WO2007004265A1

WO2007004265A1 - Filter, casing for filter, and method of assembling filter

Info

Publication number: WO2007004265A1
Application number: PCT/JP2005/012115
Authority: WO
Inventors: Kiyotaka Sugiura; Kohji Hattori; Hiroyuki Oyachi
Original assignee: Ngk Insulators, Ltd.
Priority date: 2005-06-30
Filing date: 2005-06-30
Publication date: 2007-01-11

Abstract

Provided are a filter having a simple structure and capable of being easily installed and replaced, a filter casing, and a method of assembling a filter. The filter (1) has a casing (20) and a filter element (10) received in the casing (20). The filter element (10) has porous partition walls forming cells that have openings in a lower end surface (14) of the element and penetrate up to an upper end surface of the element. The casing (20) has a casing body (25) surrounding a side surface of the filter element (10), and also has a cap (23) covering an upper part of the filter element (10) and detachably fitted to a casing body (25). The casing body (25) has a tubular side wall section (26) having a hollow section (29) through which the filter element (10) can be installed and taken out upward, and also has a flange (27) projecting inward from a lower part of the side wall section (26). The filter element (10) is supported by the flange (27).

Description

Specification

Filter, filter casing and filter assembly method

Technical field

[0001] The present invention relates to a filter, a casing for the filter, and a method for assembling the filter that can be suitably used to remove harmful substances such as suspended substances and pathogenic microorganisms in a liquid, and in particular, water purification The present invention relates to a filter, a filter casing, and a method for assembling the filter that can be suitably used for a large amount of water treatment in a field.

Background art

[0002] In recent years, the problem of pathogenic microorganisms including Cryptosporidium and O-157 has become serious due to the global water shortage. There is a need for a water purification process that can be manufactured. Fine filtration and ultrafiltration using a filter element with a porous material as a filter medium are water purification processes that can effectively remove harmful substances such as suspended substances and pathogenic microorganisms in liquids by simple operations. It attracts attention. As a filter element used for microfiltration or ultrafiltration, a filter element having a ceramic porous body partition, and a cell having a liquid flow path formed by the partition is in practical use.

For example, as shown in FIG. 1, a ceramic porous body is used as a filter medium, and the filter is used as a filter 4 force filter element in which cells 41 are formed so that liquid flow directions are parallel to each other. This filter element has a partition that also has a porous ceramic body, and has a no-cam structure in which cells 41 separated by the partition are formed! /

[0004] The monolithic filter element as described above constitutes a filtration membrane and a base material in which liquid is formed on the inner wall of a cell when a stock solution (liquid to be treated) is supplied into a plurality of cells at a predetermined pressure. When passing through the porous body and flowing out from the outer peripheral surface of the base material, suspended substances and the like are collected in the filtration membrane. Accordingly, the filter element is structured to be built in the casing in a state in which the outer peripheral surface side of the base material and the end surface of the cell opening are liquid-tightly separated by the sealing material, thereby Can be recovered.

[0005] The monolithic filter element as described above may be used alone. When it is required to process a large amount of undiluted solution (raw water) such as in a field, it is possible to store a large number of filter elements in the casing to increase the filtration area and improve the processing capacity. Has been done.

[0006] As a filter in which a large number of filter elements are housed in a casing, for example, both end portions of the large number of filter elements are supported in a state of being inserted through the upper plate and the lower plate, and the large number of filter elements are arranged in parallel. A filter is known that is housed in a casing in a state of being arranged in a regular manner (see, for example, Patent Documents 1 and 2).

Patent Document 1: Japanese Patent Laid-Open No. 10-180049

Patent Document 2: Japanese Patent Laid-Open No. 10-184919

Disclosure of the invention

[0007] The present invention is characterized by providing a filter, a filter casing, and a method of assembling the filter that are simple in structure and easy to load and replace.

[0008] The present invention provides the following filter, filter casing and filter assembly method.

[1] A filter comprising a casing and a filter element housed in the casing, wherein the filter element forms a cell having an opening at a lower end surface and penetrating to the upper end surface. The casing includes a casing body that surrounds a side surface of the filter element, an upper portion of the filter element, and a cap portion that is detachable from the casing body. The casing body includes the filter body. A filter comprising: a cylindrical side wall portion having a hollow portion through which an element can be inserted and removed upward; and a flange portion protruding inward from a lower portion of the side wall portion, wherein the filter element is supported by the flange portion.

[0010] [2] The filter according to [1], wherein the filter element is supported by a flange portion at an outer peripheral portion of the lower end surface so as not to block an opening of the lower end surface.

[0011] [3] The filter according to [1] or [2], wherein the filter element is a monolithic filter element in which a number of cells extending in parallel to each other are formed while having a ceramic porous body strength.

[4] The upper end portion of the side surface of the filter element and the casing are detachable. The filter according to any one of [1] to [3], wherein the filter is sealed with a functional seal member.

[5] The filter according to any one of [1] to [4], wherein a lower end portion of the side surface of the filter element and the casing are sealed by a detachable seal member.

[6] The filtration according to [4] or [5], wherein the seal member is an annular body having an L-shaped cross section.

[7] The filter according to [1] to [6], wherein only one filter element is housed in the casing.

[8] A filter casing for storing a filter element, the casing body for enclosing a side surface of the filter element, and the casing main body for covering the upper part of the filter element. A cylindrical side wall portion having a hollow portion in which the filter element can be taken in and out, and a lower portion of the side wall portion for supporting the filter element in the direction of the hollow portion. A casing for a filter having a flange portion.

[9] A method for assembling a filter that houses a columnar filter element in a casing having a cylindrical casing main body and a cap portion, and a step of covering the first end face of the filter element with a protective cap Placing the filter element on the assembly flange with the first end face down, covering the side of the filter element with a protective cover, lowering the casing body from above the filter element, A step of inserting the element into the casing body, a step of removing the protective cover, a step of attaching the seal member to the outer peripheral portion of the second end surface, a step of fixing the assembly flange and the casing body, and a casing Inverting the body and filter element to bring the second end face down, the assembly flange and the protective cap Assembly of the filter including the step of removing the cap, the step of attaching the seal member to the outer peripheral portion of the first end surface, and the step of attaching the cap portion so as to cover the first end surface and fixing the casing body and the cap portion Method.

[0018] The casing is divided into at least two detachable members, a casing main body and a cap portion, and a flange portion is provided on the casing main body, so that the filter element can be easily inserted and removed from the upper part. With this structure, the filter element can be easily loaded and replaced. Brief Description of Drawings

FIG. 1 is a schematic perspective view showing an example of a filter element.

FIG. 2 is a cross-sectional view schematically showing one embodiment of the filter of the present invention.

FIG. 3 is a perspective view schematically showing one embodiment of a filter element according to the present invention.

FIG. 4 is a perspective view schematically showing another embodiment of the filter element according to the present invention.

FIG. 5 (a) is a process diagram schematically showing one embodiment of a filter assembling method of the present invention.

FIG. 5 (b) is a process chart schematically showing one embodiment of the filter assembling method of the present invention.

Explanation of symbols

[0020] 1: Filter, 2: Monolithic filter, 3: Cell, 4: Filter, 5: Water collecting slit, 6: Plugging material, 8: Monolith, 10: Filter element, 12: Cell, 14 : Lower end, 15 Upper end, 16: Bulkhead, 20: Casing, 22: Cap, 23: Opening, 25: Case sink, Main body, 26: Side wall, 2 7: Brim, 28: 0 Ring, 29: Space part, 30: Sealing member, 31: Lower header, 32: Opening part, 34: Opening part, 41: Cell, 50: Filter element, 51: First end face, 52: Second end face, 5 3: Side face 54: Protective cap, 55: Flange for assembly, 56: Protective cover, 57: Stud bolt, 58: Spacer, 59: Seal member, 60: Casing body, 61: Cap part, 62: 0 ring, 63 : Lower header, 64: Rubber sheet.

BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, the best mode for carrying out the present invention (hereinafter, also referred to as “embodiment”) will be specifically described with reference to the drawings. However, the present invention is not limited to the following embodiment. However, it should be understood that appropriate modifications and improvements can be made based on the ordinary knowledge of those skilled in the art without departing from the spirit of the present invention.

FIG. 2 is a cross-sectional view schematically showing one embodiment of the filter of the present invention. FIG. 3 is a perspective view schematically showing one embodiment of a filter element according to the present invention. A filter 1 shown in FIG. 2 includes a casing 20 and a filter element 10 accommodated in the casing 20. The filter element 10 shown in FIG. 3 includes a porous partition wall 16. Thus, a cell 12 having an opening at the lower end surface 14 and penetrating to the upper end surface 15 is formed.

The casing 20 includes a casing body 25 that surrounds the side surface of the filter element 10 and a cap portion 22 that covers the upper portion of the filter element 10. The cap portion 22 is detachably attached to the casing body 25 via an O-ring 28. The O-ring 28 is not indispensable as long as the gap between the cap 22 and the casing body 25 can be liquid-tightly sealed! Usually, the cap 22 is attached to the casing body 25 via the O-ring 28. Is preferred.

The casing body 25 includes a cylindrical side wall portion 26 having a space portion 29 into which the filter element 10 can be taken in and out, and a flange portion 27 protruding inward from the lower portion of the side wall portion 26. Then, the lower end surface 14 of the filter element 10 is supported by the collar portion 27.

[0025] With such a structure, the filter element can be easily taken in and out from above, and the assembly of the filter and the replacement of the filter element are facilitated.

[0026] The collar portion 27 preferably protrudes inward so as not to block the opening of the cell 12 of the filter element 10. By supporting only the outer peripheral portion of the lower end surface 14 so that the collar portion 27 does not block the opening of the cell 12 of the filter element 10, the filtration area of the filter element can be effectively utilized.

[0027] Although the range of the outer peripheral portion supported by the collar portion 27 varies depending on the size and structure of the filter element, a preferable range is 1 mm to 3 mm from the outermost periphery to the outermost peripheral cell of the filter element. On the other hand, at least 2 mm from the outermost circumference, especially 2.5 mn to obtain good support strength and to cope with slight dimensional deviations! It is preferable to support a range of ~ 3.5 mm.

[0028] It is preferable to seal between the filter element 10 and the casing 20 by a detachable seal member 30. Further, the seal member 30 is preferably arranged so as to seal between the side surface of the filter element and the casing. In a vertical filter such as that shown in Fig. 2, dimensional changes due to temperature changes and dimensional errors during manufacturing appear more significantly in the vertical direction. Therefore, by sealing with the side face that is not the end face of the filter element, it is possible to cope with dimensional changes and dimensional errors, and the seal state can be maintained well. [0029] When sealing on the side of the filter element, it is preferable to seal on the side of the upper end of the filter element, but it is more preferable to seal on the side of the lower end. Such a configuration is particularly effective in the case of a monolithic filter in which the filter element discharges filtered water from the outer peripheral surface.

[0030] Further, the force of the seal member 30 is preferably an annular body having an L-shaped cross section as shown in FIG. By adopting such a shape, positioning of the seal position is facilitated, and attachment / detachment is facilitated. Further, it can be fitted like a cap on the outer periphery of the end face of the filter element, and can be easily sealed at the end of the side face of the filter element.

[0031] The number of filter elements stored in the casing is preferably one. By using a single filter element, the structure can be simplified and the filter can be easily assembled and the filter element can be easily replaced.

The filter 1 shown in FIG. 2 further includes a lower header 31 having an opening 32. When the filter element is a monolithic filter, the liquid to be treated such as raw water usually flows into the lower end surface 14 force, so that the lower header 31 makes it easy to connect to the pipe into which the liquid to be treated is introduced.

A casing body 25 shown in FIG. 2 includes an opening 34 in the side wall 26. When the filter element 10 is a monolithic filter, the side wall portion 26 preferably has an opening 34 through which the filtrate is discharged because the filtrate is discharged from the side force of the filter element 10. The opening 34 is preferably provided on the upper portion of the side wall 26 from the viewpoint of facilitating air bleeding in the casing 20.

The cap part 22 shown in FIG. Performing filtration while circulating the stock solution When performing filtration by cross-flow operation, it is preferable that the cap portion 22 has an opening 23 as a discharge port for discharging the stock solution by a filter. In addition, the opening 23 can be used as an air supply port when supplying compressed air during backwashing of the filter element.

[0035] The casing is preferably impermeable and highly corrosion resistant, and is preferably made of a material. In the case of a filter element made of resin, a casing made of resin is used. In the case of a filter element made of ceramic, a stainless steel casing is preferably used. [0036] The material constituting the filter element is not particularly limited, but generally, a filter element made of resin or ceramic is widely used. In the filter of the present invention, a filter element made of ceramic is preferably used.

[0037] Ceramics constituting the filter element include, for example, alumina (Al 2 O 3), titanium

23 3 (TiO 2), mullite (Al 2 O 3 .SiO 2), zirconia (ZrO 2) or the like is used. Above all,

2 2 3 2 2

Alumina is preferably used because it can form a stable slurry that can easily be obtained from a raw material with a controlled particle size and has high corrosion resistance. Ceramics have excellent mechanical strength and durability, and are highly reliable and have high corrosion resistance.Therefore, there is little deterioration during chemical cleaning with acids, alkalis, etc.Furthermore, the average pore diameter that determines the filtration capacity is precise. It has various advantages such as being controllable.

[0038] Typical examples of ceramic filter elements include tube filters and monolith filters. The tube-shaped filter has a cylindrical partition made of a ceramic porous body, and has a structure in which a single cell penetrating the center is formed, which is divided by the partition. On the other hand, the monolithic filter has a partition wall made of a ceramic porous body and has a no-cam structure in which a large number of cells divided by the partition wall are formed. Among them, a monolithic filter having a large filtration area per unit volume and high processing capability is preferably used. A monolithic filter that is easier to increase in size is preferable from the viewpoint of storing one filter element in a casing and facilitating removal of the filter element.

[0039] The tubular filter and the monolithic filter include a base material having a ceramic porous body strength and a filter membrane having a ceramic porous body force having an average pore diameter smaller than that of the base material formed on the surface of the base material. What was comprised can be used suitably.

[0040] In such a structure, the filtration function is exhibited exclusively by the filtration membrane, so that the average pore diameter of the substrate can be increased. Therefore, it is possible to reduce the flow resistance when the liquid that has permeated through the partition walls and has flowed out of the cell permeates the inside of the base material, and the amount of water permeation can be increased.

[0041] The average pore size of the ceramic porous body constituting the filtration membrane varies depending on the required filtration performance (particle size of the substance to be removed). Filter element used for microfiltration and ultrafiltration In this case, the range is from 0.01 to about LO / zm. On the other hand, the average pore diameter of the ceramic porous body constituting the substrate is determined in consideration of the balance between mechanical strength and water permeability. Usually, a ceramic porous body having an average pore diameter of about 1 to several hundred m is used as a substrate.

[0042] The base material can be obtained by a method of forming a clay containing aggregate particles, drying and firing, and the filtration membrane is formed by forming a slurry containing aggregate particles on the partition wall surface of the base material. Then, it can be formed by a method such as drying and firing. The film can be formed by a conventionally known film formation method such as a dip film formation method, but by a filtration film formation method (see Japanese Patent Publication No. 63-66566) that can effectively prevent film defects such as pinholes. I prefer to do it.

[0043] Further, as the monolithic filter, for example, a number of cells 3 are formed as in the monolithic filter 2 shown in FIG. A water collecting slit 5 is formed to connect the cell and the external space of the monolith 8, and both end openings of the cell (water collecting cell) communicating with the water collecting slit 5 are plugged by the plugging member 6. Can be suitably used.

[0044] In the monolithic filter, since the flow resistance when the filtrate flows out of the monolith is larger in the cells near the center, the flow resistance when the filtrate flows out of the monolith is small. Can be used for filtration, and the substantial filtration area and thus the water permeability can be reduced. With the above structure, the filtrate from which the cell force in the vicinity of the central portion has also flowed out can be quickly discharged into the external space of the monolith via the water collecting slit. Therefore, the cell in the vicinity of the center can be effectively used, and the substantial filtration area and thus the water permeability can be greatly increased. Such a structure is particularly effective in the case of a large monolithic filter having a long distance to the outer periphery of the cell force monolith near the center. Therefore, this is a particularly preferable form for increasing the size of the filter element and storing one filter element in the casing. The water collection cell has a structure in which the opening at both ends of the cell is plugged, so that the stock solution does not enter from the cell opening.

[0045] The water collecting slit can be formed by breaking a group of cells arranged in parallel so as to communicate with the external space of the monolith. Cell breakage is caused by the steps of the molded body and the dried body before firing. It may be performed on the floor or at the stage of the sintered body after firing. The cell opening is plugged by, for example, filling the cell opening to be plugged with a clay (plugging material) having the same material strength as that of the monolith, followed by drying and baking. be able to. As shown in FIG. 4, the water collecting slits 5 are often formed in the vicinity of both end faces of the monolith 8, respectively. The water collecting slits 5 are generally formed so as to be parallel to each other.

[0046] There are no particular restrictions on the shape of the filter element. Examples of the overall shape include a columnar shape as shown in FIG. 4, a quadrangular prism shape, a triangular prism shape, and the like. Among these, a cylindrical shape that can be easily extruded and easily sealed with a casing with less firing deformation is suitably used. There is no particular limitation on the size of the filter element, but the filter of the present invention can be easily put in and out of the filter element with a simple structure when applied to a filter containing a large filter element. More effective. Specifically, the outer diameter is preferably 50 mm or more, more preferably 200 mm or more. The length is preferably 500 mm or more, more preferably 1000 mm or more. On the other hand, if it is too large, it is difficult to manufacture, and conversely there is a problem such as an increase in cost. Accordingly, the outer diameter is preferably 300 mm or less, more preferably 250 mm or less. The length is preferably 2000 mm or less, more preferably 1500 mm or less.

[0047] Examples of the cell shape (shape in a cross section orthogonal to the liquid flow direction) include shapes such as a square cell, a hexagonal cell, and a triangular cell in addition to a circular cell as shown in FIG. . Among them, a circular cell that can be easily removed by separating and removing suspended substances deposited on the partition wall surface during backwashing is preferably used.

[0048] When such a filter is installed in a water purification plant or the like that filters a large amount of liquid, a plurality of filters are arranged in a line and connected by piping to form a module. It is preferable to install more modules.

[0049] Next, a method for assembling the filter will be described based on one embodiment. FIG. 5 (a) and FIG. 5 (b) are process diagrams schematically showing an embodiment of the filter assembling method of the present invention. (1) First, the protective cap 54 is put on the first end face 51 of the filter element 50. The material of the protective cap 54 is not particularly limited as long as the end of the filter element can also protect the impact force. For example, rubber, cloth, urethane, plastic, paper, and the like can be given as preferable examples. .

[0051] (2) Next, the filter element 50 is placed on the assembly flange 55 with the first end face down. Here, the assembly flange 55 is preferably placed on a cushioning material such as the rubber sheet 64. In addition, it is preferable that the assembly flange 55 has irregularities on the surface so that the filter element can be easily positioned.

(3) Next, a protective cover 56 is prepared, and the side surface 53 of the filter element 50 is covered with the protective cover 56. The protective cover 56 is preferably cylindrical or bag-shaped. Furthermore, it is preferable to have a bottomed cylindrical shape or bag shape so as to cover the second end face 52. With such a shape, the protective cover can be attached so as to cover the upper force of the filter element. As a material of the protective cover, for example, cloth such as quilting, rubber, film, plastic, paper and the like can be given as preferable examples.

Next, the casing body 60 is lowered from above the filter element 50, so that the casing body is placed over the protective cover 56, and the filter element 50 is placed in the casing body 60. When the casing body 60 is made of a metal such as stainless steel, and the casing body is large, it is preferable that the casing body is lifted by a crane or the like and lowered from above the filter element 50 because the casing body is quite heavy.

(4) Next, the assembly flange 55 and the casing body 60 are positioned. The positioning is preferably performed by inserting the stud bolt 57 into the bolt hole of the casing main body 60 with the stud bolt 57 attached to the assembly flange 55. At this time, it is also preferable to insert a spacer 58 between the assembly flange 55 and the casing body 60 because the seal member 59 can be easily attached in a later process.

[0055] (5) Next, the protective cover 56 is removed. At this time, it is preferable to provide a handle (not shown) for removing the protective force bar at the upper end of the protective cover 56 because the protective cover 56 can be easily removed. The handle can be lifted up by pulling the protective cover from the top of the filter element. A string-like one is preferable.

(6) Next, the seal member 59 is attached to the outer peripheral portion of the second end face 52 of the filter element. The seal member 59 is preferably an annular body (seal cap) having an L-shaped cross section. With such a shape, it can be easily attached to the end of the filter element 50 and can be sealed on the side of the filter element 50. If the spacer 58 is arranged between the assembly flange 55 and the casing body 60, the casing body 60 protrudes upward from the filter element 50. Even if (not shown) is provided at this end, the seal member 59 can be easily attached to the second end face. The sealing member 59 is flexible, and even if the dimension of the opening of the casing body 60 is smaller than the outer peripheral dimension of the annular sealing member 59, the casing can be easily formed by deforming the sealing member 59. Can be inserted into the body. Further, the seal member 59 may be attached to the outer peripheral portion of the second end face 52 before the filter element 50 is covered with the protective cover 56. However, the seal member 59 may fall off during the process. This is because it is preferable to reduce the contact area between the seal member 59 and the second end face 52 in order not to block the cell opening of the filter element 50. Further, the seal member 59 is easily deformed. Therefore, there is also a repulsive force that the seal member can easily come off from the second end face 52. Therefore, it is more preferable to attach the seal member 59 after removing the protective cover 56.

[0057] (7) Next, the casing body 60 is lifted, the spacer 58 is removed, the casing body is lowered, the nut is attached to the stud bolt and turned, and the casing body 60 is pushed downwards to obtain a predetermined value. Fix in position.

[0058] (8) Next, the whole is inverted and placed so that the first end face 51 becomes the upper end face, and the assembly flange 55 and the protective cap 54 are removed.

(9) Next, a seal member 59 similar to that attached to the second end face is attached to the first end face 51. At this time, use the back surface (flat surface) of the assembly flange 55 to seal the seal member.

It is preferable to push in 59 and attach.

(10) Next, the cap part 61 is attached to the casing body 60 via the O-ring 62. In addition, if there is a lower header 63, it is also attached to the casing body 60 via the O-ring 62. And complete the filter.

Industrial applicability

Since the filter of the present invention has a simple structure and can be easily loaded and replaced with a filter element, it can be suitably used for filtering liquid such as water treatment. In particular, it can be suitably used as a large filter for treating a large amount of water such as a water purification plant. The casing for a filter of the present invention can be suitably used as a part of such a filter. The filter assembly method of the present invention can suitably assemble such a filter.

Claims

The scope of the claims

[1] A filter comprising a casing and a filter element housed in the casing,

The filter element includes a porous partition wall having an opening at a lower end surface and forming a cell penetrating to the upper end surface;

The casing includes a casing main body that surrounds the side surface of the filter element, an upper portion of the filter element, and a cap portion that is detachable from the casing main body. The casing main body can move the filter element upward and downward. A filter comprising: a cylindrical side wall portion having a hollow portion; and a flange portion protruding inward from a lower portion of the side wall portion, wherein the filter element is supported by the flange portion.

[2] The filter according to [1], wherein the filter element is supported by a flange portion at an outer peripheral portion of the lower end surface so as not to block an opening portion of the lower end surface.

[3] The filter according to claim 1 or 2, wherein the filter element is a monolithic filter element having a number of cells extending in parallel with each other and having a porous ceramic body force.

[4] The filter according to any one of claims 1 to 3, wherein an upper end portion of the side surface of the filter element and the casing are sealed by a detachable seal member.

5. The filter according to any one of claims 1 to 4, wherein a lower end portion of the side surface of the filter element and the casing are sealed by a detachable seal member.

6. The filter according to claim 4 or 5, wherein the sealing member force section is an L-shaped annular body.

[7] The filter according to any one of claims 1 to 6, wherein only one filter element is housed in the casing.

[8] A filter casing for storing a filter element, comprising: a casing main body for enclosing a side surface of the filter element; and a cap portion detachable from the casing main body for covering an upper portion of the filter element. ,

The casing body has a hollow portion in which the filter element can be taken in and out upward. A filter casing comprising: a cylindrical side wall portion having a flange portion protruding from a lower portion of the side wall portion toward the hollow portion in order to support the filter element.

A method of assembling a filter for storing a columnar filter element in a casing having a cylindrical casing body and a cap portion,

Covering the first end face of the filter element with a protective cap;

Placing the filter element on the assembly flange with the first end face down; covering the side of the filter element with a protective cover;

Lowering the casing body from above the filter element and placing the filter element inside the casing body;

Removing the protective cover;

Attaching the seal member to the outer periphery of the second end surface;

Fixing the assembly flange and the casing body;

Inverting the casing body and the filter element so that the second end face is on the lower side; and

Removing the assembly flange and protective cap;

Attaching the seal member to the outer periphery of the first end surface;

Attaching the cap part to cover the first end surface, and fixing the casing body and the cap part;

A method for assembling a filter comprising: