Method for manufacturing a filter housing and a filter housing

Abstract

To provide a production method of a filter housing improving the reliability of a weld zone.SOLUTION: A production method of a metal filter housing 10 having first cylindrical or semi-spherical housing members 22, 23 and second discoid housing members 24 (30) closing the openings of the first housing members 22, 23 includes: a step to form annular ribs 33, 34 projecting in an axial direction from a region adjacent to at least inner peripheral side at the peripheral edge parts of surfaces 31, 32 of the second housing member 30; and a step where end parts 22a, 23a forming the openings of the first housing members 22, 23 and tip parts 33a, 34a of the ribs are caused to abut on each other and the butting part is joined by plasma welding.SELECTED DRAWING: Figure 3

Description

[Technical field]

[0001] The present invention relates to a method for manufacturing a filter housing and to a filter housing. [Background technology]

[0002] A known filter housing for filtering liquids has a disk-shaped partition member that divides the inside of a cylindrical housing into upper and lower spaces and supports a plurality of elongated cylindrical filter cartridges housed in the upper space (see, for example, Patent Document 1). Such filter housings are generally made of metal such as stainless steel, and the partition member is joined by welding to an open end of a cylindrical or hemispherical housing member that constitutes the filter housing. TIG welding has been widely used as a welding method for this purpose. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2014-087718 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, TIG welding has a low energy density, and it is difficult to penetrate to the back side of the welded surface (the inner circumference of the filter housing) in one weld, so liquid may enter the gap formed there and cause crevice corrosion. On the other hand, if welding is performed from the back side to ensure sufficient penetration, the heat input becomes large, causing sensitization that reduces corrosion resistance and causes stress corrosion cracking. On the other hand, it is possible to use other welding methods with higher energy density than TIG welding, but simply using other welding methods instead of TIG welding does not necessarily result in good penetration, and some kind of manufacturing or design ingenuity is required.

[0005] SUMMARY OF THE PRESENT DISCLOSURE An object of the present invention is to provide a filter housing and a manufacturing method thereof that improve the reliability of welds. [Means for solving the problem]

[0006] In order to achieve the above object, the manufacturing method of the filter housing of the present invention includes a filter housing having a cylindrical or hemispherical first housing member and a disk-shaped second housing member that closes an opening of the first housing member. and houses the filter cartridge inside. A method for manufacturing a metal filter housing includes the steps of forming an annular rib on the peripheral portion of the surface of a second housing member, the rib protruding axially beyond at least the area adjacent to the inner circumference, and butting an end portion forming an opening of the first housing member with a tip portion of the rib, and joining the butted portion by plasma welding.

[0007] The filter housing of the present invention has a cylindrical or semispherical first housing member and a disk-shaped second housing member that closes an opening of the first housing member. and houses the filter cartridge inside. A metal filter housing, the second housing member having an annular rib formed on the peripheral portion of the surface of the second housing member and protruding in the axial direction beyond at least an area adjacent to the inner peripheral side, the first housing member and the second housing member Between an end portion of the first housing member that forms an opening; butted against its end The tip of the rib and Joining Plasma welding The department was formed It has been done.

[0008] According to this filter housing manufacturing method and filter housing, by forming an annular rib on the second housing member, it becomes possible to use butt welding by plasma welding for welding to the first housing member. As a result, a sufficient amount of penetration can be ensured even with a smaller amount of heat input, and a good welded joint with reduced sensitization can be formed. Effect of the Invention

[0009] As described above, according to the present invention, the reliability of the welded portion can be improved. [Brief description of the drawings]

[0010] [Figure 1] 1 is a schematic cross-sectional view of a filter housing according to a first embodiment of the present invention. [Diagram 2] 1A to 1C are cross-sectional views showing each step of a method for manufacturing a batten according to a first embodiment of the present invention. [Diagram 3] FIG. 5 is a schematic enlarged cross-sectional view of a filter housing according to a second embodiment of the present invention. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0011] Hereinafter, an embodiment of the present invention will be described with reference to the drawings.

[0012] (First embodiment) First, the configuration of a filter housing according to a first embodiment of the present invention will be described with reference to Fig. 1. Fig. 1 is a schematic cross-sectional view of the filter housing of this embodiment.

[0013] The filter housing 10 is a metallic cylindrical container that accommodates a plurality of elongated cylindrical filter cartridges (not shown) therein, and includes an upper housing 1 and a lower housing 2. The upper housing 1 is formed in a cylindrical shape with an open lower end, and includes a ferrule portion 11 on the periphery of the opening. The lower housing 2 is formed in a cylindrical shape with an open upper end, and includes a ferrule portion 21 on the periphery of the opening. The upper housing 1 and the lower housing 2 are detachably fixed to each other by clamping the ferrule portions 11, 21, which sandwich an O-ring (not shown), with a clamp band 3. The metal material constituting the filter housing 10 is not particularly limited, but stainless steel is preferably used from the viewpoint of pressure resistance and mechanical strength.

[0014] The upper housing 1 is composed of a cylindrical upper body 12 with both ends open, and a hemispherical upper head plate 13. The upper head plate 13 is joined to the upper body 12 by welding (e.g., plasma welding) so as to close the opening at the top end side of the upper body 12. In addition, handles 14 are attached to both side surfaces of the upper housing 1 for grasping and moving the upper housing 1 when it is released from its fixation to the lower housing 2.

[0015] The lower housing 2 is composed of a cylindrical lower body 22 with both ends open, a hemispherical lower end plate 23, and a disk-shaped mesh plate 24. The mesh plate 24 is welded between the lower body 22 and the lower end plate 23 so as to close the opening at the lower end of the lower body 22 and the opening of the lower end plate 23, in other words, so that its peripheral portion forms a part of the side wall of the lower housing 2. As a result, the inside of the filter housing 10 is divided into an upper space 4 that contains a filter cartridge and into which the liquid to be treated flows, and a lower space 5 into which the liquid to be treated filtered by the filter cartridge flows. An inlet pipe 25 that communicates with the upper space 4 and supplies the liquid to be treated to the upper space 4 is attached to the side of the lower housing 2, and an outlet pipe 26 that communicates with the lower space 5 and discharges the liquid to be treated to the outside is attached to the lower part of the lower housing 2.

[0016] In this embodiment, plasma welding is used to weld the batten 24 to the lower body 22, and also to weld the batten 24 to the lower head plate 23. Hereinafter, this welding method of the manufacturing method of the filter housing of this embodiment will be described with reference to Fig. 2. Fig. 2(a) to Fig. 2(d) are cross-sectional views showing each step of the welding method of the batten of this embodiment, and are enlarged views corresponding to the area surrounded by circle A in Fig. 1.

[0017] 2(a), a disk member 30 that will become the mesh plate 24 is prepared, specifically, a disk member 30 having the same diameter as the diameters of the lower body 22 and the lower head plate 23 is prepared. The thickness of the disk member 30 is not particularly limited, so long as it has a thickness that can withstand the pressure difference between the primary and secondary sides (the pressure difference between the upper space 4 and the lower space 5) acting on the filter cartridge when it becomes the mesh plate 24 and is installed in the filter housing 10, and a thickness that is the sum of the heights of ribs 33 and 34 described below.

[0018] Next, a plurality of through holes (not shown) for supporting the filter cartridge are formed in the disk member 30. Then, as shown in FIG. 2(b), annular ribs 33, 34 protruding in the axial direction are formed on the peripheral portions of both sides 31, 32 of the disk member 30. Specifically, a circular recess 35 is formed in the region of the upper surface 31 of the disk member 30 excluding the peripheral portion having the same width as the thickness of the lower body 22. As a result, an upper surface rib 33 having the same thickness as the thickness of the lower body 22 is formed along the peripheral portion of the upper surface 31 of the disk member 30. Also, a circular recess 36 is formed in the region of the lower surface 32 of the disk member 30 excluding the peripheral portion having the same width as the thickness of the lower head plate 23. As a result, a lower surface rib 34 having the same thickness as the thickness of the lower head plate 23 is formed along the peripheral portion of the lower surface 32 of the disk member 30. In this way, the mesh plate 24 is completed.

[0019] Next, as shown in Fig. 2(c), the lower end portion 22a of the lower body 22 (the end portion forming the lower opening) is butted against the tip portion 33a of the upper surface rib 33 of the batten 24, and the butted portions 22a, 33a are joined by plasma welding. Specifically, a plasma arc is irradiated from the outer periphery of the butted portions 22a, 33a to melt and integrate the portions. Thus, as shown in Fig. 2(d), a welded portion 27 is formed between the lower body 22 and the upper surface rib 33 of the batten 24, where the two are joined by plasma welding.

[0020] Similarly, as shown in Fig. 2(c), the upper end portion (the end portion forming the opening) 23a of the lower end plate 23 and the tip portion 34a of the lower surface rib 34 of the baffle plate 24 are butted together, and the butted portions 23a, 34a are joined by plasma welding. Specifically, a plasma arc is irradiated onto the butted portions 23a, 34a from the outer periphery thereof, and the butted portions are melted and integrated. Thus, as shown in Fig. 2(d), a welded portion 28 is formed between the lower end plate 23 and the lower surface rib 34 of the baffle plate 24, where the two are joined by plasma welding.

[0021] Thus, in this embodiment, by forming the annular upper surface rib 33 on the mesh plate 24, it becomes possible to use butt welding by plasma welding for welding to the lower body 22. Similarly, by forming the annular lower surface rib 34 on the mesh plate 24, it becomes possible to use butt welding by plasma welding for welding to the lower end plate 23. Plasma welding is a welding method that has a higher energy density than, for example, TIG welding, and can perform welding while penetrating the plasma arc from the front side to the back side of the base material. Therefore, in this embodiment, it becomes possible to perform back-strip welding in which weld beads 27a, 28a are formed on the inner periphery of the welded parts 27, 28 in one welding, which could not be realized by conventional TIG welding, and therefore welding work from the back side (inner periphery side) is not necessary. As a result, a sufficient amount of penetration can be secured even with a smaller amount of heat input, and good welded parts 27, 28 in which the occurrence of sensitization is suppressed can be formed.

[0022] Second embodiment The configuration of a filter housing according to a second embodiment of the present invention will be described with reference to Fig. 3. Fig. 3 is a schematic enlarged cross-sectional view of the filter housing of this embodiment, and corresponds to Fig. 2.

[0023] In order to realize butt welding by plasma welding with the lower body 22 and the lower head 23, it is sufficient that the peripheral portion of the mesh plate 24 protrudes in the axial direction (up and down direction) more than at least the region adjacent to the inner periphery side. Therefore, in the first embodiment, the circular recesses 35, 36 are formed by cutting all the regions of both sides 31, 32 of the disk member 30 except for the peripheral portion, thereby forming the annular ribs 33, 34 on the mesh plate 24, but the method of forming the ribs 33, 34 is not limited to this. For example, as in this embodiment, the circular ribs 33, 34 may be formed on the mesh plate 24 by forming grooves 37, 38 by cutting only the region on the inner periphery side from the peripheral portion in an annular shape. As a result, in this embodiment, not only the amount of cutting is reduced compared to the first embodiment in which all the regions of both sides 31, 32 of the disk member 30 except for the peripheral portion are cut, but also the thickness of the disk member 30 itself can be made thinner, thereby reducing manufacturing costs. The width of the grooves 37, 38 may be any width as long as the plasma arc does not affect the region of the plate 24 that is more inward than the grooves 37, 38. The other configurations and manufacturing method (welding method) of this embodiment are similar to those of the first embodiment, and the effects obtained thereby are also similar to those of the first embodiment. [Explanation of symbols]

[0024] 1 Upper housing 2 Lower housing 3 Clamp band 4 Upper space 5 Lower space 10 Filter Housing 11,21 Ferrule part 12 Upper fuselage 13 Upper head plate 14 Handle 22 Lower body (first housing member) 22a Lower end 23 Lower head plate (first housing member) 23a Upper end 24 batten (second housing member) 25 Inlet pipe 26 Outlet pipe 27,28 Welded parts 27a, 28a Weld bead 30 Disc member 31 Top side 32 Bottom surface 33 Top rib 34 Bottom rib 33a,34a Tip 35,36 Recess 37,38 groove

Claims

1. A method for manufacturing a metal filter housing having a cylindrical or semispherical first housing member and a disk-shaped second housing member that closes an opening of the first housing member, the metal filter housing accommodating a filter cartridge therein, comprising: forming an annular rib on a peripheral portion of a surface of the second housing member, the rib protruding in an axial direction beyond at least an area adjacent to the inner peripheral side; a step of butting an end portion of the first housing member that forms the opening with a tip portion of the rib, and joining the butted portion by plasma welding.

2. 2. The method for manufacturing a filter housing according to claim 1, wherein the step of forming the rib includes forming an annular groove in an area of ​​the surface of the second housing member that is more inward than the peripheral edge portion, thereby forming the rib along the peripheral edge portion.

3. 2. The method for manufacturing a filter housing according to claim 1, wherein the step of forming the rib includes forming a circular recess in an area of ​​the surface of the second housing member excluding the peripheral edge portion, thereby forming the rib along the peripheral edge portion.

4. providing the second housing member having a diameter the same as a diameter of the first housing member; The method of claim 1 , wherein the step of forming the rib includes forming the rib to have a thickness the same as a thickness of the first housing member.

5. 5. The method for manufacturing a filter housing according to claim 1, wherein the step of joining the butted portions includes irradiating the butted portions with a plasma arc from an outer periphery side of the butted portions to form a weld bead on an inner periphery side of the butted portions.

6. The method of claim 1 , wherein the metal is stainless steel.

7. A metal filter housing having a cylindrical or semispherical first housing member and a disk-shaped second housing member closing an opening of the first housing member, and accommodating a filter cartridge therein, the second housing member has an annular rib formed on a peripheral portion of a surface of the second housing member and protruding in an axial direction beyond at least an area adjacent to the inner peripheral side, A filter housing, wherein a plasma weld is formed between the first housing member and the second housing member, joining an end portion of the first housing member that forms the opening and a tip portion of the rib that is abutted against the end portion.

Images