through the inlet or outlet of the housing, but allowing air to be released from the air release mechanism. Preferably, the second outlet comprises a closure which is movable between a closed position preventing air from passing through the second outlet and an open position allowing air to pass through the second outlet.

Preferably, the second outlet is connectable to a valve that can be opened to selectively release air from the centrifugal filter unit. Alternatively, the second outlet may be permanently open when the centrifugal filter unit is in a substantially vertical orientation.

Preferably, the outlet of the housing is tangentially angled (angled) so as to substantially coincide with the direction of flow of filtered liquid exiting the filtering chamber. Preferably, the outlet is tangentially angled such that the outlet follows at least a portion of the outer surface of the housing. Alternatively, the outlet of the housing may have a helical configuration.

Typically, at least a portion of the housing may be transparent. In this way, the interior of the housing can be directly viewed during operation of the centrifugal filter unit. This may be useful, for example, to monitor the amount of filtered solid material contained in the filter chamber. In this way, an operator of the centrifugal filter unit can easily see when maintenance of the centrifugal filter unit is required. Alternatively or additionally, the centrifugal filter unit may comprise a sensor to monitor the amount of filtered solid material collected in the filter chamber. For example, the centrifugal filter unit may include a sensor to monitor the flow through the filter chamber. For example, the sensor may be an optical sensor.

Alternatively or additionally, the centrifugal filter unit may comprise a turbidity sensor to monitor the cleanliness of the liquid flowing out through the outlet. Alternatively or further, the turbidity sensor may be located in a device using a centrifugal filtration unit.

The housing and filter may be of any suitable shape that allows the filter to be rotatably mounted in the housing. Typically, both the housing and the filter are cylindrical. Alternatively, the housing may be tapered, wherein a first end of the housing has a smaller diameter than a second end of the housing. The conical housing tapers from the second end to the first end. This arrangement has the advantage of enabling an increase in the flow rate through the centrifugal filter unit. In particular, the conical housing may help to direct filtered liquid from the filter chamber to the outlet. Preferably, the centrifugal filter unit comprises a combination of a conical housing and a tangential angle outlet along an outer surface of at least a portion of the housing. In this way, the outlet velocity of the fluid from the centrifugal filter unit can be increased. Alternatively, both the housing and the filter may be conical.

Typically, the centrifugal filter unit is configured to have an axial inlet and a radial outlet with respect to the rotatable filter.

Typically, the apparatus is a textile treatment apparatus. Preferably, the apparatus is a washing machine.

According to a third aspect of the present invention there is provided a centrifugal unit for use in an apparatus for treating a substrate with a treatment formulation, the centrifugal filtration unit comprising;

a) a housing having an outlet configured to allow filtrate to exit the centrifugal filtration unit;

b) a filter rotatably mounted within the housing, wherein the filter comprises: a first end proximate the first end of the housing; a second end proximate the second end of the housing; and a sidewall connecting a first end of the filter and a second end of the filter; wherein the first end, second end, and sidewall of the filter define a filter chamber, and wherein the sidewall includes perforations configured to allow liquid to pass through but prevent solid material from passing through;

c) an end cap configured to substantially seal a first end of the housing, wherein the end cap is openable;

d) an inlet configured to allow feed to enter the filtration chamber;

e) a cover at a first end of the filter, wherein the cover includes an aperture that mates with the inlet to allow feed to enter the filter chamber;

f) a drive means for rotating the filter; and

g) a detachable portion configured to be positioned in the filtration chamber during operation of the centrifugal filtration unit and to remove and carry at least part of the solid material prevented from passing through the perforations from the filtration chamber after operation of the centrifugal filtration unit.

According to a fourth aspect of the present invention there is provided a centrifugal unit for an apparatus for treating a substrate with a treatment formulation, the centrifugal filtration unit comprising;

a) a housing having an outlet configured to allow filtrate to exit the centrifugal filtration unit;

b) a filter rotatably mounted within the housing, wherein the filter includes a first end proximate the first end of the housing; a second end proximate the second end of the housing; and a sidewall connecting a first end of the filter and a second end of the filter; wherein the first end, second end, and sidewall of the filter define a filter chamber, and wherein the sidewall includes perforations configured to allow liquid to pass through but prevent solid material from passing through;

c) an inlet configured to allow feed to enter the filtration chamber;

d) a cover at a first end of the filter, wherein the cover includes an aperture that mates with the inlet to allow feed to enter the filter chamber;

e) a drive means for rotating the filter; and

f) a detachable portion configured to be positioned in the filtration chamber during operation of the centrifugal filtration unit and to remove and carry at least part of the solid material prevented from passing through the perforations from the filtration chamber after operation of the centrifugal filtration unit.

According to a fourth aspect, the centrifugal filter unit may further comprise an end cap, wherein the end cap is openable.

The centrifugal filtration unit of the third and fourth aspects is for removing filtered solid material from a process preparation. An advantage of this arrangement is that the filter can be easily reused without the need for disposal and replacement.

Furthermore, when the centrifugal filter unit is located in the apparatus, it is not necessary to attempt to remove solid material by entering the centrifugal filter unit, and the centrifugal filter unit of the third and fourth aspects of the invention is advantageous in that the removable portion can be brought to a position where it is more convenient to remove solid material from the removable portion, for example on a table or counter, or near a waste or refuse bin. Thus, there is less likelihood of solid material spilling when the centrifugal filtration unit is emptied. Furthermore, having a detachable portion avoids the need to place a tool in the filtering chamber to try to scoop out the solid material, which is advantageous because it reduces damage to the filtering chamber. This arrangement also avoids the operator from inserting fingers through the filter chamber which could be dangerous and cause injury to the fingers or hands. Furthermore, this arrangement also allows the operator to avoid contact with the collected solid material, which may contain bacteria, for example.

Typically, the detachable portion is configured to rotate with the filter. Thus, the detachable portion rotates at the same speed as the filter. In this way, the detachable portion does not directly engage with the drive means, but is caused to rotate when the filter is driven in rotation by the drive means. An advantage of this arrangement is that the detachable portion can be more easily removed from the centrifugal filter unit, i.e. without having to be detached from the drive shaft.

Typically, the removable portion has a recess which engages with a projection in the filter so as to fix the relative positions of the filter and the removable portion. Alternatively, the detachable portion may have a projection which engages with a recess in the filter. Typically, the projections or recesses in the filter have a plurality of shaped features that securely engage the detachable portion, preferably the filter has a splined protrusion for engaging the recess in the detachable portion.

Alternatively, the removable portion may not directly engage the filter, but may be connected to the cover. Preferably, the detachable portion is configured to rotate with the cover. In this arrangement, rotation of the filter rotates the cover and then causes rotation of the detachable portion.

Typically, the detachable portion comprises a plunger. The plunger may include a shaft and a plate. Preferably, the plate has substantially the same shape as the cross-section of the filter chamber through the filter side wall. Preferably, the plunger is configured such that when the cover is located at the first end of the filter, the plate is located proximate to or preferably at the second end of the filter. In this way, the plunger does not substantially interfere with the operation of the centrifugal filter unit, thereby filtering the feed. At the end of the filtration operation, the plunger may be removed from the filtration chamber and the plate may withdraw at least a portion of the solid material from the filtration chamber that is prevented from passing through the perforations. Preferably, said plate is substantially the same shape and size as the cross-section of said filtering chamber through the filter side wall.

The detachable portion may comprise an element having substantially the same shape as the cross-section of the filtering chamber through the side wall of the filter. Preferably, the elements of the detachable portion having substantially the same shape have substantially the same dimensions as the cross-sectional size of the filtering chamber through the filter side wall. For example, there may be a gap of less than about 5mm, preferably less than 3mm, preferably less than 2mm, preferably about 1mm, between the element and the side wall of the removable filter.

The shape of the detachable portion may be to scrape the side wall during removal of the detachable portion from the filter chamber. Thus, the amount of solid material removed from the filter chamber is increased and the inner side walls of the filter are cleaned.

The removable portion may include a plurality of brushes, wherein a plurality of the brushes are disposed on the removable portion proximate the sidewall of the filtration chamber. For example, the detachable portion may include a ring-shaped arrangement of brushes proximate the sidewall. The brush helps to remove solid material from the filter chamber and clean the inner side walls of the filter.

The removable portion may include a flexible blade, wherein the flexible blade is disposed on the removable portion proximate the filter chamber sidewall. For example, the removable portion may include a flexible scraper adjacent the sidewall. The flexible scraper helps to remove solid material from the filter chamber and clean the inner side walls of the filter. Typically, the flexible blade is silicone rubber.

The plurality of brushes and flexible scraper can accommodate variations in the cross-section of the filter chamber. In particular, when the filter chamber does not have a uniform cross-section along its length, e.g. when the filter chamber is tapered, the plurality of brushes and flexible scrapers may help to clean the inner broad wall of the filter.

The detachable portion may comprise the cover. In this way, the solid material can be removed from the centrifugal filter unit in a straightforward manner by simply removing the cover. For example, an operator may grasp the cover and pull the cover out of the centrifugal filter unit, thereby simultaneously removing the detachable portion and the collected solid material from the centrifugal filter unit.

The centrifugal filter unit may further comprise an impeller, wherein the impeller is disposed in the filter chamber. The impeller may be as described above in relation to the first aspect. Typically, the impeller is coupled with the filter such that the impeller rotates at the same speed as the filter.

The presence of a rotating filter affects the centrifugal filtration of the feed. Furthermore, by providing the impeller within the filter chamber, centrifugal filtration is improved, as the impeller increases the force with which liquid exits the filter. In particular, the presence of the impeller improves filtration, since liquid drainage out of the filter is improved even if filtered solid material accumulates on the inner surface of the filter within the filter chamber. In this way, effective filtration of the treatment formulation can be sustained for a longer period of time without the need to clean the filter.

Typically, the centrifugal filter unit is configured such that when the impeller is rotated, feed is drawn into the filter chamber through the inlet and liquid is expelled through the perforations. In this way, centrifugal filtration is improved because the impeller increases the force with which liquid is discharged through the filter. In particular, the presence of the impeller improves filtration as it assists liquid to exit the filter even if filtered solid material builds up on the filter inner surfaces in the filter chamber. In this way, effective filtration of the treatment formulation can be sustained for a longer period of time without the need to clean the filter.

Another advantage of the centrifugal filter unit having an impeller is that it can function as a combination of a filter and a pump. Depending on the arrangement of the apparatus in which the centrifugal filter unit is used, the centrifugal filter unit may act as the only pump in the apparatus. For example, where the centrifugal filtration unit is included in a recirculation arrangement of the apparatus, the centrifugal filtration unit may avoid the need for the recirculation arrangement to include a separate pump. Being able to dispense with a separate pump may mean that the centrifugal filter unit may be more easily accommodated in the device. Preferably, the end cap is configured to completely seal the first end of the housing such that the first end of the housing is air-tight and water-tight. In this way, the pumping performance can be further improved.

Typically, the detachable portion may comprise an impeller. Where the detachable portion comprises an impeller, the impeller is preferably shaped so as to comprise a portion of substantially the same cross-sectional shape of the filtering chamber through the side wall of the filter, and preferably substantially the same cross-sectional size of the filtering chamber through the side wall of the filter. Preferably, the detachable portion comprises the impeller and the cover. In this way, the solid material can be removed directly from the centrifugal filter unit by simply removing the cover. For example, an operator may grasp the cover and pull the cover out of the centrifugal filter device, thereby simultaneously removing the removable portion (including the impeller), and the solid material that has been collected, from the centrifugal filter device.

If the filter comprises an outer holder and an inner holder, there may be a connection mechanism between the inner holder and the detachable part. In this way, the detachable part and the inner holder can be removed from the centrifugal filter unit in a first step, and then, after detaching the connecting mechanism, the detachable part can be removed from the inner holder. In this way, the amount of solid material that can fall off during removal of the detachable portion from the centrifugal filter unit is reduced, since the inner holder serves to substantially contain the solid material.

The removable portion may simply be pulled or slid out of the centrifugal filter unit. Alternatively, the centrifugal filter unit may comprise a retaining mechanism or locking mechanism to secure the removable portion within the centrifugal filter unit during operation. For example, the removable portion may be separated from the centrifugal filter unit by releasing a clip or twist-lock mechanism.

According to a fifth aspect of the present invention there is provided a centrifugal filtration unit for an apparatus for treating a substrate with a treatment formulation, the centrifugal filtration unit comprising:

a) a housing having an outlet configured to allow filtrate to exit the centrifugal filtration unit;

b) a filter rotatably mounted within the housing, wherein the filter comprises: a first end proximate the first end of the housing; a second end proximate the second end of the housing; and a sidewall connecting a first end of the filter and a second end of the filter; wherein the first end, second end, and sidewall of the filter define a filter chamber, and wherein the sidewall includes perforations configured to allow liquid to pass through but prevent solid material from passing through;

c) an end cap configured to substantially seal a first end of the housing;

d) an inlet configured to allow feed to enter the filtration chamber;

e) a cover at a first end of the filter, wherein the cover includes an aperture that mates with the inlet to allow feed to enter the filter chamber;

f) a drive means for rotating the filter; and

g) an air release mechanism.

According to a sixth aspect of the present invention there is provided a centrifugal filtration unit for an apparatus for treating a substrate with a treatment formulation, the centrifugal filtration unit comprising:

a) a housing having an outlet configured to allow filtrate to exit the centrifugal filtration unit;

b) a filter rotatably mounted within the housing, wherein the filter comprises: a first end proximate the first end of the housing; a second end proximate the second end of the housing; and a sidewall connecting a first end of the filter and a second end of the filter; wherein the first end, second end, and sidewall of the filter define a filter chamber, and wherein the sidewall includes perforations configured to allow liquid to pass through but prevent solid material from passing through;

c) an inlet configured to allow feed to enter the filtration chamber;

d) a cover at a first end of the filter, wherein the cover includes an aperture that mates with the inlet to allow feed to enter the filter chamber;

e) a drive means for rotating the filter; and

f) an air release mechanism.

Typically, the end cap and cover are separate components. Typically, the air release mechanism is contained in the cap. Alternatively or additionally, the air release mechanism may be incorporated in the end cap. Preferably, the air release mechanism is as described above for the centrifugal filter units of the first and third aspects, or the centrifugal filter units of the second and fourth to seventh aspects.

According to a seventh aspect of the present invention there is provided a centrifugal filtration unit for an apparatus for treating a substrate with a treatment formulation, the centrifugal filtration unit comprising:

a) a housing having an outlet configured to allow filtrate to exit the centrifugal filtration unit;

b) a filter rotatably mounted within the housing, wherein the filter includes a first end proximate the first end of the housing; a second end proximate the second end of the housing; and a sidewall connecting a first end of the filter and a second end of the filter; wherein the first end, second end, and sidewall of the filter define a filter chamber, and wherein the sidewall includes perforations configured to allow liquid to pass through but prevent solid material from passing through;

c) an end cap configured to substantially seal a first end of the housing;

d) an inlet configured to allow feed to enter the filtration chamber;

e) a cover at a first end of the filter, wherein the cover includes an aperture that mates with the inlet to allow feed to enter the filter chamber;

f) a drive means for rotating the filter; and

g) a non-contact seal between the end cap and the cover.

Typically, the end cap and cover are separate components. Preferably, the contactless seal is as described above in relation to the first and second aspects of the centrifugal filter unit. Preferably, the non-contact seal is a labyrinth seal.

In an eighth aspect of the invention, there is provided an apparatus for treating a substrate with a treatment formulation, the apparatus comprising:

a) a tub rotatably mounting a drum having a plurality of sidewalls, and a plurality of the sidewalls including one or more apertures configured to allow the treatment formulation to exit the drum;

b) an access device movable between an open position in which at least one substrate may be placed in the drum and a closed position in which the apparatus is substantially sealed;

c) a collector located below the drum and configured to collect the treatment formulation flowing out of the drum;

d) a centrifugal filtration unit as disclosed herein; and

e) a first flow passage between the collector and the inlet of the centrifugal filter unit.

The outlet of the centrifugal filter unit may be fluidly connected to the drum. In this way, the liquid passing through the filter can be returned into the drum. Alternatively, the outlet of the centrifugal filter unit may be fluidly connected to a drain. Preferably, the apparatus further comprises a control valve configured such that filtrate flowing from the outlet of the centrifugal filter unit is selectively recirculated to the drum or delivered to the drain.

The apparatus may further comprise a recirculation means for recirculating the treatment formulation from the collector to the drum, wherein the centrifugal filtration unit is comprised in the recirculation means. In this way, the centrifugal filter unit filters the treatment agent during its recirculation from the collector to the drum. Typically, the recirculation means comprise a pump and a conduit connecting the collector and the drum. If the apparatus has a centrifugal filtration unit comprising an impeller, the centrifugal filtration unit may be configured to effect recirculation of the treatment formulation. Thus, a centrifugal filter unit with combined pumping and filtering functions has the advantage that the need for a separate pump can be eliminated in the recirculation mode.

The apparatus may comprise a second filter element positioned such that the treatment formulation flows through the second filter element before entering the inlet of the centrifugal filter unit. The second filter element may be a coarse filter to prevent large pieces or items of solid material from entering the centrifugal filter unit, for example coins or other items in a pocket when washing laundry.

The apparatus is preferably a textile treatment apparatus, more preferably the apparatus is a washing machine.

The apparatus may be configured to enable treatment of a substrate with the treatment formulation in the presence of a solid particulate material. For example, the apparatus may be configured such that solid particulate material can leave the drum through the apertures and be collected in a collector. When configured in this manner, preferably the apparatus comprises recirculation means for recirculating the solid particulate material and the treatment formulation from the collector to the drum.

Typically, the recirculation means comprise a pipe (pipe) or duct (duct) between the collector and the drum, which can be described as a "runner pipe".

Preferably, the recirculation means comprises a first pump. The first pump helps to transport the solid particles flowing from the collector outlet back to the drum. In order for the first pump to operate normally, at least a portion of the treatment formulation in the collector also leaves the collector with the solid particulate material and enters the recirculation means for recirculation to the drum. Preferably, the recirculation means comprises a separator. The recirculation device separator is used to separate the solid particulates from the treatment formulation that has been recirculated from the collector such that substantially only the solid particulates re-enter the drum. Preferably, the recirculation device separator is installed in the intake device of the apparatus. Alternatively, the recirculation device separator is preferably mounted above the entry device.

The treatment agent separated by the recirculation device separator is preferably directed to a recovery collector. The treatment formulation may be returned to the collector through a drain in the inlet device. Alternatively, the treatment formulation may be returned to the collector through a conduit, wherein the conduit does not pass through the access device.

If the apparatus comprises recirculation means for recirculating the solid particulate material, the centrifugal filter unit is preferably located in the recirculation means between the separator and the collector, such that the treatment preparation separated by the separator of the recirculation means enters the centrifugal filter unit through an inlet of the centrifugal filter unit. The filtered treatment preparation flowing out of the outlet of the centrifugal filter unit is directed to a collector. In this way, at least a portion of the residual solid material passing through the recirculation device may be removed from the treatment formulation by the centrifugal filtration unit. Preferably, substantially all residual solid material in the treatment formulation is removed by the centrifugal filtration unit. Repeated cycling of the treatment formulation through the centrifugal filtration unit can result in "polishing" of the treatment formulation.

Alternatively, if the apparatus comprises recirculation means for recirculating the solid particulate material, the centrifugal filter unit may be located between the collector and the drain. In this way, at least a portion of the residual solid material in the treatment formulation is removed prior to treatment of the formulation. Thus, the amount of solid material entering the drain pipe is reduced.

In an alternative arrangement of the apparatus, the apparatus is configured to be able to treat the substrate with the treatment formulation in the presence of solid particulate material which cannot leave the drum through the aperture. When the solid particulate material cannot leave the drum through the holes, the apparatus preferably comprises an in-drum reservoir for the solid particulate material.

Typically, the storage within the drum comprises at least one chamber comprising flow channels facilitating the ingress and egress of fluids and solid particulate materials. The storage means may comprise a plurality of said chambers. The chamber or chambers may be located on at least one inner surface of the drum. Typically, a plurality of chambers are located on the inner circumferential surface of the drum, typically at equidistant intervals. Alternatively or further, the plurality of chambers may be located on an inner end face of the drum.

The storage within the drum may be adjusted so that the ingress and egress of fluid and solid particulate material may be controlled by the direction of rotation of the drum. Thus, if the storage within the drum comprises at least one chamber comprising flow channels facilitating the ingress and egress of fluids and solid particulate materials, the ingress and egress is dependent on the direction of rotation.

The storage part in the drum may include a plurality of chambers disposed on an inner circumferential surface of the drum at equal intervals. Generally, the drum may comprise 3 to 10 chambers, preferably 4 chambers; and these chambers may also be provided as or form part of "risers". The lifters facilitate circulation and agitation of the contents of the drum, i.e., circulation and agitation of the substrate, treatment formulation, and solid particulate material, during rotation of the drum. In this way the lifter is adapted to store the solid particulate material and to promote a controlled flow of the solid particulate material between the lifter/drum storage and the drum interior. Typically, the drum interior storage is a chamber having a length substantially equal to the lifter and is adapted to provide a flow path from the aperture in the lifter to the drum interior. Thus, in operation, for a given direction of rotation of the drum, particulate material present on the inner surface of the drum enters the lifter through the apertures and is conveyed to the chamber through the flow passage. For the direction opposite to the direction of rotation of the drum, the particulate matter leaves the chamber and enters the drum through the same path. The size of the pores is selected according to the size of the solid particulate material so as to allow efficient ingress and egress thereof.

Alternatively, the in-drum storage may be located on an inner end face of the drum. The in-drum storage typically comprises chambers arranged in a circular array about the central axis of the drum, and each chamber has a relatively large cross-sectional area and a small overall depth, such that the arrangement of the chambers does not significantly adversely affect the internal volume of the drum.

In operation, during a cycle in which a contaminated substrate is typically cleaned by the apparatus, the storage section within the drum is contained within the elevator, and the substrate is first placed into the drum. Solid particulate material of suitable mass is contained in said in-drum storage before the start of the treatment cycle. The required amount of treatment formulation is then added to the drum through a delivery device or another port. Then, the drum starts to rotate in a predetermined direction. Thus, by rotation of the tub and gravity, the solid particulate material is moved relative to the in-drum storage such that for each rotation of the cylindrical holder a volume of solid particulate material is dispensed from the in-drum storage into the drum until the in-drum storage is emptied. Thereafter, the rotational direction of the drum is kept constant in most cases during the processing operation. During the substrate processing, the direction of rotation of the drum is reversed in a short time (typically less than 1 minute) to improve substrate processing, primarily to unwind the substrates from each other.

Thereafter, the rotation of the drum is typically reversed when substrate processing is complete. Thus, by the rotation of the drum and gravity, the solid particulate material separates from the substrate and enters the in-drum reservoir such that for each rotation of the drum, a volume of solid particulate material is collected from the drum into the in-drum reservoir. This process continues until all of the solid particulate material has been separated from the substrate and collected by the in-drum storage.

Typically, a tub surrounds the drum and the collector. The tub may surround the drum, preferably wherein the tub and the drum are substantially concentric. Preferably, the collector may be formed by a portion of the tub. Preferably, the walls of the barrel are not perforated, but have one or more inlets, and/or one or more outlets, provided therein, adapted to pass treatment formulation, and/or constituents of treatment formulation, and/or any solid particulate material for treatment, into and out of the barrel. Thus, the barrel is suitably watertight and liquids (such as treatment agents) are only allowed to enter and exit through the conduit or conduit assemblies.

Typically, the drum is mounted substantially horizontally in the tub.

The drum has a sidewall that includes one or more apertures configured to allow the treatment formulation to exit the drum. Optionally, the apertures may be configured to allow solid particulate material to exit the drum. Typically, the drum sidewall has one or more holes with a minimum dimension of about 1mm to about 20mm, preferably about 1mm to about 15 mm. Generally, the one or more perforations, or the one or more holes, may have a diameter of from about 1mm to about 10mm, preferably from about 1mm to about 8mm, preferably from about 1mm to about 6 mm.

When the apparatus is configured to treat a substrate with a treatment formulation and a solid particulate material, preferably the drum comprises perforated side walls, wherein the side walls comprise perforations larger than the largest dimension of the solid particulate to allow the solid particulate to pass through the perforations. Typically, the perforations have a minimum dimension of about 1mm to about 20mm, preferably about 1mm to about 15 mm. Typically, the one or more perforations have a diameter of from about 1mm to about 10mm, preferably from about 1mm to about 8mm, preferably from about 1mm to about 6 mm.

Alternatively, if the apparatus is configured to process a substrate with a process formulation and a solid particulate material, the drum may comprise perforated sidewalls, wherein the perforations comprise perforations having a diameter smaller than the diameter of the particles of the solid particulate material. Typically, the diameter of the perforations is no greater than 5.0 mm. Thus, the perforations allow ingress and egress of treatment formulation and fine particulate material having a diameter smaller than the perforations, but are adapted to prevent egress of solid particulate material having a particle diameter greater than 5.0 mm. Preferably, the perforations comprise perforations having a diameter of less than 5.0mm, most typically less than 3.0 mm. In this way, the ingress and egress of all solid particulate material is generally prevented.

The inner surface of the drum sidewall may include a plurality of spaced apart elongated projections affixed substantially perpendicular thereto. The drum may typically comprise 3 to 10, preferably 4, protrusions, which are commonly referred to as "lifters". These lifters facilitate circulation and agitation of the contents of the drum, i.e., of the substrate(s) and treatment formulation, during rotation of the drum.

When the apparatus is configured to process solid particulate material, the one or more lifters may comprise one or more apertures, providing another path for the solid particles to be transferred from the drum. The lifter can be used to collect the solid particulate matter within the drum and transfer it to the collector. The elevator may comprise a collection and transfer means in the form of a plurality of chambers. The lifters may be equidistantly placed on the inner circumferential surface of the drum. The riser may include a first aperture to allow solid particles to enter the riser and a second aperture to allow solid particles to transfer into the collector. Optionally, the riser may include a collection chamber located between the first aperture and the second aperture. The size of the pores may be selected according to the size of the solid particles so as to allow efficient entry and transfer thereof. The one or more apertures are preferably larger than the largest dimension of the solid particles. Typically, the smallest dimension of the one or more apertures of the riser is from about 1mm to about 20mm, preferably from about 1mm to about 15 mm. Generally, the diameter of the one or more apertures may be from about 1mm to about 10mm, preferably from about 1mm to about 8mm, preferably from about 1mm to about 6 mm.

Alternatively, if the apparatus comprises an in-drum storage as described above, wherein the in-drum storage comprises a plurality of chambers located at equally spaced intervals on the inner circumferential surface of the drum, the plurality of chambers may also be used as a plurality of lifters.

The apparatus is preferably a front loading apparatus and the access means is provided at the front of the apparatus. Preferably, the access means is or includes a door. It will be appreciated that suitably the drum has an opening aligned with the entry means through which the substrate is introduced into the drum.

The rollers are preferably cylindrical, but other configurations may be used, including, for example, hexagonal rollers. The inner surface of the drum is preferably a cylindrical inner surface.

When the substrate is treated with a solid particulate material, the solid particulate material preferably comprises a plurality of particles. Typically, the number of particles is not less than 1000, more typically not less than 10000, even more typically not less than 100000. A large number of particles is particularly advantageous for preventing wrinkling and/or improving the uniformity of treating or cleaning a substrate, in particular a textile.

Preferably, the average mass of the granules is from about 1mg to about 1000mg, or from about 1mg to about 700mg, or from about 1mg to about 500mg, or from about 1mg to about 300mg, preferably at least about 10mg per granule. In a preferred embodiment, the average mass of the granules is preferably from about 1mg to about 150mg, or from about 1mg to about 70mg, or from about 1mg to about 50mg, or from about 1mg to about 35mg, or from about 10mg to about 30mg, or from about 12mg to about 25 mg. In an alternative embodiment, the average mass of the granules is preferably from about 10mg to about 800mg, or from about 20mg to about 700mg, or from about 50mg to about 700mg, or from about 70mg to about 600mg, about 20mg to about 600 mg. In a preferred embodiment, the average mass of the particles is preferably from about 25 to about 150mg, preferably from about 40mg to about 80 mg. In another preferred embodiment, the average mass of the particles is preferably from about 150 to about 500mg, preferably from about 150 to about 300 mg.

Preferably, the average volume of the particles is from about 5 to about 500mm per particle³About 5 to about 275mm³From about 8 to about 140mm³Or about 10 to about 120mm³Or at least 40mm³E.g. about 40 to about 500mm³Or about 40 to about 275mm³Within the range of (1).

The average surface area of the particles is preferably 10mm per particle²To 500mm²Preferably 10mm²To 400mm²More preferably 40 to 200mm²In particular 50 to 190mm²。

The particles preferably have an average particle size of at least 1mm, preferably at least 2mm, preferably at least 3mm, preferably at least 4mm, preferably at least 5 mm. The average particle size of the particles is preferably not more than 100mm, preferably not more than 70mm, preferably not more than 50mm, preferably not more than 40mm, preferably not more than 30mm, preferably not more than 20mm, preferably not more than 10mm, optionally not more than 7 mm. Preferably, the particles have an average particle size of from 1 to 20mm, more preferably from 1 to 10 mm. The particles which provide a particularly long term effectiveness over a number of treatment cycles have an average particle size of at least 5mm, preferably 5 to 10 mm. The dimension is preferably the largest linear dimension (length). For a sphere, the equivalent is the diameter. For non-spheres, this corresponds to the longest linear dimension. The dimensions are preferably determined using a vernier caliper. The average particle size is preferably an average number. The determination of the average particle size is preferably measured by measuring the particle size of at least 10, more preferably at least 100 and especially at least 1000 particles. The above particle sizes provide particularly good properties (especially cleaning properties) while also facilitating separation of the particles from the substrate at the end of the treatment process.

The particles preferably have a particle size of greater than 1g/cm³More preferably greater than 1.1g/cm³More preferably greater than 1.2g/cm³Even more preferably at least 1.25g/cm³And particularly preferably more than 1.3g/cm³Average particle density of (a). The granules preferably have a particle size of not more than 3g/cm³And in particular not more than 2.5g/cm³Average particle density of (a). Preferably, the particles have a density of 1.2 to 3g/cm³The average density of (a). These densities contribute to a further increase in the degree of mechanical action that is beneficial during processing and to a better separation of the particles from the matrix after processing.

The particles of the solid particulate material may be polymeric and/or non-polymeric particles. Suitable non-polymeric particles may be selected from metal, alloy, ceramic and glass particles. Preferably, however, the particles of solid particulate material are polymer particles.

Preferably, the particles comprise a thermoplastic polymer. Thermoplastic polymer as used herein preferably refers to a material that softens when heated and hardens when cooled. This is in contrast to thermoset plastics (e.g., rubber), which do not soften when heated. More preferred thermoplastics are those useful in hot melt compounding and extrusion.

Preferably, the solubility of the polymer in water is no more than 1 wt%, more preferably no more than 0.1 wt%, and most preferably the polymer is insoluble in water. Preferably, the water is subjected to a solubility test at pH 7 and a temperature of 20 ℃. The solubility test is preferably carried out within 24 hours. The polymer is preferably non-degradable. By "non-degradable" is meant that the polymer is stable in water without exhibiting any significant tendency to dissolve or hydrolyze. For example, the polymer does not exhibit a significant tendency to dissolve or hydrolyze in water at a pH of 7 and a temperature of 20 ℃ for 24 hours. If no more than about 1 wt.%, preferably no more than about 0.1 wt.%, preferably no polymer is dissolved or hydrolyzed, then preferably the polymer does not exhibit a significant tendency to dissolve or hydrolyze, preferably under the conditions described above.

The polymer may be crystalline or amorphous or a mixture thereof.

The polymer may be linear, branched or partially cross-linked (preferably wherein the polymer is still thermoplastic in nature), more preferably the polymer is linear.

Preferably, the polymer is or comprises polyalkylene (polyalkylene), polyamide (polyamide), polyester (polyester) or polyurethane (polyurethane) and copolymers thereof (copolymers) and/or mixtures thereof (blends), preferably from polyalkylene, polyamide and polyester, preferably from polyamide and polyalkylene, and preferably from polyamide.

A preferred polyalkylene is polypropylene.

Preferred polyamides are or comprise aliphatic (aliphatic) or aromatic polyamides (aromatic polyamides), more preferably aliphatic polyamides (aliphatic polyamides). Preferred polyamides comprise aliphatic chains (aliphatic chain), especially C₄-C₁₆、C₄-C₁₂And C₄-C₁₀An aliphatic chain. Preferably the plurality of polyamides is or comprises a plurality of nylons. Preferably the plurality of nylons comprises nylon 4,6, nylon 4,10, nylon 5,10, nylon 6, nylon 6/6,6, nylon 6,6/6,10, nylon 6,12, nylon7. Nylon 9, nylon 10, nylon 11, nylon 12,12 and copolymers or mixtures thereof. Of these, nylon 6,6, nylon 6,10, especially nylon 6,6, and copolymers or blends thereof are preferred. It will be appreciated that these nylon-grade polyamides are not degradable, wherein the term degradable is preferably as defined above.

Suitable polyesters may be aliphatic (aliphatic) or aromatic (aromatic), and are preferably selected from aromatic dicarboxylic acids (aromatic dicarboxylic acids) and C₁-C₆Preferably C₂-C₄Derived from aliphatic diols (aliphaticdiol). Preferably, the aromatic dicarboxylic acid is selected from terephthalic acid (terephthalic acid), isophthalic acid (isophtalic acid), phthalic acid (phthalic acid), 1,4-, 2,5-, 2, 6-and 2,7-naphthalenedicarboxylic acids (1,4-, 2,5-, 2, 6-and 2,7-naphthalenedicarboxylic acids), preferably terephthalic acid or 2, 6-naphthalenedicarboxylic acid, most preferably terephthalic acid. The aliphatic diol (aliphatic diol) is preferably ethylene glycol (ethylene glycol) or 1,4-butanediol (1, 4-butandiol). Preferably, the polyester is selected from the group consisting of polyethylene terephthalate (polyethylene terephthalate) and polybutylene terephthalate (polybutylene terephthalate). Useful polyesters may have a molecular weight corresponding to an intrinsic viscosity measurement of between about 0.3 to about 1.5dl/g as measured by solution techniques such as ASTM D-4603.

Preferably, the polymer particles comprise a filler, preferably an inorganic filler, an inorganic mineral filler in suitable particulate form, for example BaSO₄. The filler is preferably present in the particles in an amount of at least 5 wt%, more preferably at least 10 wt%, even more preferably at least 20 wt%, more preferably at least 30 wt%, especially at least 40 wt%. The filler is generally present in the particles in an amount of not more than 90 wt.%, more preferably not more than 85 wt.%, even more preferably not more than 80 wt.%, yet more preferably not more than 75 wt.%, in particular not more than 70 wt.%, in particular not more than 65 wt.% and most particularly not more than 60 wt.%, relative to the total weight of the particles. The weight percentage of filler is preferably determined by ashing. Preferred ashing methods include ASTM D2584, D5630 and ISO 3451, the test methods preferably being in accordance with ASTM D5630. For any standard cited in this disclosure, unless otherwise specified, the final version of the standard is the latest version prior to the priority filing date of the present patent application. Preferably, the matrix of the polymer (optionally containing fillers and/or other additives) extends throughout the volume of the particles.

The particles may be spherical or substantially spherical, ellipsoidal, cylindrical or cuboid. Particles having shapes intermediate to these shapes are also possible. The best results of handling properties (especially cleaning properties) and separation properties (separation of substrate from particles after the handling step) are usually observed with ellipsoidal particles. Spherical particles have a tendency to separate better, but may not provide optimal handling or cleaning performance. In contrast, cylindrical or cuboid particles do not separate well, but can be effectively handled or cleaned. Spherical and ellipsoidal particles are particularly useful when fabric care improvement is important because they are less abrasive. Spherical or ellipsoidal particles are particularly useful in the present invention, which is designed to operate without a particle pump, and wherein the transfer of particles between the storage device and the interior of the drum is facilitated by the rotation of the drum.

The term "spherical" as used herein includes both spherical and substantially spherical particles. Preferably, the particles are not completely spherical. Preferably, the particles have an average aspect ratio of greater than 1, more preferably greater than 1.05, even more preferably greater than 1.07 and especially greater than 1.1. Preferably, the particles have an average aspect ratio of less than 5, preferably less than 3, preferably less than 2, preferably less than 1.7 and preferably less than 1.5. The average is preferably a numerical average. The average value is preferably an average of at least 10, more preferably at least 100 particles, in particular at least 1000 particles. The aspect ratio of each particle is preferably the ratio of the longest linear dimension divided by the shortest linear dimension. Preferably using a vernier caliper. If a good balance between handling properties (especially cleaning properties) and substrate maintenance is required, it is recommended that the average aspect ratio be within the above-mentioned range of values. When the particles have a very low aspect ratio (e.g., highly spherical particles), the particles may not provide sufficient mechanical action to obtain good handling or cleaning characteristics. When the particles have an excessively high aspect ratio, removal of the particles from the substrate may become more difficult and/or abrasion on the substrate may become excessively high, which may result in unnecessary damage to the substrate, especially when the substrate is a textile.

According to a ninth aspect of the present invention there is provided a method of filtering a treatment formulation in an apparatus as disclosed herein, comprising operating drive means to rotate a filter of a centrifugal filtration unit as described herein at a first speed and transfer the treatment formulation from a collector to an inlet of the centrifugal filtration unit, wherein at least a portion of liquid from the treatment formulation flows through the filter and at least a portion of solid material from the treatment formulation is prevented from passing through the filter.

The method of filtering the treatment formulation may begin once the substrate treatment is complete, i.e., at the end of the treatment cycle. An advantage of carrying out the method in this way is that the treatment formulation only needs to be fed to the inlet of the centrifugal filter unit at the end of the treatment cycle, thus providing more freedom to position the centrifugal filter unit in the apparatus.

Alternatively, the method of filtering the treatment formulation may occur during substrate treatment. The filtering process may be continuous or intermittent, such as pulsed, during substrate processing. When the filtration process occurs in a pulsed fashion, the filtration efficiency of the centrifugal filtration unit may be higher than when the process is carried out continuously, i.e., more solid material is generally prevented from passing through the filter. However, a method of performing continuous filtration during the treatment of a substrate may be advantageous in that the treatment formulation is continuously clean, and thus the treatment formulation may improve and/or more effectively treat the substrate, and in particular may reduce the deposition of solid materials on the substrate, such as fibers in the treatment formulation.

Preferably, the centrifugal filter unit of the apparatus used in the method comprises an impeller in a filter chamber. Thus, the centrifugal filter unit combines the functions of a filter and a pump. Thus, the transfer of the treatment composition from the collector to the inlet of the centrifugal filter unit may be effected by the impeller.

The method may further comprise the step of transferring filtrate flowing from the housing outlet of the centrifugal filter unit to the drum. Preferably, the method comprises recirculating the treatment formulation from the collector to the drum through the centrifugal filter unit in the absence of a substrate in the drum. In this way, the centrifugal filter unit can "polish" the treatment formulation, that is, the amount of solid material remaining in the treatment formulation can be reduced as compared to a single filtration of the treatment formulation.

Alternatively or further, the apparatus may comprise one or more valves which allow filtrate flowing from the housing outlet of the centrifugal filter unit to be selectively conveyed to a collector instead of the drum. Thus, alternatively or further, the method may further comprise the step of transferring filtrate flowing from a housing outlet of the centrifugal filtration unit to a collector. Preferably, the method comprises a repeated cycle of treatment formulation from the collector to the centrifugal filtration unit to the collector. In this case, the treatment formulation does not pass through the drum and/or the treatment formulation does not contact the substrate during the cycle. In this way, the centrifugal filter unit can "polish" the treatment formulation regardless of whether there is a substrate in the bowl. This arrangement may be particularly useful when the apparatus releases the drained portion of the treatment formulation during a treatment cycle.

Alternatively or additionally, the method may further comprise the step of diverting filtrate flowing from the housing outlet of the centrifugal filtration unit to a drain.

The method may further comprise the step of operating the drive means to increase the rotational speed of the filter from a first speed to a second speed higher than the first speed in order to dewater the solid material collected in the filter chamber.

The method may further comprise opening an end cap of the centrifugal filter unit and extracting the fluid collected in the filter chamberSolid material The step (2).

According to a tenth aspect of the present invention there is provided a method of treating a substrate comprising treating the substrate with a treatment formulation using the apparatus of the present invention, as described herein. Preferably, the method comprises the steps of:

(a) loading at least one of said substrates into said drum and closing said entry means;

(b) adding the treatment formulation into the drum;

(c) rotating the drum;

(d) collecting the treatment formulation from the drum to the collector; and

(e) operating a pumping device to pump the treatment formulation from the collector to the centrifugal filtration unit and to pump the filtrate from the centrifugal filtration unit back to the bowl or drain.

Preferably, the pumping means comprises an impeller disposed in the filter chamber of the centrifugal filter unit. Preferably, the access means is or includes a door.

Preferably, the method of treating a substrate further comprises introducing a solid particulate material into the drum and agitating the substrate with the solid particulate material. Preferably, the solid particulate material is reused in further processing procedures.

The method may include the additional step of rinsing the treated substrate. Preferably, rinsing is performed by adding a liquid rinsing medium to the treated substrate, the liquid rinsing medium optionally comprising one or more post-treatment additives. The liquid flushing medium is preferably an aqueous medium, i.e. the liquid flushing medium is or comprises water. To increase the bias, the liquid flushing medium comprises at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt% and at least 98 wt% of water. More preferably, the liquid flushing medium is water.

Preferably, the method for processing a plurality of batches, wherein a batch comprises at least one substrate, comprises agitating a first batch with a process formulation and a solid particulate material, wherein the method further comprises the steps of:

(a) collecting the solid particulate material in a storage device;

(b) agitating a second batch comprising at least one substrate with the collected solid particulate material from step (a); and

(c) optionally repeating the steps for one or more subsequent batches comprising at least one substrate(a) And (b).

The processing sequence of a single batch typically includes the step of agitating the batch with the solid particulate material in a stirring motion of the equipment used for the processing cycle. A processing cycle typically comprises one or more discrete processing steps, optionally one or more rinsing steps, optionally one or more steps of separating particles from a processed batch, optionally one or more extraction steps of removing a processing formulation from the processed batch, optionally one or more drying steps, and optionally a step of removing the processed batch from the apparatus.

In the process of the present invention, steps (a) and (b) may be repeated at least 1 time, preferably at least 2 times, preferably at least 3 times, preferably at least 5 times, preferably at least 10 times, preferably at least 20 times, preferably at least 50 times, preferably at least 100 times, preferably at least 200 times, preferably at least 300 times, preferably at least 400 times at least or preferably at least 500 times.

As used herein, a "substrate" can be or comprise a textile and/or animal skin substrate. In a preferred embodiment, the substrate is or comprises a fabric. The textile may be in the form of a garment, such as a coat, jacket, pants, shirt, skirt, dress, pullover, underwear, hat, scarf, overalls, shorts, swimwear, socks, and suit. The textile may also be a bag, belt, curtain, carpet, blanket, sheet or furniture covering. The fabric may also be in the form of a panel, sheet or roll of material that is later used to prepare one or more finished products. The textile may be or comprise synthetic fibers, natural fibers, or a combination thereof. Textiles may include natural fibers that have been chemically modified one or more times. Natural fibers include, for example, hair (e.g., wool), silk, and cotton. Examples of synthetic textile fibers include nylon (e.g., nylon 6,6), acrylic, polyester, and mixtures thereof. As used herein, the term "animal skin substrate" includes skins (skins), hides (skins) from which leathers are made, pelts (pelts), leathers (leather), and wools (fleees). Typically, the animal skin substrate is a leather or fur from which leather is made. The hide (hide) or pelt (pelt) may be a processed or unprocessed animal hide substrate. When the substrate is or comprises synthetic textile fibres, the centrifugal filter unit according to the invention has the advantage that less synthetic fibres are released from the apparatus in which the substrate is treated. Preferably, substantially all of the synthetic fibers from the substrate are prevented from being released from the apparatus. Reducing the amount of synthetic fibers extracted from the substrate that are released from the apparatus can have considerable environmental benefits.

The treatment of the textile substrate or the substrate comprising the textile according to the invention may be a cleaning process or any other treatment process, such as colouring (preferably dyeing), ageing or grinding (e.g. stone-washing), bleaching or other finishing processes. Stonewashing is a known method for providing textiles with "frayed" or "stonewashed" characteristics, such as a faded appearance, a soft hand, and a greater degree of flexibility. Stone mill water washing is often used to treat denim. Preferably, treating a fabric substrate or a substrate comprising a fabric refers to a cleaning process. The cleaning process may be a domestic or industrial cleaning process.

As used herein, the term "treating" in connection with treating an animal skin substrate (animal skin substrate) is preferably a tanning process (tanning process), including dyeing (tanning) and tanning (tanning) and related tanning processes, preferably selected from curing (curing), pre-tanning (tanning), retanning (re-tanning), fatliquoring (fat liquoring), enzyme treatment (enzyme treatment), tanning (tanning), crust (crusting), dyeing (dyeing) and dye fixing (dye fixing), preferably wherein the pre-tanning process is selected from soaking (soaking), liming (deliming), deliming (deliming), regrinding (unhairing), unhairing (unhairing), meat (softening), skinning (degreasing), degreasing (washing) and pickling (pickling). Preferably, said treatment of the animal skin substrate is a process for leather production. Preferably, the treatment acts to transfer the tanning agent (including colorants or other agents used in the tanning process) onto or into the animal skin substrate.

The treatment formulations described herein may comprise one or more treatment agents suitable for performing the desired treatment on the substrate.

Thus, a cleaning method according to the invention suitably comprises agitating the substrate with the treatment formulation (optionally with the solid particulate material), optionally also with the solid particulate material. Wherein the treatment formulation comprises one or more treatment agents, wherein the treatment formulation is preferably a detergent composition comprising one or more of the following ingredients: surfactants (surfactants), dye transfer inhibitors (dye transfer inhibitors), auxiliaries (builder), enzymes (enzymes), metal chelating agents (metal chelating agents), biocides (biocides), solvents (solvent), stabilizers (stablizers), acids (acids), bases (bases) and buffers (buffers).

Similarly, the treatment formulation of the coloring process preferably comprises one or more dyes, pigments, optical brighteners and mixtures thereof.

The treatment formulation of the stonewashing process may include a suitable stonewashing agent (stone-washing agent) known in the art, for example, an enzymatic treatment agent such as cellulase (cellulose).

The treatment formulation of the tanning process suitably comprises one or more formulations selected from tanning agents, retanning agents and tanning process agents. The treatment formulation may comprise one or more colorants. The tanning or retanning agents are preferably selected from synthetic tanning agents (syntactical tanning agents), vegetable tanning agents (vegetable tanning) or vegetable retanning agents (vegetable re-tanning targets) and mineral tanning agents (mineral tanning agents), such as chromium (III) salts (chromium (III) salts) or salts and complexes containing iron, zirconium, aluminum and titanium. Suitable synthetic tanning agents include amino resins (amino resins), polyacrylates (polyacrylates), fluorine (fluoro) and/or silicone polymers (silicone polymers) and formaldehyde condensation polymers (formaldehyde condensation polymers) based on phenol (phenol), urea (urea), melamine (melamine), naphthalene (naphthalene), sulfone (sulfone), cresol (cresol), bisphenol a (bisphenol a), naphthol (naphthol) and/or diphenyl ether (biphenol ether). Vegetable tanning agents include tannins, usually polyphenols. The plant tanning agent can be extracted from the leaves, roots and especially bark of plants. Examples of vegetable tanning agents include extracts from the bark of chestnut (chestnut), oak (oak), redbean (redoul), sandalwood (tanoak), hemlock (hemlock), ash tree (quebracho), mangrove (mangrove), acacia (wattle acacia) and myrtle (myrobalan). Suitable mineral tanning agents include chromium compounds, especially chromium salts and complexes, usually in the chromium (III) oxidation state, such as chromium (III) sulfate. Other tanning agents include aldehydes (glyoxal), glutaraldehyde and formaldehyde), phosphonium salts (phosphonium salts), metal compounds other than chromium (e.g., iron, titanium, zirconium and aluminum compounds). Preferably, the tanning agent is substantially free of chromium-containing compounds.

The method of the present invention can simultaneously treat one or more substrates. The exact number of substrates depends on the size of the substrates and the capacity of the equipment used.

The total weight of a dry substrate (i.e. a single batch or wash) that can be treated simultaneously can be as high as 50000 kg. For textile substrates, the total weight is typically from 1 to 500kg, more typically from 1 to 300kg, more typically from 1 to 200kg, more typically from 1 to 100kg, even more typically from 2 to 50kg and especially from 2 to 30 kg. For animal substrates, the total weight is typically at least about 50kg, and may amount to about 50000kg, typically from about 500 to about 30000kg, from about 1000kg to about 25000kg, from about 2000 to about 20000kg, alternatively from about 2500 to about 10000 kg.

Preferably, the treatment formulation is an aqueous medium, i.e. the treatment formulation is or comprises water. To increase preference, the treatment formulation comprises at least 50 wt%, at least 60 wt%, at least 70 wt%, at least 80 wt%, at least 90 wt%, at least 95 wt% and at least 98 wt% water. The treatment formulation may optionally comprise one or more organic liquids including, for example, alcohols, glycols, glycol ethers, amides, and esters. Preferably, the sum of all organic liquids present in the treatment formulation does not exceed 10 wt%, more preferably does not exceed 5 wt%, even more preferably does not exceed 2 wt%, especially does not exceed 1%, and most especially the treatment formulation is substantially free of organic liquids.

The treatment formulation preferably has a pH of 3 to 13. The pH of the treatment formulation may be different at different times, points or stages according to the treatment method of the present invention. It is desirable to treat (particularly clean) substrates under alkaline pH conditions, although higher pH values provide improved performance (particularly cleaning performance), but may not be as good for certain substrates. Thus, the desired treatment formulation has a pH of from 7 to 13, more preferably from 7 to 12, even more preferably from 8 to 12, especially from 9 to 12. In another preferred embodiment, in particular for improved fabric care, the pH is from 4 to 12, preferably from 5 to 10, especially from 6 to 9, more especially from 7 to 9. More preferably, the substrate is treated under acidic pH conditions, or at one or more specific stages of the treatment process. For example, in certain steps of treating an animal skin substrate, a pH of typically less than 6.5, even more typically less than 6 and most typically less than 5.5, and typically no less than 1, more typically no less than 2 and most typically no less than 3 is advantageous. Certain fabric or garment finishing processes, such as graphite water washing, may also employ one or more acidic stages. An acid and/or base may be added to achieve the pH values described above. Preferably, the above pH is maintained during at least a portion of the agitation period, and in some preferred embodiments, during all of the agitation period. To prevent the pH of the treatment formulation from drifting during the treatment, a buffer may be used.

Preferably, the weight ratio of treatment formulation to dry substrate is no more than 20:1, more preferably no more than 10:1, in particular no more than 5:1, in particular no more than 4.5:1, even more in particular no more than 4:1, most in particular no more than 3: 1. Preferably, the weight ratio of treatment formulation to dry substrate is at least 0.1:1, more preferably at least 0.5:1, especially at least 1: 1. In the present invention, unexpectedly small amounts of treatment formulations can be used while still obtaining good treatment performance (especially cleaning performance) which is environmentally friendly in terms of the energy required to treat water, wastewater and heat or cool water to the desired temperature.

More than one type of treatment formulation may be used during the methods of treating substrates described herein. For example, a treatment formulation consisting of water may first be added to the substrate disposed in the drum prior to the introduction of the solid particulate material. Subsequently, a treatment formulation comprising water and one or more treatment agents may be used during agitation of the substrate with the solid particulate material.

When solid particles are used in the treatment of a substrate, preferably the ratio of particles to dry substrate is at least 0.1, especially at least 0.5 and more especially at least 1:1 w/w. Preferably, the ratio of particles to dry substrate is no more than 30:1, more preferably no more than 20:1, especially no more than 15:1 and more especially no more than 10:1 w/w. Preferably, the ratio of particles to dry substrate is from 0.1:1 to 30:1, more preferably from 0.5:1 to 20:1, especially from 1:1 to 15:1w/w, and more especially from 1:1 to 10:1 w/w.

Preferably, the treatment process agitates the substrate in the presence of the solid particulate material. The agitation may be in the form of shaking, stirring, spraying, and tumbling. Among them, tumbling is particularly preferable. Preferably, the substrate and solid particulate material are introduced into a rotating drum for tumbling. The rotation may provide a centripetal force of 0.05 to 1G, in particular 0.05 to 0.7G. The centripetal force is preferably calculated at the inner wall of the drum furthest from the axis of rotation.

The solid particulate material is capable of contacting the substrate and being properly mixed with the substrate during agitation.

Agitation may be continuous or intermittent. Preferably, the method is performed over a period of from 1 minute to 10 hours, more preferably from 5 minutes to 3 hours and even more preferably from 10 minutes to 2 hours.

The treatment process is preferably carried out at a temperature of from greater than 0 ℃ to about 95 ℃, preferably from 5 ℃ to 95 ℃, preferably at least 10 ℃, preferably at least 15 ℃, preferably not more than 90 ℃, preferably not more than 70 ℃, and preferably not more than 50 ℃, not more than 40 ℃ or not more than 30 ℃, such mild temperatures allowing the particles to provide the above-mentioned advantages over a larger treatment cycle. Preferably, when treating or cleaning a plurality of batches or washes, each treatment or cleaning cycle is carried out at a temperature of not more than 95 ℃, more preferably not more than 90 ℃, even more preferably not more than 80 ℃, especially not more than 70 ℃, more especially not more than 60 ℃ and most especially not more than 50 ℃, and from more than 0 ℃, preferably at least 5 ℃, preferably at least 10 ℃, preferably at least 15 ℃, preferably from more than 0 to 50 ℃, from more than 0 to 40 ℃, or from more than 0 to 30 ℃, and advantageously from 15 to 50 ℃, from 15 to 40 ℃ or from 15 to 30 ℃. These lower temperatures can again allow the particles to provide benefits for a greater number of treatment or cleaning cycles.

It is to be understood that the above-described time duration and temperature conditions are associated with the processing of a single batch comprising at least one of the substrates.

Where a solid particulate material is used to treat the substrate, agitation of the substrate by the solid particulate material suitably replaces one or more of the discrete treatment steps in the treatment cycle described above. Thus, the above-mentioned duration and temperature conditions are preferably associated with the step of agitating the substrate with the solid particulate material, i.e. the one or more discrete treatment steps of the above-mentioned treatment cycle.

Preferably the method is a method of cleaning a substrate, preferably a lichen cleaning method, preferably a textile substrate may alternatively comprise a method of cleaning a textile substrate. Thus, preferably, one batch is one wash. Preferably, the laundry comprises at least one soiled substrate, preferably wherein said soiled substrate is or comprises a soiled textile. For example, the form of contamination may be, for example, dust, dirt, food, beverages, animal products (e.g., sweat, blood, urine, feces), plant material (e.g., grass), and inks and paints. The cleaning program of the individual laundry usually comprises a step of agitating the laundry with said solid particles in a cleaning device for a cleaning cycle. The cleaning cycle generally comprises one or more discrete cleaning steps and optionally one or more post-cleaning treatment steps, optionally one or more rinsing steps, optionally one or more steps of separating the cleaning particles from the cleaned laundry, optionally one or more drying steps, optionally one or more extraction steps of removing the treatment formulation from the cleaned laundry, and optionally a step of removing the cleaned laundry from the cleaning device.

Where the process is a cleaning process, the substrate is preferably agitated with the solid particulate material and a treatment formulation, wherein the treatment formulation preferably comprises a detergent composition. The detergent composition may comprise any one or more of the following ingredients: surfactants, dye transfer inhibitors, adjuvants, enzymes, metal chelators, bactericides, solvents, stabilizers, acids, bases, and buffers. In particular, the detergent composition may comprise one or more enzymes.

If the process is a cleaning process, optional post-cleaning additives that may be present in the rinse liquid medium include optical brighteners, perfumes, and fabric softeners.

Drawings

The invention is further described with reference to the following drawings, in which:

figure 1 shows a cross-sectional view of a centrifugal filter unit according to the invention;

figure 2 shows a cross-sectional view of an alternative centrifugal filter unit according to the invention;

FIG. 3 shows a cross-sectional view of another centrifugal filter unit according to the invention;

FIG. 4 shows a perspective view of an apparatus according to the present invention;

FIG. 5 shows an expanded perspective view of another centrifugal filter unit according to the present invention;

FIG. 6 shows a cross-sectional view of another centrifugal filter unit according to the invention;

FIG. 7 is a three-dimensional cross-sectional view of the centrifugal filter unit of FIG. 6; and

figure 8 shows a series of components of a centrifugal filtration unit: figure 8a shows the filter chamber and the removable part of the centrifugal filter unit of figures 6 and 7; figure 8b shows a detachable part of the centrifugal filter unit removed from the filter chamber, including the cover and the impeller; figure 8c shows a filter chamber; figure 8d shows the housing with the detachable portion and filter chamber removed.

Detailed Description

Fig. 1 shows a centrifugal filter unit (100) according to the invention. The centrifugal filter unit (100) comprises a housing (102) having an outlet (104) to enable filtered process formulation (as indicated by arrow a) to exit the centrifugal filter unit (100) through the outlet. The centrifugal filter unit (100) includes a filter (108) rotatably mounted in a housing (102). The filter (108) has a first end (110), the first end (110) being proximate to a first end (112) of the housing (102). The filter has a second end (114), the second end (114) being proximate to a second end (116) of the housing (102). The filter has a sidewall (118), the sidewall (118) disposed between the first end (110) and the second end (114), the sidewall (118) having perforations (122) therein. The centrifugal filter unit (100) has a filter chamber (120). The cover (128) is located at the first end (110) of the filter. The cover (128) has an aperture (130), the aperture (130) being operable to locate an inlet (126) formed on the end cap (124), but the cover (128) substantially seals the first end (110) of the filter (108) to substantially prevent solid material and liquid from exiting the filter chamber (120) through the first end (110) of the filter (108). The end cap (124) substantially seals the first end (112) of the housing (102). The end cap (124) includes an O-ring seal (164), the O-ring seal (164) cooperating with the housing (102) to seal the first end (112) of the housing (102). Feed (indicated by arrow B) can enter the filtration chamber (120) through inlet (126).

The centrifugal filter unit (100) comprises a drive means (132) for driving the filter (108) in rotation. The drive device (132) has a drive shaft (158) that engages the filter (108). An impeller (134) is coupled to the filter (108) and rotates with the filter (108). The impeller has six blades (162), two of which are shown in fig. 1. The impeller (134) is disposed near the second end (114) of the filter (108) so as not to interfere with the feed flow (arrow B) entering through the inlet (126). The cover (128) rotates with the filter (108). The end cap (124) does not rotate.

Both the filter (108) and the housing (102) are generally cylindrical.

The cover includes a first plurality of concentric rings (138), the first plurality of concentric rings (138) projecting from a side (140) of the cover (128) distal from the filter chamber (120). The end cap (124) includes a second plurality of concentric rings (142), the second plurality of concentric rings (142) projecting from a side (144) of the end cap (124) facing the filter chamber (120). The first plurality of concentric rings (138) are interspersed between the second plurality of concentric rings (142), thereby forming a labyrinth seal (136). Any liquid that leaks from the filter chamber (120) via the apertures (130) during rotation of the filter (108) must pass through the tortuous path formed by the first plurality of concentric rings (138) and the second plurality of concentric rings (142), without actually passing through the labyrinth seal. In this way, the liquid that has passed through the filter can be protected from contamination. A flange (190) extends from the first end (110) of the filter (108) toward the housing (102). The flange prevents feed that has exited the filter chamber (120) through the aperture (130) in the cover (128) and the labyrinth seal (136) from flowing from the first end (112) of the housing (102) to the second end (116) of the housing, thereby providing further protection against contamination of the filtered liquid.

When the filter (108) stops rotating, the path of least resistance to backflow of liquid that has passed through the perforations of the filter (108) into the filter chamber (120) is back through the perforations (122) of the filter (108) sidewall (118). Part of the return liquid re-entering the filter chamber (120) may leave the filter chamber (120) through the inlet (126).

The cover (128) includes six air release mechanisms (146), two of which are shown in fig. 1. Each air release mechanism (146) includes a channel (148) having a "U-bend" shape. Thus, the channel (148) has a first end (150) on a side of the cover (128) facing the filter chamber (120) and a second end (152) on a side of the cover (128) facing the end cap (124). The midpoint (154) of the channel (148) is positioned at a distance from the axis of rotation of the filter (108) that is less than the distance between the first (150) and second (152) ends and the axis of rotation of the filter. Air can be released from the filter chamber (120) through the passage (148) (arrow C). The first end (150) and the second end (152) are positioned as shown in FIG. 1, and are located the same distance from the axis of rotation of the filter (108). However, the position of the first end (150) and the second end (152) may be changed to create an inflow or outflow through the labyrinth. Preferably, the second end (152) is closer to the rotating shaft than the first end (150), thereby providing a means of inflow that helps keep the labyrinth seal clean and free of contaminating solid material.

Rotation of the filter (108) and impeller (134) has a pumping effect, drawing feed (arrow B) through the axial inlet (126) into the filter chamber (120), the rotation of the filter (108) and impeller (134) moving the feed radially towards the filter side wall (118). Solid material in the feed material is retained within the filter chamber (120) at the filter side wall (118) while liquid flows out of the perforations (122) of the filter (108) and exits the centrifugal filter unit (100) through the radial outlet (104) in the housing (102).

Fig. 2 shows another centrifugal filter unit (200) according to the invention. The centrifugal filter unit (200) comprises a housing (202) having an outlet (204) to enable filtered process formulation (as indicated by arrow a) to exit the centrifugal filter unit (200) through the outlet. The centrifugal filter unit (200) includes a filter (208) rotatably mounted in a housing (202). The filter (208) has a first end (210), the first end (210) being proximate to a first end (212) of the housing (202). The filter has a second end (214), the second end (214) being proximate to a second end (216) of the housing (202). The filter has a sidewall (218), the sidewall (218) disposed between the first end 210 and the second end 214, the sidewall 218 having perforations (222). The centrifugal filter unit (200) has a filter chamber (220). The cover (228) is located at the first end (210) of the filter (208). The cover (228) has an aperture (230) that can be used to position the inlet (226) formed in the end cap (224), but the cover (228) substantially seals the first end (210) of the filter (208) to substantially prevent solid material and liquid from exiting the filter chamber (220) from the first end (210) of the filter (208). The end cap (224) substantially seals the first end (212) of the housing (202). The end cap (224) includes an O-ring seal (264), the O-ring seal (264) cooperating with the housing (202) to seal the first end (212) of the housing (202). Feed (indicated by arrow B) can enter the filtration chamber (220) through inlet (226).

The centrifugal filter unit (200) comprises a drive means (232) for driving the filter (208) in rotation. The drive device (232) has a drive shaft (258) that engages the filter (208).

Both the filter (208) and the housing (202) are generally cylindrical.

The cover includes a first plurality of concentric rings (238), the first plurality of concentric rings (238) projecting from a side (240) of the cover (228) distal from the filter chamber (220). The end cap (224) includes a second plurality of concentric rings (242), the second plurality of concentric rings (242) projecting from a side (244) of the end cap (224) facing the filter chamber (220). The first plurality of concentric rings (238) are interspersed between the second plurality of concentric rings (242), thereby forming a labyrinth seal (236). Any liquid that leaks from the filter chamber (220) via the apertures (230) during rotation of the filter (208) must pass through the tortuous path formed by the first plurality of concentric rings (238) and the second plurality of concentric rings (242) without actually passing through the labyrinth seal. In this way, liquid that has passed through the filter (208) can be protected from contamination. A flange (290) extends from the first end (210) of the filter (208) toward the housing (202). The flange prevents feed that has exited the filtration chamber (220) through the aperture (230) in the cover (228) and the labyrinth seal (236) from flowing from the first end (212) of the housing (202) to the second end (216) of the housing, thereby providing further protection against contamination by the filtered liquid.

When the filter (208) stops rotating, the path of least resistance to backflow of liquid that has passed through the perforations of the filter (108) into the filter chamber (120) is back through the perforations (122) of the filter (108) sidewall (118). Part of the liquid return flow re-entering the filtering chamber (220) may leave the filtering chamber (220) through the inlet (226).

The centrifugal filter unit (200) has a removable portion (260) comprising (260) a cover (228) and a plunger comprising a shaft (266) and a plate (268). After a filtration operation using the centrifugal filter unit (200), the end cap (224) is removed from the housing (202), thereby exposing the cover (228). The removable portion (260) is removed by pulling the cover (228) out of the first end (210) of the housing, thereby carrying any solid material (not shown) collected in the filtration chamber (220).

The cover (228) includes six air release mechanisms (246), two of which are shown in FIG. 2. Each air release mechanism (246) includes a channel (248) having a "U-bend" shape. Thus, the passage (248) has a first end (250) on a side of the cover (228) facing the filter chamber (220) and a second end (252) on a side of the cover (228) facing the end cap (224). The midpoint (254) of the channel (248) is positioned at a distance from the axis of rotation of the filter (208) that is less than the distance between the first (250) and second (252) ends of the channel and the axis of rotation of the filter. Air can be released from the filter chamber (120) through the passages (148) (arrows C and D). The first end (250) and the second end (252) are located as shown in fig. 2, and are located the same distance from the axis of rotation of the filter (208). However, the position of the first end (250) and the second end (252) may be changed to create an inflow or outflow through the labyrinth. Preferably, the second end (252) is closer to the rotating shaft than the first end (250), thereby providing a means of inflow that helps keep the labyrinth seal clean and free of contaminating solid material.

Fig. 3 shows another centrifugal filter unit (300) according to the invention. The centrifugal filter unit (300) comprises a housing (302) having an outlet (304) to enable filtered process formulation to exit the centrifugal filter unit (300) through the outlet. The centrifugal filter unit (300) includes a filter (308) rotatably mounted in a housing (302). The filter includes an inner cage (305) nested within an outer cage (306), the outer cage (306) for providing structural support. The inner cage (305) of the filter (308) comprises a filter material with perforations (not shown). The filter (308) has a first end (310), the first end (310) of the filter (308) being proximate to a first end (312) of the housing (302). The filter has a second end (314) proximate to the second end (316) of the housing (302). The filter has a sidewall (318), the sidewall (318) disposed between the first end (310) and the second end (314). The centrifugal filter unit (300) has a filter chamber (320). The cover (328) is located at the first end (310) of the filter (308). The cover (328) has an aperture (330) that can be used to position the inlet (326) formed in the end cap (324), but the cover (328) substantially seals the first end (310) of the filter (308), thereby substantially preventing solid materials and liquids from exiting the filter chamber (320) through the first end (310) of the filter (308). The cover (328) includes a seal (370) surrounding the inlet (326). The end cap (324) substantially seals the first end (312) of the housing (302). Feed (indicated by arrow B) can enter the filter chamber (320) through inlet (326).

The centrifugal filter unit (300) comprises a drive means (390) for driving the filter (308) in rotation. The drive device has a drive shaft (380) that engages the filter (308). An impeller (334) is coupled to the filter (308) and rotates with the filter (308). The impeller (334) has grooves (374) that engage projections (378) of the filter (308). The impeller (334) is fixedly connected to the cover (328). The impeller (334) has six blades (362). Vanes (362) of the impeller (334) are located proximate the second end (314) of the filter (308) to reduce interference with the feed stream (arrow B) entering through the inlet (326). The cover (328) rotates together with the filter (308). The end cap (324) does not rotate.

Both the filter (308) and the housing (302) are generally cylindrical. The housing (302) has a second outlet (386), the second outlet (386) is connected to a valve (not shown), and the second outlet can be used to release (or "vent") air from the centrifugal filter unit (300).

The centrifugal filter unit (300) has a detachable portion (360), the detachable portion (360) comprising a cover (328) and an impeller (334). After a filtration operation is performed using the centrifugal filter unit (300), the end cap (324) is detached from the housing (302), thereby exposing the cover (328). The inner holder (305) and detachable portion of the filter (308) are also removed from the housing (302) by pulling the cover (328) out of the first end (310) of the housing. Once in place to pour the solid material into, for example, a waste container, the cover (328) may be separated from the inner holder (305) by a twist-lock operation. The detachable portion (360) may be removed by pulling on the cap (328). Thus, the cover (328) carries the impeller (334) and collected solid material (not shown) out of the filter chamber (320) for disposal of the solid material. The outer cage (306) of the filter (308) is fixedly connected to the drive shaft (380) and is generally not removable from the housing (302).

Rotation of the filter (308) and impeller (334) has a pumping effect, drawing feed (arrow B) into the filter chamber (320) through the axial inlet (326), and rotation of the filter (308) and impeller (334) moves feed radially (arrow a) towards the filter side wall (318). Solid material in the feed material is retained within the filter chamber (320) at the filter side wall (318), while liquid flows out of the filter (308) and exits the centrifugal filter unit (300) through the radial outlet (304) in the housing (302).

Fig. 4 shows a perspective view of an apparatus (400) for treating a substrate with a treatment formulation in the presence of a solid particulate material according to the present invention. The apparatus (400) has a tub (402) in which a rotatable cylindrical drum (406) is mounted. The roller (406) has a plurality of sidewalls (408), and the sidewalls (408) are provided with a plurality of holes (410). During use, the apertures (410) are capable of allowing the treatment formulation to exit the drum (406), but not the solid particulate material (not shown) to exit the drum (406). The drum (406) has an in-drum storage portion including a plurality of chambers (434) located on an inner circumferential surface of the drum (406) with equal spacing therebetween. The plurality of chambers (434) may also act as a plurality of lifters to facilitate circulation and agitation of the drum contents during use. The chamber 434 is configured to allow the solid particulates to enter the chamber 434 when the drum (406) rotates in a first direction and to allow the solid particulates to exit the chamber 434 when the drum (406) rotates in a reverse direction.

The device has a housing (404) which is transparent in fig. 4 to enable the components within the device (404) to be shown.

The apparatus (400) includes an access device (not shown) movable between an open position in which at least one substrate (not shown) may be placed in the drum (406), and a closed position in which the apparatus (400) is substantially sealed. A collector (412) is located below the drum (406) and is configured to collect the treatment formulation discharged from the drum (406). In the arrangement shown in fig. 4, the collector (412) is formed as part of the tub (402).

According to the disclosure herein, a first flow passage (416) connects the collector (412) and an inlet (418) of the centrifugal filter unit (414). The centrifugal filter unit (414) comprises a drive means (432) and an outlet (428). The apparatus (400) has a recirculation arrangement (430) for recirculating the treatment formulation from the collector (412) to the drum (406). The centrifugal filter unit (414) is comprised in a recirculation device (430). In this way, the treatment formulation is filtered by the centrifugal filter unit (414) before being returned to the drum (406) for continued or subsequent treatment of the substrate. The recirculation device further comprises a conduit (424) and a control valve (420). The control valve (420) may be operated to selectively deliver liquid filtered by the centrifugal filter unit (414) to a drain (422).

Fig. 5 illustrates another centrifugal filter unit (500) according to the present disclosure, and shows the centrifugal filter unit components in partially exploded form. The centrifugal filter unit (500) comprises a housing (502) having an outlet (504) through which filtered process agent can leave the centrifugal filter unit (500). The centrifugal filter unit (500) comprises a filter (508) rotatably mounted in a housing (502). The filter includes an inner holder (505) that, when assembled, nests within an outer holder (506) that provides structural support. The inner holder (505) of the filter (508) comprises a filter material with perforations. The cover (528) may substantially seal the filter (508) and may be coupled to the outer holder (506) by a twist-lock mechanism (594). The cover (528) has a hole (530) through which an inlet (526) formed in the end cap (524) can be mounted. When assembled, end cap (524) substantially seals housing (502). Feed can enter the centrifugal filtration unit (500) through inlet (526).

Attached to the cover (528) is an impeller (534), the impeller (534) and the cover (528) together forming a removable portion (560). When assembled, the impeller (534) is coupled to the filter (508) and rotates with the filter (508). The impeller (534) has six blades (562). The impeller further comprises a flat plate portion (550) having an annular ring of flexible material around its periphery. The flat plate portion (550) may drag solid material collected in the inner holder (505) of the filter (508) when the detachable portion (560) is removed from the inner holder (505). When the detachable portion (560) is removed from the inner holder (505), the pliable material around the edge of the flat plate portion (550) may scrape against the inner holder (505), thereby cleaning the inner holder (505).

The cover (528) is rotatable with the filter (508) due to the twist-lock mechanism (594). The end cap (524) does not rotate. The end cap (524) may be secured to the housing (502) with three quick release clips (592).

The cover (528) includes a set of concentric rings (540) that can mate with a set of concentric rings (not shown) in the end cap (524) to form a labyrinth seal.

Both the filter (508) and the housing (502) are generally cylindrical. Fig. 5 also shows a mounting block (600), the mounting block (600) not forming part of the centrifugal filter unit (500). The mounting block (600) gives one way in which the centrifugal filter unit (500) can be supported in the apparatus.

Fig. 6 shows another centrifugal filter unit (700) according to the invention, and fig. 7 shows a 3D section of the same centrifugal filter unit. The centrifugal filter unit is configured to run substantially in a vertical direction. The centrifugal filter unit (700) comprises a housing (702) with an outlet (704), through which outlet (704) filtered process agent can leave the centrifugal filter unit (700). The centrifugal filter unit (700) comprises a filter (708) rotatably mounted in a housing (702). The filter (708) has a first end (710), the first end (710) being proximate to a first end (712) of the housing (702). The filter has a second end (714), the second end (714) being proximate to a second end (716) of the housing (702). The filter includes an inner cage (705), the inner cage (705) being nested within an outer cage (706) that provides structural support when assembled. The inner cage (705) of the filter (708) has a sidewall (718), the sidewall 718 comprising filter material having perforations (not shown). The centrifugal filter unit (700) has a filter chamber (720).

A cover (728) is positioned at the first end (710) of the filter (708). The cover (728) has an aperture (730) through which an inlet (726) formed in the end cap (724) can be positioned. A gap (790) exists between the aperture edge and the inlet (726), but the cover (728) substantially seals the first end (710) of the filter (708) to substantially prevent solid materials and liquids from exiting the filter chamber (720) through the first end (710) of the filter (708).

The end cap (724) includes a second outlet (786), the second outlet (786) allowing air to be released from the centrifugal filter unit (700). The end cap substantially seals a first end (712) of the housing (702). Feed (indicated by arrow B) can enter the filtration chamber (720) through inlet (726).

When the filter is clogged, the gap (790) between the aperture (730) and the inlet (726) provides a path for feed to exit the first end of the filter chamber (720). The end cap (724) includes an overflow collection chamber (792) fluidly connected to the gap (790). During rotation of the filter (708), any liquid that leaks from the filter chamber (720) through the aperture (730) will flow out of the gap (790) into the overflow collection chamber (792) and not out of the filter side wall (718). Similarly, if feed cannot exit the filtration chamber (720) through the filter wall (718), e.g., due to filter plugging, it can enter the overflow collection chamber (792) through the gap (790). For feed flowing from the filter chamber (720) through the aperture (730) or gap (790) in the cover (728), the overflow collection chamber (792) prevents the feed from flowing directly from the first end (712) of the housing (702) to the second end (716) of the housing. An overflow port (796) is located in the overflow collection chamber (792). The bottom of the overflow collection chamber (792) is fitted with an overflow sensor (794), which overflow sensor (794) detects liquid flowing through, into, or collected in the overflow collection chamber (792). In this way, the user may be alerted that the filter (708) is clogged or that it is necessary to clean or replace the filter (708).

The centrifugal filter unit (700) comprises a drive means (732) for driving the filter (708) in rotation. The drive device (732) has a drive shaft (758) that engages the filter (708). The impeller (734) is coupled to the filter (708) and rotates with the filter (708). The impeller (734) has a groove (774) that engages a protruding portion (778) of the filter (708). The impeller (734) is fixedly coupled to the cover (728). The impeller (734) has six blades (762). Vanes (762) of the impeller (734) are positioned near the second end (714) of the filter (708) to reduce interference with the feed stream (arrow B) entering through the inlet (726). The cover (728) rotates with the filter (708). End cap (724) does not rotate.

The filter (708) is generally cylindrical, the housing (702) is tapered, and a second end (716) of the housing (702) has a diameter greater than a diameter of the first end (712). The outlet (704) has a tangential angle and is along an outer surface of the housing (702) so as to be aligned with the direction of flow of the filtered liquid exiting the filter chamber. The conical housing (702) helps to direct the filtered liquid to the tangential outlet (704).

Feed (arrow B) enters or is drawn into the filter chamber (720) through an axial inlet (726). Rotation of the filter (708) and impeller (734) causes the feed to move radially (indicated by arrow a) toward the filter sidewall (718). Solid material in the feed material remains within the filter chamber (720) at the filter side wall 718, while liquid flows out of the filter (708) and exits the centrifugal filter unit (700) through the tangential outlet (704) in the housing (702). If the filter (708) becomes clogged, the feed will eventually overflow and enter an overflow collection chamber (792). The overflow sensor (794) detects fluid flowing through, into, or collected in the overflow collection chamber (792) and alerts the user that the removable portion (760) shown in fig. 8b can be removed to allow for cleaning of solid material and to keep the filter from clogging.

As shown in fig. 8, the centrifugal filter unit (700) has a removable portion (760), the removable portion (760) including a cover (728) and an impeller (734). After a filtration operation using the centrifugal filter unit (700), the end cap (724) is removed from the housing (702), thereby exposing the cover (728). As shown in fig. 8a, the detachable portion (760) and filter (708) are also removed from the housing (702) by pulling the cover (728) out of the first end (710) of the housing. Once in place to pour the solid material into, for example, a waste container, the removable portion (760) may be separated from the filter (708) by a twist-lock operation. As shown in fig. 8b, the impeller (734) may also be removed from the filter (708) by pulling on the cover (728). The cover (728) thus carries away the impeller (734) and the solid material (not shown) collected from the filter chamber. The remainder comprises a filter chamber (720), the filter chamber (720) comprising an inner cage (705) and an outer cage (706). The solid material can be easily cleaned. Fig. 8d shows the housing (702) after removal of the detachable portion (760) and the filter (708).

Examples of the invention

After the wash cycle of the cotton/polyester hybrid substrate is complete, the particles (also referred to as "lint") are collected from the washer. 6g of microparticles are placed in a container and 20l of water are added. The resulting mixture in the vessel was a visibly turbid "dirty water" mixture.

The centrifugal filter unit is connected to the vessel in a circuit by connecting a first conduit from the vessel to an inlet of the centrifugal filter unit and a second conduit from an outlet of the centrifugal filter unit to the vessel. The centrifugal filter unit is of the type shown in figure 5, but in assembled form. The filter diameter of the centrifugal filter unit was 75mm, and the filter included a 32 μm sieve.

The centrifugal filtration unit was run for 5 minutes with the filter rotating at 1100 rpm. This time of operation allowed multiple passes of the water through the centrifugal filtration unit, with a measured flow rate of 12.6L per minute. After 5 minutes, the water in the vessel was clearly clear with no visible cloud residue, indicating a significant reduction in the amount of solid material remaining in the water.

Next, the water supply to the inlet of the centrifugal filtration unit is closed using a valve, so that no new feed is allowed to enter the centrifugal filtration unit. The solid material collected in the centrifugal filtration unit was dewatered by operating the centrifugal filtration unit at a filter speed of 1400 rpm. The dewatered solid material is retained in the filtration chamber. The solid material is easily removed from the centrifugal filter unit by loosening the end cap of the centrifugal filter unit and pulling out the cover and the inner holder of the filter. The removable portion (cover and impeller) is then separated from the inner holder of the filter by releasing the twist-lock mechanism. When the cover is pulled, the removable portion is withdrawn from the filter, carrying away the collected solid material, thereby easily removing the solid material from the filter chamber.

As used herein, the terms "comprising" includes "including … as well as" consisting of "and" consisting essentially of …, "e.g., a composition that" comprises "X may consist of X alone, or may alternatively include additional things, such as X + Y.

As used herein, the word "a" or "an" is not limited to the singular, but is understood to include the plural unless the context requires otherwise.

It should be understood that any item, feature, parameter or component described herein may relate to any aspect of the invention where appropriate.

A non-exhaustive list of aspects of the invention is set forth in the numbered clauses:

1. a centrifugal filtration unit for an apparatus for treating a substrate with a treatment formulation, the centrifugal filtration unit comprising;

a) a housing having an outlet configured to allow filtrate to exit the centrifugal filtration unit;

b) a filter rotatably mounted within the housing, wherein the filter comprises: a first end proximate the first end of the housing; a second end proximate the second end of the housing; and a sidewall connecting a first end of the filter and a second end of the filter; wherein the first end, second end, and sidewall of the filter define a filter chamber, and wherein the sidewall includes perforations configured to allow liquid to pass through but prevent solid material from passing through;

c) an end cap configured to substantially seal a first end of the housing;

d) an inlet configured to allow feed to enter the filtration chamber;

e) a cover at a first end of the filter, wherein the cover includes an aperture that mates with the inlet to allow the feed to enter the filtration chamber;

f) a drive means for rotating the filter; and

g) an impeller contained in the filter chamber;

wherein the centrifugal filter unit is configured such that when the impeller is rotated, the feed is drawn into the filter chamber through the inlet and liquid is expelled through the perforations.

2. The centrifugal filter unit of clause 1 wherein the impeller is coupled to the filter such that the impeller rotates at the same speed as the filter.

3. The centrifugal filter unit of clause 1 or 2, wherein the end cap is openable.

4. A centrifugal filtration unit for an apparatus for treating a substrate with a treatment formulation, the centrifugal filtration unit comprising;

a) a housing having an outlet configured to allow filtrate to exit the centrifugal filtration unit;

b) a filter rotatably mounted within the housing, wherein the filter comprises: a first end proximate the first end of the housing; a second end proximate the second end of the housing; and a sidewall connecting a first end of the filter and a second end of the filter; wherein the first end, the second end, and the sidewall of the filter define a filter chamber, the sidewall including perforations configured to allow passage of liquid but prevent passage of solid material;

c) an end cap configured to substantially seal a first end of the housing, wherein the end cap is openable;

d) an inlet configured to allow feed to enter the filtration chamber;

e) a cover at a first end of the filter, wherein the cover includes an aperture that mates with the inlet to allow the feed to enter the filtration chamber;

f) a drive means for rotating the filter; and

g) a removable portion configured to be positioned in the filtration chamber during operation of the centrifugal filtration unit and to remove and carry with it solid material at least partially prevented from passing through the perforations after operation of the centrifugal filtration.

5. The centrifugal filter unit of clause 4, wherein the removable portion is configured to rotate with the filter.

6. The centrifugal filter unit of clause 4 or 5, wherein said removable portion comprises a plunger.

7. A centrifugal filter unit as described in any of clauses 4-6 wherein said removable portion has substantially the same shape as the cross-section through said filter chamber at the side wall of said filter.

8. A centrifugal filter unit as described in any of clauses 4-7 wherein the detachable portion is shaped to scrape against the sidewall during removal of the detachable portion from the filter chamber.

9. The centrifugal filter unit of any of clauses 4-8, wherein said removable portion comprises a plurality of brushes, wherein said brushes are disposed on said removable portion proximate a sidewall of said filter.

10. A centrifugal filter unit as recited in any of clauses 4-9 wherein the removable portion includes a cover.

11. The centrifugal filter unit of any of clauses 4-10, further comprising an impeller, wherein the impeller is contained in the filter chamber.

12. A centrifugal filtration unit as recited in clause 11, wherein the impeller is coupled with the filter such that the impeller rotates at the same speed as the filter.

13. The centrifugal filter unit of clause 11 or 12, wherein said centrifugal filter unit is configured such that when said impeller is rotated, said feed is drawn into said filter chamber through said inlet and liquid is discharged through said perforations.

14. A centrifugal filter unit as recited in any of clauses 11-13 wherein the removable portion comprises an impeller.

15. The centrifugal filter unit of clause 14, wherein the removable portion comprises an impeller and a cover.

16. A centrifugal filtration unit as recited in any of clauses 4-15 wherein the removable portion is separated from the filter by a twist lock mechanism.

17. A centrifugal filter unit as claimed in any one of the preceding clauses wherein the housing and the filter are cylindrical.

18. A centrifugal filter unit as in any one of the preceding clauses wherein the filter is removable from the housing.

19. A centrifugal filtration unit as in any one of the preceding clauses further comprising a controller for the drive device, wherein the controller is programmed to cause the drive device to drive the filter in rotation at a first speed to filter the solid material from the feed and a second speed to dewater the filtered solid material.

20. A centrifugal filter unit as in any one of the preceding clauses wherein the cover is configured to rotate with the filter.

21. The centrifugal filter unit of any one of the preceding clauses wherein the cover and the end cap form a labyrinth seal.

22. The centrifugal filter unit of clause 21, wherein the cover comprises a first plurality of concentric rings on a side of the cover facing away from the filter chamber, and the endcap comprises a second plurality of concentric rings facing a side of the endcap of the filter chamber; wherein the first plurality of concentric rings are interspersed with respect to the second plurality of concentric rings to form a labyrinth seal.

23. A centrifugal filter unit as described in any one of the preceding clauses further comprising an air release mechanism.

24. The centrifugal filter unit of clause 23, wherein the air release mechanism is included in the cover.

25. The centrifugal filter unit of clause 24, wherein the air release mechanism comprises a channel having a first end, a second end, and a midpoint, wherein the first end of the channel is located on a side of the cover facing the filter chamber and the second end of the channel is located on a side of the cover facing away from the filter chamber, wherein the midpoint of the channel is located at a distance from the axis of rotation of the filter that is less than the distance between the first and second ends of the channel and the axis of rotation of the filter.

26. The centrifugal filter unit of clause 25, wherein the channel is u-bend shaped.

27. The centrifugal filtration unit of any of clauses 1-19, wherein the cap is contained within the end cap.

28. A centrifugal filter unit as claimed in any one of the preceding clauses further comprising attachment means for securing said end cap to said housing.

29. A centrifugal filter unit as recited in any of the preceding clauses wherein the end cap includes an inlet.

30. A centrifugal filter unit as claimed in any one of the preceding clauses wherein at least a portion of the housing is transparent.

31. A centrifugal filter unit as claimed in any one of the preceding clauses wherein at least a portion of the housing is transparent.

32. A centrifugal filter unit as in any one of the preceding clauses wherein the apparatus is a washing machine.

33. An apparatus for treating a substrate with a treatment formulation, the apparatus comprising:

a) a barrel rotatably mounted with a drum having a plurality of sidewalls including one or more apertures configured to allow the treatment formulation to exit the drum;

b) an access device movable between an open position in which at least one substrate may be placed in the drum and a closed position in which the apparatus is substantially sealed;

c) a collector located below the drum and configured to collect the treatment formulation flowing out of the drum;

d) the centrifugal filtration unit defined in any of clauses 1-32; and

e) a first flow passage between the collector and the inlet of the centrifugal filter unit

34. The apparatus of clause 33, wherein the outlet of the centrifugal filter unit is fluidly connected to the bowl.

35. The apparatus of clause 33, wherein the outlet of the centrifugal filter unit is fluidly connected to a drain.

36. The apparatus of clause 33, further comprising a control valve configured to selectively recirculate filtrate exiting the outlet of the centrifugal filtration unit to the drum or to a drain.

37. The apparatus of clause 33 or 34, further comprising a recirculation device for recirculating the treatment formulation from the collector to the drum, wherein the centrifugal filtration unit is contained in the recirculation device.

38. The apparatus of any of clauses 33-37, wherein the apparatus is configured to enable treatment of a substrate with a treatment formulation in the presence of a solid particulate material.

39. The apparatus of clause 33, wherein the solid particulate material cannot exit the drum through the apertures.

40. The apparatus of any clause 33-39, wherein the apparatus is a textile treatment apparatus.

41. The apparatus of any of clauses 33-40, wherein the apparatus is a cleaning machine.

42. A method of filtering a treatment formulation in an apparatus as described in any of clauses 33-41 comprising operating the drive device to rotate the filter of the centrifugal filtration unit at a first speed and transfer the treatment formulation from the collector to the inlet of the centrifugal filtration unit, wherein at least a portion of liquid from the treatment formulation flows out of the filter and at least a portion of solid material from the treatment formulation is prevented from passing through the filter.

43. The method of clause 42, wherein the centrifugal filtration unit comprises an impeller disposed in a centrifugal filter chamber, wherein the impeller affects transfer of the treatment formulation from the collector to the inlet of the centrifugal filtration unit.

44. The method of clause 42 or 43, further comprising the step of transferring filtrate flowing from an outlet of the housing of the centrifugal filter unit into the bowl.

45. The method of clause 42 or 43, further comprising the step of diverting filtrate exiting the outlet of the housing of the centrifugal filtration unit to a drain.

46. The method of any of clauses 42-45, further comprising the step of operating the drive to increase the rotational speed of the filter from a first speed to a second speed higher than the first speed to dewater the solid material collected in the filter chamber.

47. The method of any of clauses 42-46, further comprising the step of opening the end cap of the centrifugal filter unit and extracting solid material collected in the filter chamber.

48. A method of treating a substrate comprising treating the substrate with a treatment formulation using the apparatus of any of clauses 33-41.

49. The method of clause 48, including the steps of:

(a) loading at least one substrate to the drum and closing the entry device;

(b) introducing the treatment formulation into the drum;

(c) rotating the drum;

(d) collecting the treatment formulation flowing from the drum to the collector; and

(e) operating a pumping device to pump treatment formulation from the collector to the centrifugal filtration unit and to pump filtrate from the centrifugal filtration unit back to the bowl or drain.

50. The method of clause 49, wherein the pumping device comprises an impeller disposed within the filter chamber of the centrifugal filter unit.