US3787026A

US3787026A - Chromatography valve

Info

Publication number: US3787026A
Application number: US00309495A
Authority: US
Inventors: J Lazar
Original assignee: Honeywell Inc
Current assignee: DANIEL ELECTRONICS INSTRUMENTATION Corp
Priority date: 1972-11-24
Filing date: 1972-11-24
Publication date: 1974-01-22
Anticipated expiration: 1991-01-22
Also published as: JPS4984494A; JPS5732269U; CA995558A; DE2357719A1

Abstract

A valve using a valve body having a plurality of valving elements, each valving element including three fluid ports located on a flat face of the valve body. Fluid passages are provided in the valve body to communicate with the fluid ports. A corresponding resilient member covers each valving element and is selectively urged toward the flat face to seal the fluid ports in the respective valving elements from each other. A pair of concentric fluid actuated plungers are slidably supported in a plunger body located on the other side of the resilient member from the valving element and having operative ends arranged to bear on the resilient member. The concentric plungers are selectively urged against the resilient member by either a fluid pressure supplied to a closed volume defined by the other ends of the concentric plungers, by the fluid pressure of a fluid being controlled by the valve or by a stationary spring means arranged to apply axial pressure to one of the plungers.

Description

States Patent [191 CHROMATOGRAPHY VALVE [75] inventor: Jeffrey M. Lazar, Warminster, Pa. [73] Assignee: Honeywell lnc., Minneapolis, Minn. [22] Filed: Nov. 24, 1972 [21] Appl. No.: 309,495

Primary Examiner-Henry T. Klinksiek 'Attorney, Agent, or FirmArthur H. Swanson;

Lockwood D. Burton; Mitchell J. l-lalista m1 ansmze [4 1 Jan. 22, 1974 [5 7 ABSTRACT A valve using a valve body having a plurality of valving elements, each valving element including three fluid ports located on a flat face of the valve body. Fluid passages are provided in the valve body to communicate with the fluid ports. A corresponding resilient member covers each valving element and is selectively urged toward the flat face to seal the fluid ports in the respective valving elements from each other. A pair of concentric fluid actuated plungers are slidably supported in a plunger body located on the other side of the resilient member from the valving element and having operative ends arranged to bear on the resilient member. The concentric plungers are selectively urged against the resilient member by either a fluid pressure supplied to a closed volume defined by the other ends of the concentric plungers, by the fluid pressure of a fluid being controlled by the valve or by a stationary spring means arranged to apply axial pressure to one of the plungers.

7 Claims, 1 Drawing Figure CHROMATOGRAPHY VALVE CROSS REFERENCE TO RELATED APPLICATION Subject matter shown but not claimed herein is shown and claimed in a co-pending application of Jeffrey M. Lazar, Ser. No. 268,853, filed on July 3, 1972 and assigned to the same assignee as the present application.

BACKGROUND OF THE INVENTION Valves using flexible diaphragms as a sealing member for fluid ports are well known in the art, e.g., such valves are shown in U.S. Pat. Nos. 3,140,615; 3,464,448 and 3,613,729. However, such valves have generally been found to be unsuitable for using controllingextremely small fluid quantities, e.g., less than a microliter. Current chromatographic analyzers use samples of a fluid to be analyzed having a volume of less than 1 microliter in order to expedite the processing of thesample andthe detection of the fluid constituants. Thus the sampling valve for chromatographic analysis is used to selectively direct a sample of a fluid to be analyzed into a fluid storage volume, and subsequently, inject the stored sample into a fluid analyzing stream including a chromatographic absorption column for separating constituents from the fluid sample. In order to allow such a system to operate as a sensor for a chemical process, the sampling valve must be capable of handling the aforesaid small volume of the sample fluid to be analyzed as well as incorporating a fluid-tight valve structure to prevent the fluid sample from becoming contaminated. Additionally, the sampling valve must be capable of a relatively high speed operation and contain a minimal dead space, i.e., extraneous fluid storage volume, within the valve body. Finally, the sampling valve should be operable over a wide range of fluid sample pressures in order to be adaptable for sampling high and low pressure sample streams. In order to standardize the quantity of the fluid sample extracted from the fluid stream for analysis, the storage loop is preferably integrated as part of the valve structure wherebythe quantity of the sample is maintained for each analysis at a standardized value and external connections to the valve body are minimized.

Accordingly, it is an object of the present invention to provide an improved fluid valve for handling extremely small fluid quantities.

Another object of the present invention is to provide an improved fluid valve having integral means for sequencing and storing test fluids supplied to the valve.

SUMMARY OF THE INVENTION In accomplishing these and other objects, there has been provided, in accordance with the present invention a valve having a valve block incorporating a valving element with each valving element including a plurality of fluid ports connected to a face of the valve block and valve passages arranged to connect the valving elements with a side surface of the valve block. An elastic diaphragm is positioned above the face of the valve blockhaving the fluid ports therein and is selectively urged toward the face of the valve block by a pair of fluid actuated plungers slidably supported in a valve plate located on the other side of the diaphragm from the fluid ports. A contact induced by either of the plungers between the diaphragm and the face of the valve block surrounding the fluid ports is effective to seal the fluid ports in either of two port combinations to allow a fluid passage between two of the valve ports in each combination. A recess is provided in the valve body on the other side of the diaphragm from the fluid ports to allow the diaphragm to be displaced therein by fluid pressure from the fluid ports when a plunger is allowed to release the diaphragm. The valve plate is arranged to incorporate a fluid passage for connecting a space defined by flanges on the plungers with an outside surface of the valve plate. A spring means is arranged to apply pressure to one of the plungers to normally bias this plunger into a first fluid port sealing position. Second and third resilient diaphragms are provided in contact with the center plunger to seal the space defined by the flanges of the plungers to isolate the actuating fluid pressure applied therein.

BRIEF DESCRIPTION OF THE DRAWING A better understanding of the present invention may behad when the following detailed description is read in connection with the-accompanying single FIG. drawing which is a cross section of a valve embodying the present invention.

DETAILED DESCRIPTION Referring to the single FIG. drawing in more detail, there is shown a valve structure embodying the present invention and incorporating a valve block 2. The following description uses such terms as upper, lower, front and back and is intended only to refer to the embodiment of the valve structure as is shown in the accompanying illustrative drawing, while an actual valve, may, of course, be oriented in any desired manner whereby the aforesaid descriptive word would not be directly applicable. Further, the term fluid as used herein refers to either a liquid or gaseous fluid since the valve for the present invention is useable with either fluid medium. The valve block 2 has a first side face 4 and a second side face 6. Further, the valve block 2 has a lower, or first, end face 8 an upper, or second, end face 10 used in first and second valving elements, respectively. A fluid storage bore, or volume, 12 is provided in the valve block 2 between the first and second end faces 8 and 10. Thevolume of the bore 12 is arranged to be consistent with the required volume of a sample fluid to be obtained for the chromatographic analysis. The location of the bore 12 between the

side faces

4 and 6 is determined by the location of other elements of the valve, as described hereinafter.

A first fluid passage 14 is provided in the valve block 2 to connect the first side face 4 with the second end face 10. The end of the fluid passage 14 exiting in the side face 4 may be provided with a threaded portion suitable for excepting a threaded connector for providing a fluid tight connection to the fluid passage 14. A second fluid passage 16 is provided in the valve block to connect the second side face 6 with the second end face 10 and is, also, provided with a threaded portion at the side face 6 to provide a means for obtaining a fluid-tight connection to the fluid passage 16. The exit ports for the fluid passages 14 and 16 are arranged to be on opposite sides of the bore 12 and form part of a first valving element. A third fluid passage 18 is provided in the valve block 2 to connect the first end face 8 with the first side face 4 and a fourth fluid passage 20 is provided in a valve block 2 to connect the second side face 6 with the first end face 8. The

fluid passage

18 and 20 are also provided with threaded portions for obtaining fluid-tight connections thereto similar to those discussed above with respect to fluid passages 14 and 16. The exit ports for the

fluid passages

18 and 20 are, also arranged to be on opposite sides of the bore 12 and form part of a second valving element.

A first resilient member 22 is arranged to cover the second end face and, consequently, the exit ports for the fluid passages 14 and 16 and one end of the bore 12. A second resilient member 24 is, similarly, arranged to cover the first end face 8 and the exit ports of the

fluid passages

18 and 20 and the other end of the bore 12. A valve plate 26 is located on the other side of the first resilient member 22 from the valve block 2. The valve plate 26 is arranged to slidably support two

concentric plungers

28 and 30. The first plunger 28 is provided with an integral peripheral annular ridge 32 at one end thereof and a flange 34 at the other end. Similarly, the second plunger is provided with an integral peripheral annular ridge 36.at one end thereof and a flange 38 at the other end. The

ridges

32 and 36 are arranged to be in contact with the first resilient member 22. Further, the ridge 32 on the first plunger 28 is arranged by virtue of the plunger 28 being supported in the valve plate 26, to encompass within the area defined by the ridge 32 the ports of the first fluid passage 14 and one end of the bore 12. Concurrently, the ridge 36 of the second plunger 30 is arranged to encompass an area only over the port end of the first fluid passage 14.

A first recess 39 is provided in the valve plate 26 adjacent to the first resilient member 22 and the encompassing an area on the resilient member 22 which includes the ports of the first and second fluid conduits 14 and 16 and the bore 12. A second recess 40 is provided in the other side of the valve plate 26 to admit the flange end 34 of the first plunger 28. A third resilient member 42 is arranged to cover the side of the valve plate 26 above the first resilient member 22. Further, the third resilient member 42 is provided with a center hole having a diameter smaller than the diameter of the second plunger 30. The plunger 30 is provided with a circumerential recess 43 to accomodate the hole in the third resilient member 42 whereby a fluid-tight connection between the plunger 30 and the third resilient member 42 is obtained by the stretching of the resilient member 42 in the recess 43. An intermediate plate 44 is located on the other side of the third resilient member 42 from the valve plate 26 and is provided with a center opening 45 of sufficient diameter to admit the flange 38 of the second plunger 30 while having a diameter smaller than the recess 40 in the valve plate 26 whereby the intermediate member 44 overlies the recess 40 to act as a stop for the flange 34 of the first plunger 28. A fluid passage 46 is provided in the intermediate plate 44 between a side face thereof and the central opening 45 therein. The end of the fluid passage 46 at the side face of the intermediate plate 44 may be provided with a threaded portion to effect a fluid-tight connection to the fluid passage 46. A fourth resilient member 47 is positioned above the intermediate plate 44 and the flanged end 38 of the first plunger 30. A hollow rigid cover 48 is located on the other side of the fourth resilient member 47 from the intermediate plate 44 and is used to clamp the fourth resilient member 47 to the intermediate plate 44. A clamp plate 49 is located within the cover 48 in contact with the fourth resilient member 47 and is attached to the flange 38 of the plunger 30 by any suitable means. A spring 50 is located within the cover 48 between the inner surface of the cover 48 and the clamp plate 49 to apply pressure against the second plunger 30.

A similar structure to that described above is positioned on the other side of the first resilient member 8. Specifically, a second valve block 52 is located on the other side of the first resilient member 8 from the valve block 2. This second valve plate 2 is arranged to slidably support a pair of

concentric plungers

54 and 56. The first plunger 54 has an integral peripheral annular ridge 58 at the end adjacent to the second resilient member 8 and a flange 60 at the other end thereof. Similarly, the second plunger 56 has an integral peripheral annular ridge 62 at the end adjacent to the first resilient member 8 and a flange 64 at the other end thereof. The valve block 52 is provided with a recess 65 in the end adjacent to the second resilient member 24 similar to the recess 39 described above. Thus, the recess 65 is arranged to encompass an area including the ports in the end face 8 of the valve block 2 corresponding to the third and fourth

fluid passages

18 and 20 and the bore 12. The valve block 52 is also provided with a second recess 66 in the other end of the valve block 2 similar to the recess 40 described above with respect to the first valve block 26. The recess 66 is arranged to have a diameter suitable for allowing movement of the flange 60 of the first plunger 54 therein. A fifth resilient member 67 is positioned adjacent to the other end of the valve block 52 from the second resilient member 24. A center opening in the fifth resilient member 67 is arranged to mate with a peripheral recess 68 located in the second plunger 56 to form a fluid-tight seal therewith. I

A second intermediate plate 69 is located on the other side of the fifth resilient member 67 from the valve block 52 and is provided with a center hole 70 having a diameter sufficient to accomodate the flange 64 of the second plunger 56. A fluid passage 71 is provided in the intermediate plate 69 between the slide face of the intermediate plates and the center hole 70. The fluid passage 70 may be provided with a threaded portion adjacent to the side face of the intermediate plate 69 to provide means for effecting a fluid-tight connection to the fluid passage 71. A sixth resilient member 72 is located in contact with the intermediate plate 69 on the other end from the fifth resilient member 67. A hollow cover shell 73 similar to the shell 48 described above is located on the other side of the sixth resilient member 72 to clamp the sixth resilient member 72 against the intermediate plate 69. A clamp plate 74 is located on the other side of the flange 64 of the second plunger 56 and is attached thereto by any suitable means whereby to clamp the sixth resilient member 72 between the flange 64 and the clamp plate 74. A spring 76 is located between the clamp plate 74 and an inside surface of the cover 73 whereby to apply pressure to the second plunger 56. The aforesaid layered construction of the valve may be rigidly maintained by any suitable means such as bolts 78 passing through the layers and nuts 80 attached to the threaded end of the bolts 78 whereby to clamp the aforesaid layered structure between the heads of the bolts and the nuts 80.

MODE OF OPERATION In operation, the valve shown in the single FIGURE drawing is effective to provide a series of valve operations by the selective application of fluid pressures to the fluid passages 46 and 71'. The effect of applying a fluid pressure to either of the fluid passage 46 and 71 is illustrated in the upper half of the valve shown in the single FIGURE drawing. Thus, the central plunger 30 is raised against the pressure of the spring 50 with a consequent stretching of the third membrane 42 and the fourth membrane 47 while the outer concentric plunger 28 is pushed against the first resilient member 22 to seal the resilient member 22 against the valve block 2 by the peripheral ridge 32. On the other hand,

the position of the valve inner structure when the control fluid pressure is removed from the control fluid passages 46 and 71 is illustrated in the bottom of the valve structure shown in the single FIGURE drawing. Thus, in the bottom half of the illustrated valve structure, the control fluid pressure is not applied to the control fluid passage 71. This lack of fluid pressure .within thecentral space 70 of the intermediate plate 69 allows the spring 76 to push the plunger 56 against the second resilient member 24. The annular ridge 62 of the plunger 56 is, accordingly, effective to seal the port of the fluid passage 18 in the end face 8 of the valve block 2. Concurrently, the pressure of a fluid in the fluid sample storage bore 12 is effective to lift the portion of the second resilient member 24 above the port end of the bore 12 in the end face 8 and establish a fluid path between the bore 12 and the fluid passage having a port adjacent to the bore 12 in the end face 8.

In order to operate the illustrated valve as a sampling valve, a control fluid pressure is initially applied to the control fluid passages 46 and 71 to produce a position of the

plungers

28, 30, 54 and 56 in both halves of the valve to assume the state shown in the upper half of the valve illustrated in the drawing. In this position, the fluid passage 14 is connected by a fluid channel to the storage bore 12 which, in turn, is connected by a fluid passage under the second resilient member 24 to the fluid passage 18. The fluid passages 16 and 20 are sealed by the

resilient member

22 and 24, respectively, in response to a sealing pressure from the

outer plungers

38 and 54, respectively. The source of the sample to be analyzed is connected to the fluid passage 14 while the fluid passage 18 is used as a vent. Accordingly, the fluid sample is flowing through the storage bore 12 during this operational state of the valve. Subsequently, a sample of the fluid to be analyzed is obtained by removing the-fluid pressure from both of the control fluid passages 46 and 71 to allow the

plungers

38, 30, 54 and 56 to assume the position shown in the lower half of the valve structure shown in the drawing. In this operational state of the valve, the inlet sample passage 14 and the vent passage 18 are sealed and isolated by the

resilient member

22 and 24, respectively, while the fluid passages 16 and 20 are connected by fluid passages under the

member

22 and 24, respectively, to respective ends of the bore 12. The fluid passage 16 is connected to a source of a carrier gas while the fluid passage 20 is connected to a chromatographic column. Thus, a carrier gas from the fluid passage 16 is now effective to sweep the fluid sample stored in the storage bore 12 into the fluid passage 20 to be con veyed to the chromatographic column for analysis. The

size of the sample is, of course, determined by the volume of the fluid storage bore 12. Subsequent operation of the valve is a recycling of the aforesaid sequence of operation to store a new sample in the storage bore 12 and, subsequently, to have this sample transferred to the chromatographic column by the carrier fluid supplied to the fluid passage 16.

Accordingly, it may be seen that there has been provided, in accordance with the present invention, an improved valve for handling extremely small fluid quantities and having integral means for sequencing and storing a test fluid supplied to the valve.

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:

1. A valve comprising a valve body having a plurality of fluid passages therein extending between fluid ports in a face and a side of said valve body,

a first resilient member covering said face of said valve body and encompassing the locations of said ports,

a pair of plungers positioned on the other side of said resilient member from said valve body,

a valve block arranged to slidably support said pair of plungers,

a first one of said plungers having an operative end adjacent to said resilient member and encompassing an area including a port of one of said fluid passages in said face and a second one of said plungers having an operative end adjacent to said resilient member and encompassing an area including another one of said ports of said fluid passages in said face,

second resilient means forming a closed volume between the other end of said first plunger and the other end of said second plunger,

means for introducing a control fluid into said closed volume, and

means for exerting a pressure against said first plunger to urge said first plunger against said first resilient member.

2. A valve as set forth in claim 1 wherein said means for forming said closed volume includes a second and a third resilient member having fluid-tight seals with said plungers. v

3. A valve as set forth in claim 1 wherein said first and second plungers are concentric plungers and said area encompassed by said operative end of said second plunger includes said port encompassed by said area of said operative end of said first plunger.

4. A valve as set forth in claim 3 wherein said means for forming said closed volume includes a second and a third resilient member having fluid-tight seals-with an inner one of said concentric plungers.

S. A valve as set forth in claim 4 wherein said means for exerting a pressure includes a cover over said other end of first one of said concentric plungers and a spring means positioned between said cover and said other end of said first one of said concentric plungers.

6. A valve as set forth in claim 4 and including a fluid passage having a port lying outside of the area encompassed by said annular ridge of said second one of said concentric plungers.

7. A valve as set forth in claim 1 wherein said operative end of said first plunger includes an annular ridge encompassing an area including two of said ports of said fluid passages and including said port of said one of said fluid passages.

Claims

1. A valve comprising a valve body having a plurality of fluid passages therein extending between fluid ports in a face and a side of said valve body, a first resilient member covering said face of said valve body and encompassing the locations of said ports, a pair of plungers positioned on the other side of said resilient member from said valve body, a valve block arranged to slidably support said pair of plungers, a first one of said plungers having an operative end adjacent to said resilient member and encompassing an area including a port of one of said fluid passages in said face and a second one of said plungers having an operative end adjacent to said resilient member and encompassing an area including another one of said ports of said fluid passages in said face, second resilient means forming a closed volume between the other end of said first plunger and the other end of said second plunger, means for introducing a control fluid into said closed volume, and means for exerting a pressure against said first plunger to urge said first plunger against said first resilient member.

2. A valve as set forth in claim 1 wherein said means for forming said closed volume includes a second and a third resilient member having fluid-tight seals with said plungers.

4. A valve as set forth in claim 3 wherein said means for forming said closed volume includes a second and a third resilient member having fluid-tight seals with an inner one of said concentric plungers.

5. A valve as set forth in claim 4 wherein said means for exerting a pressure includes a cover over said other end of first one of said concentric plungers and a spring means positioned between said cover and said other end of said first one of said concentric plungers.