Metal fiber filter, filter unit, and vaporizer

Abstract

To provide a metal fiber filter or the like capable of suppressing staying of a fluid at the end of a filter medium.SOLUTION: A metal fiber filter 1 comprises: a cylindrical support 2 having a first end E1; a filter medium 3 disposed outside the support in a radial direction; and a first end member 4 fixed to the first end E1 side of the support. The support includes a first support part 11 having a first outer diameter D1, and a second support 12 having a second outer diameter D2 larger than the first outer diameter D1. A plurality of through-holes 11a are formed in the first support part. The filter medium is a metal fiber sintered body including a medium body 30 including a first extension 31 joined to the first end member and disposed outside the first support body in the radial direction and outside the second support part in the radial direction. The first extension continuously extends with a third outer diameter D3 in an axial direction, and is joined at a first swelled part having a fourth outer diameter D4 larger than the third outer diameter D3 to the first end member 4 by a first joint 6.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a metal fiber filter, a filter unit, and a vaporizer. [Background technology]

[0002] Patent Document 1 (JP 2003-102666 A) describes a filter element comprising a sintered fiber media. The filter element comprises a cylindrical body having an outer diameter that decreases from a central portion of the element to one end portion of the element, and the fiber media has a density that increases from the central portion of the element to the one end portion of the element. The increased density at the ends of such a filter element is expected to facilitate welding at the ends. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Special Publication No. 2011-502743 Summary of the Invention [Problem to be solved by the invention]

[0004] 5, the above-described filter element a may be housed in a housing b and used as a filter unit c. The housing b of the filter unit c has a fluid inlet d, an inlet flow path e that guides the fluid that has entered from the inlet d to the outer peripheral surface of the filter element a, and an outlet f for removing the fluid filtered by the filter element a.

[0005] In the filter unit c described above, the fluid flowing through the inlet flow path e tends to stagnate near the portion a1 where the outer diameter is reduced and which is provided at the axial end of the filter element a. Such fluid stagnation reduces the filtration efficiency.

[0006] Furthermore, for example, as shown in Figure 6, even when the filter element a is arranged on one wall surface h in a large chamber, fluid tends to stagnate in the region a2 between the wall surface h and the portion of the filter element a with a reduced outer diameter provided at the axial end of the filter element a.

[0007] The present invention was devised in consideration of the above-mentioned problems, and its main object is to provide a metal fiber filter or the like that can suppress fluid retention at the ends of the filter media (filter element). [Means for solving the problem]

[0008] The present invention provides a metal fiber filter, a support member having a cylindrical shape defining an axial direction and a radial direction and having a first end; a filter medium disposed radially outside the support; a first end member fixed to the support body at the first end side, the support body includes a first support portion having a first outer diameter, and a second support portion on the first end side of the first support portion, the second support portion having a second outer diameter larger than the first outer diameter, a plurality of through holes are formed in the first support portion, the second support portion is connected to the first support portion and forms the first end, The filter medium is a sintered body of metal fibers, the filter media includes a media body disposed radially outward of the first support portion for filtering a fluid, and a first extension portion disposed radially outward of the second support portion and joined to the first end member; the media body and the first extension portion extend continuously in the axial direction at a third outer diameter; the first extension portion is joined to the first end member via a first joining portion, the first joint portion includes a first protrusion portion having a fourth outer diameter greater than the third outer diameter; It is a metal fiber filter.

[0009] In the present invention, the first protrusion may be formed by a weld bead.

[0010] In the present invention, the thickness of the first extension portion may be in the range of 5% to 40% of the thickness of the medium body.

[0011] In the present invention, the thickness of the medium body may be 4.0 mm or more.

[0012] In the present invention, the first end member may have a fifth outer diameter that is equal to or greater than the third outer diameter.

[0013] In the present invention, it is preferable that the second support portion is not provided with a through-hole that penetrates through in the radial direction.

[0014] In the present invention, the fourth outer diameter may be larger than the third outer diameter by 1.0 mm or more.

[0015] In the present invention, the porosity of the first extension portion may be smaller than the porosity of the medium body.

[0016] In the present invention, the porosity of the first extension portion may be 70% or less, and the porosity of the medium body may be 80% or more.

[0017] In the present invention, the first end member may be an end cap that closes the first end side of the support body.

[0018] In the present invention, the support has a second end opposite the first end; the support body includes a third support body on the second end side of the first support body, the third support body having a sixth outer diameter larger than the first outer diameter, the third support portion is connected to the first support portion and forms the second end, a second end member is fixed to the second end of the support body, the filter media includes a second extension portion disposed radially outward of the third support portion and joined to the second end member; the medium body and the second extension portion extend continuously in the axial direction at the third outer diameter, The second end side of the second extension portion is joined to the second end member via a second joining portion, The second joint may include a second ridge having a seventh outer diameter greater than the third outer diameter.

[0019] In the present invention, the second protrusion may be formed by a weld bead.

[0020] In the present invention, the thickness of the second extension portion may be in the range of 5% to 40% of the thickness of the medium body.

[0021] In the present invention, the first end member is an end cap that closes the first end side of the support body, the second end member is a housing mounting member for fastening the second end side of the support body to a housing, The second end member may have an opening for extracting fluid from a radially internal space of the support body.

[0022] The present invention provides a filter comprising any one of the above metal fiber filters and the housing capable of accommodating the metal fiber filter; The housing includes: an inlet for the fluid; an inlet flow path that guides the fluid that has entered from the inlet to an outer peripheral surface of the filter medium; The filter unit may have an outlet for removing the fluid that has been filtered by the filter media and passed through the through-hole of the first support portion and the opening of the second end member.

[0023] The present invention may also be a vaporizer using any of the metal fiber filters described above. [Effects of the Invention]

[0024] The metal fiber filter of the present invention can reduce the risk of filtration fluid stagnation at the ends of the filter media, thereby increasing filtration efficiency. [Brief explanation of the drawings]

[0025] [Figure 1] FIG. 2 is a cross-sectional view of the metal fiber filter of the present embodiment. [Figure 2] FIG. 2 is an enlarged view of part II in FIG. [Figure 3] FIG. 2 is an enlarged view of part III in FIG. [Figure 4] FIG. 1 is a cross-sectional view of a filter unit using the metal fiber filter of the present embodiment. [Figure 5] FIG. 10 is a cross-sectional view of a conventional filter unit. [Figure 6] FIG. 10 is a cross-sectional view of another conventional filter unit. DETAILED DESCRIPTION OF THE INVENTION

[0026] An embodiment of the present invention will now be described with reference to the drawings. It should be understood that the drawings include representations that differ from the dimensional ratios of the actual structures in order to facilitate understanding of the present invention. Furthermore, when there are multiple embodiments, the same or common elements are designated by the same reference numerals throughout the specification, and redundant explanations are omitted. Furthermore, the specific configurations shown in the embodiments and drawings are for the purpose of understanding the contents of the present invention, and the present invention is not limited to the specific configurations shown in the drawings.

[0027] [Metal fiber filter] Fig. 1 is a cross-sectional view of a metal fiber filter 1 of this embodiment. As shown in Fig. 1, the metal fiber filter 1 of this embodiment includes a support 2, a filter medium 3 arranged radially outside the support 2, and a first end member 4 arranged at one axial end of the support 2. The metal fiber filter 1 of this embodiment is also shown to include a second end member 5 arranged at the other axial end of the support 2.

[0028] The metal fiber filter 1 of this embodiment is used to capture foreign matter such as fine particles in a fluid. In particular, the metal fiber filter 1 of this embodiment is used as a high-performance filter that captures foreign matter with high filtration efficiency from fluids used in the manufacturing process of industrial products (e.g., semiconductors) that are manufactured in an extremely clean environment. However, the fluid to be filtered by the metal fiber filter 1 of the present invention is not limited to a specific one.

[0029] [Support] The support body 2 is configured in a cylindrical shape that defines an axial direction and a radial direction that is perpendicular to the axial direction. In a cross section of the support body 2 that is perpendicular to the axial direction, the direction along the outer surface is defined as the circumferential direction. The support body 2 extends in the axial direction from a first end E1 to a second end E2. The inside of the support body 2 in the radial direction is defined as a space i. The support body 2 in this embodiment is cylindrical with a circular cross section. In another aspect, the support body 2 may be cylindrical with a polygonal cross section.

[0030] The support 2 is made of a metal material. There are no particular limitations on the metal material, but for example, stainless steel is used, and austenitic stainless steel, which is particularly excellent in workability and corrosion resistance, is preferred. In a preferred embodiment, the support 2 of this embodiment is made of SUS316L, which has even better corrosion resistance.

[0031] Fig. 2 shows an enlarged view of part II in Fig. 1. As shown in Fig. 1 and Fig. 2, the support body 2 includes a first support portion 11 and a second support portion 12 provided on the side of the first end E1 of the first support portion 11. In this embodiment, the first support portion 11 has a sufficiently larger axial length than the second support portion 12.

[0032] [1st support part] The first support portion 11 is formed in a cylindrical shape having a first outer diameter D1. The first support portion 11 of this embodiment extends continuously in the axial direction with the first outer diameter D1.

[0033] A plurality of through holes 11a are formed in the first support portion 11. Therefore, fluid on the radially outer side of the first support portion 11 can flow into the space i inside the first support portion 11 through the through holes 11a. The first support portion 11 of this embodiment may be formed, for example, by processing a metal plate, such as a punched metal, having holes formed at a regular pitch into a cylindrical shape. The diameter and shape of the through holes 11a are not particularly limited and are set appropriately depending on the application. In this embodiment, the through holes 11a are circular and have a diameter of 1.5 mm, and are arranged at approximately equal intervals in the axial and circumferential directions.

[0034] [Second support part] The second support portion 12 has a second outer diameter D2 that is larger than the first outer diameter D1. That is, the second support portion 12 protrudes radially outward from the outer surface of the first support portion 11. The second support portion 12 of this embodiment is formed in an annular shape and includes, for example, a radial outer peripheral surface 121, a radial inner peripheral surface 122, an axial inner end surface 123, and an axial outer end surface 124. Note that in this specification, with respect to the axial direction, the terms "inner" and "outer" refer to relative directions in the axial direction, and the direction toward the axial end is defined as "outer" and the direction toward the axial center as "inner."

[0035] The outer circumferential surface 121 of the second support portion 12 extends continuously in the axial direction with a second outer diameter D2, for example.

[0036] In this embodiment, for example, an end portion of the first support portion 11 is fixed to the inner circumferential surface 122 of the second support portion 12. More specifically, the inner circumferential surface 122 is formed as a stepped surface including a recessed portion 122a extending in the axial direction with a constant inner diameter and a protruding portion 122b located on the first end E1 side of the recessed portion 122a and protruding radially inward from the recessed portion 122a. The end portion of the first support portion 11 is disposed in the recessed portion 122a, and the axial outer end surface of the first support portion 11 abuts against the stepped surface of the protruding portion 122b. The first support portion 11 and the second support portion 12 are fixed to each other by welding or the like. In this embodiment, the inner circumferential surface of the first support portion 11 and the inner circumferential surface of the protruding portion 122b of the second support portion 12 are formed to be continuous in the axial direction.

[0037] In this embodiment, the inner end surface 123 in the axial direction of the second support portion 12 is formed as, for example, a tapered surface in which the outer diameter gradually decreases toward the inside in the axial direction.

[0038] In this embodiment, the outer end surface 124 of the second support portion 12 in the axial direction is formed, for example, as a plane perpendicular to the axial direction, and this plane forms the first end E1 of the support body 2.

[0039] In this embodiment, the second support portion 12 is made of a solid material that does not have any through holes extending in the radial direction. Therefore, the fluid cannot pass through the second support portion 12.

[0040] [Filter media] The filter media 3 is fixed to the outer peripheral surface in the radial direction of the support body 2. Therefore, the filter media 3 in this embodiment has a cylindrical shape corresponding to the cylindrical shape of the support body 2. In this embodiment, the filter media 3 is fixed to the outer peripheral surface in the radial direction of the support body 2 during sintering. However, the method for fixing the filter media 3 to the support body 2 is not particularly limited.

[0041] The filter media 3 is composed of a sintered body of metal fibers. The metal fibers constituting the filter media 3 are not particularly limited, but examples thereof include stainless steel, particularly austenitic stainless steel (e.g., SUS316L) with excellent corrosion resistance, nickel alloys, and pure nickel. The diameter of the metal fibers used in the filter media 3 is also not particularly limited, but short fibers of approximately 0.5 to 10 μm are desirable to improve filtration efficiency. After being arranged on the outer circumferential surface of the support 2, these metal fibers are placed in a mold or the like and subjected to external heat and pressure. As a result, the assembly of metal fibers is integrally formed with the outer circumferential surface of the support 2 as a cylindrical sintered body. The filter media 3 has a porous structure with fine voids formed therein through which fluids pass, and therefore functions as a filtering member with high filtration accuracy.

[0042] The filter media 3 includes a media body 30 and a first extension 31 formed on the first end E1 side of the media body 30. The filter media 3 of this embodiment also includes a second extension 32 formed on the second end E2 side of the media body 30.

[0043] The media body 30 is a portion of the filter media 3 that is disposed radially outward of the first support portion 11. The media body 30 is a portion that performs the filtering function, which is the original function of the filter media 3. In this embodiment, the media body 30 has a cylindrical shape that extends in the axial direction corresponding to the shape of the support body 2. The first extension portion 31 is a portion of the filter media 3 that is disposed radially outward of the second support portion 12. The first extension portion 31 is integrated with the media body 30. The first extension portion 31 is used for joining to the first end member 4, which will be described later.

[0044] In FIG. 2 , in this embodiment, the media body 30 and the first extension portion 31 extend continuously in the axial direction with a third outer diameter D3. That is, the media body 30 and the first extension portion 31 are continuous in the axial direction with the same outer diameter without any substantial steps. However, because the filter media 3 is a sintered metal fiber compact, microscopic observation reveals the presence of minute irregularities on the surface of the filter media 3. Therefore, the term "substantially without steps" as used above means that the presence of such minute irregularities on the surface, which are unavoidable for a sintered metal fiber compact, is acceptable. More specifically, the term "substantially without steps" as used above should be understood to mean that a person skilled in the art, upon observing the media body 30 and the first extension portion 31 with the naked eye (macroscopic observation) with ordinary care, can recognize that they are continuous in the axial direction with the same outer diameter. Note that, in microscopic observation, the difference between the maximum and minimum diameters of the filter media 3 can be, for example, 2 mm or less, preferably 1.5 mm or less, to more effectively suppress fluid retention.

[0045] [First end member] The first end member 4 is fixed to the first end E1 side of the support body 2. In this embodiment, the first end member 4 is configured, for example, as an end cap that closes the first end E1 side of the cylindrical support body 2. The first end member 4 has a plate shape made of a metal material, particularly austenitic stainless steel (SUS316L in this embodiment) that has excellent corrosion resistance. The first end member 4 includes an axially inner end face that abuts against the axial outer end face 124 of the second support part 12. The first end member 4 prevents fluid in the space i of the support body 2 from flowing out from the first end E1 side of the support body 2 to the outside.

[0046] Furthermore, the first extension portion 31 is joined to the first end member 4 via a first joint portion 6. In this embodiment, the first joint portion 6 also joins the first end member 4 and the second support portion 12 of the support body 2, but it is sufficient that the first joint portion 6 joins at least the first extension portion 31 and the first end member 4. Furthermore, the first joint portion 6 includes a first raised portion 6A having a fourth outer diameter D4 larger than the third outer diameter D3.

[0047] [Operation of this embodiment] In the filter media 3 of this embodiment, the media body 30 and the first extension portion 31 extend continuously in the axial direction with a third outer diameter D3. In other words, the radial outer surfaces of the media body 30 and the first extension portion 31 are formed as a continuous surface with no substantial recesses, except for microscopic irregularities of the media. The first joint portion 6 includes a first raised portion 6A having a fourth outer diameter D4 larger than the third outer diameter D3. Therefore, the metal fiber filter 1 of this embodiment can suppress retention of the fluid to be filtered on the side of the first end E1. Furthermore, the first raised portion 6A, which has a relatively large outer diameter (fourth outer diameter D4), can also guide the fluid toward the media body 30, which has a smaller outer diameter. As described above, the metal fiber filter 1 of this embodiment is useful for reducing pressure loss and generating a uniform flow rate of the fluid to be filtered, and also has excellent filtration efficiency.

[0048] Further preferred embodiments of the present invention will be described below, but the following are all optional components of the present invention.

[0049] The first joint 6 may be formed by various joining means. The first joint 6 may be generated by, for example, welding, brazing, diffusion bonding, or friction welding. From the viewpoint of preventing fluid leakage (short path) from the first joint 6, welding, which can easily obtain an airtight joint, is particularly desirable as the joining means, and TIG welding is particularly desirable. The first joint 6 in this embodiment is a circumferentially continuous weld bead formed by welding, and the first protrusion 6A is also formed by a portion of this weld bead that protrudes radially outward.

[0050] The radial protrusion of the first protrusion 6A from the outer surface of the filter media 3 (i.e., (D4-D3) / 2) is not particularly limited, but from the perspective of improving the bonding strength and expecting the effect of guiding the fluid toward the media body 30, it may be preferably 0.5 mm or more, and more preferably 0.9 mm or more. In other words, it is desirable that the fourth outer diameter D4 be 1.0 mm or more larger than the third outer diameter D3.

[0051] In this embodiment, the first extension portion 31 of the filter media 3 has a thickness t1 that is smaller than that of the media body 30. Furthermore, because the first extension portion 31 has a porous structure made of sintered metal fibers, it is susceptible to deformation and other problems due to heat during welding. However, because the first extension portion 31 of this embodiment is supported from the radially inner side by the second support portion 12, it can be joined to the support body 2 and the first end member 4 while suppressing burn-through and void formation during welding. Furthermore, because the filter media 3 has an integral structure joined to the support body 2 and the first end member 4, it has high rigidity and can demonstrate excellent strength, for example, even in a vibrating environment or under high pressure.

[0052] The outer diameter of the first end member 4 (hereinafter referred to as the "fifth outer diameter D5") is not particularly limited, but in this embodiment it is set to be equal to or larger than the third outer diameter D3 of the filter media 3. Therefore, fluid retention around the first end member 4 can also be suppressed.

[0053] The thickness t0 of the medium body 30 is not particularly limited, but may be, for example, 3.0 mm or more, preferably 3.5 mm or more, in order to further increase the filtration accuracy.

[0054] The thickness t1 of the first extension 31 is also not particularly limited, and may be, for example, 5% or more, preferably 10% or more, and more preferably 15% or more of the thickness t0 of the medium body 30. By making the thickness t1 of the first extension 31 5% or more of the thickness t0 of the medium body 30, for example, when the first extension 31 and the first end member 4 are welded together, it is possible to more reliably prevent burn-through of the first extension 31 and thereby form an airtight first joint 6. This helps to effectively prevent short-passing of fluids near the first joint 6.

[0055] On the other hand, if the thickness t1 of the first extension portion 31 is excessively large, it may be difficult to form a deep first joint portion 6 that reaches the second support portion 12. From this perspective, the thickness t1 of the first extension portion 31 may be set to, for example, 40% or less of the thickness t0 of the medium body 30, preferably 35% or less, and more preferably 30% or less.

[0056] From the above viewpoint, in one embodiment, when the thickness t0 of the medium body 30 is 5.0 mm, the thickness t1 of the first extension portion 31 is, for example, in the range of 0.25 to 2.0 mm, preferably in the range of 0.50 to 1.75 mm, and more preferably in the range of 0.75 to 1.5 mm.

[0057] The porosity of the first extension portion 31 is desirably smaller than that of the media body 30. This relatively increases the rigidity of the first extension portion 31 joined to the first end member 4, and suppresses poor joining during welding. In a preferred embodiment, the porosity of the first extension portion 31 may be, for example, 70% or less, preferably 65% ​​or less, and more preferably 60% or less. Such a porosity of the first extension portion 31 can be obtained, for example, by adjusting the degree of compression acting on the first extension portion 31 during the sintering process so that it is higher than that of the media body 30. Furthermore, the first extension portion 31 is desirably a porous structure mainly containing pores with diameters of, for example, 2 to 6 μm.

[0058] In this specification, the "porosity" of a porous structure is expressed as the ratio of the volume of the void portion to the total apparent volume of the target area. In this specification, the porosity is calculated. In this case, the mass of the filter media is first measured, and the volume of the filter media, including the voids, is calculated. Next, the mass of solid wood that is set to the same volume as the filter media is measured. The porosity can then be calculated using the following formula (1). Porosity (%) = {1-(mass of filter media / mass of solid wood)}*100 ... (1)

[0059] Because the media body 30 is supported from the radially inner side by the first support portion 11, it is possible to ensure high differential pressure resistance against fluid pressure during filtration. Therefore, deformation of the filter media 3 is suppressed even when the fluid velocity is increased, which contributes to improved filtration efficiency. To fully exert favorable filtration function, the porosity of the media body 30 may be greater than that of the first extension portion 31. In a preferred embodiment, the porosity of the media body 30 may be, for example, 80% or more, preferably 85% or more, and more preferably 90% or more. Similarly, the media body 30 may have a porous structure predominantly containing pores with a larger diameter than the first extension portion 31. In a preferred embodiment, the media body 30 is preferably a porous structure predominantly containing pores with a diameter of 5 to 30 μm.

[0060] [Third support part] The support body 2 of this embodiment further includes a third support portion 13 on the second end E2 side of the first support portion 11, the third support portion 13 having a sixth outer diameter D6 larger than the first outer diameter D1. That is, the third support portion 13 protrudes radially outward from the outer surface of the first support portion 11. The outer peripheral surface 131 of the third support portion 13 extends continuously in the axial direction with the sixth outer diameter D6, for example. In this embodiment, the sixth outer diameter D6 is set to be the same as the second outer diameter D2 of the second support portion 12, but the sixth outer diameter D6 may be different.

[0061] The configuration of the third support portion 13 is the same as that of the second support portion 12, and therefore a description thereof will be omitted. That is, a radial outer peripheral surface 131, a radial inner peripheral surface 132, an axial inner end surface 133, and an axial outer end surface 134 of the third support portion 13 have the same configurations as the radial outer peripheral surface 121, the radial inner peripheral surface 122, the axial inner end surface 123, and the axial outer end surface 124 of the second support portion 12, respectively. In addition, an end portion of the first support portion 11 on the second end E2 side is fixed to the inner peripheral surface 132 of the third support portion 13.

[0062] [Second end member] A second end member 5 is fixed to the second end E2 side of the support body 2. In this embodiment, the second end member 5 is a housing attachment member for fixing the second end E2 side of the support body 2 to a housing (described later). More specifically, the second end member 5 is disk-shaped with an opening 5a formed in the center. The second end member 5 is fixed to the second end E2 side of the support body 2 with its center aligned with the axis of the support body 2. The outer diameter of the second end member 5 is an eighth outer diameter D8, which is the largest in the metal fiber filter 1, and its outer periphery is fixed to the housing (described later). The opening 5a of the second end member 5 is used to extract fluid from the radial internal space i of the support body 2.

[0063] [Second extension] The filter media 3 of this embodiment includes a second extension portion 32 that is disposed radially outward of the third support portion 13 and is joined to the second end member 5. The second extension portion 32 is integrated with the media body 30. The second extension portion 32 is used for joining to the second end member 5, which will be described later.

[0064] In this embodiment, the medium body 30 and the second extension portion 32 extend continuously in the axial direction with a third outer diameter D3. That is, the medium body 30 and the second extension portion 32 are continuous in the axial direction with the same outer diameter without any substantial step. As described above, the term "substantially without any step" should be understood to mean that a person skilled in the art, upon observing the connection portion between the medium body 30 and the second extension portion 32 with the naked eye (macroscopic observation) with ordinary care, would be able to recognize that they are continuous in the axial direction with the same outer diameter.

[0065] Additionally, the second extension portion 32 is joined to the second end member 5 via a second joint portion 7. In this embodiment, the second joint portion 7 also joins the second end member 5 and the third support portion 13 of the support body 2, but it is sufficient that the second joint portion 7 joins at least the second extension portion 32 and the second end member 5. Furthermore, the second joint portion 7 includes a second raised portion 7A having a seventh outer diameter D7 that is larger than the third outer diameter D3.

[0066] In this embodiment, the media body 30 and the second extension portion 32 extend continuously in the axial direction at a third outer diameter D3. In other words, the radial outer surfaces of the media body 30 and the second extension portion 32 are formed as continuous surfaces with no substantial recesses, except for microscopic irregularities of the media. Therefore, in the metal fiber filter 1 of this embodiment, the section between the first joint portion 6 and the second joint portion 7 of the filter media 3 is substantially continuous in the axial direction at the third outer diameter D3. Therefore, the metal fiber filter 1 of this embodiment can suppress retention of the fluid to be filtered, even on the side of the second end E2 of the filter media 3. Furthermore, the second raised portion 7A, which has a relatively large outer diameter (seventh outer diameter D7), can also guide the fluid toward the media body 30, which has a smaller outer diameter.

[0067] The second joint 7 may be formed by various joining means. For example, the second joint 7 may be produced by welding, brazing, diffusion bonding, or friction welding. From the viewpoint of preventing fluid leakage (short path) from the second joint 7, welding, which can easily produce an airtight joint, is particularly desirable as the joining means, and TIG welding is particularly desirable. The second joint 7 of this embodiment is also a circumferentially continuous weld bead formed by welding, and the second raised portion 7A is also formed by a portion of this weld bead that bulges outward in the radial direction.

[0068] The radial protrusion of the second protrusion 7A from the outer surface of the filter media 3 (i.e., (D7-D3) / 2) is not particularly limited, but from the perspective of improving the bonding strength and expecting the effect of guiding the fluid toward the media body 30, it may be preferably 0.5 mm or more, and more preferably 0.9 mm or more. In other words, it is desirable that the seventh outer diameter D7 be 1.0 mm or more larger than the third outer diameter D3.

[0069] In this embodiment, the second extension portion 32 of the filter media 3 has a thickness t2 that is smaller than that of the media body 30. Furthermore, because the second extension portion 32 has a porous structure made of sintered metal fibers, it is susceptible to deformation and other problems due to heat during welding. However, in this embodiment, the second extension portion 32 is supported from the radially inner side by the third support portion 13. This allows for bonding to the support body 2 and the second end member 5 while suppressing burn-through and void formation during welding, thereby preventing short-passing of fluids. Furthermore, because the filter media 3 has an integral structure bonded to the support body 2 and the second end member 5, it has high rigidity and can demonstrate excellent strength, for example, even in vibrating environments or under high pressure.

[0070] The thickness t2 of the second extension portion 32 is not particularly limited, but is preferably set to, for example, the same range as the thickness t1 of the first extension portion 31. That is, the thickness t2 of the second extension portion 32 may be set to 5% or more of the thickness t0 of the medium body 30, preferably 10% or more, and more preferably 15% or more.

[0071] On the other hand, if the thickness t2 of the second extension portion 32 is excessively large, it may be difficult to form a deep second joint 7 that reaches the third support portion 13. From this perspective, the thickness t2 of the second extension portion 32 may also be set to, for example, 40% or less of the thickness t0 of the medium body 30, preferably 35% or less, and more preferably 30% or less.

[0072] From the above viewpoint, in one embodiment, when the thickness t0 of the medium body 30 is 5.0 mm, the thickness t2 of the second extension portion 32 is also, for example, in the range of 0.25 to 2.0 mm, preferably in the range of 0.50 to 1.75 mm, and more preferably in the range of 0.75 to 1.5 mm.

[0073] The porosity of the second extension portion 32 is desirably smaller than the porosity of the media body 30. This relatively increases the rigidity of the second extension portion 32 joined to the second end member 5, and suppresses poor joining during welding. In a preferred embodiment, the porosity of the second extension portion 32 may be, for example, 70% or less, preferably 65% ​​or less, and more preferably 60% or less. Furthermore, the second extension portion 32 is desirably a porous structure mainly containing pores with diameters of, for example, 2 to 6 μm.

[0074] [housing] Fig. 4 is a cross-sectional view of a filter unit 100 using the metal fiber filter 1 of this embodiment. As shown in Fig. 4, the filter unit 100 includes a housing 101 having a space capable of accommodating the metal fiber filter 1. The housing 101 has an inlet 102 for a fluid, an inlet flow path 103 that guides the fluid that has entered from the inlet 102 to the outer peripheral surface of the filter media 3, and an outlet 104 for the fluid that has been filtered by the filter media 3.

[0075] The housing 101 is made of, for example, stainless steel, preferably austenitic stainless steel. The housing 101 of this embodiment is made of SUS316L, which has particularly excellent corrosion resistance. For example, when used as an in-line filter, the housing 101 forms an exterior body of the metal fiber filter 1.

[0076] In the filter unit 100 of Fig. 4, the fluid to be filtered enters from the inlet 102 and passes through the inlet flow path 103 between the housing 101 and the metal fiber filter 1, and flows around to the outer peripheral surface of the filter media 3. As the fluid that has flowed around to the outer peripheral surface of the filter media 3 passes through the filter media 3, foreign matter such as fine particles are captured by the filter media 3, and the fluid is purified. The purified fluid then passes through the through-hole 11a of the first support part 11, the space i inside the support body 2, and the opening 5a of the second end member 5, and is taken out from the outlet 104.

[0077] In the filtration process described above, as explained above, the outer surfaces of the media body 30, first extension portion 31, and second extension portion 32 of the filter media 3 are axially continuous with each other and have a substantially identical third outer diameter D3. Furthermore, the first and second joint portions 6 and 7, located at both axial ends of the filter media 3, respectively include first and second raised portions 6A and 7A, each having an outer diameter greater than the third outer diameter D3. This allows fluid to flow more easily from the first and second raised portions 6A and 7A toward the media body 30, preventing fluid from accumulating on both axial sides of the media body 30. This reduces pressure loss and creates a uniform flow rate during the filtration process.

[0078] Furthermore, because the filter media 3 is supported from the radially inner side by the support 2, it is possible to maintain high differential pressure resistance during filtration, even though it has a porous structure. Therefore, the metal fiber filter 1 and filter unit 100 of this embodiment can be suitably used even in high filtration pressure environments, which also contributes to improving filtration efficiency.

[0079] The metal fiber filter 1 of this embodiment can reduce pressure loss associated with filtration, and therefore can prevent re-liquefaction within the filter media 3, even when filtering a low vapor pressure liquid. Therefore, the metal fiber filter 1 of this embodiment can also be used as a vaporizer. For example, in the semiconductor manufacturing process, when filtering a low vapor pressure liquid that is a fluid obtained by vaporizing a precursor, re-liquefaction within the filter media 3 can be prevented.

[0080] The metal fiber filter 1 of the present invention may be used without the housing 101. For example, as shown in Fig. 6, when the filter is used as a diffuser (vent filter) mounted in a vacuum chamber, such that the gas immediately after filtration is directly passed to the next process, the housing 101 is not necessary.

[0081] Although the embodiments of the present invention have been described in detail above, the present invention is not limited to the above specific disclosure, and can be implemented in various modified forms within the scope of the technical idea described in the claims. [Explanation of symbols]

[0082] 1 Metal fiber filter 2 Support 3. Filter Media 4 First end member 5 Second end member 5a opening 6 1st joint 6A 1st protuberance 7 Second joint 7A 2nd raised part 11 First support part 11a Through hole 12 Second support part 13 Third support part 30 Media unit 31 1st extension 32 Second extension 100 filter units 101 Housing 102 Entrance 103 Inlet channel 104 Exit E1 1st end E2 2nd end

Claims

1. A metal fiber filter, a support member having a cylindrical shape defining an axial direction and a radial direction and having a first end; a filter medium disposed radially outside the support; a first end member fixed to the support body on the side of the first end, the support body includes a first support portion having a first outer diameter, and a second support portion on the first end side of the first support portion, the second support portion having a second outer diameter larger than the first outer diameter, A plurality of through holes are formed in the first support portion, the second support portion is connected to the first support portion and forms the first end, The filter medium is a sintered body of metal fibers, the filter media includes a media body disposed radially outward of the first support portion and configured to filter a fluid, and a first extension portion disposed radially outward of the second support portion and joined to the first end member, the media body and the first extension portion extend continuously in the axial direction at a third outer diameter; the first extension portion is joined to the first end member via a first joining portion, the first joint portion includes a first protrusion portion having a fourth outer diameter greater than the third outer diameter; Metal fiber filter.

2. 2. The metal fiber filter according to claim 1, wherein the first protrusion is formed by a weld bead.

3. 2. The metal fiber filter according to claim 1, wherein the thickness of the first extension portion is in the range of 5% to 40% of the thickness of the media body.

4. 4. The metal fiber filter according to claim 3, wherein the thickness of said media body is 4.0 mm or more.

5. 2. The metal fiber filter according to claim 1, wherein the first end member has a fifth outer diameter equal to or greater than the third outer diameter.

6. The metal fiber filter according to claim 1 , wherein the second support portion is not provided with a through-hole passing through in the radial direction.

7. 2. The metal fiber filter according to claim 1, wherein the fourth outer diameter is greater than the third outer diameter by 1.0 mm or more.

8. The metal fiber filter according to claim 1 , wherein the porosity of the first extension portion is smaller than the porosity of the media body.

9. 2. The metal fiber filter according to claim 1, wherein the first extension portion has a porosity of 70% or less, and the media body has a porosity of 80% or more.

10. 2. The metal fiber filter according to claim 1, wherein the first end member is an end cap that closes the first end of the support.

11. the support has a second end opposite the first end; the support body includes a third support body on the second end side of the first support body, the third support body having a sixth outer diameter larger than the first outer diameter, the third support portion is connected to the first support portion and forms the second end, a second end member is fixed to the second end of the support body, the filter media includes a second extension portion disposed radially outward of the third support portion and joined to the second end member; the medium body and the second extension portion extend continuously in the axial direction at the third outer diameter; The second end side of the second extension portion is joined to the second end member via a second joining portion, 2. The metal fiber filter according to claim 1, wherein the second joint portion includes a second protrusion portion having a seventh outer diameter greater than the third outer diameter.

12. 12. The metal fiber filter according to claim 11, wherein the second raised portion is formed by a weld bead.

13. 12. The metal fiber filter according to claim 11, wherein the thickness of the second extension portion is in the range of 5% to 40% of the thickness of the media body.

14. the first end member is an end cap that closes the first end of the support body, the second end member is a housing mounting member for fastening the second end side of the support body to a housing, 12. The metal fiber filter according to claim 11, wherein the second end member has an opening for taking out fluid from a space inside the support in the radial direction.

15. The metal fiber filter according to claim 14; the housing capable of accommodating the metal fiber filter, The housing includes: an inlet for the fluid; an inlet flow path that guides the fluid that has entered from the inlet to an outer peripheral surface of the filter medium; a filter unit having an outlet for removing the fluid filtered by the filter media and passing through the through hole of the first support portion and the opening of the second end member.

16. A vaporizer using the metal fiber filter according to any one of claims 1 to 14.

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