Patent US4647285A successfully refreshed from Google Patents.
Patent US4647299A successfully refreshed from Google Patents.
US4647299A
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US
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Process to produce an oxygen-free krypton-xenon concentrate
Assignee: Union Carbide Industrial Gases Technology Corp
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Filing: 1984-08-16
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Granted: 1987-03-03
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Expires: 2004-08-16
Abstract
Abstract A method to concentrate krypton and xenon in a substantially oxygen-free liquid employing a two-section exchange column, the top section of which is refluxed by a substantially rare gas-free liquid.
Inventors
- 👤 Harry Cheung
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-09 01:09
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/04; F25J3/04642; F25J3/04745; F25J2200/00; F25J2200/32; F25J2200/34; F25J2205/00; F25J2205/30; F25J2210/00; F25J2210/42; F25J2230/00; F25J2230/42; F25J2245/00; F25J2245/42; F25J2245/50; Y; Y10; Y10S; Y10S62/00; Y10S62/923; Y10S62/925
Claims Analysis
Total Claims: 19
Claim 1
Independent Claim
257 words
A method for processing a liquid feed comprising krypton, xenon and oxygen to produce krypton and xenon concentrated in a substantially oxygen-free medium whereby substantially all of the krypton and xenon in the feed is concentrated in said medium comprising: (1) introducing a feed liquid comprising oxygen, krypton and xenon into an exchange column at an intermediate point of the column for downward flow through the column; (2) introducing vapor, having a low concentration of oxygen and rare gases, into said exchange column at a point below said intermediate point to form upflowing exchange vapor; (3) introducing substantially rare gas-free liquid into said column at a point above said intermediate point to form downflowing reflux liquid; (4) passing the upflowing vapor against the downflowing liquids to exchange oxygen from the downflowing liquids to the upflowing vapor and non-oxygen medium from the upflowing vapor to the downflowing liquids; (5) passing the oxygen-containing upflowing vapor against downflowing liquid reflux whereby krypton and xenon which may have passed to the upflowing vapor during step (4) are transferred into downflowing liquid; (6) removing from the exchange column the oxygen-containing vapor substantially free of rare gases; (7) passing the downflowing liquids to a reboiling zone to form a reboiling liquid; (8) partially vaporizing the reboiling liquid in the reboiling zone to form a vapor, and a liquid krypton-xenon concentrate having a low concentration of oxygen; (9) passing the vapor formed in step (8) up the exchange column to form part of the upflowing exchange vapor; and (10) recovering substantially oxygen-free krypton-xenon concentrate.
Claim 2
Independent Claim
257 words
A method for processing a liquid feed comprising krypton, xenon and oxygen to produce krypton and xenon concentrated in a substantially oxygen-free medium whereby substantially all of the krypton and xenon in the feed is concentrated in said medium comprising: (1) introducing a feed liquid comprising oxygen, krypton and xenon into an exchange column at an intermediate point of the column for downward flow through the column; (2) introducing vapor, having a low concentration of oxygen and rare gases, into said exchange column at a point below said intermediate point to form upflowing exchange vapor; (3) introducing substantially rare gas-free liquid into said column at a point above said intermediate point to form downflowing reflux liquid; (4) passing the upflowing vapor against the downflowing liquids to exchange oxygen from the downflowing liquids to the upflowing vapor and non-oxygen medium from the upflowing vapor to the downflowing liquids; (5) passing the oxygen-containing upflowing vapor against downflowing liquid reflux whereby krypton and xenon which may have passed to the upflowing vapor during step (4) are transferred into downflowing liquid; (6) removing from the exchange column the oxygen-containing vapor substantially free of rare gases; (7) passing the downflowing liquids to a reboiling zone to form a reboiling liquid; (8) partially vaporizing the reboiling liquid in the reboiling zone to form a vapor, and a liquid krypton-xenon concentrate having a low concentration of oxygen; (9) passing the vapor formed in step (8) up the exchange column to form part of the upflowing exchange vapor; and (10) recovering substantially oxygen-free krypton-xenon concentrate.
Claim 3
Dependent Claim
23 words
The method of claim 1 wherein in step (2) said vapor which has a low concentration of oxygen and rare gases is nitrogen.
Claim 4
Dependent Claim
16 words
The method of claim 2 wherein said nitrogen is taken from a cryogenic air separation plant.
Claim 5
Dependent Claim
24 words
The method of claim 3 wherein the said nitrogen is taken from the lower pressure column of a double column cryogenic air separation plant.
Claim 6
Dependent Claim
16 words
The method of claim 1 wherein in step (3) said substantially rare gas-free liquid is nitrogen.
Claim 7
Dependent Claim
24 words
The method of claim 1 wherein the reboiling liquid is partially vaporized by heat exchange with gaseous nitrogen which condenses to form liquid nitrogen.
Claim 8
Dependent Claim
23 words
The method of claim 6 wherein a portion of the liquid nitrogen is employed as the substantially rare gas-free liquid of step (3).
Claim 9
Dependent Claim
50 words
The method of claim 1 wherein gaseous nitrogen from a cryogenic air separation plant is compressed and cooled, one part is employed as the vapor which has a low concentration of oxygen and rare gases of step (2), and a second part is condensed to partially vaporize the reboiling liquid.
Claim 10
Dependent Claim
25 words
The method of claim 8 wherein a portion of the condensed second part is employed as the substantially rare gas free liquid of step (3).
Claim 11
Dependent Claim
25 words
The method of claim 8 wherein the oxygen-containing vapor removed from the exchange column in step (6) is warmed to cool the compressed gaseous nitrogen.
Claim 12
Dependent Claim
15 words
The method of claim 1 wherein said feed liquid contains at least 100 ppm krypton.
Claim 13
Dependent Claim
15 words
The method of claim 1 wherein said feed liquid contains at least 7 ppm xenon.
Claim 14
Dependent Claim
28 words
The method of claim 1 wherein the concentration of krypton in the liquid krypton-xenon concentrate is at least 20 times the concentration of krypton in the feed liquid.
Claim 15
Dependent Claim
28 words
The method of claim 1 wherein the concentration of xenon in the liquid krypton-xenon concentrate is at least 20 times the concentration of xenon in the feed liquid.
Claim 16
Dependent Claim
23 words
The method of claim 1 wherein said exchange column is operating at a pressure in the range of from 15 to 75 psia.
Claim 17
Dependent Claim
20 words
The method of claim 1 wherein the oxygen concentration in the substantially oxygen-free krypton-xenon concentrate does not exceed 2 percent.
Claim 18
Dependent Claim
27 words
The method of claim 1 wherein the substantially rare gas-free liquid which forms downflowing reflux liquid is introduced into the column at the top of the column.
Claim 19
Dependent Claim
19 words
The method of claim 1 wherein the substantially rare gas-free liquid which forms downflowing reflux liquid is liquid air.
References Cited (Backward Citations)
US3191393A
Cited
US3596471A
Cited
US3609983A
Cited
US3779028A
Cited
US3751934A
Cited
US3768270A
Cited
US4384876A
Cited
US4421536A
Cited
US4401448A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-03-02 | 1990-09-01 | 1991-03-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-03-02 | 1994-09-01 | 1995-03-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-03-02 | 1998-09-01 | 1999-03-03 | $7700.00 | Window Closed / Lapsed |