Filter arrangement at a pressure regulator

Abstract

A compact arrangement and method for removing particulate generated by a fluid pressure regulator including location of a filter element within the pressure regulator downstream of the regulating member and valve seat is disclosed. The fluid pressure regulator can be adapted to allow replacement of the filter element. The filter element and corresponding filter receiving space can be configured to account for different fluid flow ranges and particulate removal ratings.

Description

INDUSTRIAL APPLICABILITY

[0001] The present invention finds applicability in environments where ultra-clean fluids are desired. Of particular importance is the invention's incorporation into fluid pressure regulators.

BACKGROUND ART

[0002] Fluid pressure regulators are well known. They are utilized in many applications and settings in which clean pressurized fluid sources are utilized and must be maintained. Examples include but are not limited to semiconductor chip manufacturing. Controlling the pressure of the fluid supply is typically carried out by utilizing a fluid pressure regulator. The purity of the pressurized fluid is achieved by placing a filter in the fluid flow to separate and trap contaminants out of the fluid. Contaminants can be caused by a number or sources. For example, the interaction between the pressure regulating member and the seal inside a fluid pressure regulator, for instance, a gas pressure regulator, can cause particulate to be dislodged off of the interactive components which are then swept into the passing fluid flow. Another example is particulates entering from the fluid supply or generated by other system elements such as valves. Presently, this problem is addressed by placing a particle filter somewhere upstream of the fluid pressure regulator as exemplified in U.S. Pat. No. 5,904,178 or downstream of the fluid pressure regulator as exemplified in SEMI F13. The environments in which these clean pressurized fluid supplies are utilized, however, typically provided only a minimum amount of space in which to locate both the regulator and filter. This can cause a significant problem in such industries as semiconductor chip manufacturing where available space for the fluid delivery system components is especially limited.

[0003] Several inventive arrangements and methods for filtering pressurized fluids are described hereinbelow that minimize, or remedy these deficient aspects of known designs, and/or provide benefits, in and of themselves, to the user. These new, improved and otherwise potentiated solutions are described in greater detail hereinbelow with respect to several alternative embodiments of the present invention.

DISCLOSURE OF THE INVENTION

[0004] In one aspect, the present invention removes particles that are generated by a fluid pressure regulator essentially at the point of generation by locating a particle filter within the pressure regulator. As described in further detail below, the particle filter is located immediately downstream of the pressure regulating member and its corresponding seal. This configuration results in a filtered, precisely pressured gas supply in a reduced amount of space.

[0005] In another aspect of the present invention, the fluid pressure regulator can be manufactured to allow internal inspections and/or replacement of the filter element. The filter element can be constructed into a variety of forms ranging from simple geometric shapes to more complex shapes to increase the filtration area and accommodate different fluid flow rates.

[0006] The general beneficial effects described above apply generally to the exemplary descriptions and characterizations of the devices, mechanisms and methods disclosed herein. The specific structures and steps through which these benefits are delivered will be described in detail hereinbelow.

BRIEF DESCRIPTION OF THE DRAWINGS

[0007] In the following, the invention will be described in greater detail by way of examples and with reference to the attached drawings, in which:

[0008] FIG. 1 is a cross-sectional view of a conventional fluid pressure regulator.

[0009] FIG. 2a is cross-sectional view of a fluid pressure regulator according to the present invention with a cylindrical filter element positioned downstream of the regulating member and valve seat.

[0010] FIG. 2b is a detailed perspective view of a cylindrically-shaped filter element depicting radial fluid flow across the screen portion of the filter element.

[0011] FIG. 3a is a cross-sectional view of a fluid pressure regulator according to the present invention with a ring-shaped filter element positioned downstream of the regulating member and valve seat.

[0012] FIG. 3b is a detailed perspective view of a ring-shaped filter element depicting longitudinal or axial fluid flow across the screen portion of the filter element.

MODE(S) FOR CARRYING OUT THE INVENTION

[0013] As required, detailed embodiments of the present invention are disclosed herein; however, it is to be understood that the disclosed embodiments are merely exemplary of the invention(s) that may be embodied in various and alternative forms. The figures are not necessarily to scale; some features may be exaggerated or minimized to show details of particular components. Therefore, specific structural and functional details disclosed herein are not to be interpreted as limiting, but merely as a basis for the claims and as a representative basis for teaching one skilled in the art to variously employ the present invention.

[0014] For illustrative purposes, the typical single stage fluid pressure regulator, as depicted in FIG. 1, includes a valve assembly 10 consisting of a top portion 15 and a pressure regulator housing 20. Formed within the housing 20 is a fluid flow path 35 which starts at a fluid supply inlet 25 and ends at a fluid supply outlet 30. A regulating member 55 and valve seat 70 are arranged in the housing 20 to control the fluid supply which flows along the fluid flow path 35. More particularly, the regulating member 55 is made up of a stem portion 65 at one end and a sealing body 60 at the other end which makes sealing engagement with the valve seat 70. The stem portion 65 causes the sealing body to separate or make sealing engagement with the valve seat 70 to precisely regulate the pressure of the fluid supply which flows along the fluid flow path 35. A low pressure cavity 40 is positioned in the fluid flow path 35 immediately downstream of the regulating member 55.

[0015] In order to maintain a relatively constant pressure downstream of the regulating member 55, the distance between the regulating member 55 and the valve seat 70 is varied when the pressure downstream of the regulating member 55 deviates from an initial set pressure. The distance increases when the downstream pressure drops below the initial set pressure and decreases (or closes) when the downstream pressure nears the initial set pressure. In short, the downstream pressure variations cause a reciprocating motion of opening and closing the distance between the regulating member 55 and the valve seat 70.

[0016] While other types of fluid pressure regulators, such as a double stage fluid regulator (not depicted), have different configurations and uses, each include a regulating member 55 and a valve seat 70 which exhibit the reciprocating action described above. It is the experience of the inventors that the reciprocating action of the regulating member 55 causes particulate to be generated, especially when the regulating member 55 and the valve seat 70 contact and wear against each other. This causes particulate to contaminate the fluid flow path 35 at or downstream of the regulating member 55 and valve seat 70.

[0017] In the present invention, the fluid pressure regulator is similar in make up to the typical valve assembly 10 described above. The invention lies in part with the configuration of the low pressure cavity 40 to receive a filter element 75 thereby making a compact fluid pressure regulator and filter. In the present invention, the low pressure cavity 40 as shown in FIGS. 2a and 3a is formed with a filter receiving space 45 configured to receive and accommodate a filter element 75. In a preferred embodiment, the filter element 75 includes a sealing portion 85 which sealably engages the filter receiving space 45 at a filter engagement surface 50. Although not depicted, one skilled in the art can appreciate that the filter element 75 can be configured for bolting or screwing into the filter receiving space 45. This arrangement allows the filter element 75 to be removable. In an alternative embodiment, the filter element 75 includes a weld receiving portion 90 which mates with the filter engagement surface 45. A weld at the interface between the weld receiving portion 90 and the filter engagement surface 45 permanently seals the filter element 75 into the filter receiving space 45.

[0018] As depicted in FIGS. 2b and 3b, the filter element 75 includes a screen portion 80 which can be made from a variety of material including but not limited to nickel, stainless steel and polytetrafluoroethylene (PTFE). The sealing portion 85 as shown in FIG. 2b can be made from a variety of material which allows resealable engagement of the filter element 75 in the filter receiving space 45. Likewise, the weld receiving portion of the filter element 75 can be made from those materials which allow welding to occur with the filter engagement surface 50.

[0019] The shape and size of the filter element 75 and filter receiving space 45 can be adjusted to account for different flow ranges and particle removal ratings. For example, in FIGS. 2a and 2b, the filter element 75 is configured as a hollow tube or cylinder, with the sealing portion 85 located at the ends of the tube/cylinder. The filter receiving space 45 is shaped to accept and seal the ends the filter element 75 so that the fluid flow is radial through the screen portion 80. In another example as depicted in FIGS. 3a and 3b, the filter element 75 is configured in a washer- or ring-shape with a longitudinally measured length extending between the two ends. The weld receiving portions 90 are located at the inner and outer circumferences of each end and mate with the filter engagement surface 50. The filter receiving space 45 is shaped to accept and seal by welding the weld receiving portion 90 of the filter element 75 so that the fluid flow is longitudinally through the screen portion 80.

[0020] Although the present invention has been described and illustrated in detail, it is to be clearly understood that the same is by way of illustration and example only, and is not to be taken as a limitation. The spirit and scope of the present invention are to be limited only by the terms of any claims presented hereafter.

Claims

1. A method for providing a compact gas pressure regulated valve arrangement, said method comprising:

providing a pressure regulator housing configured for inclusion in a compact fluid pressure regulated valve arrangement, said housing having: a filter receiving space formed at a low pressure cavity of said housing and a regulating member arranged for reciprocating motion in said housing for controlling a gas supply that flows along a gas flow path formed, at least partially, in said housing; and

locating a filter element in said filter receiving space, said location of said filter element being downstream of said regulating member with respect to said gas supply that flows along said gas flow path thereby assuring that any particulate freed by operation of said regulating member and any other component located upstream of said filter element along said gas flow path is captured at said filter element thereby delivering an assured clean gas supply downstream of said compact fluid pressure regulated valve arrangement.

2. The method as recited in claim 1 further comprising:

providing an entrance to said gas flow path formed, at least partially, in said housing in the form of an fluid supply inlet.

3. The method as recited in claim 1 further comprising:

providing an exit to said gas flow path formed, at least partially, in said housing in the form of an fluid supply outlet.

4. The method as recited in claim 1 further comprising:

configuring said filter element to be releasably engageable in said filter receiving space.

5. The method as recited in claim 4 further comprising:

configuring said filter element as a hollow cylinder having a longitudinally measured length extending between two ends of said filter element.

6. The method as recited in claim 5 further comprising:

configuring said filter element for substantially radial gas flow through a screen portion of said hollow cylinder.

7. The method as recited in claim 5 further comprising:

providing a sealing arrangement at an end of said filter element, said sealing arrangement adapted for abutting engagement with a filter engagement surface formed at said filter receiving space.

8. The method as recited in claim 1 further comprising:

configuring said filter element to be permanently fixed in said filter receiving space.

9. The method as recited in claim 8 further comprising:

fixing said filter element permanently in said filter receiving space by welding.

10. The method as recited in claim 8 further comprising:

configuring said filter element to be washer-shaped and having a longitudinally measured length extending between two ends of said filter element.

11. The method as recited in claim 10 further comprising:

configuring said washer-shaped filter element for substantially longitudinally directed gas flow through a screen portion thereof.

12. The method as recited in claim 10 further comprising:

sealing an end of said filter element to a filter engagement surface formed at said filter receiving space.

13. A compact fluid pressure regulated valve arrangement, said arrangement comprising:

a pressure regulator housing configured for inclusion in a compact fluid pressure regulated valve arrangement, said housing having: a filter receiving space formed at a low pressure cavity of said housing and a regulating member arranged for reciprocating motion in said housing for controlling a gas supply that flows along a gas flow path formed, at least partially, in said housing; and

a filter element in said filter receiving space, said location of said filter element being downstream of said regulating member with respect to said gas supply that flows along said gas flow path thereby assuring that any particulate freed by operation of said regulating member and any other component located upstream of said filter element along said gas flow path is captured at said filter element thereby delivering an assured clean gas supply downstream of said compact fluid pressure regulated valve arrangement.

14. The arrangement as recited in claim 13 further comprising:

an entrance provided to said gas flow path formed, at least partially, in said housing in the form of an fluid supply inlet.

15. The arrangement as recited in claim 13 further comprising:

an exit provided to said gas flow path formed, at least partially, in said housing in the form of an fluid supply outlet.

16. The arrangement as recited in claim 13 further comprising:

said filter element configured to be releasably engageable in said filter receiving space.

17. The arrangement as recited in claim 16 further comprising:

said filter element configured as a hollow cylinder having a longitudinally measured length extending between two ends of said filter element.

18. The arrangement as recited in claim 17 further comprising:

said filter element configured for substantially radial gas flow through a screen portion of said hollow cylinder.

19. The arrangement as recited in claim 17 further comprising:

a sealing arrangement provided at an end of said filter element, said sealing arrangement adapted for abutting engagement with a filter engagement surface formed at said filter receiving space.

20. The arrangement as recited in claim 13 further comprising:

said filter element configured to be permanently fixed in said filter receiving space.

21. The arrangement as recited in claim 20 further comprising:

said filter element being permanently fixed in said filter receiving space by welding.

22. The arrangement as recited in claim 20 further comprising:

said filter element configured to be washer-shaped and having a longitudinally measured length extending between two ends of said filter element.

23. The arrangement as recited in claim 22 further comprising:

said washer-shaped filter element configured for substantially longitudinally directed gas flow through a screen portion thereof.

24. The arrangement as recited in claim 22 further comprising:

sealing an end of said filter element to a filter engagement surface formed at said filter receiving space.