US3545479A - Flow diverting device for gas chromatographs - Google Patents

Description

United States Patent 72] Inventor Winston C. Loe

Mountain View, California [2]] Appl. No. 839,279 [22] Filed July 7, 1969 Division of Ser. No. 645,435, June I2, 1967, Pat. No. 3,473,557. [45] Patented Dec. 8, 1970 [73] Assignee Loeuco Inc.

Altadena, California a corporation of California [54] FLOW DIVERTING DEVICE FOR GAS CI-IROMATOGRAPHS 2 Claims, 8 Drawing Figs.

[52] US. Cl 137/360, l37/625.68 [51] Int. Cl. ..Fl6k 11/07, Fl 6| 5/00 [50] Field of Search 137162525. 625.26, 625.68, 625.48, 625.49; 25 l/347, 353, 325

[56] References Cited UNITED STATES PATENTS 2,5 I 5,085 7/l950 Hawk et al l37/625.49X

14 v v v v v MIAMI/11% 2,574,556 11/1951 Good l37/625.68 2,906,492 9/1959 Conrad 251/325 FOREIGN PATENTS 497,295 9/1954 Italy 25 l/325 Primary Examiner-Henry T. Klinksiek Attorney-Robert C. Comstock ABSTRACT: An in-line flow diverting device for diverting a stream through a panel or other bulkhead of a gas chromatograph or similar instrument for flow measurement or other purposes. The device includes an inlet connection, an outlet connection, and a divert connection which is accessible from the front of the panel.

A valve stem is slidably mounted for reciprocal movement within an opening in a valve body. The valve stem has an opening which is adapted to connect the inlet connection to the divert connection when the valve stem is in its inward position. In this position, the inner end of the valve stem seals off the outlet connection.

When the valve stem is in its outward position, the inner end of the valve stem is withdrawn so that: the inlet connection is connected to the outlet connection, while the divert connection is sealed off. The device can be operated manually or automatically.

PATENTEU DEC 8 I970 479 SHEET 2 OF 2 L A B 7 F 1 0 FLOW M 7'0 00WA/5TREAM 5 Y5 7' EM 5 T EM OUTLET T0 FLOW MEASUR/A/G DE V/C E T0 DOWNSTREAM 5 Y5 TE M 5TEM OUTLET AT REGULATE PRESSURE REfiTR/CT/VE 7'0 FLOW DEA/ICE MEASURING DE VICE NORMAL PA Th STEM CONNECT/0N I 70 ALTER/VA TE BEST/NA T/OA/ T A amwsmaw PA 7 INVEAITOQ Wwsmw C. LOE

ATTORNEY l 1 FLOW DIVERTING DEVICE ron GAS CHROMATOGRAPHS REFERENCE TO RELATED APPLICATION BACKGROUND OF THE INVENTION 1. Fieldof the Invention In gas chromatographs or other instruments, it is frequently desirable to divert a flowing stream from one path to another,

particularly for the purpose of making measurements to determine the rate of flow-of the stream. It is particularly desirable tohave a flow divert connection which is easily accessible, preferably from the frontof the instrument panel. It is also desirable to have a divert device which permits thestream to be diverted as frequently as desired without breaking any piping connections.

2. Description of the Prior Art The prior art known to the applicant consists of three-way valves, which'are more expensive and bulky and which lack the simplicity and other desirable "characteristics of the present device. If ,athree-way valve is not used, the prior art 'panel ofthe instrument. I

SUMMARY QF THE INVENTION The invention comprises an in-line flow diverting device for gas chromatographs and other instruments. The device is adapted to be mounted in a single hole in the front panel or other bulkhead of the instrument. 'It occupies a limited amount of panel area and the functional position of the device is readily apparent to the user without resorting to position indexing devices.

The device permits the stream to be diverted through the front panel whenever and as frequently as desired without requiring the breaking of any piping connections. It eliminates the need for a rotometer. I

The device includes a twoposition divert valve which is accessible and operable from the front panel of theinstrument to divert the stream as frequently as desired to flow through a divert outlet connection extending throughithe front of the instrument panel, for the purpose of making flow measurements or for other purposes, as set forth more fully hereinafter in this application. I l

In an instrument-having a flame ionization detector, the ordinary way of making a" bubblerneter measurement is to disconnect the exist end of the column and attach the bubblemeter. The end of the column is generally hot and this is a time consuming operation which is eliminated by use of the present invention.

The present invention also avoids opening the upstream end of the column to the atmosphere, which is undesirable.

It is accordingly among the objects of the invention to provide a flow diverting device for gas chromatographs and other instruments which is simpler and more economical and efficient in manufacture and in use, and which has all of the advantages and benefits setforth above and described in detail hereafter. I

My: invention also comprises such other objects, advantages and capabilities as will later more fully appear and which are inherently possessed by my invention.

While I have shown in the accompanying drawings preferred embodiments of my invention, it should be understood that the same are susceptible of modification and change without departing from the spirit of my invention.

. 2 DESCRIPTION or THE DRAWINGS I FIG. 1 is a side elevationalview of a first embodiment of the invention, with the operating portions shown in section and with the valve in divert position;

FIG. 2 is a partial view similar to FIG. 2, showing the same embodiment in normal position; I

FIG. 3 isa view similar .to FIG. 1 of an alternative embodiment of the invention, in;which O-rings are used in place of the invention can be used. 7

DESCRIPTION or THE PREFERRED EMBODIMENTS A first embodiment which has been selected to illustrate the invention is shown in FIGS. 12 of the drawings. It is adapted to be mounted in an opening 10, formed in a panel 11 or other bulkhead of a gas chromatograph or other instrument.

The device includes an elongated "valve body 12 having a portion 13 which extends through the opening 10. Adjacent to one end of the portion l3is a shoulder 14 which abuts against the inside of the panel 11. A nut l5'is screw threadedly mounted on the valve body 12 and abuts against the outside of the panel 11. v

Mounted within a cylindrical recess 40 which extends into the inner end of the valve body 12. are a pair of cylindrical sealing members 16 and 17, which are preferably formed of silicon rubber, or other suitable elastomeric material. Mounted between the sealing members .16 and 17, is a nonresilient spacer 18, which has .an opening 20 extending through its longitudinal axisfwhich opening is aligned with similar axial openings 21 and 22 which extend through the sealing members 16 and 17, Aligned with these openings is an axial opening 23 which extends through the outer end of the valve body 12.

The spacer 18 has a circumferential groove 19 extending around its midportion. The groove 19 is connected to the opening 20 by one or more radial openings 42.

An end member 24 isscrew thr eadedly mounted on the inner end of the valve body 12. An aligned axial opening 25 extends through the end member 24 and connects with an outlet connection 26. I p

A cap fitting 27 is screwthreadedly mounted on the outer end of the valve body 12; The capfitting 27 has an axial cylindrical chamber 28 formed therein, the inner end of the chamber 28 being closed off by the outer end of the valve body 12, except for the opening 23.

A stop member 29 is disposedwitlhin the chamber 28 and is mounted on an elongated sleeve 30 which extends outwardly through the outer end of the cap fitting 27 along its longitudinal axis. A circular knob 31 is held on the sleeve 30 inwardly from the outer end thereof by. a set screw 32.

A tube 33 extends inwardly from the stop member 29 through the aligned axial openings 23, 22 and 20. The diameter of the axial opening 20 in the spacer 18 is greater than the outside diameter of the tube 33, so that an annular space exists around the tube 33, through which space fluid can flow. The tube 33 has a closed inner end which extends into the outer portion of the opening 21 in the inner sealing member 16 when the stop member 29 is disposed in its inward position (abutting against the outer end of the valve body 12).

A fluid passage 34 extends continuously through the tube 33, stop member 29 and sleeve-30. The inner end of the tube 33 is solid, closing off the innerend of the passage 34, but the outer end of the sleeve 30 is open and forms a divert outlet connection 35.

The tube 33 is provided adjacent its inner end with a radial opening 36, which is disposed within the axial opening 20 in the spacer 18 when the tube 33 and stop member 29 are in inward position.

connected to an inlet connection 39.

The sealing member 16 engages and is compressed from its ends by the end member 24 and the spacer 18, so that its outer periphery forms a sealing engagement with the inner periphery of the recess 40. Thesealing member 17 likewise engages and is compressed from its ends by the spacer l8 and the end of the recess40, so that its outer periphery forms a sealing engagement with the inner periphery of the recess 40.

The diameter of the tube 33'is somewhat greater than the diameter of the axial openings Hand 22 and the sealing members l6 and 17. The sealing members 16 and 17 accordingly make a sliding sealing engagement with the outer periphery of thetube'3 3. It will be noted that the device includes an inlet connection 39, an outlet connection 26' and a divert outlet connection 35. The flow of fluid (which maybe gas or liquid) through the device is controlled by manual or automatic reciprocal movement of the valve control member-which comprises the sleeve 30, stop member 29 and tube 33. If manual control is used, it is accomplished through the use of the knob 31.

- When the stop'mer'nber 29 and related parts of the valve control member are disposed in their inward positions, as

shown in FIG. 1 of the drawings, the inner end of the tube 33 enters into and closes off the outer-end of the opening 21,

' preventing any flow of fluid to the outlet connection 26. v The radial opening 37 which is connected to the inlet connection39 is aligned with'the groove '19, so that fluid flows through the openings 42 to the opening 36 in the tube 33. Fluid is thus free to flow between the inlet connection 39 and the divert outlet connection 35.

accordingly free to flow only between the inlet connection 39 t and the outlet connection 26.

Several ways in which this divert valve may be used are illustrated in block diagrams comprising FIGS. -8 of the drawings. The divert'valve is particularly useful for gas chrorriatographs having hydrogen flame ionization detectors because the valve permits simple and rapid bubblemeter flow measurements whenever required 'without breaking any piping connections.

It is a very simple matter to divert the stream momentarily through the front of thepanel llto a bubblemeter or other flow measuring device. The device also eliminates the need for a roto'meter, which is less accurate and less reliable because the balls sometimes stick and cause small'pressure surges and signal noise responses.

In a system where there are appreciable variations in downstream pressure, the divert valve is preferably used in connection with a flow controller, as shown in FIG. 5 of the drawings;

In a system where there is negligible flow resistance downstream from a flow restricting device and the operating pressure is constant, "so as to maintain a constant pressure differential across the flow resistance device, the divert valve can be used withouta flow' conti'oller, as shown in FIG. 6 of the drawings.

In addition to its use for making flow measurements, the dive'rt valve is capable of other uses as well. As shown in FIG.

'7 of the drawings, it can also be lise'd to divert the flow of the stream fr'om its normal destination to an alternative destination-through the divert outletconnection.

As shown in FIG. 8 of the drawings, the divert valve can also be used as an inlet connection to substitute a front bulkhead fluid source for the normal fluidsource;

FIG. 3 of the drawings shows an alternative embodiment of the invention which is identical in its purpose and operation and which differs from the embodiment described above only in the fact that O-ring sealing assemblies are substituted for the sealing members 16 and 17.

Instead of the sealing members 16 and 17, a pair of alternative identically formed sealing members are provided. Such sealing members comprise a body 50 and 51 having a pair of inwardly directed recesses at the opposite ends thereof in which are mounted O- rings 52 and 55, which form seals against the endsof the recess, and .O- rings 53 and 54, which form seals around the outside of the tube. Annular grooves 56 and 57 extend around the midportions of the bodies 50 and 5l. O-ringsj58 and 59 which are mounted in the grooves 56 and 57 form seals against the adjacent inner periphery of the recess in the valve body in which they are mounted. J

FIG. 4 .of the drawings shows a second alternative embodiment of the invention in which the inner end of the end member is provided with an annular groove in which an 0 ring is mounted. The O-ring 71 forms .a sealing engagement with the inner end of the valve body.

The device is provided with an elongated valve stem 72 which is mounted for reciprocal movement within a cylindrical opening 73 in the valve body. The valve stem 72 has an axial opening 74, the inner end of which is connected to a radialopening 81 which is adapted to form a connectionwith the radial. inlet opening 87 which extends through the valve body.

' The outer, periphery of the valve stem 72 is provided with a pair of annular grooves 75 and 76 in which are mounted O.- ringsor quadrings 77 and 78, which form sealingengagement with the inner periphery of the cylindrical opening 73.

The valve stem 72 has an annular groove 79 which is aligned with the radial opening 87 throughthe valve body when the valve stem 72 is in its inward position. The rings 77 and 78 form seals on opposite sides of the. groove 79. In its inward position, flat inner end face 82 of the valve stem 72 abuts against the inner end wall 83 of the cylindrical opening 73 to limit the inward movement of the valve stem 72 and simultaneously to dispose said valvestem in inward flow diverting position. In its outward position, an annular radial shoulder formed on the'valve stem 72 abuts against the inner end of the cap fitting 85 at the outer end of the device, to limit the outward movement of the valve stem 72 and simultaneously to dispose said valve stem in its alternative outward position.

The inner end of the valve stem 72 has a frustoconical end portion 86 which tapers outwardly from the inner end face 82. When the valve stem 72 is in its outward flow diverting position, the frustoconical end portion 86 is disposed adjacent to the radial inlet opening 87 so that the opening 87 is not closed off by the valve stem 72.

It will be noted that the circumferential groove -.and openings in the nonresilientspacer provide positive passages for the flow of fluid from the inlet connection to the opening in the tube which leads to the 'divert connection, or alternatively to the opening through the inner sealing member which leads to the outlet connection. The groove 79 in FIG..4 per forms the same function.

Iclaim: J l

l. A flow diverting device for an instrument having a panel or bulkhead, said device including a valve body, an inlet connection and an outlet connection connected to said valve body, a flow divert connection extendingthrough said panel and available from the opposite side thereof from said inlet and outlet connections, aflow control member operable from the outside of said panel, said flow control member being mounted for sliding reciprocal axial movementwithin said valve body between two positions, in the, first of which said inlet connection is connected to said outlet connection through said valve body, while said divert connection is sealed off, and in the second of which said inlet connection isconnected to said divert connection through said valve body, while said outlet connection is seale d ofi, said valve body having a recess, said flow control member comprising a valve stem having its inner end disposed within said recess, the outer end of the portion of said valve stem which is disposed within said recess having an annular radial shoulder adapted to abut the outer end of said recess to limit the outward movement of said valve stem and flow control member and simultaneously to dispose said flow control member is said first position, an inner and an outer sealing member carried by the portion of said valve stem disposed within said recess, the inner end of said valve stem having a pair of annular grooves disposed on opposite sides of said radial opening, an O-ring mounted in each of said grooves, said O-rings comprising said inner and outer sealing members, said outlet connection being connected to the inner end of said recess, said inlet connection being connected to said recess outwardly from said outlet connection, said sealing member frictionally contacting the walls of said recess to form sealing engagement therewith and simultaneously to hold saidflow control member in said first and second positions, said valve stem having a closed inner end, said inner end of said valve stem having a flat end face adapted to abut the inner end of said recess to limit the inward movement of said valve stem and flow control member and simultaneously to dispose said flowcontrol member in said second position, said valve stem having a radial opening connectedto said axial opening, said radial opening being spaced inwardly from said closed inner end of said valve stem and being disposed between said inner and outer sealing members, said radial opening adapted to be connected with said inlet connection when said valve stem is disposed in said second position, while the closed inner end of said valve stem closes off said outlet connection, the closed inner end of said valve stem being withdrawn in said first position to open said outlet connection, while said outer sealing member seals off the radial opening in said valve stem from said inlet connection to close said divert connection.

2. The structure described in claim ll, said valve stem having an annular groove extending around the portion of its periphery through which said radial opening extends, said groove providing a positive passage for the flow of fluid between said inlet connection and said divert connection, the inner end of said valve stem having a frustoconical end tapering outwardly from said flat end face, said frustoconical end being disposed adjacent to said inlet connection when said valve stem is in said second position, so that said valve stem does not close off said inlet connection.

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