WO2000053289A1

WO2000053289A1 - Purifier assemblies

Info

Publication number: WO2000053289A1
Application number: PCT/US2000/006533
Authority: WO
Inventors: Brian Palermo; William Murphy
Original assignee: Pall Corporation
Priority date: 1999-03-12
Filing date: 2000-03-13
Publication date: 2000-09-14
Also published as: JP2002538635A; AU3742000A

Abstract

A purifier assembly comprising: a housing including first and second surfaces, a first bore intersecting the first surface, a second bore intersecting the first and second surfaces, and an opening encompassing a line passing through the center of the housing, the first bore intersecting the opening; and a purifier element disposed in the housing and sealingly mounted to the second surface.

Description

PURIFIER ASSEMBLIES

THE FIELD OF THE INVENTION

This invention relates to purifier assemblies. More particularly, the invention relates to purifier assemblies used in fluid systems, such as high-purity gas delivery systems used in the manufacture of semiconductors.

THE BACKGROUNS OF THE INVENTION

Purifier assemblies are often used in various fluid systems, such as high-purity gas delivery systems employed in the manufacture of semiconductors. A purifier assembly may be used to remove undesirable substances from the gas or gases used in the manufacture of semiconductors. The undesirable substances may include heterogeneous contaminants, such as solid or liquid particulate contaminants, and/or homogeneous contaminants, such as liquid or gaseous chemical contaminants, or they may include one or more components of the fluid being purified.

A typical purifier assembly can be illustrated using the purifier assembly 10 shown in Figure 1. The purifier assembly 10 shown in Figure 1 includes a housing 20 and a purifier element 50 disposed in the housing 20. The housing 20 includes a housing base 22 and a housing cover 24, and the purifier element 50 is sealingly mounted on the housing base 22. The housing base 22 includes a sealing surface 26 having an inlet port 28 and an outlet port 30. The positions of the inlet and outlet ports 28, 30 on the sealing surface 26 may be determined in accordance with industry standards. The housing base 22 also includes first and second bores 32, 34 that provide fluid communication between the inlet port 28 and the purifier element 50 and between the purifier element 50 and the outlet port 30, respectively. Because of the geometry of the housing base 22, the two bores 32, 34 are not perpendicular to the sealing surface 26.

The purifier assembly 10 may be mounted on a manifold (not shown) with the sealing surface 26 of the purifier assembly 10 facing a surface of the manifold. The manifold has two openings on its surface, which are aligned with the inlet and outlet ports 28, 30 of the purifier assembly 10, respectively. The manifold is installed in the high-purity gas delivery system, and the openings of the manifold allow the gas to enter and exit the purifier assembly 10. Seals (not shown) are generally provided to prevent leakage at the interface between the manifold surface and the sealing surface 26 of purifier assembly 10. In the purifier assembly 10 shown in Figure 1 , an annular seal, such as a Z-seal, a W-seal, a C-seal or an O-ring seal, is disposed between the manifold surface and the sealing surface 26 around each flow path at the interface of each port 28, 30 and the corresponding manifold opening. The annular seal is compressed between the sealing surface 26 and the manifold surface to seal the gap between the two surfaces. The annular seal may be seated within a counterbore 36, 38 on the sealing surface 26. In operation, the gas exits an opening on the manifold surface and enters the purifier assembly 10 through the inlet port 28. The gas then passes through the first bore 32 and enters the housing 20. Next, the gas passes through the purifier element 50. Then the gas exits the purifier assembly 10 through the second bore 34 and the outlet port 30 and returns to the manifold through the other opening on the manifold surface. Conventional purifier assemblies have a number of drawbacks. For example, the housing base used in conventional purifier assemblies is difficult to manufacture. The bores in the housing base are difficult and costly to drill. Costly tools are required to drill the bores because the bores are angled with respect to the housing base and must be drilled at an angle from a surface of the housing base. In addition, it takes longer to polish the inner surfaces of the bores because the bores are relatively long. In the semiconductor industry, the inner surfaces of bores are generally highly polished to reduce contamination. Further, because the opening of the bore on the sealing surface preferably is smaller than the inner diameter of the annular seal, the diameter of the bore may be smaller if the bore is not substantially perpendicular to the base surface. The reason is that such a bore has an elliptical opening on the base surface, and the long axis of the opening, as opposed to the short axis of the opening (i.e. , the diameter of the bore), preferably is smaller than the inner diameter of the annular seal. A small bore is less desirable because it is difficult to polish and offers more resistance to fluid flow. THE SUMMARY OF THE INVENTION This invention provides purifier assemblies, which overcome many of the drawbacks associated with the prior art purifier assemblies.

In accordance with one aspect of the invention, a purifier assembly includes a housing including first and second surfaces, a first bore intersecting the first surface, a second bore intersecting the first and second surfaces, and an opening encompassing a line passing through the center of the housing, the first bore intersecting the opening; and a purifier element disposed in the housing and sealingly mounted to the second surface.

In accordance with another aspect of the invention, a purifier assembly includes a housing including first and second surfaces, a first bore intersecting the first surface, the first bore being substantially parallel to an axial line of the housing, a second bore intersecting the first and second surfaces, and an opening, the first bore intersecting the opening; and a purifier element disposed in the housing and sealingly mounted to the second surface.

In accordance with still another aspect of the invention, a purifier assembly includes a housing including first and second a second bore intersecting the first and second surfaces, and surfaces, a first bore intersecting the first surface, an opening intersecting an axial line of the housing, the first bore intersecting the opening; and a purifier element disposed in the housing and sealingly mounted to the second surface.

In accordance with a further aspect of the invention, a purifier assembly includes a housing including first and second surfaces, a first bore intersecting the first surface, the first bore being substantially perpendicular to the first surface, a second bore intersecting the first and second surfaces, and an opening, the first bore intersecting the opening; and a purifier element disposed in the housing and sealingly mounted to the second surface.

BRIEF DESCRIPTION OF THE DRAWINGS

Figure 1 is a cross-sectional elevation view of a prior art purifier assembly. Figure 2 is a cross-sectional elevation view of one embodiment of a purifier assembly according to the present invention.

Figure 3 is a bottom view of an embodiment of a purifier assembly shown in Figure 2.

Figure 4 is a cross-sectional elevation view of another embodiment of a purifier assembly according to the present invention. Figures 5 and 6 are cross-sectional top views of a housing base shown in Figure 4, the views being at a location including a notch.

Figure 7 is a cross-sectional elevation view of a further embodiment of a purifier assembly according to the present invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

Figures 2, 4 and 7 illustrate several exemplary embodiments of the purifier assembly according to the present invention. The purifier assembly may include a housing and purifier element disposed in the housing. The housing may include first and second surfaces, a first bore intersecting the first surface and a second bore intersecting the first and second surfaces, and an opening that the first bore may intersect. The opening may be a bore (Figures 2 and 7) or a notch (Figure 4) or the like. The purifier element preferably is mounted to the second surface. The housing may also include a third surface, and the opening may open onto the third surface. Figure 2 illustrates one exemplary embodiment of the purifier assembly 100 according to the present invention. The purifier assembly 100 may include a housing 110 and a purifier element 150 that is disposed in the housing 110. The housing 110 may include a housing base 112 and a housing cover 114 mounted on the housing base 112. Alternatively, the housing may have more or fewer components. The purifier element 150 is sealingly mounted on the housing base 112.

The housing base may have any suitable configuration. For example, the housing base 112 shown in Figure 2 has a generally cylindrical configuration, although it may have any regular or irregular configuration, such as a generally polygonal or trapezoidal configuration. Alternatively, the housing base 112 may include a combination of various configurations, such as a stack of concentrically arranged cylindrical and square configurations of various sizes.

Preferably, the housing base provides fluid passages that allow fluid to enter the purifier assembly 100, to pass through the purifier element 15Q, and to exit the purifier assembly 100. The housing base 112 shown in Figure 2, for example, includes first and second surfaces 116, 130, a first bore 122 intersecting the first surface 116, a second bore 124 intersecting the first and second surfaces 116, 130, and a third bore 132 (or any opening, such as a notch) extending through the housing base 112 and intersecting the first bore 122. The fluid may enter the purifier assembly 100 through the opening of the first bore 122 on the first surface 116 and pass through the first and third bores 122, 132. The fluid may then pass through the purifier element 150. Next, the fluid may pass through the second bore 124 and exit the purifier assembly 100 through the opening of the second bore 124 on the first surface 116. Alternatively, the direction of the fluid flow may be reversed, and the fluid may enter the purifier assembly 100 through the opening of the second bore 124 on the first surface 116 and exits the purifier assembly 100 through the opening of the first bore 122 on the first surface 116.

The first and second surfaces may each be any substantially flat or curved surface or a combination of flat and curved surfaces. The two surfaces may be oriented with respect to each other in various ways. For example, they may be parallel with respect to each other or at an angle with each other, and they may face generally away from one another. In the embodiment shown in Figure 2, the first surface 116 may be one end surface of the generally cylindrical housing base 112 and the second surface 130 may be the other end surface of the housing base 112. The first surface 116 may be used as the sealing surface of the purifier assembly 100, which sealing surface faces the manifold when the purifier assembly 100 is mounted to the manifold (not shown). Preferably, the sealing surface 116 is substantially flat, although it may have any suitable surface configuration that allows the purifier assembly 100 to be securely mounted to the manifold.

The second surface 130 of the housing base 112 may be used to mount the purifier element 150. The second surface 130 may have any surface configuration which allows the purifier element 150 to be sealingly mounted to the housing base 112 and does not interfere with fluid flow to and from the purifier element 150. For example, as shown in Figure 2, the second surface 130 may be substantially flat if the purifier element 150 has a dome-shaped configuration similar to that of an inverted cup, a semisphere, a cone, a trapezoid and the like. If the purifier element is substantially flat, as shown in Figure 7, the second surface 330 may include a concave area in the middle surrounded by a substantially flat rim 331. The substantially flat purifier element 350 may be sealingly mounted on the rim 331. The first and third bores may be variously configured. The third bore (or any opening, such as a notch) may substantially parallel to an axial line of the housing. Alternatively, the third bore (or any opening, such as a notch) may encompass a line passing through the center of the housing. Further, the third bore (or any opening, such as a notch) may intersect an axial line of the housing.

In Figure 2, the first and third bores 122, 132 preferably are substantially straight bores. Straight bores are preferred because they are easier to drill and polish. The first and third bores 122, 132 preferably intersect each other so that fluid may flow from one of the bores 122, 132 to the other. The first and third bores 122, 132 may be substantially perpendicular to each other, or they may be at an angle. The diameters of the bores 122, 132 are preferably large enough to facilitate polishing and to offer little resistance to fluid flow. The diameter of the first bore 122 generally is limited by the inner diameter of the seal (not shown) used to seal the opening of the first bore 122 on the first surface 116 and is further limited by the distance between the axes of the first and second bores 122, 124. Both the size of the seal and the distance between the axes of the first and second bores 122, 124 may be determined in accordance with industry standards. The diameter of the third bore 132 is preferably larger than the diameter of the first bore 122. The axis of the third bore 132 preferably is offset from the axis of the first bore 122 in a direction away from the second bore 124, so that the diameter of the third bore 132 may be made as large as desirable. Alternatively, the diameter of the third bore may be smaller than or substantially equal to the diameter of the first bore, and/or the axis of the third bore may not be offset from the axis of the first bore, as shown in Figure 7.

Preferably, neither the first bore nor the third bore creates a dead-end or a portion of a dead-end because a dead-end or a portion of a dead-end is difficult to polish. A "bore having no dead-end" as used herein is defined as a bore that does not terminate at either end in the base, either completely or partially, in other words, the bore terminates completely at a surface. In order not to create a dead-end at the intersection of the first and third bores 122, 131, the diameter of the first bore 122 preferably is less than the diameter of the third bore 132, and the distance between the axes of the first and third bores 122, 132 preferably is less than the difference between the radii of the first and third bores 122, 132. The distance between two axes is defined as the shortest distance between any two points on the two axes. In this way, the first bore 122 may drilled clear through the third bore 132.

The first bore 122 preferably is substantially perpendicular to the first surface 116. A bore is considered to be substantially perpendicular to a surface if the axis of the bore is substantially perpendicular to the normal surface at the point on the surface where the axis of the bore and the surface intersect. A "substantially perpendicular" position as used herein is defined as a position that is within 15°, preferably within 10°, more preferably within 5°, most preferably within 2°, from the perpendicular position. A bore that is substantially perpendicular to the housing base surface is easier and less costly to drill because it can be drilled with a drill positioned substantially perpendicularly with the housing base surface. The housing base may include a third surface that preferably is in fluid communication with the upstream side of the purifier element, and the third bore may intersect the third surface. The third surface may be substantially flat or curved, and the third bore may intersect the third surface at one or both ends of the third bore. Preferably, the third bore is substantially perpendicular to the third surface so that the third bore may be easily drilled from the third surface. In the embodiment shown in Figure 2, for example, the third surface 134 is a cylindrical surface, and the third bore 132 intersects the third surface 134 at both ends. Alternatively, the housing base may include third and fourth surfaces (not shown), at least one of which preferably is in fluid communication with the upstream side of the purifier element. The third bore may intersect the third surface at one end and the fourth surface at the other end. Further, the third bore preferably is a through bore and does not create a dead-end.

The second bore 124 preferably is a substantially straight bore and preferably intersects the first surface 116 substantially perpendicularly, for ease of drilling and polishing. Preferably, the second bore 124 does not create, i.e., the entire circumference of the second bore 124 intersects both the first and second surfaces, so that the second bore 124 does not create any dead-end or a portion of a dead-end.

Preferably, seals (not shown) are provided to prevent leakage at the interface between the seal surface 116 of the purifier assembly 100 and the manifold surface. The purifier assembly 100 is attached the manifold surface with the sealing surface 116 facing the manifold surface. An annular seal may be disposed around each flow path at the interface of each opening 118, 120 on the sealing surface 116 and the corresponding opening on the manifold surface. The annular seal may be compressed between the sealing surface 116 and the manifold surface to seal the gap between the two surfaces. The annular seal may be seated within a counterbore 126, 128 on the sealing surface 116, within a counterbore on the manifold surface, or within a counterbore 126, 128 on the sealing surface 116 and a counterbore on the manifold surface. Alternatively, instead of a counterbore, other means, such as an annular groove (not shown), may be used to accommodate the annular seal. The annular seal may be of any suitable type, such as a Z-seal, a W-seal, a C- seal or an O-ring seal, and may be fabricated from any suitable material, such as a metal or an elastomer. Alternatively, instead of an annular seal, other sealing methods may be employed. For example, a flat gasket with holes corresponding to the openings 118, 120 on the sealing surface 116 (or the manifold surface) may be placed between the sealing surface 116 and the manifold surface to provide a seal. The purifier element 150 may be sealingly joined to the second surface 130 of the housing base 112 in any suitable way, such as welding, brazing, crimping, or by means of an adhesive. Preferably, the second surface 130 is in fluid communication with the downstream side 152 of the purifier element 150. When the housing base 112 and the purifier element 150 are both formed from metal, it is convenient to join the two by welding. For example, laser welding, TIG (GTAW) welding, or electron beam welding may be used to form a weld between the housing base 112 and the purifier element 150. When the housing base 112 and the purifier element 150 are made of a non-metal such as a polymeric material, they can be joined by methods such as adhesive or solvent bonding or thermal welding. Depending upon the materials of which the purifier element 150 and the housing base 112 are formed, it may instead be preferable to join the housing base 112 and the purifier element 150 by a method such as soldering or brazing. Alternatively, a polymeric or metallic purifier element may be joined to the housing base by interference fit, which is described in detail in U.S. Patent No. 5,510,026, entitled "Filter Arrangement Including a Non-Reentrant Shape," which patent is incorporated by reference in its entirety. The structure and pore size of the purifier element 150 can be chosen in accordance with the substances which are to be removed, the maximum operating temperature, and the desired flow characteristics through the purifier element 150. When the purifier element 150 is used for purifying gases used in semiconductor manufacture, it is preferably capable of removing a wide variety of substances including solid liquid and gaseous substances and may be made of a low outgassing, bakeable, and corrosion resistant material, such as stainless steel, nickel, or a Hastelloy metal.

Some examples of a suitable purifier element for use in purifying a fluid such as a high purity semiconductor grade gas are (a) a depth type purifier element comprised of metal fibers sintered together at their points of contact, such as that sold by Pall Corporation under the trade designation PMF, (b) a sintered wire mesh such as that sold by Pall Corporation under the trade designation Rigimesh, (c) a wire mesh supporting sintered metal powder or fibers, such as that sold by Pall Corporation under the trade designation PMM, (d) a composite including more than one type of material, such as a depth type purifier element sandwiched between two layers of wire mesh which provide support to the upstream and downstream sides of the depth type purifier element, (e) a reactive membrane, such as the membrane disclosed in U.S. Patent No. 5,637,544, entitled "Reactive Membrane for Filtration and Purification of Gases of Impurities and Method Utilizing the Same," which patent is incorporated by reference in its entirety, (f) a reactive material, such as a bed of resin beads, or any combination of (e) and (f). Several of these purifier media can be formed of a corrosion resistant metal such as stainless steel or Hastelloy. A non- metallic purifier element made of a polymer or a ceramic, for example, can also be employed if fluid compatibility and operating conditions are appropriate.

The housing cover may have any suitable configuration that may form an enclosed space with the housing base. In Figure 2, for example, the housing cover 114 has a hollow, cylindrical configuration with an open end and a closed end. The closed end of the housing cover 114 has a semispherical configuration. Alternatively, the housing cover 114 may have, for example, a cylindrical, polygonal, trapezoidal, conical or semispherical configuration or a combination thereof. Preferably, the housing base 112 has a shoulder 140, and the housing cover 114 may rest on the shoulder 140 and may be sealingly welded or bonded to the housing base 112.

The inlet and outlet ports of the purifier assembly may be the openings 118, 120 of the first and second bores 122, 124 on the sealing surface 116. In the embodiment shown in Figure 2, the inlet port is the opening 118 of the first bore 122, and the outlet port is the opening 120 of the second bore 124. Alternatively, the inlet port is the opening 118 of the second bore 124, and the outlet port is the opening 118 of the first bore 162.

The purifier assembly 100 may be mounted on the manifold surface in various ways. For example, the purifier assembly 100 may be bolted to the manifold surface. In the embodiment shown in Figures 2 and 3, the purifier assembly 100 may include a square flange 136 at the first end 116 of the housing base 112 and four through holes 138 placed at the corners of the square flange 136. The manifold surface may include four corresponding threaded holes (not shown). A bolt may extend through a through hole 138 of the square flange 136 of the purifier assembly 100 into a corresponding threaded hole on the manifold surface to bolt the purifier assembly 100 onto the manifold surface. When the purifier assembly 100 is mounted on the manifold surface, preferably each of the inlet and outlet ports 118, 120 of the purifier assembly 100 is aligned with the corresponding opening on the manifold surface so that the inlet and outlet ports 118, 120 may be in fluid communication with the openings of the manifold. Figure 4 illustrates another embodiment of the purifier assembly according to the present invention. This purifier assembly 200 is similar to the purifier assembly 100 shown in Figures 2 and 3. The main differences between the purifier assemblies 100, 200 are in the housing bases 112, 212. In the housing base 112 of the embodiment shown in Figure 2, the first bore 122 preferably intersects a third bore 132 which includes a diametrial line through the base 112. In the housing base 212 of the embodiment shown in Figure 4, on the other hand, the first bore 222 preferably intersects a notch 260 or any opening, such as a bore. The notch (or any opening, such as a bore) may substantially parallel to an axial line of the housing. Alternatively, the notch (or any opening, such as a bore) may encompass a line passing through the center of the housing. Further, the notch (or any opening, such as a bore) may intersect an axial line of the housing. The housing base 212 of the purifier assembly 200 may include first, second and third surfaces 216, 230, 234, a first bore 222 intersecting the first and third surfaces 216, 234, and a second bore 224 intersecting the first and second surfaces 216, 230. Each of the first and second bores 222, 324 preferably does not create a dead-end and preferably is substantially perpendicular to the first surface 216. The second surface 230 preferably is in fluid communication with the downstream side 254 of the purifier element 250, while the third surface 234 preferably is in fluid communication with the upstream side 252 of the purifier element 250. Preferably, the first and second bores 222, 224 do not create a deadend. In the embodiment shown in Figure 4, the notch 260 opens onto the third surface 234 of the base 212. The notch may have any suitable configuration. Two examples of the notch are illustrated in Figures 5 and 6. In Figure 5, the notch 260 has a substantially semicircular configuration, and what remains of the cross-section of the housing base 212, as indicted by the crosshatching, also has a semicircular configuration surrounding the second bore 244. In the Figure 6, the notch 260 has an irregular configuration, and what remains of the cross-section of the housing base 212, as indicted by the crosshatching, is a small circular configuration surrounding the second bore 244.

Figure 7 illustrates another embodiment 300 of the purifier assembly according to the present invention. This purifier assembly 300 is similar to the purifier assembly 100 shown in Figures 2 and 3. The main differences are that the purifier assembly 300 shown in

Figure 7 has a substantially flat purifier element 350, as discussed above, and that the axes of the first and third bores 322, 332 are not offset from each other.

The operation of the purifier assembly according to the present invention may be illustrated using the purifier assembly 100 shown in Figures 2 and 3. The purifier assembly 100 may be installed in a high-purity gas delivery system used in the manufacture of semiconductors. Specifically, the purifier assembly 100 may be mounted to a surface of a manifold (not shown) used in the gas delivery system. Preferably, the inlet port 118 of the purifier element 150 is aligned with an opening on the manifold surface, and the outlet of the purifier assembly 100 is aligned with another opening on the manifold surface. A gas may be introduced into the purifier assembly 100 through the inlet port 118. The gas then may pass though the first bore 122 and the third bore 132, and then may enter the space enclosed by the housing base 112 and the housing cover 114. Next, the gas may pass through the purifier element 150 and the second bore 124. Finally, the gas may exits the purifier assembly 100 through the outlet port 120. Alternatively, the gas may enter purifier assembly 100 through the "outlet port" and exit through the "inlet port 118."

While various aspects of the invention have been described with respect to several embodiments, many variations in these embodiments would be obvious to those of ordinary skill in the art, especially in light of the teachings in this specification. For example, in accordance with the present invention, one or more or all of the features of any of the disclosed embodiments may be substituted and/or combined with one or more or all of the features of any of the disclosed embodiments. Further, in accordance with the present invention, one or more of the features of each of the disclosed embodiments may be omitted and/or fewer than all of the features of each of the disclosed embodiments may be included. Accordingly, all features, modifications and variations of the disclosed embodiments are encompassed within the spirit and scope of the invention as currently or hereafter claimed.

Claims

1. A purifier assembly comprising: a housing including first and second surfaces, a first bore intersecting the first surface, a second bore intersecting the first and second surfaces, and an opening encompassing a line passing through the center of the housing, the first bore intersecting the opening; and a purifier element disposed in the housing and sealingly mounted to the second surface.

2. A purifier assembly comprising: a housing including first and second surfaces, a first bore intersecting the first surface, the first bore being substantially parallel to an axial line of the housing, a second bore intersecting the first and second surfaces, and an opening, the first bore intersecting the opening; and a purifier element disposed in the housing and sealingly mounted to the second surface.

3. A purifier assembly comprising: a housing including first and second surfaces, a first bore intersecting the first surface, a second bore intersecting the first and second surfaces, and an opening intersecting an axial line of the housing, the first bore intersecting the opening; and a purifier element disposed in the housing and sealingly mounted to the second surface.

4. The purifier assembly according to any one of the preceding claims, wherein the first bore is substantially perpendicular to the first surface.

5. A purifier assembly comprising: a housing including first and second surfaces, a first bore intersecting the first surface, the first bore being substantially perpendicular to the first surface, a second bore intersecting the first and second surfaces, and an opening, the first bore intersecting the opening; and a purifier element disposed in the housing and sealingly mounted to the second surface.

6. The purifier assembly according to any one of the preceding claims, wherein the second bore is substantially perpendicular to the first surface.

7. The purifier assembly according to any one of the preceding claims, wherein the opening is a notch.

8. The purifier assembly according to any one of claims 1 to 6, wherein the opening is a third bore.

9. The purifier assembly according to claim 8, wherein the radius of the third bore is different from the radius of the first bore.

10. The purifier assembly according to claim 9, wherein the radius of the third bore is greater than the radius of the first bore.

11. The purifier assembly according to claim 9 or 10, wherein the axes of the first and third bores are offset with each other.

12. The purifier assembly according to any one of claims 9 to 11, wherein the distance between the axes of the first and third bores is less than the difference between the radii of the first and third bores.

13. The purifier assembly according to any one of claims 8 to 12, wherein the first and third bores are substantially perpendicular to each other.

14. The purifier assembly according to any one of claims 8 to 13, wherein the housing includes a third surface, and the third bore intersects the third surface, the third bore being substantially perpendicular to the third surface.

15. The purifier assembly according to claim 10 or 11, wherein the housing includes a fourth surface, and the third bore intersects the fourth surface.

16. The purifier assembly according to any one of claims 8 to 15, wherein the third bore is a through bore.

17. The purifier assembly according to any one of the preceding claims, wherein the second bore is a through bore.

18. The purifier assembly according to any one of the preceding claims, wherein the housing includes an annual recess on the first surface around each of the openings of the first and second bores