阅读说明：本技术 用于制造纳米纤维素的设备和方法 (Apparatus and method for producing nanocellulose ) 是由 迈克尔·亚罗利姆 于 2019-05-08 设计创作，主要内容包括：本发明涉及用于由含纤维(3,4)的材料混合物(2)制造纳米纤维(5)、特别是纳米纤维素(6)的设备(1)和方法,该设备(1)包括：具有排出口(12)的至少一个排出元件(11),其用于使含纤维的材料混合物(2)通过；至少一个供给装置(19),其用于利用可预设的过程压力(15)在排出元件(11)上提供含纤维的材料混合物(2)；至少一个进给装置(18),其用于将所述排出元件(11)定位；其中,为了将含纤维的材料混合物(2)粉碎,与所述至少一个排出元件(11)相对置地设置有可运动的加工主体(7),其中,在含纤维(3)的材料混合物(2)通过所述排出元件(11)时在该排出元件(11)与可运动的加工主体(7)的加载有材料混合物的部分面(10)之间构成间隙状的加工区(16)。(The invention relates to a device (1) and a method for producing nanofibres (5), in particular nanocelluloses (6), from a material mixture (2) containing fibres (3, 4), the device (1) comprising: at least one discharge element (11) having a discharge opening (12) for the passage of a fiber-containing material mixture (2); at least one supply device (19) for supplying a fiber-containing material mixture (2) at a discharge element (11) using a predefinable process pressure (15); -at least one feeding device (18) for positioning the discharge element (11); wherein a movable processing body (7) is arranged opposite the at least one discharge element (11) for comminuting the fiber-containing material mixture (2), wherein a gap-like processing region (16) is formed between the discharge element (11) and the partial surface (10) of the movable processing body (7) on which the material mixture is applied, when the fiber-containing material mixture (2) passes through the discharge element (11).)

1. Device (1) for producing nanofibres (5), in particular nanocelluloses (6), from a material mixture (2) containing fibres (3, 4), comprising:

-at least one discharge element (11) with a discharge opening (12) for the passage of the fibre-containing material mixture (2);

-at least one supply device (19) for providing a fibre-containing material mixture (2) on the discharge element (11) with a predefinable process pressure (15);

-at least one feeding device (18) for positioning the discharge element (11);

the method is characterized in that: for comminuting the material mixture (2) containing fibers, a movable processing body (7) is arranged opposite the at least one discharge element (11), wherein a gap-like processing region (16) is formed between the discharge element (11) and the partial surface (10) of the movable processing body (7) on which the material mixture is applied, when the material mixture (2) containing fibers (3) passes through the discharge element (11).

2. The apparatus (1) according to claim 1, characterized in that: the movable processing body (7) is designed to be drivable by means of a drive device (2) along a movement direction (23) substantially lateral to, preferably perpendicular to, an ejection element axis (21) of the ejection element (11).

3. The device (1) according to claim 1 or 2, characterized in that: the movable machining body (7) is rotationally symmetrical, for example in the form of a disk (22), cylinder, cone, or in the form of a belt, such as a chain or belt.

4. The apparatus (1) according to any one of the preceding claims, wherein: the movable processing body (7) is designed as a disk (22) which is rotatable laterally, preferably perpendicularly, to the discharge element (11).

5. The apparatus (1) according to claim 4, characterized in that: the at least one feed device (18) is designed to be movable parallel to the rotational axis (24) of the disk (22) in order to set a predefinable radial distance (25) of the discharge element axis (21) from the rotational axis (24).

6. The apparatus (1) according to any one of the preceding claims, wherein: the outlet element (11) is designed with a functional surface (13) which is designed at least partially around the outlet opening (12) and is used to form a hydrodynamic bearing (29) in the machining zone (16).

7. The apparatus (1) according to claim 6, characterized in that: the functional surface (13) has a greater longitudinal extent in the direction of movement (23) than in the transverse direction and/or opposite to the direction of movement (23).

8. The apparatus (1) according to claim 6 or 7, characterized in that: the functional surface (13) is configured to be substantially complementary in shape to the partial surface (10) of the movable processing body (7) that is loaded with the material mixture.

9. The apparatus (1) according to any one of the preceding claims, wherein: the at least one discharge element (11) is configured to be orientable in a predefinable solid angle (26) of a surface (8) of the machining body (7) in which the discharge element axis (21) is movable relative to the surface.

10. The apparatus (1) according to any one of the preceding claims, wherein: the at least one feed device (18) is configured to be orientable in order to adjust a working distance (17) and/or a solid angle (26) between the at least one discharge element (11) and the material mixture-loaded partial surface (10) of the movable machining body (7).

11. The apparatus (1) according to any one of the preceding claims, wherein: the end section (14) of the at least one outlet element (11) is mounted at least partially movably relative to the opposite partial surface (10) that is loaded with the material medium.

12. The apparatus (1) according to any one of the preceding claims, wherein: at least two ejection elements (11) are arranged symmetrically to the movable machining body (7) in the circumferential direction and/or the radial direction.

13. The apparatus (1) according to any one of the preceding claims, wherein: at least one second discharge element (11) is arranged substantially opposite the first discharge element (11), wherein the first discharge element (11) is associated with a first surface (8) of the movable processing body (7) and the corresponding second discharge element (11) is associated with a second surface (9) opposite the first surface (8).

14. The apparatus (1) according to any one of the preceding claims, wherein: at least two ejection elements (11) are arranged along a movement direction (23) of the movable processing body (7) and/or perpendicular to the movement direction (23).

15. The apparatus (1) according to any one of the preceding claims, wherein: at least the movable machining body (7) is sealed from the drive device (20) by a housing (28) by means of a contact and/or non-contact sealing element (30), preferably a maintenance-free labyrinth seal.

16. Method for producing nanofibres (5), in particular nanocelluloses (6), from a material mixture (2) containing fibres (3), in particular pulp (4), comprising the following method steps:

-providing a device (1) according to any one of claims 1 to 15;

-providing a material mixture (2) comprising at least one liquid component, preferably water and fibres (3), preferably pulp (4);

-moving the movable processing body (7) relative to the at least one ejection element (11) at a predefinable relative speed (27);

-pressing the material mixture (2) containing fibres (3) through the at least one ejection element (11) with a predefinable process pressure (15);

-processing the material mixture (2) by positioning the ejection element (11) relative to the movable processing body (7) to form a gap-like processing zone (16) for comminuting the fibers (3) between the ejection element (11) and the partial surface (10) of the movable processing body (7) loaded with the material mixture.

17. The method of claim 16, wherein: the movable processing body (7) is moved by means of a drive device (20) in a movement direction (23) substantially laterally, preferably perpendicularly, to an ejection element axis (21) of the ejection element (11).

18. The method according to claim 16 or 17, characterized in that: at least one outlet element (11) having a functional surface (13) which is formed at least partially around the outlet opening (12) is used to form a hydrodynamic bearing (29) between the outlet element (11) and the partial surface (10) which is loaded with the material mixture.

19. The method according to any one of claims 16 to 18, wherein: the relative speed of the moving machining body (7) is adjusted to adjust the shear forces generated in the gap-like machining zone (16).

20. The method according to any one of claims 16 to 19, wherein: the working distance (17) between the at least one discharge element (11) and the respective partial surface (10) loaded with the material mixture is set by means of at least one feed device (18) in order to set the pressure on the moving machining body (7).

21. The method according to any one of claims 16 to 20, wherein: the solid angle (26) of the discharge element axis (21) of at least one discharge element (11) is adjusted by means of at least one feed device (18), preferably to form the necessary liquid wedge of a hydrodynamic bearing (29).

22. The method according to any one of claims 16 to 21, wherein: before providing the material mixture (2), the material mixture (2) is subjected to a chemical and/or enzymatic and/or mechanical pretreatment, preferably during a grinding process in a refiner.

23. The method according to any one of claims 16 to 22, wherein: the method steps of extruding through and processing are repeated at least with the processed at least partial material mixture (2).

Technical Field

The present invention relates to an apparatus and a method for producing nanofibres/especially nanocelluloses from a material mixture containing fibres/especially pulp or cellulose.

Background

Heretofore, in order to produce nanocellulose, a series of apparatuses and methods for producing nanofibers from natural raw materials, particularly from cellulose or pulp, have been developed. In the technical literature, a distinction is made mainly between microfibers and/or nanofibers, wherein many different concepts are used, such as micronized cellulose (MFC) or nanofibrillated fibers or nanofibrillated cellulose (NFC). Such materials are increasingly used in many technical fields, for example as reinforcing materials or also as barrier layers for paper, cardboard and the like.

The processing of fibers, in particular cellulose, takes place here by separating the cell walls and exposing the nanofibers, in particular nanocellulose. Thus, the pulverization is mainly performed in the longitudinal direction of the fibers and rarely performed by cutting the fibers in the transverse direction.

For the production of nanocellulose, microfluidizers are mainly known in the prior art. In a microfluidizer, such as in EP3088605a1, a first fluid stream containing fibres is crossed with a second fluid stream containing fibres to break down the cellulose into nanocellulose. The fibers are thus guided under high pressure through microchannels with a fixed internal geometry, in which the cell walls of the fibers are broken apart by shear and impact effects.

As disclosed for example in JP201304142a1, a further method for producing nanocellulose can be realized in the manner of a homogenizer. In this case, the fiber-containing material mixture is pressed by means of a high-pressure pump through the valve seat, then radially through the homogenization gaps, which are only a few micrometers wide, and then onto the radially arranged impingement ring. The effect of such a high pressure homogenizer is based on the shearing of the fibers by the fluid velocity changes, the impact load on the impact ring and the cavitation.

Nanocellulose can also be produced by means of a refiner or a grinder, as disclosed for example in WO2013072558a 1. In the case of refiners, two mutually corresponding grinding plates are usually guided close to each other up to the grinding gap and the fibre-containing material mixture is pressed into the centre of the grinding plate. The opposite movement of the fully wetted lapping plates can achieve the pulverization of the fibers into nanofibers.

The methods and/or apparatuses known to date require high energy consumption and are prone to process interruptions due to clogging of narrow parts such as valve seats, channels, nozzles and the like. Furthermore, the known apparatus is not suitable for processing large amounts of fiber-containing material mixtures for producing nanofibers, in particular nanocellulose, with low energy consumption.

Disclosure of Invention

In the context of the following description, the principle of comminuting fibres into nanofibres is explained mainly by means of examples of the paper and pulp industry. The device according to the invention and the method associated therewith are, however, not used in the sense only for plant fibers, but analogously also for other fiber-containing material mixtures which have animal fibers, such as fibers of the sea squirt type or synthetic fibers.

The purpose of the invention is: the disadvantages of the prior art are overcome and an apparatus and a method are provided with which a user can simply, energy-efficiently and easily carry out a comminution of fibers, in particular cellulose, of a material mixture for the production of nanofibers, in particular nanocellulose. Another object of the invention is: the process reliability is improved, clogging is reduced to a minimum or even completely avoided, and a large amount of material mixtures containing fibers, in particular pulp, can be processed. Furthermore, the object of the invention is: improve the homogeneity of the processed material mixture and/or ensure continuous production.

The object is achieved by a device and a method according to the claims.

According to the invention, the fibers to be comminuted, in particular cellulose or pulp, are provided in the form of a material mixture with a liquid component, in particular water. The material mixture may have a fiber distribution of different diameters and/or lengths. Also fibers that have been previously comminuted can be included in the material mixture. The fibers to be comminuted can in particular have a large number of microfibers which usually have a diameter of 10 to 100nm and a length of 0.5 to 10 μm.

Within the scope of the present invention, nanofibers mean essentially longitudinally extending constituents of fibers or microfibers, which fibers or microfibers either have a diameter in the thickness direction or in the range of about 5 to 30nm and a much larger longitudinal extension. This ratio of longitudinal extension to nanofiber thickness may be expressed as "aspect ratio" and is typically greater than 50.

An apparatus for producing nanofibres, in particular nanocellulose, from a fibre-containing material mixture comprises: at least one discharge element having a discharge opening for the passage of the fiber-containing material mixture; at least one supply device for providing a fiber-containing material mixture at a discharge element with a predeterminable process pressure; and at least one feed device for positioning the discharge element. In order to comminute the fiber-containing material mixture, a movable processing body is arranged opposite the at least one outlet element, wherein a gap-like processing region is formed between the outlet element and the partial surface of the movable processing body, on which the material mixture is applied, when the fiber-containing material mixture passes through the outlet element.

The method according to the invention uses such a device and comprises the following method steps:

-providing a device according to the invention;

-providing a material mixture comprising at least one liquid component, preferably water and fibres, preferably pulp;

-moving the movable processing body relative to the at least one ejection element at a predefinable relative speed;

-pressing the fibre-containing material mixture through the at least one discharge element with a predefinable process pressure;

the material mixture is processed by positioning the ejection element relative to the movable processing body to form a gap-like processing region for comminuting the fibers between the ejection element and the partial surface of the movable processing body, which is loaded with the material mixture.

By means of the relative movement of the machining body with respect to the discharge element and thus also with respect to the discharge opening, a shear region is formed at least in the machining zone of the gap-like formation. The predeterminable process pressure produces a speed change of the fluid or of the material mixture in the processing zone and allows the material mixture to flow continuously through, the fibers of which are comminuted in the shearing zone with cell wall rupture. In this case, long and/or insufficiently comminuted or processed fibers and/or other impurities can be removed from the processing zone by the relative movement of the processing body and clogging of the apparatus can be prevented. A larger amount of material mixture can thus be processed and the homogeneity of the processed material mixture can also be improved.

Furthermore, the device according to the invention can be produced and operated relatively simply and economically, since complex components are dispensed with. Possible wear parts can be accessed and replaced more easily and conveniently, whereby the working time can be increased considerably.

In known setting units, such as refiners, the reaction bodies, which are movable relative to each other, are completely immersed in the material mixture in order to be able to do soThe motion requires high idling power. The invention therefore differs from the prior art in particular in that: only a small portion of the surface of the processing body is subjected to the material mixture, as a result of which a particularly high energy efficiency can be achieved. The processed material mixture is greatly accelerated when it is discharged from the processing zone and can be collected in a simple manner in a housing that at least partially encloses the processing body and/or the discharge element. Thus working the bodyOne part is not in direct contact with the material mixture. The machining body can be moved with low resistance, whereby the total power consumption can be reduced by a reduced amount of idling power.

The device or method according to the invention is therefore very suitable for processing material mixtures with synthetic and/or organic fibres. The proportion of fibers in the material mixture can be selected, depending on the particular purpose, from about 0.1% to about 25% by volume, preferably from 1% to 8% by volume.

The movable processing body can be guided to move "passively" in the direction of movement by discharging the material mixture on the discharge element onto the partial surfaces of the oppositely disposed processing body.

It may also be suitable: the movable processing body is designed to be drivable by means of a drive device in a movement direction substantially lateral, preferably perpendicular, to the discharge element axis of the discharge element.

This corresponds to an "active" and thus adjustable movement of the movable machining body in the direction of movement. The discharge element axis substantially corresponds to an imaginary longitudinal axis through the discharge element in the center of the discharge opening. The movement is carried out substantially laterally, preferably perpendicularly, to the discharge element axis of the discharge element and can be introduced and adjusted by means of a drive device. In this way, the relative speed and thus the magnitude of the shearing force in the processing zone can be adjusted relatively simply.

In principle, it is also conceivable: the direction of movement of the processing body is substantially opposite to the direction of flow of the material mixture which is sprayed at a predetermined angle onto the material-loaded partial surface of the processing body.

Furthermore, provision can be made for: the movable processing body is configured rotationally symmetrical, for example as a disk, cylinder, cone, drum, or as a belt, such as a chain or a belt.

The geometry of the machining body can be selected by the expert in view of the available space conditions, the delivery volume, the drive power, etc. In some cases, therefore, strip-shaped processing bodies can be advantageous, which are likewise only partially surface-loaded with the material mixture. The rotationally symmetrical machining body likewise allows a comparatively simple, expedient design and can furthermore be designed to be very dimensionally stable without having to withstand the excessively high energy consumption of the movement, since only the partial surface loaded with material is sprayed with the material mixture in each case.

A feature is also particularly advantageous, according to which it can be provided that: the movable processing body is designed as a disk which is rotatable laterally, preferably perpendicularly, to the discharge element.

The advantages of favorable procurement, long service life and low maintenance costs can be well utilized in the embodiment as a tray or plate.

In addition, provision can be made for: the at least one feed device is designed to be movable parallel to the rotational axis of the disk for setting a predefinable radial distance of the discharge element axis from the rotational axis.

This embodiment allows the possibility of adjusting the relative speed in the processing zone independently or additionally, which can be adjusted relatively simply by different peripheral speeds depending on the radial spacing from the axis of rotation. In addition or as an alternative to the rotational speed regulation of the drive, provision can be made for this measure, which provides an extremely effective method for regulating the shear forces, in particular in the case of "passively" driven machining bodies.

According to one refinement, it is possible to: the outlet element has a functional surface which is formed at least partially around the outlet opening for forming a hydrodynamic bearing in the machining zone. The outlet element is preferably formed integrally with the functional surface, but can also be assembled from several parts and formed, for example, in the form of an exchangeable end section of the outlet element.

The use of a discharge element designed in this way allows a hydrodynamic bearing to be formed, as a result of which the discharge element can be separated from the material-loaded partial surface at a predetermined working distance without touching it. The material-loaded partial surface corresponds substantially in terms of its shape and/or size to the functional surface. This allows the pressure forces which are favorable for the formation of the shear forces required for comminuting the fibers, such as the process pressure of the material mixture and/or the pressing force of the discharge element, to be increased in a simple manner without the discharge element sliding on the processing body. The discharge element or the functional surface can be prevented from slipping, mainly by forming a liquid wedge in the processing zone.

It may furthermore be expedient: the functional surfaces have a greater longitudinal extension in the direction of movement than in the transverse direction and/or counter to the direction of movement.

By optimizing the shape of the functional surface, the discharge of the material medium along the periphery of the functional surface can be homogenized. In addition, in this way, the stability of the hydrodynamic bearing can be increased and the homogeneity and/or quality of the processed material mixture can be improved.

In addition, provision can be made for: the functional surface is configured to be substantially complementary in shape to the partial surface of the movable machining body that is loaded with the material mixture.

In particular in the case of curved inner or outer surfaces of the machining body, such as in the case of a cylinder or a cone, this measure makes it possible to increase the homogeneity of the discharge of the material mixture from the machining zone configured for uneven partial surfaces loaded with the material medium. This primarily contributes to a homogenization of the local discharge velocity and/or shear forces on the fibers to be processed in the processing zone via the functional surface, which contributes to an improvement in quality.

Furthermore, provision can be made for: the at least one ejection element is configured to be orientable in a predefinable solid angle of the surface of the processing body in which the ejection element axis is movable relative to the surface.

An advantage of this embodiment is the adjustability and stability of the hydrodynamic bearing. Furthermore, the angled arrangement of the discharge elements can be used, in particular in the case of "passively" moving bodies, for adjusting the relative speed and/or the shear forces in the processing zone. This possibility can be realized comparatively simply and economically and allows the quality of the processed material mixture to be improved.

According to a particular feature, it is possible to: the at least one feed device is configured to be orientable for adjusting a working distance and/or a solid angle between the at least one outlet element and the material mixture-loaded partial surface of the movable processing body.

This can be done independently or also in combination with other measures, such as an angled arrangement or adjustment of the process pressure of the material mixture.

It can be particularly advantageous here that: in order to adjust the shear forces which are formed in the gap-like machining zone, the relative speed of the moving machining body is adjusted. It would also be beneficial to: in order to set the pressure exerted on the moving machining body, the working distance between the at least one ejection element and the corresponding partial surface loaded with the material mixture is adjusted at least by means of the feed device.

For example, the contact pressure of the discharge element and thus the discharge speed of the processed material mixture can be set in a targeted manner, as a result of which the magnitude of the shear forces in the gap-like processing zone can be set in a targeted manner.

According to an advantageous further development: preferably, the solid angle of the outlet element axis of the at least one outlet element is adjusted by means of the at least one feed device in order to form the necessary liquid wedge of the hydrodynamic bearing.

The magnitude of the shear forces in the machining zone can thus be set in a targeted manner. Furthermore, this measure can be used to compensate for worn discharge elements and/or functional surfaces. This achieves an increased homogeneity and/or quality of the processed material mixture over the service time or service life of the wear part.

It would be particularly beneficial to: the end section of the at least one outlet element is mounted at least partially movably relative to the opposite partial surface loaded with the material medium.

The end section of the outlet element may comprise a functional surface, thereby creating stability of the hydrodynamic bearing. The end section can be designed as a floating bearing of the outlet element so as to be essentially freely movable or can be designed to be adjustable, whereby compensation for wear of the outlet element and/or the functional surface can be achieved. Furthermore, clogging by long and/or insufficiently processed fibers can be avoided.

It can also be provided that: at least two ejection elements are arranged symmetrically to the movable processing body in the circumferential direction and/or the radial direction.

The provision of a plurality of outlet elements, which form a processing zone with a common processing body, can significantly increase the throughput of the material mixture. This is particularly advantageous because, in continuous operation, one or more discharge elements can be switched on/off relatively easily as required and even maintenance work on the respective discharge element can be carried out. In addition, this measure can be used to reduce, or even completely counteract, possible bending moments which are exerted on the machining body by the process and/or pressing forces. This measure enables a more stable and less maintenance-demanding device.

Furthermore, provision can be made for: at least one second discharge element is arranged substantially opposite the first discharge element, wherein the first discharge element is associated with a first surface of the movable processing body and the corresponding second discharge element is associated with a second surface opposite the first surface.

The formation of a plurality of outlet elements, each of which forms a processing zone with a processing body, enables a significant increase in the throughput of the material mixture. By arranging two corresponding ejection elements opposite to each other, the bending moments acting on, for example, the drive shaft of the machining body or on the machining body itself can be reduced until they are completely counteracted. This measure is advantageous both in the band-shaped machining body and in the rotationally symmetrical machining body, such as a cylinder or a disk, as long as the partial surfaces of the respective outlet element, which are loaded with the material medium, are essentially opposite on the first and second surfaces.

In addition, provision can be made for: at least two ejection elements are arranged along and/or perpendicular to the direction of movement of the movable processing body.

In this case, the following can also be considered: the outlet elements are arranged spaced apart in at least one direction, i.e. offset from one another. The provision of a plurality of discharge elements enables a higher throughput rate with the use of only one common processing body. This advantage, like the construction of the above-described ejection elements arranged opposite each other on the first and second surface, is mainly due to: the power consumption for driving the movable machining body rises only slightly, even negligibly. In this way, large amounts of material mixtures can be processed simultaneously in a very energy-efficient and economical manner. It can therefore be easily considered that: a plurality of discharge elements may be provided along the column or the cone. In this case, the ejection elements can in principle also be arranged opposite one another on the first surface, for example on the outer side of the cylinder, so that bending moments acting on the drive shaft of the machining body can be counteracted. It is also conceivable to arrange the discharge elements along the circumference of one disc, which produces the same effect on the disc.

A feature is also advantageous, according to which it is possible to specify: at least the movable machining body is arranged to be sealed off from the housing by means of at least one contact and/or non-contact sealing element, preferably a maintenance-free labyrinth seal, relative to the drive.

The relatively simple construction of the device according to the invention makes it possible to dispense with expensive sealing solutions. Although the processing of the material mixture takes place under the application of process pressure, the material mixture is usually only under atmospheric conditions after discharge. A housing is advantageously used for collecting the processed material mixture, which housing protects at least part of the surface loaded with the material medium, preferably the entire processing body, from the surrounding environment. As is well known to those skilled in the art, simple contact rubber seals, for example, may be used to seal housing openings such as the discharge element or the drive shaft, or self-sealing, maintenance-free labyrinth seals may also be used. This enables particularly long service intervals and low manufacturing costs.

It has proven to be advantageous: the housing is provided with a collecting container for collecting and/or further processing the processed material mixture. In some cases, a substantially complete sealing of the housing can be advantageous for the process space to be under negative pressure or overpressure or for a protective gas atmosphere to be formed therein, as a result of which the quality of the processed material mixture can be influenced in a targeted manner.

According to one refinement, it is possible to: before providing the material mixture, the material mixture is preferably subjected to a chemical and/or enzymatic and/or mechanical pretreatment during the grinding in the refiner.

By means of a chemical and/or enzymatic pretreatment, the splitting of the fiber components can be influenced in a targeted manner, as a result of which the comminution into nanofibers, in particular nanocellulose, can be facilitated. Such a pretreatment can be carried out in an external device, but also in a section of the supply device provided for this purpose. Mechanical pretreatments for setting a predefinable fiber length or a distribution of fiber lengths and/or fiber diameters are likewise conceivable, which can be carried out, for example, by refiners and methods known to the skilled person in connection with this. Suitable pretreatments can therefore be used to improve the quality of the processed material mixture.

It may also be suitable: the method steps of extruding and processing are repeated at least with the processed at least partial material mixture.

By processing the fiber-containing material mixture a plurality of times, the quality and homogeneity of the processed material mixture can be improved. It is conceivable here to feed at least part of the once-through processed material mixture, or all of it, again to the installation. The circulation system between the collecting container and the supply device can be used very simply to achieve a predefinable fiber diameter distribution and/or fiber length distribution. It may be beneficial in some cases to: the liquid component of the material mixture processed and reset for further transport is adjusted in such a way that, for example, water is added. This makes it possible to achieve a particularly fine decomposition of the fiber components into nanofibers, in particular nanocellulose, with a low energy and/or pressure consumption.

Drawings

The invention is explained in detail with the aid of the following figures in order to facilitate a better understanding of the invention.

In greatly simplified schematic diagrams:

fig. 1 is a schematic cross-sectional view of an ejector element and a processing body for illustrating the principle of action;

fig. 2 is a schematic cross-sectional view of an ejector element with functional surfaces and a processing body for illustrating the principle of action;

fig. 3 is a schematic cross-sectional view of a possible embodiment of the device with two discharge elements disposed circumferentially distributed on a first surface (a) and oppositely disposed on a first and a second surface (b);

FIG. 4 is a schematic cross-sectional view of a processing body as a cylinder (a), cone (b), or belt (c) having a plurality of ejection elements;

FIG. 5 is a schematic illustration of a cross-section of an ejection element, wherein (a) shows tipping over a solid angle, (b) shows a movable end section, (c) shows a complementarily-shaped functional face, or (d) shows a bottom view;

fig. 6 is a schematic overview of a possible set-up structure of the apparatus for manufacturing nanofibres.

Detailed Description

As an introduction, it is first explained that: in the various embodiments described in the different figures, identical components are provided with the same reference numerals or the same component names, wherein the disclosure contained throughout the description can be transferred in a meaningful manner to identical components provided with the same reference numerals or the same component names. Further, orientation descriptions such as up, down, side, and the like selected in the specification are directed to the figures described and illustrated directly, and when the orientation changes, these orientation descriptions may be transferred to a new orientation in a meaning.

Fig. 1 schematically shows an apparatus 1 for producing nanofibres 5, in particular nanocellulose 6, from a material mixture 2 containing fibres 3, in particular pulp 4. The principle of action for comminuting the fiber-containing material mixture 2 can be seen from the cross-sectional view. According to the invention, a movable machining body 7 is arranged opposite at least one ejection element 11. A gap-like machining region 16 is formed between the outlet element 11 and the material mixture-loaded partial surface 10 of the movable machining body 7.

As is schematically shown in fig. 1, the material mixture 2 comprises a liquid component and fibers 3, which may comprise pulp 4 or cellulose, in particular. The material mixture 2 is pressed through the outlet element 11 with a predefinable process pressure 15. The movable processing body 7 can be moved relative to one another in the direction of movement 23, for example passively by discharging the processed material mixture 2 from the processing zone 16. The machine body 7 can likewise be actively moved in the movement direction 23 by means of a drive device 20, as shown, for example, in fig. 6. The shear forces generated during the passage of the material mixture 2 containing the fibers 3 through the discharge element 11 are used in the gap-like formation of the processing zone 16 to break the fibers 3, in particular the pulp 4, into nanofibers 5, in particular the nanocellulose 6.

The exemplary embodiment in fig. 1 is a machining body 7 configured as a disk 22. In this case, the processing body 7 is mounted rotatably or movably about the axis of rotation 24. The outlet element 11 has an outlet element axis 21 which coincides substantially with an imaginary longitudinal axis through the outlet element 11 in the center of the outlet opening 12. As can be seen particularly clearly from fig. 1 in conjunction with fig. 2, the relative speed 27 in the machining zone 16 can be set by the radial distance 25 between the discharge element axis 21 and the axis of rotation 24.

As can be seen from fig. 1 in conjunction with fig. 2 to 6: the movable processing body 7 is guided past the ejection element 11 in the direction of movement 23. This relative movement preferably takes place substantially laterally, particularly preferably perpendicularly, to the discharge element axis 21.

Fig. 2 shows a further and possibly self-contained embodiment of the device according to the invention. In this embodiment, the outlet element 11 has a functional surface 13 which is at least partially formed around the outlet opening 12. As shown, the functional surface 13 can be formed integrally with the outlet element 11. However, it is also conceivable: the functional surface 13 can be connected to the outlet element 11 as a component of the end section 14 or as a separate component, in order to ensure simple replacement. As the material mixture 2 passes or is pressed through the outlet element 11, a hydrodynamic bearing 29 can be formed in the processing zone 16. In this case, the processing region 16 comprises the functional surface 13 and the corresponding, opposite partial surface 10, which is loaded with the material medium. By forming a liquid wedge in the hydrodynamic bearing 29, the discharge element 11 and/or the functional surface 13 can be prevented from coming into contact with the machining body 7.

It can also be seen from fig. 2 that: the outlet element 11 has a working distance 17 from the partial surface 10 loaded with the material mixture. Such a working distance 17 can likewise be adjusted for the device shown schematically in fig. 1.

The structure of the feed device 18 for positioning the discharge element 11 is shown by way of example in fig. 3, 4 and 6 and can be transferred in a manner to fig. 1, 2 and 5. As can be seen in particular from fig. 3a and b, the feed device 18 can be used to move the at least one ejection element 11 in the direction of the processing body 7 and/or transversely thereto. Such a feed device 18 can be used in particular for adjusting the working distance 17.

Fig. 3a and b and 4a to c schematically show an apparatus 1 in which two or more discharge workpieces 11 are arranged relative to a machining body 7. Fig. 3a shows two ejection elements 11 here, which are spaced apart from the first surface 8 of the machining body 7 symmetrically with respect to the axis of rotation 24. Fig. 3b schematically shows a situation in which two ejection elements are arranged substantially opposite and symmetrical to each other on the first surface 8 or the second surface 9 of the machining body 7. By configuring the machining body 7 as a disk 22, possible bending moments on the disk 22 and thus on the axis of rotation 24 can be counteracted in the embodiment shown in fig. 3a and b.

The supply of the at least one outlet element 11 can be effected in each case via a separate supply device 19 for the fiber-containing material mixture 2 or via a common supply device 19 for the fiber-containing material mixture. Such a supply device 19 is omitted from fig. 1, 2, 4 and 5 for the sake of simplicity.

According to the invention, the movable machining body 7 can be designed as a rotationally symmetrical body, such as a cylinder or drum or cone or disk 22, as is schematically shown in fig. 4a, 4b and 3. As a further alternative, it is possible: the movable processing body 7 is of a belt-like design, for example a chain or a belt, as can be seen schematically in fig. 4 c. As can be seen in particular from fig. 3 and 4: a plurality of discharge elements 11 can be assigned to a common processing body 7. The movable processing body 7 can be connected to a drive device 20, as can be seen from fig. 3, 4 and 6. Such a drive device 20 can be designed, for example, as a hydraulic or pneumatic motor and particularly preferably as an electric motor and has a rotational speed adjustment.

The feed device 18, which is schematically illustrated in fig. 3, 4 and 6, can be configured to be orientable or positionable in order to adjust the working distance 17 and/or the solid angle 26 between the at least one outlet element 11 and the material mixture-loaded partial surface 10 of the movable processing body. Likewise, it is conceivable: a plurality of ejection elements 11 can be positioned jointly relative to the machining body by means of a common feed device 18. Furthermore, as can be seen in fig. 3 and 4: at least two ejection elements 11 can be arranged along the processing body 7 which can be moved relative to one another in the circumferential direction and/or in the radial direction. The discharge elements 11 can be arranged symmetrically and/or offset to one another on the first surface 8 and/or the second surface 9.

A special embodiment of a cylinder, cone, belt or chain is not shown, in which at least one second ejection element 11 is arranged substantially opposite the first ejection element 11, wherein the first ejection element 11 is arranged on the first surface 8 of the movable processing body 7 and the corresponding second ejection element 11 is arranged on the second surface 9 opposite the first surface 8. This situation can be seen in fig. 3b for a processing body 7 designed as a disk 22 and the situation of other rotationally symmetrical and/or band-shaped processing bodies 7 can be deduced by the person skilled in the art.

Fig. 5a to d show different possible embodiments of a plurality of outlet elements 11.

Fig. 5a shows an outlet element 11 whose outlet element axis 21 is arranged at a preferably predefinable solid angle 26 from the normal to the material mixture-loaded partial surface 10 of the machining body 7. As previously mentioned, such positioning of the ejection element 11 can be performed by means of the feeding device 18. The formation of the hydrodynamic bearing 29 can also be seen particularly clearly from this illustration.

Fig. 5b schematically shows a further example of a discharge element 11, wherein an end section 14 of the discharge element 11 is mounted at least partially movably relative to the opposite partial surface 10 loaded with the material medium. In this way, a floating bearing of the end section 14 can be formed at the same time as the hydrodynamic bearing 29, without this leading to jamming or jamming of the end section 14.

Fig. 5c shows a schematic cross-sectional view of the discharge element 11, the functional surface 13 surrounding the discharge element opening and the curved machining body 7. The functional surface 13 is configured to be substantially complementary in shape to the partial surface 10 of the processing body 7 loaded with the material mixture. In particular, concave and convex shapes of the functional surface 13 are conceivable here, as can be seen particularly clearly in fig. 5 c.

Fig. 5d schematically shows a bottom view of another possible embodiment of the ejector element 11 and the functional surface 13. The functional surface 13 is configured here with a greater longitudinal extent in the direction of movement 23 than in a direction transverse to the direction of movement and/or opposite to the intended direction of movement 23. The illustrated movement arrows schematically show the discharge of the processed material mixture 2. In the case of the functional surfaces 13 shaped in this way, their shape can be optimized by the skilled person for the respective application and geometry of the machining body 7. As already mentioned, the processing zone 16 is to be formed essentially between the functional surface 13 and the corresponding partial surface 10 loaded with the material medium.

The discharge element 11 and its combination shown in fig. 5a to d may, according to the invention, be introduced into the description of fig. 2, 3, 4 and 6 and are not described in detail separately for the sake of brevity, but refer to the corresponding description.

Fig. 6 is a schematic overview of the apparatus 1 according to the invention. Only one ejection element 11 is oriented relative to the movable processing body 7. The positioning of the ejection element 11 is performed by means of the feeding device 18. The material mixture 2 is fed via a feed device 19. The processing body 7 configured as a disk 22 is driven by the drive device 20 in a direction of movement 23. As can be seen from fig. 6, the device 1 has a housing 28, which is shown in an open state. The housing 28 serves to capture material during processing and can be sealed at least against the drive device 20 by means of one or more sealing elements 30. Such a sealing element 30 is exemplary of the type which can also be seen in fig. 3 and can be designed to be either contact or contactless. The processed material mixture 2 may be received in a collection container 31. Likewise, it is conceivable: the supply device 19 is connected to the collecting container 31 in order to realize the circulation principle.

Within the scope of the invention, the individual processing steps can also be automated and preferably controlled via a central plant control system, not shown. Further, it is considered that an operation is performed on an operation panel or a touch screen for device monitoring and control.

The adjustment of the fiber length and/or the predefinable distribution of the fiber cross section and/or the distribution thereof can thus be preset by the user and adjusted by means of the device control system. Multiple passes of the processed at least partial material mixture 2 can likewise be used to adjust the homogeneity and/or quality of the nanofibres 5 or of the nanocelluloses 6.

The material density of the material mixture 2 can influence the quality of the processed material mixture 2. With the present apparatus 1 and the corresponding method, suspensions with a fiber fraction of 0.1 to about 10% by volume, preferably 1 to about 8% by volume, i.e. material mixtures 2, can be processed reliably and simply. Material densities of up to 25% by volume and above are also contemplated. In this case, a skilled person may be required to use a suitable supply device 19 which is capable of delivering a material mixture 2 having such a high material density with the application of a sufficiently high process pressure 15. For example, high-pressure worm feed units are particularly suitable in this case.

The examples show possible variant embodiments, it being noted here that: the invention is not limited to the specific illustrated variant embodiments of the invention, but rather the individual variant embodiments can also be combined differently with one another and these variant possibilities are within the ability of the person skilled in the art on the basis of the teaching of the technical means of the invention.

The scope of protection is determined by the claims. The description and drawings can be used to interpret the claims. Individual features or combinations of features from the different embodiments shown and described can individually constitute independent, inventive solutions. The object of the independent, inventive solution can be obtained from the description.

All statements as to ranges of values in the specification should be understood to include any and all subranges therefrom, e.g., 1 to 10 statements should be understood to include all subranges beginning with a lower limit of 1 and an upper limit of 10, that is, all subranges beginning with a lower limit of 1 or more and ending with an upper limit of 10 or less, e.g., 1 to 1.7 or 3.2 to 8.1 or 5.5 to 10.

Finally, according to the regulation, the following points are indicated: for a better understanding of the structure, elements are shown disproportionately and/or enlarged and/or reduced.

List of reference numerals

1 apparatus

2 mixture of materials

3 fiber

4 pulp

5 nanometer fiber

6 nanometer cellulose

7 processing the main body

8 first surface

9 second surface

10 partial surface loaded with a material mixture

11 discharge element

12 discharge port

13 functional noodles

14 end section

15 process pressure

16 processing zone

17 working distance

18 feeding device

19 feeding device

20 drive device

21 axis of the discharge element

22 disc

23 direction of motion

24 axis of rotation

25 radial spacing

26 solid angle

27 relative velocity

28 casing

29 hydrodynamic bearing

30 sealing element

31 collecting container