Method for operating a filter device
阅读说明:本技术 过滤装置的运行方法 (Method for operating a filter device ) 是由 高桥裕一 高桥宽行 堀米昭典 于 2017-11-30 设计创作,主要内容包括:本发明提供一种过滤装置的运行方法,能够从去除对象物(非过滤物质)中有效地分级筛分出在过滤以及反向清洗(清洁)时附着、堆积于滤芯的过滤用材料的无需去除物质而有效利用。过滤装置具备:滤芯(3),其在过滤时在过滤用材料(31)的一面捕获流体中的物质,在反向清洗时使捕获物质从过滤用材料脱离;以及刷子(144),其配置为能够相对于过滤用材料的一面进行相对移动,在该相对移动时,对捕获物质的脱离以及针对捕获物质的筛分进行辅助,在实施过滤的过程中过滤用材料的两面间的压差超过规定值的情况下等开始反向清洗,在压差解除后或者在经过规定时间后返回到过滤,在该过滤装置的运行方法中实施如下筛分作业:在过滤过程中,使刷子动作而从捕获物质中筛分出无需去除物质,并使该无需去除物质向另一面侧通过。(The invention provides a method for operating a filtering device, which can effectively screen out filtering materials attached to a filter element and accumulated in a filter element during filtering and reverse cleaning (cleaning) from objects to be removed (non-filtering materials) without removing the materials and effectively utilize the materials. The filtering device is provided with: a filter element (3) which traps substances in a fluid on one surface of a filter material (31) during filtration and which separates the trapped substances from the filter material during reverse cleaning; and a brush (144) which is configured to be capable of relatively moving relative to one surface of the filtering material, assists detachment of the captured material and screening of the captured material during the relative movement, starts reverse cleaning when a pressure difference between the two surfaces of the filtering material exceeds a predetermined value during the filtering process, and returns to the filtering process after the pressure difference is removed or after a predetermined time has elapsed, wherein the following screening operation is performed in the operation method of the filtering device: in the filtering process, the brush is operated to screen the unnecessary removal substance from the captured substance, and the unnecessary removal substance is passed through to the other side.)
1. A method for operating a filter device, in which,
the filter device is provided with:
a filter element having a filter material made of a metal mesh material, and capturing substances in a fluid at one surface of the filter material when the filter material is used for filtering the fluid from the one surface to the other surface of the filter material, and separating the captured substances from the filter material when reverse cleaning is performed for passing the fluid from the other surface to the one surface of the filter material;
a brush configured to be capable of moving relative to the one surface of the filter material, and to assist detachment of the captured material and sieving of the captured material during the relative movement;
a drive unit that moves at least one of the brush and the filter element relative to the other;
a filter mechanism for passing a fluid from one surface side of the filter material to the other surface side;
a reverse cleaning mechanism for passing a fluid from the other surface side to the one surface side of the filter material;
a housing supporting at least the filter element, the filter mechanism, and the reverse purge mechanism; and
a control unit that controls the drive unit, the filter mechanism, and the reverse cleaning mechanism,
starting the reverse cleaning when a pressure difference between both surfaces of the filter material exceeds a predetermined value or when a predetermined time elapses during the filtration, returning to the filtration after the pressure difference is removed or after the predetermined time elapses,
the method of operating the filter device is characterized in that,
the control unit performs the following screening operations: in the filtration, the driving unit is driven to move the brush relative to the filter material, thereby separating the unwanted material from the captured material and allowing the unwanted material to pass through to the other surface side.
2. Method for operating a filter device according to claim 1,
in the operation of screening the non-removable substance from the captured substance, when the particles constituting the non-removable substance are in a plurality of lump shapes, the brush is moved relative to the wall of the filter material to break the lump particles into pieces having a size allowing the pieces to pass through the openings of the filter material.
3. Method for operating a filter device according to claim 1 or 2,
the opening diameter of the filtering surface of the filter element is less than 100 mu m, and preferably 50 mu m +/-30 mu m.
4. Method for operating a filter device according to one of claims 1 to 3,
the fluid to be filtered is a ceramic raw material slurry, a pigment slurry, a coating liquid to be applied to paper or a film, heavy oil, cooling water, or ballast water for a ship.
5. Method for operating a filter device according to one of claims 1 to 4,
the fluid to be filtered is a fluid having a viscosity of 0.2 to 1000 mPas.
6. Method for operating a filter device according to one of claims 1 to 5,
a non-filter material reservoir portion for storing non-filter material that has not passed through the filter material and has been detached from one surface side of the filter material during the filtration,
the housing is provided with a accumulated material discharge means for discharging the non-filtered material to the outside of the housing.
7. Method for operating a filter device according to claim 6,
the operation method of the filtering device comprises the following steps:
a step of continuously or intermittently performing a sieving operation by relative movement between the brush and the filter material during the filtration;
measuring a filtration differential pressure between one surface side and the other surface side of the filter material, and performing the screening operation when the filtration differential pressure exceeds an allowable value; and
and measuring the filtration differential pressure, and when the filtration differential pressure exceeds an allowable value, discharging the non-filter material in the non-filter material reservoir to the outside of the casing by the accumulated material discharge means, or performing reverse cleaning by the reverse cleaning mechanism.
Technical Field
The invention relates to an operation method of a filter device, which has a reverse cleaning function and a cleaning function, and effectively separates and screens substances captured by a filter element without removing the substances, thereby preventing blockage and reducing the frequency of reverse cleaning and cleaning.
Background
Conventionally, various filtration apparatuses have been used for filtration of water such as seawater, lake water, river water, water supply pipelines, and drainage pipelines, filtration of liquids generally used in industries such as cooling water and treatment liquids of various apparatuses, and filtration of various raw materials in fluid form including gas, powder, granules, powder and the like used in chemical plants and the like, in order to capture and remove fine particles, dust and the like contained in these fluids.
When the filtration is continued for a long time by the filter device, solid matter, colloidal dust, and the like that cannot pass through the opening of the filter element are accumulated on the surface of the filter material, and resistance to the fluid passing through the opening of the filter material increases, which eventually makes the filtration of the fluid difficult. In order to solve this problem, for example, an operation called "back washing" in which a fluid is passed through the filter element in the direction opposite to the direction at the time of filtration to peel off a captured substance adhering to the filter element is periodically performed to recover the filtration performance of the filter element.
Although the back washing operation is an effective operation, the trapped substance adhering to the filter element may not be completely removed by the back washing and may remain. In this case, even if the filtration and the regeneration by the back washing are repeated, the resistance of the filter material constituting the filter element to the fluid may not be reduced, and the filtration of the target fluid may be difficult.
In contrast, a filter device has been proposed which takes measures for recovering the filtering performance of the filter element.
Patent documents 1 and 2 disclose filters that are: the captured substance removing brush is disposed in the hollow cylindrical filter element so as to be movable in the axial direction, and the captured substance attached to the inner surface of the filter element is removed by moving the captured substance removing brush in the axial direction by the flow of the fluid during filtration or reverse cleaning.
In this way, in the conventional cleaning method using a brush and a reverse washing in combination, the following is realistic: in the filtration, substances captured by the primary side filtration surface of the filter element contain unnecessary substances (valuable substances) having a particle size smaller than the opening of the filter element and not intended to be removed, in addition to the objects to be removed actually having a particle size larger than the opening of the filter element.
For filtration, the removal of an object to be removed is a main object, but it is also inevitable to capture a substance including particles smaller than the opening diameter of the filter element without removal to some extent, and even an evaluation of high filtration performance is obtained. That is, once particles are trapped at the openings of the filter element and the diameter of the openings is narrowed, a phenomenon occurs in which the trapped particles become smaller and smaller, which determines an important part of the filtering properties. Further, the particles thus trapped include: particles formed by aggregation of fine particles, colloidal particles, particles which are not strong enough to be captured by the filter element but easily broken, and the like. Depending on the stock solution to be filtered, particles smaller than the opening of the filter element, that is, particles that do not need to be removed by filtration, or particles that should not be removed, may be removed in large amounts. Examples of the object to be filtered include: ceramic raw material slurry, pigment slurry, coating liquid for coating paper or film, heavy oil, cooling water, ballast water for ships, and the like.
Next, in the case of a ballast water filtration apparatus for a ship, organisms having a certain size or more need to be removed by filtration with a filter element, and fibrous algae and the like do not need to be removed. However, fibrous algae and the like are easily entangled with the filter material, and are captured by the filter material at a certain ratio during filtration. The filter material also captures other particles, other living organisms, and the like, and once they are integrated and covered with a viscous substance, it is difficult to return to the original state only by back-washing with the filtrate as in the filter device of patent document 4, and eventually, the complicated work as described below has to be performed: the filter box is opened, the filter element is taken out and cleaned, and the filter element is recovered.
In the filter device disclosed in patent document 5, the filter-captured substance covered with the viscous substance is crushed by the brush washing at the time of back washing and then discharged to the outside of the system, as compared with the filter device disclosed in patent document 4, and the filter-back washing can be repeated for a long period of time as compared with the case of performing back washing only with the filtrate as disclosed in patent document 4. However, in this ballast water filtration process, if filtration and backwashing are repeated for a longer period of time, the pressure difference may still increase, and cleaning by a method other than backwashing is necessary.
When the filter element was removed to try to investigate the cause, it was confirmed that: the fibrous algae clog the filter element from the filtrate side (secondary side). And found that this is because: in the reverse cleaning, algae are captured at the opening circumferential edge while the filtrate passes from the filtrate side to the raw liquid side (primary side). Here, a phenomenon occurs in which fibrous algae covered with a viscous substance is entangled and attached to the opening circumferential edge.
Thus, it is clear that: as long as reverse cleaning is not performed in which liquid passes through the filter element on the side opposite to the filtration direction, clogging in the reverse direction does not occur. Therefore, reducing the number of back washes is particularly important to reduce the incidence of clogging from the reverse direction.
When filtering ballast water in a marine vessel, the fibrous algae are typically small enough to not need to be captured by the filter element, but the opening through the filter element will depend on the orientation of the fibrous algae relative to the opening. That is, even if fibrous algae passes through the opening of the filter element temporarily during filtration, the fibrous algae may be trapped when passing through the opening again during reverse cleaning. The same phenomenon may occur with respect to other plankton and irregular particles.
That is, in the filter device in which the filtrate obtained by filtering the raw liquid is directly used for the backwashing as the backwashing liquid, if the raw liquid contains irregular particles or fibrous algae, not only the openings of the filter element may be blocked during the filtration but also the openings of the filter element may be blocked during the backwashing.
In addition, when the raw liquid contains a solid material at a concentration of a predetermined value or more and contains particles having a size close to the diameter of the opening of the filter element, a plurality of particles flow into the opening of the filter element at the same time during filtration and are blocked at the inlet and the inside of the opening so as to be blocked from each other. Alternatively, a phenomenon may occur in which the particles themselves are aggregated into a lump exceeding the diameter of the opening and are trapped at the opening, or the like. Fig. 10 (a) is a schematic view of a state where the filter side of the
Next, fig. 10 (c) is a cross-sectional view showing a state where clogging is caused from the reverse cleaning side due to the reverse cleaning. Clogging during filtration is highly likely to occur during backwashing. For openings where clogging is not eliminated by reverse cleaning, particles intended to pass through the opening may further cause clogging during the reverse cleaning. Then, at the opening, the flow of the liquid will disappear, so the particles are compacted against each other and the blockage will become stronger. A more robust plug will develop if a gelatinous or strongly viscous substance solidifies the particles together.
In the case of the back washing by the filter device shown in patent document 4 or the back washing by brushing as shown in patent document 5 at the time of the filtering operation, the substances caught at the opening of the filter element can be removed, but since the back washing is performed every time the opening of the filter element is closed, there is no mechanism for removing the solid substance when the solid substance is caught at the opening of the filter element from the direction opposite to the filtering direction at the time of the back washing.
Further, as a practical example in which all valuable components contained in the raw liquid after filtration are captured and removed by the filter element, a filtration apparatus for C heavy oil for marine diesel engine fuel is exemplified. In C heavy oil, it is FCC bottoms and hard coke particles that should be filtered and removed. However, when the C heavy oil is filtered by a metal mesh having an opening diameter of less than 50 μm or other types of filter materials (such as a steel mesh, a wedge-shaped mesh, and a metal etched plate), the heavy oil component, which is changed into a gel form and can be used as a fuel, is captured in addition to these particles, and the opening of the filter element is sealed off in advance. The heavy oil C may contain a large amount of the heavy oil component changed into a gel state, and the heavy oil C may be subjected to reverse cleaning to remove the clogging. In most of filter elements commonly used in the process of filtering C heavy oil, since filtrate is used as a reverse cleaning liquid, active ingredients in the filtrate are captured and further, the active ingredients are discharged to the outside as a reverse cleaning liquid, thereby causing a loss. In addition, the heavy oil component changed into a gel state is difficult to completely peel off from the opening of the filter element during the back washing, and in many cases, a part of the heavy oil component remains, so that the back washing interval is shortened, and more effective filtrate component must be lost due to the back washing.
It is preferable that the non-filtering material (material to be removed) such as coarse particles peeled off from the surface of the filtering material is deposited and retained on the bottom portion of the primary side in the casing, but in practice, due to the influence of the rotation of the filter element or the brush and the influence of the fluid to be filtered after flowing in from the inlet of the casing, the non-filtering material may fly and adhere again to the surface of the filtering material. Once the non-filtering material is attached to the surface of the filtering material again, the filtering efficiency is obviously reduced.
Patent document
Patent document 1: japanese patent laid-open publication No. 2013-91046
Patent document 2: japanese patent laid-open No. 2014-34029
Patent document 3: japanese patent laid-open publication No. 2013-150947
Patent document 4: japanese Kohyo publication No. 2003-509200
Patent document 5: japanese patent laid-open publication No. 2017-6876
Disclosure of Invention
The present invention has been made in view of the above circumstances, and an object thereof is to provide a method of operating a filter device capable of efficiently separating an unnecessary removal substance, which is a filter material attached to and accumulated in a filter element during filtration and reverse cleaning (cleaning), from an object to be removed, and effectively utilizing the unnecessary removal substance.
In order to achieve the above object, a filter device to which an operation method of a filter device according to the present invention is applied includes: a filter element having a filter material; a brush configured to be capable of moving relative to the one surface of the filter material, and to assist detachment (removal) of the captured material and sieving of the captured material during the relative movement; a drive unit that moves at least one of the brush and the filter element relative to the other; a filter mechanism for passing a fluid from one surface side of the filter material to the other surface side; a reverse cleaning mechanism for passing a fluid from the other surface side to the one surface side of the filter material; a housing that supports at least the filter element, the filter mechanism, and the reverse cleaning mechanism; and a control unit which starts reverse cleaning when a pressure difference between both surfaces of the filter material exceeds a predetermined value or when a predetermined time elapses during the filtration, and returns to the filtration after the pressure difference is removed or when the predetermined time elapses, wherein the control unit performs the following screening operation: in the filtration, the brush is moved relative to the filter material by driving the driving unit, and the unnecessary removal substance is separated from the captured substance and passed through the other side.
According to the present invention, it is possible to effectively screen unnecessary removal substances of a filter material adhering to and accumulated in a filter element during filtration and reverse cleaning (cleaning) from an object to be removed, and to effectively use the unnecessary removal substances.
Drawings
Fig. 1 is a schematic longitudinal sectional view showing the entire configuration of a 1 st embodiment of a filter device according to a 1 st application example of the operation method of the present invention.
FIG. 2 is a flow chart showing steps of an exemplary method of operation of the present invention.
Fig. 3 (a) and (b) are enlarged sectional views of essential parts of the filter material in a state of being sieved by brushing, and (c) is a sectional view showing an example of a metal mesh used as the filter material.
Fig. 4 (a) is a schematic longitudinal sectional view showing the entire configuration of the 2 nd embodiment of the filter device according to the 1 st application example of the operation method of the present invention, (B) is a sectional view taken along the line a-a, and (c) is a sectional view taken along the line B-B.
Fig. 5 is a schematic longitudinal sectional view showing the entire configuration of embodiment 1 of a filter device according to application example 2 to which the operation method of the present invention is applied.
Fig. 6 is a schematic longitudinal sectional view showing the entire configuration of embodiment 2 of the filtering apparatus according to application example 2 to which the operation method of the present invention is applied.
Fig. 7 is a schematic longitudinal sectional view showing the entire configuration of
Fig. 8 (a) and (B) are schematic diagrams showing the relationship between the thickness T of the brush bristles B and the diameter W of the opening O.
FIG. 9 is a graph showing the optimum value of the angle at which the surface of the filter material comes into contact with the bristles.
Fig. 10 (a) is a schematic view showing a state where the filter side of the filter medium is clogged when viewed from a direction perpendicular to the surface of the filter medium, (b) is a cross-sectional view showing a state where the filter side is clogged, and (c) is a cross-sectional view showing a state where clogging is caused from the reverse cleaning side by the reverse cleaning.
Detailed Description
Hereinafter, an operation method of the filter device according to an embodiment of the present invention will be described in further detail with reference to embodiments shown in the drawings.
[ basic principle of operation method of the present invention ]
The filter device to which the operation method of the filter device of the present invention is applied includes: a filter element having a filter material made of a metal mesh material, and capturing substances in a fluid on one surface when filtering the fluid from one surface side to the other surface side of the filter material, and separating the captured substances from the filter material when performing reverse cleaning for passing the fluid from the other surface side to the one surface side of the filter material; a brush configured to be capable of moving relative to one surface of the filter material, and to assist detachment (removal) of the captured material and sieving of the captured material during the relative movement; a drive unit that moves at least one of the brush and the filter element relative to the other; a filter mechanism for passing a fluid from one side of the filter material to the other side thereof during filtration; a reverse cleaning mechanism for passing a fluid from the other surface side to the one surface side of the filter material during reverse cleaning; a housing that supports at least the filter element, the filter mechanism, and the reverse cleaning mechanism; a control unit for controlling the driving part, the filtering mechanism and the reverse cleaning mechanism, wherein the operation method of the filtering device is characterized by implementing the following operation method: in the filtration process, when the pressure difference between both surfaces of the filter material exceeds a predetermined value, or when a predetermined time has elapsed, the reverse cleaning is started, and after the pressure difference is released, or after the predetermined time has elapsed, the filter is returned to the filtration.
In the present operating method, the control unit performs the following operations: in the filtering operation at the start of the filtering and the filtering operation restarted after the completion of the backwashing, the driving unit is driven to move the brush relative to the filtering material, thereby separating the unnecessary removal substance from the captured substance and allowing the unnecessary removal substance to pass through to the other surface side.
In the operation of screening the unnecessary removal substance from the captured substance, when the particles constituting the unnecessary removal substance are in a plurality of block shapes, the brush is moved relative to the wall of the filter material, whereby the block-shaped particles are classified and screened (crushed) to have a size of an opening through which the filter material can pass.
In the present specification, the captured matter means a matter captured on the primary side of the filter material before being sieved by the brush, and is a concept including a matter to be removed and a matter not to be removed. The non-filtering material mainly includes coarse particles left after removing unnecessary substances such as substances crushed by brushing, in addition to substances larger than the filter pores (substances to be removed) captured by the filtering material without passing through the filtering material. This definition is common to all the following application examples and embodiments.
In one embodiment of the present invention, the following operations are performed: in the filtration operation, the primary side surface of the filter material of the filter element is brushed to disperse the captured substance and the residue captured therein, and a substance smaller than the opening diameter of the filter element (without removing the substance) flows to the downstream side (secondary side) of the filter element and is dispersed in the filtrate to be recovered.
In other words, the following sieving is performed in the filtering operation: the filter-trapped substance attached to the primary side of the filter element is crushed by brushing, and the substance smaller than the opening of the filter element flows out to the downstream side, leaving only the substance to be removed such as coarse particles larger than the diameter of the opening of the filter element on the primary side of the filter element.
In the operation method of the present filter device, it is preferable that the non-filter material (material to be removed) such as coarse particles peeled off from the surface of the filter material be settled and retained at the bottom of the primary side in the housing, but in practice, the non-filter material may fly and adhere again to the surface of the filter material due to the influence of the rotation of the filter element or the brush and the influence of the fluid to be filtered thereafter flowing in from the inlet of the housing. As a corresponding countermeasure, the following configuration is adopted: the coarse particles are efficiently precipitated and discharged by providing a reservoir for the non-filtering material precipitated inside the casing, appropriately discharging (discharging) the non-filtering material accumulated to the outside by the accumulated material discharge means, and further providing means (baffle) for preventing the non-filtering material from flying up as necessary.
In the operation method of the filter device, the accumulated matter that has fallen to the bottom of the casing and is accumulated is a matter from which the matter that is not to be removed is removed from the captured matter captured on the primary side surface of the filter material, and is, for example, an unfiltered matter such as coarse particles.
In addition, as a result of the screening work during filtration, the clogging period during filtration can be greatly delayed, and the number of times of reverse cleaning can be reduced to reduce clogging from the reverse direction.
When the ballast water of a ship is assumed to be a fluid to be filtered, the diameter of the mesh opening of the filter material of the filter element made of the sintered metal mesh is 100 μm or less, preferably in the range of 50 μm ± 30 μm.
Although the ballast water of a ship is exemplified as the fluid to be filtered in the present embodiment, for example, ceramic raw material slurry, pigment slurry, coating liquid for coating paper or film, heavy oil, and cooling water may be used as the fluid.
In addition, screening is useful for liquids and gases, and is useful for sorting and draining powders (synthetic resins, paints, pigments, metal powders, ceramic materials, and ceramic materials), and sorting unnecessary components from coating liquids.
In the filtration generally known, the purpose is to separate all solid materials by filtration without sorting. In contrast, the screening of the present invention is intended to separate and screen solid materials according to their sizes, and is different from simple filtration in terms of its essential meaning, purpose, and effect.
Hereinafter, a configuration example of a filtering apparatus to which the operation method according to the embodiment of the present invention can be applied will be described.
[ A. Filter device of application example 1 ]
Fig. 1 to 3 are explanatory views of a filter device according to application example 1 of the operation method of the present invention.
< A-1: filter device of embodiment 1
Fig. 1 is an explanatory view showing an entire configuration of a 1 st embodiment of a filter device according to a 1 st application example of the present invention. For example, the filter device filters ballast water of a ship, and filters a fluid by passing the fluid through a filter element from a fluid inlet and flowing the fluid out from a fluid outlet.
In addition, in the backwashing, the flow path of the fluid is switched by an external piping system, and the backwashing of the filter element is not performed by introducing the fluid from the fluid outlet and passing the fluid through the filter element, and then flowing the fluid to the fluid inlet.
The filter device F1 according to embodiment 1 generally includes: casing 1, partition wall 2,
As the reverse cleaning unit, a
The case 1 constitutes a housing of the filter device F1, and includes a case
The interior of the housing 1 is divided into: a
Inside the housing 1, the
This
As shown in fig. 3(c), the
In the case where the filtration direction is inside → outside, contrary to fig. 3(c), the innermost layer is the finest mesh.
The
On the other hand, the
The
In the present specification, the term "suction" is not necessarily limited to the case of introducing a fluid at a pressure lower than atmospheric pressure, and means the case of introducing a fluid to a side having a relatively low pressure in the case of a pressure difference in general.
The
Since the removing
In addition, the material of the bristles of the
On the other hand, a backwash
Further, a drain pipe (accumulated material discharge means) 150 for discharging unfiltered material, which communicates with the raw
As a piping system connected to the outside of the fluid to be filtered of the filter device F1, an inlet-
In this case, it is necessary to control the outlet side valve V to perform the reverse cleaning0By applying pressure from the outside, the pressure P in the
In addition, an opening and closing valve VF(discharge pipe 145), liquid discharge side valve VG(liquid discharge pipe 150) even if it is opened to the atmospheric pressure, for example, a pump (pump inlet) for pressure reduction (not shown) may be connected to each of the opening and closing valves VFLiquid discharge side valve VGThereby making the valve VFThe pressure on the side is reduced to a pressure lower than 2 times, and the valve V is openedGThe pressure on the side is reduced to a pressure lower than 1.
In the operation method of the present filter device F1, it is preferable that the non-filtering material such as coarse particles peeled off from the surface of the filter material be deposited and retained on the bottom portion of the primary side in the casing, but in practice, the non-filtering material may fly upward and adhere again to the surface of the filter material due to the influence of the rotation of the filter element or the brush and the influence of the fluid to be filtered after flowing in from the inlet of the casing. As a corresponding countermeasure, the following configuration is adopted: a
In addition, the invention adopts the following steps: since the appropriate amount of the unfiltered substance falling to the bottom of the case is discharged to the outside of the system from the small-
It should be noted that, by selecting a portion where the water flow and the water amount are small and where the retention is likely to occur as a portion where the
In the configuration example of fig. 1, the outer peripheral portion of the
In other embodiments described below, the location of
The above description of the operation method of the filter device is applied to all of the following application examples and embodiments in principle.
The operation of the filter device F1 according to embodiment 1 configured as described above is as follows.
During filtration, the
At this time, the captured substance (solid matter, colloidal dust, or the like) which is desired to be attached to or already attached to the outer surface of the filter material with which the
Therefore, not only can most of the unnecessary removal substance contained in the trapped substance flow out to the secondary side, but also the rise of the filtration pressure difference can be greatly delayed.
Therefore, the filter is not easy to block due to the screening operation in the filtering process, the filtering duration can be prolonged, the reverse cleaning times can be reduced, and the efficiency of the device can be improved. In addition, by reducing the number of times of reverse cleaning, the occurrence rate of clogging in the reverse direction due to reverse cleaning can also be reduced.
In reverse cleaning, the inlet side valve VIAnd an outlet side valve V0Continuing to open and reversely cleaning the on-off valve V of the fluid discharge systemFWhen the
It should be noted that, in actual operation, the inlet side valve V is not closedIUsing the valve V from the outlet side0The reverse cleaning is performed. The inlet side valve V is not opened except at the time of starting operation, stopping operation, and maintenance of the filter deviceIAnd an outlet side valve V0The opening and closing operation is performed. This applies to all the following application examples and embodiments.
The filter device F1 according to embodiment 1 includes: a
In the present operating method, the control unit performs the following operations: on-off valve V for cleaning fluid discharge system in reverse direction when closedFThe filter unit of (1) is driven to move the brush relative to the filter material to screen the unnecessary removal object from the captured object, and to pass the unnecessary removal object to the other side.
In order to solve the problem that a large amount of unnecessary substances are discharged to the outside of the system by brushing in the back washing, as in the present embodiment, only brushing is performed during filtration, so that non-filtration substances such as coarse particles remaining in the
By introducing the fluid from the
By opening the drain side valve VGAfter the non-filtered material accumulated in the non-filtered
As the operation step at the time of the rise in differential pressure, the operation may be performed by opening the on-off valve V, in reverse to the above-described stepFAfter the reverse cleaning
By performing the brushing during the filtration operation, the duration of the filtration operation can be prolonged to delay the occurrence of clogging during the filtration, and unnecessary substances among the trapped substances can be effectively secured in the filtrate. As a result, the number of times of reverse cleaning and the reverse cleaning time can be reduced, so that the work efficiency can be improved, and the occurrence of clogging from the secondary side, which is a drawback of reverse cleaning, can be prevented.
As described above, the small amount of liquid is sufficient to discharge the non-filtered substances from the
On the other hand, in the reverse cleaning, a method of flowing the fluid flowing in from the
As described above, in the present invention, the flow path of the fluid is switched by the external piping system, and the reverse cleaning of the filter element can be performed by introducing a large amount of fluid from the
Further, the
The non-filtration substance re-adhering to the surface of the filter material needs to be peeled off and dropped by re-brushing, or the inlet side valve V needs to be opened and closedIAnd an outlet side valve V0Is discharged, according to the operation method of the present invention, the on-off valve V of the reverse cleaning fluid discharge system is opened only while the
As described above, the term "suction" in the present specification is not limited to the case where the fluid is introduced by using a pressure lower than the atmospheric pressure, but means a general meaning that the fluid is introduced to a side having a relatively low pressure when there is a pressure difference. Specifically, for example, in fig. 1(b), the on-off valve V of the reverse cleaning fluid discharge systemFAnd a liquid discharge side valve VGWith atmospheric pressure (P)o) However, this is only an example and may be via valves VF(discharge pipe 145) VG(drain pipe 150) and is sucked by a pump (not shown). Therefore, in this case, the fluid is discharged through the opening and closing valve V of the reverse purge fluid discharge systemFAnd sucking (discharging) the reverse cleaning fluid by a pumpBAnd 2-time pressure (P) with the filtrate storage tank2) The relation between is PB<P2. In addition, via a liquid discharge side valve VGAnd the pressure P at the time of sucking (discharging) the discharged liquid by the pumpDAnd via the inlet side valve VI1 time pressure (P)1) The relation between is PD<P1. This applies to all the following application examples and embodiments.
The above-described characteristic configurations, operations, and effects of the present invention are common to all of the following application examples and embodiments.
Fig. 2 is a flowchart showing a program of an operation method according to an example of the present invention. The operation steps according to the flowchart can be commonly used in all other application examples and embodiments described below.
The
In step S3, the drain side valve V as the accumulated material discharging means is used periodically or continuouslyGThe
Next, in step S4, it is determined whether the filtration differential pressure reaches a predetermined value, in other words, whether the filtration differential pressure exceeds an allowable value, by a measurement device for the filtration differential pressure, not shown, and if the filtration differential pressure exceeds the allowable value, the flow proceeds to step S5, where reverse cleaning is started simultaneously with brushing. If the allowable value is not exceeded, the process returns to step S2. In step S4, the filtering time may be measured by a timer, and the flow proceeds to step S5 to start reverse cleaning when a predetermined filtering time elapses.
In the reverse cleaning operation, the inlet side valve V is continuously openedIAnd an outlet side valve V0And opening an on-off valve V of the reverse cleaning fluid discharge systemF。
Even if the filtering differential pressure is detected to exceed the allowable value in the measurement of the filtering differential pressure in step S4, if the back washing is started simultaneously with the brushing, the filtering differential pressure lower than the allowable value may be detected by the measuring device at a time when the filter element rotates by a slight rotation angle less than one rotation, for example, by about 15 degrees. However, at this stage, the reverse cleaning by the brushing is not completed for the entire peripheral surface of the filter element, and the captured matter remains on the surface not subjected to the brushing. To cope with such a problem, as shown in step S5, the timer is used to count the time, and it is necessary to confirm that: the filter element is uniformly brushed and reversely washed over the entire peripheral surface of the filter element by at least one rotation of the filter element with respect to the brush, in this example, at most 3 rotations.
After the reverse cleaning is performed simultaneously with the brushing in step S5, if the filtration pressure difference is measured in step S6 and the filtration pressure difference is reduced to a predetermined value (for example, 0.002MPa) as a result of the measurement, the flow returns to step S2 after the reverse cleaning is completed.
If the filtration differential pressure is not lower than the predetermined value in step S6, the process proceeds to step S7 to stop the filtration, and a warning indicating that maintenance is required is issued by the alarm device in step S8.
In step S6, when the differential pressure is not lower than the allowable value, the accumulated material discharging means V may be implementedG150, or/and, a reverse purge performed with a reverse purge mechanism.
In addition, it is determined which of the reverse cleaning and the accumulated material discharging operation should be performed first or to be processed first, depending on the situation.
Next, fig. 3 is an enlarged cross-sectional view of a main part of the filter material showing a state where the filter material is sieved by brushing.
In fig. 3 (a), the particulate matter M not to be removed is coagulated and clogged on the primary side of the
In fig. 3 (b), the fibers N are entangled with the particles M that are not to be removed, and the
Fig. 3(c) shows an example of a metal mesh used as the
< A-2: filter device of embodiment 2
Fig. 4 (a) is a schematic longitudinal sectional view showing the entire configuration of the 2 nd embodiment of the filter device according to the 1 st application example of the operation method of the present invention, (B) is a sectional view taken along the line a-a, and (c) is a sectional view taken along the line B-B.
This filter F2 is a modification of fig. 1, and is a horizontal type in which the filter F1 of fig. 1 is rotated 90 degrees to the right, and is mainly distinguished by the following configuration: shielding
Therefore, the same components as those in fig. 1 are denoted by the same reference numerals, and redundant description and operation are omitted.
As shown in fig. 4(b), the fluid a introduced from the
As described above, as the place where the
As shown in fig. 4 (c), the brush bristles of the removing
The backwashing mechanism 104 (backwashing head 141) and each valve V for the
The method, procedure and effect of brushing during the filtration process are the same as in the embodiment of fig. 1.
[ B. Filter device of application example 2 ]
< B-1: embodiment 1 of the Filter device
Fig. 5 is a schematic longitudinal sectional view showing the entire configuration of embodiment 1 of a filter device according to application example 2 to which the operation method of the present invention is applied.
The filter device F3 filters a fluid such as a ceramic raw material slurry, a pigment slurry, a coating liquid applied to paper or a film, heavy oil, cooling water, or ballast water for a ship, and filters the fluid by allowing the fluid to pass through the
The filter device F3 of embodiment 1 includes: casing 1,
The filter device F3 uses the
The housing 1 includes a housing
The interior of the housing 1 is divided into: a raw
The
The
A
The
The
According to the structure using the backwashing head, the water flow passes only a part of the filter material facing the suction holes 143, so that the water amount of the fluid used for backwashing can be saved, and the apparatus structure and the system structure for supplying backwashing water can be miniaturized and simplified, compared with the type of passing the backwashing water all over the surface of the filter material at a time.
This effect is also the same in other embodiments described below.
The outer surface of the lower end portion of the
Reverse cleaning
In the configuration example of fig. 5, the outer peripheral portion of the backwashing
A
The filtering apparatus F3 configured as described above performs operations during filtering and during backwashing, the configuration of the
However, in the filter device F3, unlike fig. 1 in which the
The
According to the present embodiment, by using the
The filter device of this embodiment includes: a
In addition, during the filtration process, the filtration is carried out between the two surfaces of the filter materialOpening the drain side valve V when the differential pressure exceeds a predetermined value or when a predetermined time has elapsedGThereby discharging the non-filtered matter D from the
In the present operation method, the
The method, procedure and effect of brushing in the filtering process are the same as the application examples and embodiments.
The above-described operation and effect are also applicable to the following embodiments.
< B-2: embodiment 2 of the Filter device
Fig. 6 is a schematic longitudinal sectional view showing the entire configuration of embodiment 2 of the filtering apparatus according to application example 2 to which the operation method of the present invention is applied.
Since the
The filter device F4 according to embodiment 2 generally includes: a housing 1; a
Unlike fig. 5, the
The
A baffle, not shown, may be disposed between the
The backwashing mechanism 104 (backwashing head 141) for the
< B-3:
Fig. 7 is a schematic longitudinal sectional view showing the entire configuration of
This filter device F5 is a horizontal type in which the filter device F4 of fig. 6 is rotated 90 degrees to the right, and is different in the structure in which the
By disposing the
The reverse cleaning mechanism 104 (reverse cleaning head 141) for the
Example 1: method for operating ballast Water Filter device
When the ballast water is filtered by the filter element, fibrous substances centered on algae adhere to and are wound around the opening circumferential edge of the filter material, and they are covered with other plankton, particles, or viscous substances to form a strong plug. Further, although the filtration is switched to the reverse cleaning when the differential pressure exceeds the allowable value during the filtration, there is a problem that the filter material is clogged from the reverse direction if the reverse cleaning is performed after the filtration. In the method of removing clogging of the filter element relying only on the backwashing, as already explained, the frequency of the washing becomes high, and the loss of the unnecessary removal substance in the liquid by the backwashing flow increases.
In example 1, the operation method of the present invention was applied to the filtration apparatuses of application examples 1 and 2 to filter ballast water. As a result of continuing the brushing during the filtration period, the separation effect of the captured substance and the classifying and screening effect can be exhibited to the maximum extent. Although the result depends on the quality of seawater, the time required until the pressure difference rises and exceeds the allowable value in the filtration operation is 50 times or more the reverse cleaning cycle, the reverse cleaning cycle is performed every 10 minutes or so, and the reverse cleaning frequency is improved to a frequency of 1/50 or less, on average, every 10 hours or so.
In addition, the following was confirmed: the filter element after filtering the ballast water while brushing hardly adheres algae to the filter surface, and the filter element does not see the residue of the algae even on the filtrate side, and only other plankton is seen, and the algae flows down through the filter element to the downstream side.
As described above, according to the operation method of the present invention, by causing particles that do not need to be trapped to flow toward the filtrate side during the filtration operation, the burden on the filter element can be substantially reduced, and the clogging of the filter side of the filter element opening due to the back washing can be prevented.
As a filter element used for filtering ballast water, it is required to remove plankton of about 50 μm, and when it is desired to realize the filter element using a metal mesh, for example, a metal mesh of about 150 to 300 mesh (mesh number per 1 inch) is required depending on the wire diameter of the mesh.
However, these filter elements are relatively thin and have low strength, and therefore need to be reinforced for filtration and backwashing, and even if reinforced, the filter elements cannot be directly and effectively brushed. In particular, this is true of the filter element of the shape shown in application 2.
As a filter element satisfying such a requirement in terms of strength, a sintered metal mesh obtained by sintering 1 to a plurality of layers of metal meshes as described in the above embodiments is preferable.
The opening diameter of the filter element made of the sintered metal mesh is 100 μm or less, preferably 50 μm. + -. 30 μm.
By using the filter element made of the sintered metal mesh as described above, the filter surface can be directly brushed. By performing the brushing during the filtration by the filter device using the filter element, the operation time until the filter element is clogged, such as an increase in the filtration differential pressure, a decrease in the filtration flow rate, and an increase in the backwashing frequency, can be extended as compared with a conventional type of method in which the filtration and backwashing are repeated without performing the brushing during the filtration, and the number of cycles of the filtration and the backwashing can be increased.
Example 2: method of operating C heavy oil filtration apparatus
The method of the present invention was applied to the filtration apparatuses of application examples 1 and 2 to filter C heavy oil.
That is, the C heavy oil was filtered at a flow rate of 10m/h by a filter element having an opening diameter of 50 μm made of a sintered metal mesh without being brushed during the filtering period, and as a result, the differential pressure was increased in 15 to 20 minutes, and the filtering was not continued without performing the back washing. On the other hand, the pressure difference started to rise after 9 hours or more since the filtration was performed while the brushing was performed under the same other conditions.
After that, the filter element was inspected, and as a result, it was confirmed that: as in the state assumed by the non-filtered matter D of fig. 1, the matter larger than the opening diameter of the filter element is concentrated to be captured at the primary side of the filter element, and it is found that: heavy oil components (except for large particles) changed into a gel state by brushing during the filtration process are dispersed and flow to the downstream side of the filter element, and clogging of the filter element can be reduced. Further, the substances concentrated on the primary side of the filter and larger than the opening diameter of the filter element can be discharged through the backwashing line or through the drain pipe for liquid discharge, and after this operation, filtration can be continued for about 6 hours.
In order to sort particles that are unnecessary substances to be removed without passing through the openings of the filter element, it is necessary to move the particles relative to the filter element, and in order to prevent the particles from aggregating with each other and adhesion and aggregation of a viscous substance or a colloidal substance, it is desirable to have a function of dispersing the aggregated particles together with a function of separating and dispersing the viscous substance or the colloidal substance from the particles.
The present invention is made based on the following findings: as a method which can exhibit such a separating function and a dispersing function and has a simple structure and a good effect, a method of brushing the surface of the filter material during filtration is excellent.
[ relationship between opening diameter of filter material and thickness of bristles, and others ]
In the case of a filter element having an opening diameter of less than 200 μm, if the captured matter of the filter element is wiped off by a plate-like scraper, the front end of the scraper does not adhere to the irregularities on the surface of the filter material, and therefore the concave surface tends to be clogged with the filter captured matter, which is not preferable.
On the other hand, when the brush is used, the brush is attached to the irregularities (particularly, the inside of the recessed portion) on the surface of the filter material to efficiently remove the filter-captured substance, or the filter-captured substance is crushed and flows downstream of the filter element. When the brush bristles are too thick, the captured material is pushed into the opening of the filter element without being attached to the unevenness of the filter surface, as in the case of wiping with a scraper, and the clogging occurs. This tendency is more pronounced in the case of using a mesh as the filtering material.
When the thickness of the brush bristles is about 4 times or less the opening diameter of the filter element, the screening effect of the captured matter without removing the matter is exhibited, and particularly, the screening effect is significant with bristles having a thickness of about 2 times the opening diameter. Fig. 8 (a) and (B) are schematic views showing the relationship between the thickness T of the brush bristles B and the diameter W of the opening O, and it goes without saying that when the thickness T1 of the brush bristles B is about 3 times the opening diameter as shown in (a), and when the thickness T2 of the brush bristles B is slightly larger than the opening diameter W as shown in (B), the tips of the bristles can be attached to the recessed portion of the filter surface, and the clogging of the filter element is not accelerated by the trapped matter being pushed into the opening O of the filter element.
In particular, immediately after filtration, the captured matter adhering to the surface of the filter material is sufficiently soft, and therefore, the non-removed matter and the unnecessary-removed matter can be separated (pulverized) by the elastic force of the brush bristles.
As shown in fig. 9, it is preferable that the angle at which the surface of the filter material comes into contact with the bristles B during brushing is 60 degrees or more (60 to 70 degrees). When the angle is less than 60 degrees, the effect of inserting the filter-trapping substance into the opening tends to be increased.
[ summary of the Structure, action, and Effect of the invention ]
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