Method and apparatus for analyzing gas components and apparatus for collecting sample gases

• US 5,714,676 A
• Filed: 06/06/1995
• Issued: 02/03/1998
• Est. Priority Date: 06/06/1994
• Status: Expired due to Fees

• Current Assignee: NEC Corporation
• Original Assignee: NEC Corporation
• Inventors: Hase, Ushio
• Primary Examiner(s): NOLAND, THOMAS
• Application Number:
  US08/469,877
• Time in Patent Office: 973 Days
• Field of Search: 73/23.41, 73/864.83, 73/864.84
• US Class Current: 73/23.41
• CPC Class Codes: G01N 2030/025 Gas chromatography
• CPC Class Codes: G01N 2030/065 using different phases to separate parts of sample
• CPC Class Codes: G01N 30/06 Preparation
• CPC Class Codes: G01N 30/08 using an enricher
• CPC Class Codes: G01N 30/16 Injection G01N30/24 takes precedence
• CPC Class Codes: G01N 35/1097 characterised by the valves valves in general F16K

Abstract

A gas component analyzing system having a diffusion scrubber and a chromatograph wherein a flow passage switch valve and a sample injection valve are switched to form a non-circulation flow passage for feeding an absorption liquid into the diffusion scrubber so that absorption liquid captures sample gas components until the sample gas components come into an equilibrium state. Then, both the above valves are switched to form a circulation flow passage for feeding the absorption liquid into a concentration column. Then, both the above valves are further switched to form the non-circulation flow passage to elute the sample gas components for subsequent detection thereof by the chromatograph.

Claims

1. An apparatus for collecting gas components comprising:

a diffusion scrubber comprising an inner tube and an outer tube, said inner tube comprising a gas penetrating membrane through which sampling gases only may penetrate, wherein sampling gases flow through inside of said inner tube and an absorption liquid flows through between said inner and other tubes so that said absorption liquid absorbs said sampling gases penetrated through said membrane from the inside of the inner tube;

an absorption liquid feeding pump upstream from said diffusion scrubber for feeding said absorption liquid between said inner and outer tubes of said diffusion scrubber; and

at least a flow passage switch valve downstream from said diffusion scrubber, said flow passage switch valve having at least three flow passages, each of which has a port, one of said ports being coupled to said diffusion scrubber;

an absorption liquid reservoir coupled to one of said ports other than said one port coupled to said diffusion scrubber, said reservoir reserving said absorption liquid for subsequent feeding of said absorption liquid through said flow passage switch valve;

a circulation flow passage for said absorption liquid, said circulation flow passage connecting among said flow passage switch valve, said absorption liquid feeding pump and said diffusion scrubber; and

a non-circulation flow passage for said absorption liquid, said non-circulation flow passage connecting said absorption liquid reservoir through said flow passage switch valve and said absorption liquid feeding pump into said diffusion scrubber;

wherein said flow passage switch valve provides the current flow passage switch between said circulation and non-circulation flow passages.

2. The apparatus as claimed in claim 1, wherein said diffusion scrubber fixes said inner and outer tubes by a set of joint members provided at longitudinally opposite ends of said diffusion scrubber, an inlet port for said absorption liquid being provided at one of said opposite ends and an outlet port for said absorption liquid being provided at another of said opposite ends.

3. The apparatus as claimed in claim 1, further comprising:

a sample injection valve between upstream of said diffusion scrubber and downstream of said absorption liquid feeding pump, said sample injection valve comprising at least six flow passages, each of which has a port; and

a concentration column to said sample injection valve through different ports from said ports used for coupling between said diffusion scrubber and said absorption liquid feeding pump;

wherein said sample injection valve switches between different two flow passages, in one flow passage said concentration column is incorporated into said circulation or non-circulation flow passage, in another flow passage said concentration column is isolated from said circulation or non-circulation flow passage.

4. The apparatus as claimed in claim 1, further providing a gas sampling pump at one end of said diffusion scrubber for feeding sampling gases into said diffusion scrubber.

5. The apparatus as claimed in claim 1, wherein said flow passage switch valve has four flow passages.

6. The apparatus as claimed in claim 1, wherein said flow passage switch valve has three flow passages.

7. The apparatus as claimed in claim 6, further comprising:

a defoamer upstream of said flow passage switch valve for removing any foam from said absorption liquid, said defoamer having at least three ports, a first one being used for import of said absorption liquid, a second one being used for export of said absorption liquid and a third one being used for export of said sampling gases; and

a check valve at said third port for restricting flow ways of said absorption liquid into one way.

8. The apparatus as claimed in claim 7, wherein said absorption liquid reservoir is positioned at a higher level than a level of said defoamer which is positioned at a higher level than one end portion of a pipeline, an opposite end of which is connected to a gas export of said defoamer, so that there is fed from said absorption liquid reservoir into said defoamer a larger amount of said absorption liquid than an amount thereof fed by said absorption liquid pump due to siphon effect.

9. The apparatus as claimed in claim 1, wherein said absorption liquid reservoir has a cap and at least two connective ports, one port being for feeding said absorption liquid in said reserver into said non-circulation flow passage, another one being coupled a pipeline with a control valve for introducing air or an inert gas into said reservoir.

10. An apparatus for analyzing gas components comprising one or more gas collectors and a gas analyzer:

said gas collector comprising;

a diffusion scrubber comprising an inner tube and an outer tube, said inner tube comprising a gas penetrating membrane through which sampling gases only may penetrate, wherein sampling gases flow through inside of said inner tube and an absorption liquid flows through between said inner and outer tubes so that said absorption liquid absorbs said sampling gases penetrated through said membrane from the inside of the inner tube;

an absorption liquid feeding pump upstream from said diffusion scrubber for feeding said absorption liquid between said inner and outer tubes of said diffusion scrubber; and

at least a flow passage switch valve downstream from said diffusion scrubber, said flow passage switch valve having at least three flow passages, each of which has a port, one of said ports being coupled to said diffusion scrubber;

an absorption liquid reservoir coupled to one of said ports other than said one port coupled to said diffusion scrubber, said reservoir reserving said absorption liquid for subsequent feeding of said absorption liquid through said flow passage switch valve;

a circulation flow passage for said absorption liquid, said circulation flow passage connecting among said flow passage switch valve, said absorption liquid feeding pump and said diffusion scrubber; and

a non-circulation flow passage for said absorption liquid, said non-circulation flow passage connecting said absorption liquid reservoir through said flow passage switch valve and said absorption liquid feeding pump into said diffusion scrubber;

a sample injection valve between upstream of said diffusion scrubber and downstream of said absorption liquid feeding pump, said sample injection valve comprising at least six flow passages, each of which has a port; and

a concentration column connected to said sample injection valve through different ports from said ports used for coupling between said diffusion scrubber and said absorption liquid feeding pump;

wherein said flow passage switch valve provides the current flow passage switch between said circulation and non-circulation flow passages; and

said gas analyzer comprising;

an eluate reservoir for reserving an eluate to be used for eluting sampling gas components for subsequent analysis thereof;

an eluate pump between said sample injection valve and said eluate reservoir for feeding said eluate from said eluate reservoir into said sample injection valve, said eluate pump being coupled to a port of said sample injection valve other than the ports coupled to said diffusion scrubber and said concentration column respectively;

a detector for detecting gas components eluted in said elution, said detector being coupled to said sample injection valve through a different port of said valve from said ports respectively coupled to said diffusion scrubber, said concentration column and said elution reservoir so as to form a gas analyzer flow passage connecting said eluate reservoir through said eluate pump and said sample injection valve into said detector;

wherein said sample injection valve switches between two different flow passages, in one flow passage said concentration column is incorporated into an absorption liquid flow passage system, in another flow passage said concentration column is separated from said absorption liquid flow passage system.

11. The apparatus as claimed in claim 10, wherein said detector comprises a liquid chromatograph.

12. The apparatus as claimed in claim 10, wherein said detector comprises an ion chromatograph.

13. The apparatus as claimed in claim 10, wherein said diffusion scrubber fixes said inner and outer tubes by a set of joint members provided at longitudinally opposite ends of said diffusion scrubber, an inlet port for said absorption liquid being provided at one of said opposite ends and an outlet port for said absorption liquid being provided at another of said opposite ends.

14. The apparatus as claimed in claim 10, further comprising:

a sample injection valve between upstream of said diffusion scrubber and downstream of said absorption liquid feeding pump, said sample injection valve comprising at least six flow passages, each of which has a port; and

a concentration column connected to said sample injection valve through different ports from said ports used for coupling between said diffusion scrubber and said absorption liquid feeding pump;

wherein said sample injection valve switches between different two flow passages, in one flow passage said concentration column is incorporated into said circulation or non-circulation flow passage, in another flow passage said concentration column is isolated from said circulation or non-circulation flow passage.

15. The apparatus as claimed in claim 10, further comprising a gas sampling pump at one end of said diffusion scrubber for feeding sampling gases into said diffusion scrubber.

16. The apparatus as claimed in claim 10, wherein said flow passage switch valve has four flow passages.

17. The apparatus as claimed in claim 10, wherein said flow passage switch valve has three flow passages.

18. The apparatus as claimed in claim claim 17, further comprising:

a defoamer upstream of said flow passage switch valve for removing any foam from said absorption liquid, said defoamer having at least three ports, a first one being used for import of said absorption liquid, a second one being used for export of said absorption liquid and third one being used for export of said sampling gases; and

a check valve at said third port for restricting flow ways of said absorption liquid into one way.

19. The apparatus as claimed in claim 18, wherein said absorption liquid reservoir is positioned at a higher level than a level of said defoamer which is positioned at a higher level than one end portion of a pipeline, an opposite end of which is connected to a gas export of said defoamer, so that there is fed from said absorption liquid reservoir into said defoamer a larger amount of said absorption liquid than an amount thereof fed by said absorption liquid pump.

20. The apparatus as claimed in claim 10, wherein said absorption liquid reservoir has a cap and at least two connective ports, one port being for feeding said absorption liquid in said reservoir into said non-circulation flow passage, another one being coupled a pipeline with a control valve for introducing an air or an inert gas into said reservoir.

21. The apparatus as claimed in claim 10, further comprising a central control system coupled to said absorption liquid feeding pump for controlling operations of said absorption liquid feeding pump, said central control system being also coupled to said eluate pump for controlling operations of said eluate pump, said central control system being also coupled to said flow passage switch valve for controlling operations of said flow passage switch valve, said central control system being also coupled to said sample injection valve for controlling operations of said sample injection valve and said central control system being also coupled to said detector for fetching detected data about sampling gas components from said detector and subsequent data processing.

22. The apparatus as claimed in claim 10, wherein there are provided a plurality of said gas collectors and wherein said sample injection valves of said gas collectors are connected in series between said eluate pump and said detector.

23. The apparatus as claimed claim 10, further comprising:

a rinse water injection valve being provided between said eluate pump and said sample injection valve, said rinsing water valve having six flow passages;

a rinse water measuring tube being coupled to said rinse water injection valve through its ports other than ports coupled respectively to said eluate pump and to said sample injection valve, said rinse water measuring tube being capable of measuring an amount of a rinse water by reserving said rinse water therein; and

a rinse water feeder being coupled to said rinse water injection valve through a port other than said ports coupled respectively to said eluate pump, to said sample injection valve and to said rinse water measuring tube, said rinse water feeder feeding said rinse water to said rinse water injection valve;

wherein said rinse water injection valve switches between two different flow passages, one flow passage allowing said rinse water fed from said rinse water feeder to be charged in said rinse water measuring tube, another flow passage allowing said rinse water charged in said rinse water measuring tube to be fed to said sample injection valve.

24. The apparatus as claimed in claim 10, further comprising:

a rinse water injection valve coupled between said eluate pump and said sample injection valve, said rinse water injection valve being coupled between said diffusion scrubber and said sample injection valve, said rinsing water valve having six flow passages;

a rinse water measuring tube coupled to said rinse water injection valve through ports other than ports coupled respectively to said eluate pump and said sample injection valve and said diffusion scrubber, said rinse water measuring tube being capable of measuring an amount of a rinse water by reserving said rinse water therein; and

a rinse water feeder being coupled to said rinse water injection valve through a port other than said ports coupled respectively to said eluate pump, to said sample injection valve and to said rinse water measuring tube, said rinse water feeder feeding said rinse water to said rinse water injection valve;

wherein said rinse water injection valve switches between two different flow passages, one flow passage allowing said rinse water fed from said rinse water feeder to be charged in said rinse water measuring tube, another flow passage allowing said rinse water charged in said rinse water measuring tube to be fed to said sample injection valve.

25. The apparatus as claimed in claim 10, further comprising:

a rinse water injection valve coupled between said sample injection valve and an absorption liquid import of said diffusion scrubber, said rinse water injection valve being also coupled between said flow passage switch valve and an absorption liquid export of said diffusion scrubber, said rinse water injection valve having a discharge port from which said rinse water is discharged;

wherein said rinse water injection valve switches between different two flow passages, one flow passage both connecting said sample injection valve to said discharge port and connecting said absorption liquid import to said absorption liquid export, the other flow passage both connecting said sample injection valve to said absorption liquid import and connecting said absorption liquid export to said flow passage switch valve.