US3681998A - Sample valve for chromatographic apparatus - Google Patents

Sample valve for chromatographic apparatus Download PDF

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Publication number
US3681998A
US3681998A US3681998DA US3681998A US 3681998 A US3681998 A US 3681998A US 3681998D A US3681998D A US 3681998DA US 3681998 A US3681998 A US 3681998A
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US
United States
Prior art keywords
valve
sample
fluid
ports
column
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Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
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English (en)
Inventor
Edwin L Karas
David S Lee
Robert A Vanslette
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Schneider Electric Systems USA Inc
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Foxboro Co
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    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
    • G01N30/02—Column chromatography
    • G01N30/04—Preparation or injection of sample to be analysed
    • G01N30/16—Injection
    • G01N30/20—Injection using a sampling valve
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
    • G01N30/02—Column chromatography
    • G01N30/04—Preparation or injection of sample to be analysed
    • G01N30/16—Injection
    • G01N30/20—Injection using a sampling valve
    • G01N2030/204—Linearly moving valves, e.g. sliding valves
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/4238—With cleaner, lubrication added to fluid or liquid sealing at valve interface
    • Y10T137/4358—Liquid supplied at valve interface
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
    • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
    • Y10T137/00—Fluid handling
    • Y10T137/4238—With cleaner, lubrication added to fluid or liquid sealing at valve interface
    • Y10T137/4358—Liquid supplied at valve interface
    • Y10T137/4442—External pressure

Definitions

  • 73/42 improvement comprises a sample valve including slidably engaged members formed of a hard, wear-re- [51] [11L C1 ..G0ln 1/10, F16k 25/00 sistam alumina lapped to a i degree of flatness [58] Fleld 0f Search...73/23 R, 23.1, 421 R, 422 CC, These valve members are adapted to be molded using 73,4215 ⁇ 37/146, 2 relatively inexpensive techniques.
  • the valve surfaces also are formed with grooves carrying a flow 3,116,642 1/1964 Weir ..73/422 GC of carrier to aid in isolating the injection ports f 3,040,770 6/1962 Boettcher et a1.
  • the chromatographic technique is capable of determining the concentration of minute amounts of a cornponent in the mixture.
  • the sampling of the mixture must be carried out consistently and accurately.
  • the sample valve employed to inject a sample of the mixture into the column must be essentially leakproof, and must be capable of reliably metering a predetermined amount of sample each time it is actuated.
  • valve which will operate without significant leakage for a substantially greater number of operating cycles than conventional valves.
  • This new valve moreover is relatively inexpensive to make.
  • This new valve incorporates planar sealing surfaces molded of a very hard ceramic material, advantageously comprising alumina which has been found to be unusually well suited for this chromatographic application.
  • FIG. 1 is a block diagram and perspective view of a sample valve in. accordance with the invention as used in connection with a chromatographic instrument;
  • FIG. 2 is a perspective schematic representationv of fluid sampling port interconnections for the valve or
  • FIG. 3 is a plan view of a valve slide employed with the valve ofFIG. l;
  • FIG. 4 is a sectional view of the valve slide taken along line 4-4 in FIG. 3;
  • FIG. Si is a plan view of a valve seat employed with the valve of FIG. 1;
  • FIG. 6 is a sectional view of the valve seat taken along line 6-6 in FIG. 5;
  • FIG. 7 is a section view of the mounted valve slide and seat taken along line 7-7 in FIG. 3;
  • FIG. 8 is a plan view of the manifold employed with the valve of FIG. 1.
  • a chromatographic apparatus 10 utilizing a sample valve 12 of this invention employs a source 14 of carrier gas such as helium.
  • the carrier gas is continuously supplied through the valve 12 to a conduit 34 leading to a chromatographic column sche matically shown at 16.
  • the column 16 typically would consist of a small-diameter tube, wound in compact configuration, but has been shown as an upright element merely for illustrative purposes.
  • a detector 18 such as a thermal-conductivity cell, to provide electrical signals representative of the various components separated by the column.
  • the electrical signals are pased to a utilization device 20 which may include an electronic integrator, memory, display, controller, recorder and alarm, in various combinations as needed for utilization of the chromatographic measurement;
  • the gases which emerge from the" column arevented at an exhaust port schematically indicated at 22.
  • the chromatographic instrument operates by injecting in series with the carrier gas stream flowing to the 1 column 16 a preselected amount of a mixture to be analyzed.
  • a supply of the mixture is illustrated at 24.
  • the mixture gas in the embodiment of FIG. 1 flows continuously through a conduit 26 to the valve and thence through another conduit ZSleading to a sample vent.
  • the valve 12 serves upon actuation to inject a precisely metered quantity of the mixture into the carrier gas stream flowing through conduit 34 to the column.
  • the valve 12 basically comprises two relatively'slidable parts, a valve slide 38 and a valve seat 40.
  • a manifold 42 which interconnects the several conduits with ports located in the valve interaction surfaces between the slide and the seat.
  • the valve seat 40 is secured to the manifold 42 preferably by a sealant adhesive such as epoxy, and the manifold in 7 turn is supported by a suitable housing (not shown).
  • valve slide 38 and valve seat 40 are each formed of the invention will be untion surfaces lapped to a high degree of flatness and polished to a high degree of smoothness.
  • the flatness after lapping is of the order of a quarter wavelength of light, that is, about 1 5 millionths of aninch.
  • the preferred material is a ceramic comprising at least 80 percent alumina, and preferably between 90-95 percent alumina, the remainder being a suitable binder such as a glass silicate material, or the like.
  • the valve slide 38 is reciprocably shiftable along an axis 36 as by means of a suitable driver, such as a solenoid or air cylinder, not shown in the drawing.
  • This valve slide is provided with a spring receiving recess 46 to receive a spring 48 used to urge the slide onto the seat 40.
  • the spring 48 acts at an inclined angle to the upper surface 50 of the slide to maintain the side surface of the slide in contact with an abutting cylindrical tube 52.
  • the tube 52 is supported by the valve housing not shown in the drawing, and is made of the same material as the valve slide and seat.
  • the flatness and smoothness of the interaction surfaces between the valve slide and seat assures a close and tight fit between them, so as to effect a leakproof seal for the multiplicity of ports and passages.
  • the spring 48 aids in this, and also aids in assuring that any particles which pass into the region between the valve slide and seat will be ground or abraded away by the hard ceramic interaction surfaces.
  • the valve body 40 is formed with four pairs of centrally located verticalpassages 62,72; 86,90 and 62,72'; 86,90 communicating between the manifold 42 and the top face of the valve body.
  • the first two pairs of passages 62,72; 86,90 are operative in injecting a sample into the column when the valve slide 38 is shifted in one direction
  • the other two pairs 62,72'; 86',90' are operative in injecting a sample into the column when the slide is shifted in the other direction. That is, the valve is double acting, by injecting a prefixed amount of sample mixture when shifted in either direction.
  • a single acting valve is also contemplated by the invention.-
  • the interaction face of the valve slide 38 is formed with a plurality of spaced transverse grooves 70,80; 70,80'; 88,88 adapted to connect together the pairs of valve body passages 62,72; 86,90, etc., in either position of the valve slide.
  • groove 70 connects passages 62 and 72
  • groove 88 connects passages 86 and 90
  • the end groove 80 does not register with any passage.
  • groove 70 While groove 70 is thus being supplied with a flow of sample mixture, carrier gas simultaneously is-flowing up through valve seat passage 86, across the next adjacent groove 88 in valve slide 38, and down through valve seat passage 90 to theconduits leading to the column 16.
  • carrier gas simultaneously is-flowing up through valve seat passage 86, across the next adjacent groove 88 in valve slide 38, and down through valve seat passage 90 to theconduits leading to the column 16.
  • valve slide By shifting the valve slide to the left (FIG. 2), groove 70 with its precisely metered amount of sample mixture is brought into registration with passages 86 and 90.
  • the continued flow of carrier through these passages entrains the sample slug and forces it through the column for analysis.
  • the carrier gas flowing through groove 88 at injection station 54 comes from a manifold passage 82 connecting valve seat passage 86 to the carrier gas conduit 30 leading to supply 14.
  • the output of injection station 54 is directed to the input of the other injection station 56 by a horizontal manifold channel 94.
  • the injected slug of sample from metering section groove follows the carrier gas path over to injection station 56, up valve seat passage 86, traverses groove 88' (which replaces groove 70) and flows down through passage '90 and an exit passage 94 out through conduit 34 to the column 16.
  • groove 70' is supplied with sample mixture through vertical passages 62' and 72' at sample station 58, venting from outlet passage 62' through manifold passage 78 and sample vent 28.
  • the sample mixture passing up through inlet passage 72 is derived from conduit 26' leading to conduit 26 and thence to mixture supply 24.
  • the sample mixture connected to passage 72' may be a supply separate from supply 24, to provide redundancy assuring operation if one supply fails.
  • valve seat and the valve slide can be made in corresponding dies comprising cavities into which may be placed the ceramic material as a powder, to form the green mold.
  • the bottom surfaces of the die have a topography corresponding to the reverse of the desired shape of the interacting valve surfaces, i.e., predominantly flat sections with raised ridges to make the surface grooves and upstanding core members to make the vertical passages.
  • This green form is fired at a high temperature in a furnace to-produce the hard ceramic parts.
  • the flat interacting surfaces then are lapped to a fine degree of smoothness and flatness.
  • Continued operation of the valve tends to improve the seal between the two interacting surfaces, as a result of the self-lapping action of planar surfaces. No lubricant is required between these surfaces, nor are special wedge shapes needed for effective sealing.
  • the extremely hard alumina ceramic is not scored by dirt, metal chips or other foreign material, as are the surfaces of conventional chromatographic valves. Wear tests have indicated actual improvement in the sealing surfaces with usage at least up to 750,000 valve actuations.
  • valves in accordance with this aspect of the invention will have a life which may be upwards of ten times that of prior art valves.
  • valves in accordance with the present invention advantageously may, if the ports become clogged with foreign substances, be cleaned simply by baking at an elevated temperature, e.g., high enough to oxidize gum, varnish and tars to a powder which may readily be removed.
  • a valve of this design may be quite compact, e.g., having an axial length of about 1 inch and a width of about three-quarters of an inch.
  • the stroke in a typical unit may be about 0.14 inches.
  • resilient bumper stops are provided to cushion the ceramic material from excessive shock at the end of each stroke.
  • the valve advantageously may be provided with what might be termed fluid shields around the sample injection stations 54 and 56.
  • These fluid shields are composed of interconnected gutters through which carrier fluid from source 14 flows continuously to drain so as to intercept any leaking sample fluid and wash it away with the carrier.
  • This carrier may be obtained from a source having a higher pressure than source 14, but in any event after passage through the shield is discarded through vents and not used in the columns.
  • gutters are formed in the interaction surfaces of the valve slide 38 and valve seat 40 which cooperates to form enclosed channels between the adjacent surfaces.
  • These channels provide a closed rectangular shield around each of the two sample injection stations 54 and 56.
  • the shields are operated in series, i.e., carrier first flows through one rectangular shield, then passes through an interconnecting channel 114 in the manifold 42 to the other shield, and from there to carrier vent passage 98 and vent conduit 32.
  • carrier gas at either atmospheric or elevated pressure is first supplied from a flow controlled source (not shown) through shield passage l00102 in the manifold and valve seat respectively to a corner inlet port 104 in the valve seat.
  • the carrier passes from the port 104 through two separate paths-to an opposite corner outlet port 106.
  • One path comprises a first gutter 108 which connects to a comer recess 110, both being formed in the valve seat interaction surface; and a second gutter 112 which is formed transversely in the valve slide 38 and provides a carrier passage between the corner recess 110 and the comer outlet port 106.
  • the second path includes transverse gutter 112' formed in the valve slide to connect to a comer recess 110' formed in the valve seat 40, and a second gutter 108' completing the path from the comer recess 110' to the outlet port 106.
  • the carrier flows down through interconnecting passage 113 and across channel 114 in the manifold to comer inlet port 104 in the rectangular shield around the other injection station 56.
  • the arrangement of this shield is similar to the first shield and thus will not be described in detail.
  • each fluid shield in the slide and the other'part in the valve seat The reason for locating part of each fluid shield in the slide and the other'part in the valve seat is to disconnect the moving gutter passages from each other, thereby to prevent short circuitingthe sample ports directly to the injection ports during movement of the valve slide.
  • the gutters in the valve slide disconnect completely from the valve seat gutters during transit so as to prevent injecting fluid into (or removing fluid from) the injection passages.
  • valve manifold 42 and seat 40 it may be desirable to enhance the sealing between the valve manifold 42 and seat 40 by a similar shielding technique.
  • a fluid shield is formed in surface 43 by etching a gutter around the several ports.
  • the gutter 120 is fed with carrier at channel 122 communicating with passageway 82 and the carrier in the gutter 120 is removed at channel 124 leading to carrier vent conduit 98. 1
  • sample mixture metering section in the disclosed embodiment consists of a groove in the valve slide, it will be apparent that for larger samples it may be desirable to form vertical passages through the valve slide to make connection to relatively large volume metering tubes supported on the slide.
  • fluid shields is not limited to liquid applications, nor to the mixture metering valve only, but may be beneficial to various types of column switching and backflush valves as used in chromatographic instruments.
  • the valve seat and the manifold may be provided with additional passages to furnish a continuous flow of carrier gas through groove 88' in order to assure that no contamination accumulates in that groove.
  • rotary instead of linear valve slide action may be employed with ports and passages and fluid shields correspondingly rotatably aligned. Other changes within the scope of the invention will be obvious.
  • Chromatography apparatus including a sample valve for developing a metered amount of sample to be sent to the chromatographic column for analysis and comprising:
  • valve slide and valve seat slidingly mounted to one another with said valve slide and valve seat being provided with smooth valve interaction surfaces for fluid sealing engagement during relative motion between the valve slide and seat;
  • one of said interaction surfaces being provided with a sample storage passage means and the other interaction surface being provided with sample inlet and outlet ports located to align with the sample storage passage means at a first valve position;
  • the other interaction surface being provided with injection inlet and outlet ports located to align with the sample storage passage means at a second valve position;
  • a fluid protective shield comprising a fluid channel between the interaction surfaces and positioned between the sample ports and the injection ports to serve as a barrier to prevent contamination of the fluid flowing to the column.
  • Apparatus as claimed in claim 1 including means to produce a continuous flow of carrier fluid through said channel.
  • valve seat and valve slide interaction surfaces are formed with interconnected carrier-filled gutters as said protective shield, the one interaction surface containing the sample storage passage means being provided with a pair of protective gutters flanking the sample storage passage means to assure shielding in alternate valve positions.
  • the fluid protective shield further includes a first pair'of parallel gutters formed in the other interaction surface containing the injection ports and flankingly located adjacent thereto, a second pair of parallel gutters formed in the one interaction surface in overlapping relationship with the first pair of gutters to provide fluid flow communication between the gutters around the injection ports.
  • the fluid protective shield further includes a third gutter located in said one interaction surface to effect a fluid protective shield around said injection ports in the injection positions.
  • a double-acting sampling valve for a chromatographic instrument comprising:
  • valve slide and a valve seat slidingly mounted to one another with said seat and valve being provided with smooth valve interaction surfaces for fluid sealed engagement with relative motion between the valve slide and seat along a valve action axis;
  • valve seat being provided with first sample inlet and outlet ports, first injection inlet and outlet ports axially located from the first sample ports,
  • valve slide being provided with a first sample storage cavity sized and located for alternate operative engagement between the first sample and injection ports and further provided with a second sample storagecavity sized and located for alternate operative engagement between the second sample and injection ports;
  • first and second protective fluid shields include gutters formed in the interaction surface of the valve slide and valve seat with selected ones of said gutters being effectively spaced axially and transverse of the valve action axisalongside of first and second injection ports.
  • Chromatography apparatus of the type including a valve for introducing a sample mixture to a column, wherein the valve comprises:
  • first and second valve members mounted together for relative sliding movement into first and second positions and provided with smooth sliding surfaces for fluid sealing engagement;
  • said surface of one of said valve members being formed with a sample passage opening out into the region of sealing engagement between said two surfaces and providing communication to a quantity of sample mixture to be injected into the column for processing;
  • said surface of the other valve member being formed with a column passage opening out into the region of sliding engagement between said two surfaces and providing communication to the chromatographic column;
  • sample passage being non-aligned with said column passage in said first valve position and aligned therewith in said second valve position, whereby to provide for injecting sample mixture into the column when in the second position;
  • a fluid protective shield comprising a fluid channel adapted to carry non-contaminating fluid in the region between said surfaces, said channel being located between said sample passage and said column passage when said valve is in said first position to serve as a barrier to prevent portions of the sample mixture from being drawn from said sample passage over to said column passage and thereby entering the column in said first position;
  • sample passage being aligned with both said inlet and outlet when said valve is in said second position, whereby the sample mixture is forced by the incoming carrier fluid through the outlet port to the column.

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  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
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  • Pathology (AREA)
  • Treatment Of Liquids With Adsorbents In General (AREA)
  • Multiple-Way Valves (AREA)
US3681998D 1969-06-02 1969-06-02 Sample valve for chromatographic apparatus Expired - Lifetime US3681998A (en)

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Application Number Priority Date Filing Date Title
US82957669A 1969-06-02 1969-06-02

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JP (1) JPS4924713B1 (enExample)
GB (1) GB1286341A (enExample)

Cited By (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4351193A (en) * 1979-08-02 1982-09-28 Carlo Erba Strumentazione S.P.A. Sampler for analytical detection systems
WO1993010432A1 (en) * 1991-11-22 1993-05-27 Coulter Corporation Fluid metering, mixing and transfer valve assembly and analyzing system employing same
EP0519425A3 (enExample) * 1991-06-19 1994-03-16 Buehler Edmund Gmbh & Co
US5419208A (en) * 1993-01-29 1995-05-30 Upchurch Scientific, Inc. Multiport selection valve
US6910394B2 (en) * 2001-05-31 2005-06-28 Wayne A. Kriel Chromatograph valve and method of use

Families Citing this family (2)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
FR2652897B1 (fr) * 1989-10-10 1994-01-07 Institut Francais Petrole Dispositif et procede pour transferer un echantillon de fluide entre deux chambres et application notamment a la chromatographie gazeuse.
DE10061029A1 (de) * 2000-12-08 2002-06-13 Sandler Helmut Helsa Werke Ventileinrichtung für einen Balgengaszähler

Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2981092A (en) * 1957-11-25 1961-04-25 Cons Electrodynamics Corp Chromatographic sampling valve
US3040770A (en) * 1959-06-22 1962-06-26 Speedlap Corp Valve
US3070990A (en) * 1960-02-11 1963-01-01 Pittsburgh Plate Glass Co Sampling device and method for analysis of furnace gases
US3116642A (en) * 1961-02-28 1964-01-07 Atlas Chem Ind Fluid sampling device
US3150517A (en) * 1961-06-26 1964-09-29 Beckman Instruments Inc Gas chromatograph integrated valve
US3297053A (en) * 1963-12-30 1967-01-10 Carle Instr Inc Selector valve
US3349800A (en) * 1964-01-15 1967-10-31 Herion Multi-way changeover valve in the form of a flat slide valve with servo drive
US3442285A (en) * 1966-05-18 1969-05-06 American Optical Corp Valving mechanism having continuously flushed liquid seal
US3489011A (en) * 1966-12-02 1970-01-13 Distillers Co Yeast Ltd Sampling valve

Patent Citations (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2981092A (en) * 1957-11-25 1961-04-25 Cons Electrodynamics Corp Chromatographic sampling valve
US3040770A (en) * 1959-06-22 1962-06-26 Speedlap Corp Valve
US3070990A (en) * 1960-02-11 1963-01-01 Pittsburgh Plate Glass Co Sampling device and method for analysis of furnace gases
US3116642A (en) * 1961-02-28 1964-01-07 Atlas Chem Ind Fluid sampling device
US3150517A (en) * 1961-06-26 1964-09-29 Beckman Instruments Inc Gas chromatograph integrated valve
US3297053A (en) * 1963-12-30 1967-01-10 Carle Instr Inc Selector valve
US3349800A (en) * 1964-01-15 1967-10-31 Herion Multi-way changeover valve in the form of a flat slide valve with servo drive
US3442285A (en) * 1966-05-18 1969-05-06 American Optical Corp Valving mechanism having continuously flushed liquid seal
US3489011A (en) * 1966-12-02 1970-01-13 Distillers Co Yeast Ltd Sampling valve

Cited By (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4351193A (en) * 1979-08-02 1982-09-28 Carlo Erba Strumentazione S.P.A. Sampler for analytical detection systems
EP0519425A3 (enExample) * 1991-06-19 1994-03-16 Buehler Edmund Gmbh & Co
WO1993010432A1 (en) * 1991-11-22 1993-05-27 Coulter Corporation Fluid metering, mixing and transfer valve assembly and analyzing system employing same
US5460055A (en) * 1991-11-22 1995-10-24 Coulter Corporation Sampling metering and transfer valve assembly and analyzing system employing same
US5419208A (en) * 1993-01-29 1995-05-30 Upchurch Scientific, Inc. Multiport selection valve
US6910394B2 (en) * 2001-05-31 2005-06-28 Wayne A. Kriel Chromatograph valve and method of use

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Publication number Publication date
GB1286341A (en) 1972-08-23
JPS4924713B1 (enExample) 1974-06-25

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