JP6982577B2 - Filtration device - Google Patents

Description

The present invention relates to a filtration device comprising a filter housing and a replaceable filter cartridge housed and arranged within the filter housing, allowing liquid to pass through the filter portion of the filter cartridge to filter, and in particular, the filter housing. We propose a technology that can be applied to filter cartridges of various dimensions.

This type of filtration device typically has a head with inlets and outlets for liquids to flow in and out, as well as a filter housing with a bottomed tubular bowl that is removable and connected to the head, and a head within the filter housing. It consists of a filter cartridge that is attached to and housed in a bowl, and is used in a filtration process for filtering pure water, chemicals, etc. used in the manufacture of semiconductors, electronic components, and various other products. ..

Here, if the filtration device is used for a certain period of time, the pollutant collection performance deteriorates due to the adhesion of pollutants contained in the sewage to be filtered to the filter portion of the filter cartridge. The filter cartridge is generally replaced with a new one after a predetermined period of use.
As a technique related to such a filtration device, there are conventionally those described in Patent Documents 1 to 3.

Japanese Patent No. 4664596 Japanese Unexamined Patent Publication No. 2016-2522 International Publication No. 2016/174777

By the way, there are various sizes of filter cartridges having different lengths in the axial direction of the housing. When used by arranging it inside the filter housing, the length of the bowl in the housing axis direction should be shortened after the filter housing is manufactured, from the viewpoint of space restrictions for arranging the filtration device in the above filtration process. There is. Such ex post facto shortening of the bowl length cuts and removes an intermediate segment of a predetermined length along the housing axis of the bowl, as well as the bottom segment of the cut bowl and the opening to which the head can be attached. It can be done by joining the side segments to each other at their cut end faces.

However, in a filter housing having a tapered portion in which the bowl tapers from the opening side to the bottom side, for example due to the die-cutting property of injection molding, the bottom side segment of the bowl after cutting as described above. And the cut end faces of the opening side segments are displaced from each other in the radial direction due to the lack of the tapered intermediate segment. In this case, there is a problem that it is not possible to secure a sufficient area for joining the end faces of the bottom side segment and the opening side segment of the bowl, and it is not possible to firmly join them.

An object of the present invention is to solve such a problem of the prior art, the purpose of which is to effectively change the bowl length of the filter housing to accommodate filter cartridges of various dimensions. It is to provide a filtration device capable of.

The filtration device of the present invention includes a head, a filter housing having a removable bowl on the head, and a filter cartridge housed and arranged inside the filter housing and having a filter portion, and flows in from the inlet of the head. The liquid is filtered by passing the liquid through the filter portion of the filter cartridge and flowing out from the outlet of the head, and the bowl of the filter housing has a tubular side portion and the side portion. It is configured to include an opening located on one end side of the above and to which a head is attached, and a bottom portion that seals the other end side of the side portion, and the side portion is directed from the opening side to the bottom portion side. It has a tapered portion that is tapered, and faces the opening side in the middle of the axial direction of the tapered portion, extends from the outer surface of the tapered portion to the outer peripheral side, and / or the inner circumference of the inner surface of the tapered portion. A bonding surface is formed that protrudes to the side over the entire circumference and increases the cross-sectional area.

Here, preferably, the bowl has an outer flange that annularly protrudes toward the outer peripheral side from the outer surface of the tapered portion in the middle of the tapered portion in the axial direction, and the surface of the outer flange facing the opening side. Is the bonding surface that protrudes toward the outer peripheral side from the outer surface of the tapered portion.
In this case, it is preferable that the diameter of the outer edge protruding toward the outermost periphery of the outer flange is smaller than the maximum outer diameter of the tapered portion.

Also preferably, the bowl has an inner step in the middle of the tapered portion in the axial direction, with a corner portion protruding over the entire circumference on the inner surface of the tapered portion, and faces the opening side of the inner step. The surface is the bonding surface that protrudes toward the inner peripheral side from the inner surface of the tapered portion.

In the filtration device of the present invention, the bowl has an opening-side segment partitioned from each other at the position of the joining surface in the axial direction of the bowl, and a bottom-side segment including the joining surface, and is open. The part-side segment and the bottom-side segment may be joined to each other by welding or welding on the joining surface.
In this filtration device, it is preferable that the entire end surface of the opening side segment on the bottom side segment side is fixed to the end surface including the bonding surface of the bottom side segment.

Further, in the filtration device of the present invention, the bowl may be integrally formed.

According to the filtration device of the present invention, the bowl length is formed by forming the above-mentioned bonding surface for increasing the cross-sectional area in the middle of the axial direction of the tapered portion of the side portion of the bowl of the filter housing. When the intermediate segment on the opening side of the tapered portion of the bowl is cut and removed in order to shorten the length, the cut end faces of the bottom segment and the opening segment, which are the rest of the bowl after the intermediate segment is removed, are removed. Even if it shifts to the inner and outer peripheral sides due to the tapered shape, the joining surface located on the bottom side segment side and the end face of the opening side segment can be firmly joined with a sufficient area. Thereby, in this filtration device, the bowl length of the filter housing can be effectively changed to accommodate filter cartridges of various dimensions.

It is a vertical sectional view along the housing axis direction which shows the filtration apparatus of one Embodiment of this invention. It is a perspective view which shows the bowl which the filter housing of the filter housing of FIG. 1 has. It is a vertical sectional view of the bowl of FIG. FIG. 3 is a vertical cross-sectional view showing a bowl in which the intermediate segment is cut and removed and the bottom side segment and the opening side segment are joined. It is a partial cross-sectional view which shows the main part of the bowl of FIG. 4 enlarged. It is a vertical sectional view which shows the bowl of a reference example. 6 is a vertical cross-sectional view showing a bowl in which the intermediate segment is cut and removed and the bottom side segment and the opening side segment are joined. It is a partial cross-sectional view which shows the main part of the bowl of FIG. 7 enlarged. FIG. 3 is a vertical cross-sectional view showing a bowl in which the intermediate segment is cut and removed and the bottom side segment and the opening side segment are joined. FIG. 6 is a vertical cross-sectional view showing a filtration device of another embodiment having the bowl of FIG. 9 is a vertical cross-sectional view showing still another embodiment of the filtration device having the bowl of FIG.

Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
The filtration device 1 illustrated in the vertical sectional view in FIG. 1 includes a container-shaped filter housing 10 with a lid and a cylindrical filter cartridge 20 housed and arranged in the filter housing 10.

Here, in the illustrated embodiment, in the filter housing 10, one end side (left side in FIG. 1) of the cylindrical or other cylindrical side portion 11a in the housing axis direction is opened by the opening portion 11b, and the side portion 11a is opened. The other end side in the housing axis direction (right side in FIG. 1) is sealed with a bottom portion 11c, and the opening 11b on one end side in the housing axis direction of the bowl 11 is liquid-tight so as to be removable by a connecting ring 12 or the like. It is configured to include a head 13 connected to the head 13.

Of these, the head 13 has, for example, a cylindrical inflow port 14 and an outflow port 15 extending toward opposite sides of the housing axis AD in the cross section shown in the drawing, and these inflow port 14 and the outflow port 15 are provided. The outlets 15 allow the inflow of liquid into the filter housing 10 and the outflow of liquid from the filter housing 10, respectively.
The housing axis direction referred to here means the direction in which the housing axis AD extends through the center position of the cross section of the bottomed cylindrical bowl 11.

Here, in the illustrated embodiment, the filter cartridge 20 has a substantially cylindrical main body portion 20a, an opening portion 20b provided on one end side of the main body portion 20a in the direction of the housing axis, and a bottom portion 11c of the bowl 11. It has a bottom portion 20c provided on the other end side of the main body portion 20a on the same side as the above. Here, most of the filter cartridge 20 is located inside the bowl 11 inside the filter housing 10, and the end of the filter cartridge 20 protruding from the opening 11b of the bowl 11 toward the head 13 to the head 13 at the end on the opening 20b side. Be concatenated.

The filter cartridge 20 is provided with a filter arrangement space 21 in the main body portion 20a, and a filter portion (not shown) for passing the liquid flowing into the filter housing 10 is arranged in the filter arrangement space 21. To. The cylindrical portion constituting the main body portion 20a is provided with a large number of openings through which a liquid can pass.

Such a filtration device 1 is used for filtering liquids such as ultrapure water and chemicals used in the manufacture of semiconductors, microelectronics and the like, for example.
To filter such a liquid using the filtration device 1, for example, the liquid is allowed to flow into the head 13 from the inflow port 14 of the head 13, and the bowl 11 is introduced from the end of the filter cartridge 20 on the opening 20b side. Flow inside the filter cartridge 20 inside. Then, the liquid passes through the main body portion 20a from the inside to the outside of the filter cartridge 20 while removing contaminants in the liquid in the filter portion of the filter arrangement space 21 inside the liquid. After that, the liquid sequentially passes through the inside of the bowl 11 and the head 13 and flows out from the filter housing 10 by the outlet 15. However, this filtration method using the filtration device 1 describes an example thereof, and the present invention is not limited to such a filtration method.

By the way, as shown in the perspective view of FIG. 2, the bowl 11 of the filter housing 10 has a cylindrical side portion 11a, an opening portion 11b located on one end side of the side portion 11a in the housing axial direction, and a side portion 11a. It may be formed by injection molding, for example, if it is made of resin so as to have a bottom portion 11c located on the other end side in the housing axial direction.

In this case, such a bottomed cylindrical bowl 11 is sided, as can be seen from FIG. 3, in consideration of die cutting from the die after being cured in the injection molding die. Most of the portion 11a is a tapered portion 16 whose inner and outer diameters gradually decrease in a linear shape in a vertical cross section from the opening 11b side to the bottom 11c side, for example. In this embodiment, the tapered portion 16 is formed from the mounting flange 17 used for mounting with the head 13 by the connecting ring 12 to the portion where the inner and outer surfaces on the bottom 11c side are curved. The taper angle of the tapered portion 16 with respect to the housing axis AD can be, for example, 0.5 ° to 3 ° as measured on the outer surface of the tapered portion 16. The portion from the surface of the mounting flange 17 facing the bottom 11c side to the opening 11b in the housing axis direction is not tapered and is not included in the tapered portion 16.
However, although not shown, the tapered portion includes a tapered portion having a curved or other linear shape in the vertical cross section, and the outer diameter is at least toward the bottom 11c side regardless of the shape. Anything that gradually decreases may be used.

Here, in this embodiment, in the middle of the housing axis direction of the tapered portion 16 as described above, the entire circumference extends from the outer surface of the tapered portion 16 to the outer peripheral side and / or from the inner surface of the tapered portion 16 to the inner peripheral side. The bonding surface 18 is formed so as to face the opening 11b side. By forming this joining surface 18, when viewed in a cross section cut along a plane including the joining surface 18 orthogonal to the housing axis direction, a tapered portion is formed at the joining surface 18 forming position. The cross-sectional area of 16 is increased.

The advantage of forming the bonding surface 18 in the middle of the tapered portion 16 will be described in detail by taking this embodiment as an example.
The filter cartridge 20 described above may have a short length in the housing axis direction depending on its use, performance, and other conditions. When such a short filter cartridge 20 is used, in the bowl 11 whose length in the housing axis direction is too long, the inside of the filter housing 10 is an extra space in which the filter cartridge 20 is not present, especially on the bottom 11c side of the bowl 11. While space is available, the outside of the filter housing 10 may not have enough empty space to accommodate the bowl 11, which is too long, depending on where the filtration device 1 is installed. In such a situation, it may be necessary to shorten the length of the bowl 11 in the housing axial direction after the production of the bowl 11.

For this, for example, the intermediate segment Sm in the housing axial direction of the bowl 11 (that is, the intermediate region of the tapered portion 16 in the housing axial direction) is cut at the two cutting positions CL1 and CL2 shown by the broken line in FIG. The part sandwiched between the two broken lines of CL1 and CL2, which are located at the respective positions and separated from each other, is removed, and the remaining bottom side segment Sb and opening side segment Sa are removed as shown in FIG. It is possible to deal with this by joining the cut end faces of the above.

Here, in this embodiment, the joining surface 18 for increasing the cross-sectional area is formed in the middle of the tapered portion 16 of the bowl 11 in the direction of the housing axis, so that the two cutting positions CL1 and CL2 are formed. By matching the cutting position CL2 on the bottom 11c side with the forming position of the joining surface 18, the cut end surface of the opening side segment Sa is set on the bottom side as shown in an enlarged view of the main part CA in FIG. It can be joined to a cut end face having a large area including the joining surface 18 of the segment Sb. As a result, it is possible to secure a joining area between the cut end faces of the opening side segment Sa and the bottom side segment Sb, and it is possible to firmly join the cut end faces.

On the other hand, in the bowl 81 of the filter housing of the filter housing of the reference example shown in FIG. 6, when cutting is performed at the cutting positions CL1 and CL2 in the same manner and the intermediate segment Sm is removed, the tapered shape of the tapered portion 86 causes FIG. As can be seen from the above, the cut end face of the bottom side segment Sb is positioned so as to be offset to the inner peripheral side from the cut end face of the opening side segment Sa. Then, if the cut end faces of the bottom side segment Sb and the opening side segment Sa are to be joined to each other, the above-mentioned joining surface 18 does not exist. There is a problem that it is not possible to realize a strong joint due to the small size, or it is extremely difficult to join because there is no part that can be joined between the cut end faces.

The cut end faces of the opening side segment Sa and the bottom side segment Sb can be joined by welding when made of a resin material or by welding when made of a metal material. Although other joining methods such as the use of an adhesive can be adopted, welding or welding is advantageous from the viewpoint of material cost, workability, and the like. However, depending on the material of the resin such as vinyl chloride and other conditions, adhesion may be advantageous.

In order to realize strong joining between the cut end faces as described above, the joining surface 18 needs to be formed over the entire circumference of the tapered portion 16 of the side portion 11a in the circumferential direction. This is because the cut end faces of the bottom side segment Sb and the opening side segment Sa can be joined to each other in a sufficiently large area over the entire circumference. The bonding surface 18 may have a radial length that changes in the circumferential direction, but is generally a substantially circular annular shape having a constant radial length over the entire circumference. The joining surface 18 having such a constant radial length in the circumferential direction makes it easier to manufacture the bowl 11.

At the joints between the cut end faces, the entire end face of the opening side segment Sa on the bottom side segment Sb side is the end face including the joining surface 18 of the bottom side segment Sb when viewed in both the circumferential direction and the radial direction. It is preferable that it is fixed.

Further, in the illustrated example, the bonding surface 18 is formed substantially parallel to the plane orthogonal to the housing axis direction, and the outer edge of the bonding surface 18 is on the opening 11b side or the bottom 11c side. It can be tilted to either side and tilted at 0 ° to 60 ° with respect to a plane orthogonal to the housing axis direction. If the inclination angle of the joining surface 18 is too large, the cut end surface of the opening side segment Sa will be joined to the diagonal joining surface 18 of the bottom side segment Sb, and the joining strength between the cut end faces will be slightly lowered. I have concerns.

Further, the forming position of the bonding surface 18 in the housing axial direction is a position separated from the outermost end Eb of the bottom portion 11c by 10 mm or more toward the opening 11b and a position separated from the end surface of the opening 11b by 20 mm or more toward the bottom portion 11c. It is preferably between the positions. If the bonding surface 18 is too close to the end surface of the opening 11b, there is no gripping allowance (chucking) for gripping the opening side segment Sa during welding or welding, and welding or welding becomes difficult. On the other hand, if the bonding surface 18 is too close to the outermost end Eb of the bottom portion 11c, there is a concern that the bottom portion 11c may be deformed due to heat during welding / welding. The formation position of the joining surface 18 in the housing axial direction is based on the contact point between the joining surface 18 and the outer surface of the tapered portion 16.

Although not shown, a plurality of bonding surfaces 18 can be formed at different positions in the axial direction of the housing.

As shown in FIG. 3, the joining surface 18 protrudes only toward the outer peripheral side from the outer surface of the tapered portion 16, and also protrudes toward the outer peripheral side from the outer surface of the tapered portion 16 as shown in FIGS. At the same time, it may be one that protrudes from the inner surface of the tapered portion 16 toward the inner peripheral side. In the bowl 31 shown in FIGS. Also has.
Furthermore, although it is an extreme example, the cutting position CL1 on the opening 11b side of the two cutting positions CL1 and CL2 shown in FIG. 3 is set to the position on the most opening 11b side of the tapered portion 16 (that is, that is). As the position of the surface of the mounting flange 17 on the bottom 11c side), as shown in FIG. 9, the bowl 41 may have a shorter length in the housing axis direction. In this case, the bonding surface 18 protrudes only from the inner surface of the tapered portion 16 to the inner peripheral side.

That is, the present invention also includes the filtration device 1 of FIG. 10 having the bowl 31 shown in FIG. 4 and the filtration device 1 of FIG. 11 having the bowl 41 shown in FIG. In addition to the bowls 31 and 41 described above, the filtration device 1 of FIGS. 10 and 11 has substantially the same configuration as that shown in FIG. 1 except that the length of the filter cartridge 20 in the housing axis direction is different. Have.
In the bowls 31 and 41 shown in FIGS. 4 and 9, the opening side segment Sa and the bottom side segment Sb including the joining surface 18 are joined to each other by welding or welding, and the housing axes of the bowls 31 and 41 are formed. At the position of the bonding surface 18 in the direction, the opening side segment Sa and the bottom side segment Sb are partitioned from each other. On the other hand, the bowl 11 shown in FIG. 3 is formed as an integral body.

The bowl 11 shown in FIG. 3 has an outer flange 18a that annularly protrudes toward the outer peripheral side from the outer surface of the tapered portion 16 in the middle of the tapered portion 16 in the direction of the housing axis, and the opening of the outer flange 18a. The surface facing the portion 11b is a bonding surface 18 that protrudes toward the outer peripheral side from the outer surface of the tapered portion.

In the bowl 11 having such an outer flange 18a, it is preferable that the diameter Df of the outer end edge projecting to the outermost peripheral side of the outer flange 18a is smaller than the maximum outer diameter Dt of the tapered portion 16. Thereby, when the head 13 is attached to the bowl 11 and the connecting ring 12 is moved from the bottom portion 11c side of the bowl 11 to the mounting flange 17 on the opening 11b side, the outer flange 18a is the corresponding portion of the connecting ring 12. It does not hinder the movement and facilitates the arrangement of the connecting ring 12. However, if the diameter Df of the outer end edge of the outer flange 18a is too small, the joining surface 18 existing on the outer flange 18a may also become small, and it may not be possible to realize a strong joining of the cut end faces. The maximum outer diameter Dt of the tapered portion 16 is the position of the boundary (that is, the tapered portion) with the portion of the tapered portion 16 on the most opening 11b side where the outer diameter is constant when the mounting flange 17 is not taken into consideration. The position of the boundary between the portion 16 and the base of the mounting flange 17) is measured.

The outer flange 18a may be a member separate from the tapered portion 16 of the bowl 11 and may be attached to the tapered portion 16 of the bowl 11 after manufacturing by welding or welding. In this case, the ex post facto attachment of the outer flange 18a may be performed at any time before or after cutting the bowl 11 at the forming position of the joining surface 18.
However, since mounting the outer flange 18a after manufacturing the bowl 11 increases man-hours, it is preferable that the outer flange 18a is integrally formed with the tapered portion 16 of the bowl 11. When the bowl 11 is manufactured by injection molding, it is preferable that the outer flange 18a is also integrally molded at that time.

On the other hand, the bowl 41 shown in FIG. 9 has an inner step 18c provided with a corner portion 18b protruding over the entire circumference on the inner surface of the tapered portion 16 in the middle of the tapered portion 16 in the housing axial direction, and the inner step 18c is provided. The surface facing the opening 11b side of the above is a bonding surface 18 that protrudes from the inner surface of the tapered portion 16 toward the inner peripheral side. The dimensional shape of the inner step 18c makes it possible to realize a strong bond between the cut end faces, and is appropriate so as not to hinder the arrangement of the filter cartridge 20 inside the bowl 41 and the smooth flow of the liquid in the bowl 41. Can be set.

The bowl 31 shown in FIG. 4 has both the outer flange 18a and the inner step 18c described above at the same position in the housing axial direction, whereby in the bowl 31, the bonding surface 18 has a tapered portion 16. It protrudes to both sides of the outer peripheral side from the outer surface and the inner peripheral side from the inner surface.

In order to assemble the filtration device 1 of the embodiment described above, the end portion of the filter cartridge 20 on the opening 20b side is fixed to a predetermined position inside the head 13 with a screw or the like, and then the filter cartridge 20 is fixed. , Insert into the bowl 11, 31 or 41, cover the opening 11b of the bowl 11, 31 or 41 with the head 13, and then connect the connecting ring from the bottom 11c side of the bowl 11, 31 or 41 toward the opening 11b. Screws provided on the inner surface of the connecting ring 12 and the outer surface of the head 13 with the mounting flange 17 of the bowl 11, 31 or 41 sandwiched between the inward flange of the connecting ring 12 and the head 13 through the 12 To screw. If necessary, an O-ring or other sealing member for preventing liquid leakage can be provided at these connecting points.

The bottom 11c of the bowls 11, 31, and 41 can be provided with a drain 11d for discharging the liquid from the filtration device 1 to the outside of the device, and when the liquid is discharged from the drain 11d. A vent 13a that allows the passage of gas inside and outside the filtration device 1 can be provided at the top of the head 13. During normal use of the filtration device 1, these drains 11d and vents 13a are sealed with caps (not shown) attached.

Of the constituent members of the filtering device 1, the materials of the head 13, the bowls 11, 31, 41, the connecting ring 12, and the main body 20a of the filter cartridge 20 may be any material as long as they are resistant to the liquid to be filtered. For example, plastics (preferably polyethylene including ultra-high molecular weight polyethylene, polypropylene, PTFE / PFA / PVDF and other fluororesins, polycarbonate, polysulfone, polyethersulfone, polyvinyl chloride, aromatic polyetherketone such as PEEK, PAI and the like, etc. Polycarbonate, polyphenylensulfide, liquid crystal polymer, cycloolefin polymer (COP), etc.) can be used. For the head 13 and the bowls 11, 31, 41, in addition to the above materials, glass, stainless steel, aluminum, copper, nickel, chromium, titanium, or a metal such as an alloy or mixture thereof may be used depending on the application. You can choose the best one.

The material of the filter portion of the filter cartridge 20 may be paper, cellulosic material, glass fiber and woven material, metal such as stainless steel, nickel and chromium, alloys and mixtures thereof, ceramics and plastics. Among them, in the case of plastic, preferably, a thermoplastic material such as polyethylene such as ultrapolymer polyethylene, polypropylene, PVDF / PTFE / PFA and other fluororesins, PCV, nylon, polyamide, polysulfone, polyimide, polycarbonate, PET and the like. However, it is possible to use various materials that can be used in general filtration.

1 Filtration device 10 Filter housing 11, 31, 41 Bowl 11a Side 11b Opening 11c Bottom 11d Drain 12 Connecting ring 13 Head 13a Vent 14 Inlet 15 Outlet 16 Tapered part 17 Mounting flange 18 Joining surface 18a Outer flange 18b Corner 18c Inner step 20 Filter cartridge 20a Main body 20b Opening 20c Bottom 21 Filter placement space CL1, CL2 Cutting position Sm Intermediate segment Sa Opening side segment Sb Bottom side segment Df Outer edge of outer flange diameter Dt Tapered Maximum outer diameter of part Eb Outermost end of bottom 11c AD Housing axis CA main part

Claims (7)

A filter housing having a head and a bowl that can be attached to and detached from the head, and a filter cartridge that is housed and arranged inside the filter housing and has a filter portion are provided, and a liquid flowing from the inlet of the head is collected from the filter cartridge. A filtration device that filters the liquid by passing it through the filter section and letting it flow out from the outlet of the head. The bowl of the filter housing is located on the tubular side portion and one end side of the side portion. It is configured to include an opening to which the head is attached and a bottom that seals the other end side of the side portion, and the side portion is tapered from the opening side toward the bottom side. Have a part,
In the middle of the axial direction of the tapered portion, facing the opening side, the tapered portion is projected from the outer surface to the outer peripheral side and / or from the inner surface of the tapered portion to the inner peripheral side over the entire circumference to reduce the cross-sectional area. A filtration device formed with an increasing bonding surface. The bowl has an outer flange that annularly projects outward from the outer surface of the tapered portion in the middle of the tapered portion in the axial direction, and the surface of the outer flange facing the opening side is tapered. The filtration device according to claim 1, which serves as the bonding surface that protrudes toward the outer peripheral side from the outer surface of the above. The filtration device according to claim 2, wherein the diameter of the outer edge protruding toward the outermost periphery of the outer flange is made smaller than the maximum outer diameter of the tapered portion. The bowl has an inner step in the middle of the tapered portion in the axial direction with a corner portion protruding over the entire circumference on the inner surface of the tapered portion, and the surface of the inner step facing the opening side is tapered. The filtration device according to any one of claims 1 to 3, which is a surface for joining that protrudes from the inner surface of the shaped portion toward the inner peripheral side. The bowl has an opening side segment partitioned from each other at the position of the joining surface in the axial direction of the bowl, and a bottom side segment including the joining surface, and the opening side segment and the bottom side segment. The filtration device according to any one of claims 1 to 4, wherein the two parts are joined by welding or welding on the joining surface. The filtration device according to claim 5, wherein the entire end surface of the opening side segment on the bottom side segment side is fixed to the end surface including the joining surface of the bottom side segment. The filtration device according to claim 2 or 3, wherein the bowl is integrally formed.

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