APPARATUS FOR INTRODUCING A METERED AMOUNT OF SAMPLE LIQUID INTO A CONTINUOUS STREAM OF A CARRIER LIQUID

• US 3,762,609 A
• Filed: 06/12/1972
• Issued: 10/02/1973
• Est. Priority Date: 06/18/1971
• Status: Expired due to Term

• Current Assignee: Alexander Hagen, Dirk Mewes, Gruber Wolfgang, Hans Ulrich Bergmeyer
• Original Assignee: Alexander Hagen, Dirk Mewes, Gruber Wolfgang, Hans Ulrich Bergmeyer
• Inventors: Gruber, Wolfgang, Bergmeyer, Hans Ulrich, Hagen, Alexander, Mewes, Dirk
• Primary Examiner(s): Tollberg, Stanley H.
• Application Number:
  US05/261,701
• Time in Patent Office: 477 Days
• Field of Search: 222/152,194,370 141/7 73/422TC,422R
• US Class Current: 222/636
• CPC Class Codes: G01N 35/1097 characterised by the valves valves in general F16K
• CPC Class Codes: G05D 11/001 with discontinuous action
• CPC Class Codes: G05D 11/003 using interconnected flow control elements

Abstract

A sample to be analyzed is injected into a stream of carrier liquid by coupled dual valves in two branches of the stream. One of the two valves is open and the other closed at any one time. The bore of the closed valve provides a metering cavity which is filled with the sample to be analyzed, and the sample is injected by simultaneously closing the previously open valve and opening the sample-bearing closed valve. The specific, dual valve arrangement disclosed has a single movable disc arranged between two stationary discs, the discs being provided with passages filled and emptied in the necessary sequence when the movable disc is rotated.

Claims

1. Apparatus for introducing a predetermined amount of a first liquid into a continuous strEam of a second liquid comprising, in combination:

a. a source of said second liquid;

b. a first conduit communicating with said source for receiving said second liquid;

c. two branch conduits of equal flow section simultaneously connected to said source by said first conduit;

d. a valve in each of said branch conduits, each valve having a valve member formed with a bore and movable between an operative position in which said second liquid may flow through said bore and the associated branch conduit, and an inoperative position in which said bore is out of communication with at least a portion of said associated branch conduit and the latter is blocked;

e. operating means for shifting each of said valve members from the operative to the inoperative position while simultaneously shifting the other valve member from the inoperative to the operative position;

f. feeding means for substantially completely filling the bore of one of said valve members with said first liquid while said one valve member is in the inoperative position thereof; and

g. a second conduit simultaneously connected to said branch conduits for receiving liquid therefrom in the operative positions of the respective valves.

2. Apparatus as set forth in claim 7, wherein said operating means includes means for shifting said valve members at a speed sufficient to substantially maintain in said second conduit a continuous stream of liquid at a uniform flow rate.

3. Apparatus as set forth in claim 1, further comprising a source of vacuum, and connecting means for connecting the bore of said one valve with said source of vacuum while said one valve is in the inoperative position and prior to the filling of said bore by said feeding means.

4. Apparatus as set forth in claim 3, further comprising coupling means coupling said operating means, said feeding means, and said connecting means for operation in timed sequence.

5. Apparatus as set forth in claim 1, wherein three sealingly engaged members of solid material constitute at least portions of said branch conduits, of said valves, of said operating means, and of said feeding means, a first one and a third one of said members therebetween movably receiving the second member, said first and third members being formed with passages constituting respective portions of said two branch conduits, respective valve parts of said second member being formed with said bores and yet another part of said second member connecting said valve parts and constituting a portion of said operating means.

6. Apparatus as set forth in claim 5, wherein said operating means further include means for rotating said second member about an axis relative to said first and second members.

7. Apparatus as set forth in claim 6, wherein said second member has two axially spaced radially extending faces, and said first and third members have respective radially extending faces contiguously adjacent said two faces in an axial direction and forming therewith two pairs of contiguous faces, one face of each pair being formed with a groove, extending about said axis in a circular arc of sufficient length to connect respective passages in said first and third members and one bore in said second member during all but a small fraction of each revolution of said second member during said rotating thereof, said respective passages constituting portions of one of said branch circuits, and the portion of said second member formed with said one bore constituting the valve member in the valve of said one branch circuit.

8. Apparatus as set forth in claim 7, wherein said first member is formed with a feed conduit communicating with one of said bores in said inoperative position of the associated valve part, and feed conduit constituting a part of said feeding means, said feeding means further including means for evacuating said one bore prior to said filling of said one bore with said first liquid.

9. Apparatus as set forth in claim 8, wherein said evacuating means include a chamber formed in said third member, and cooperating valve means on said second and third members responsive to movement of said second member relative to said first and third members for first sealing said chamber from said one bore while simultaneously connecting said chamber to a vacuum line, and for thereafter sealing said chamber from said line while simultaneously connecting the chamber to said one bore.

10. Apparatus as set forth in claim 9, further comprising purging means responsive to movement of said second member relative to said first and third members for purging said one bore and said feed conduit of liquid.