US4615716A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Process for producing ultra high purity oxygen
Assignee: Air Products and Chemicals Inc
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Filing: 1985-08-27
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Granted: 1986-10-07
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Expires: 2005-08-27
Abstract
Abstract A method of oxygen recycle on the bottom section of the low-pressure column of a dual-pressure column, with an increase in the bottom section reboil vapor rate, allows an appreciable increase in the production rate of ultra high purity oxygen and a substantial decrease in power required as compared to conventional processes.
Inventors
- 👤 Thomas E. Cormier
- 👤 Bruce K. Dawson
- 👤 Keith B. Wilson
- 👤 Thomas C. Young
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-27 16:12
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/04; F25J3/04151; F25J3/04187; F25J3/04218; F25J3/04224; F25J3/0423; F25J3/04248; F25J3/04333; F25J3/04406; F25J3/04412; F25J3/04642; F25J3/04648; F25J3/04654; F25J3/04666; F25J3/04672; F25J3/04678; F25J2200/00; F25J2200/90; F25J2250/00; F25J2250/20; F25J2270/00; F25J2270/02; Y; Y10; Y10S; Y10S62/00; Y10S62/912
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
111 words
In a method for the production of ultra high purity oxygen by means of liquefying and fractionally distilling air in a dual-column air separation plant having a high-pressure column and a low-pressure column, the improvement for reducing the net energy requirement comprising the steps of: removing an oxygen-rich vapor stream from a first intermediate level of the low-pressure column, compressing the vapor stream, condensing the compressed vapor stream to liquid in an auxiliary low-pressure column reboiler, flashing the condensed liquid stream to the pressure of the low-pressure column to form a stream of a gas and liquid mixture, returning the flashed stream to a second intermediate level of the low-pressure column.
Claim 2
Dependent Claim
111 words
In a method for the production of ultra high purity oxygen by means of liquefying and fractionally distilling air in a dual-column air separation plant having a high-pressure column and a low-pressure column, the improvement for reducing the net energy requirement comprising the steps of: removing an oxygen-rich vapor stream from a first intermediate level of the low-pressure column, compressing the vapor stream, condensing the compressed vapor stream to liquid in an auxiliary low-pressure column reboiler, flashing the condensed liquid stream to the pressure of the low-pressure column to form a stream of a gas and liquid mixture, returning the flashed stream to a second intermediate level of the low-pressure column.
Claim 3
Dependent Claim
18 words
The method of claim 1 wherein the compressed vapor stream is cooled in a heat exchanger before condensation.
Claim 4
Dependent Claim
22 words
The method of claim 1 wherein the second intermediate level is at the same tray or higher than the first intermediate level.
Claim 5
Dependent Claim
17 words
The method of claim 1 wherein crude argon is produced in addition to ultra high purity oxygen.
Claim 6
Dependent Claim
26 words
The method of claim 1 wherein the oxygen-rich vapor stream is removed at the same location that a feed to an argon sidearm column is withdrawn.
Claim 7
Dependent Claim
27 words
The method of claim 1 wherein the vapor stream is compressed to a pressure such that it will condense when in indirect heat exchange with boiling oxygen.
Claim 8
Dependent Claim
31 words
The method of claim 1 wherein the vapor stream is compressed to about 32 to 46 psia when in indirect heat exchange with boiling oxygen at about 20 to 27 psia.
Claim 9
Dependent Claim
143 words
In a method for the production of ultra high purity oxygen by means of liquefying and fractionally distilling air in a dual-column air separation plant having a high-pressure column and a low-pressure column, the improvement for reducing the net energy requirement comprising the steps of: removing an oxygen-rich vapor stream from a first intermediate level of the low-pressure column, heating the vapor stream to ambient temperature, compressing the heated vapor stream followed by cooling in an after-cooler, cooling the compressed vapor stream by heat exchange against said vapor stream as it leaves the low-pressure column, condensing the cooled vapor stream to liquid in an auxiliary low-pressure column reboiler, flashing the condensed liquid stream to the pressure of the low-pressure column to form a stream of a gas and liquid mixture, returning the flashed stream to a second intermediate level of the low-pressure column.
Claim 10
Dependent Claim
143 words
In a method for the production of ultra high purity oxygen by means of liquefying and fractionally distilling air in a dual-column air separation plant having a high-pressure column and a low-pressure column, the improvement for reducing the net energy requirement comprising the steps of: removing an oxygen-rich vapor stream from a first intermediate level of the low-pressure column, heating the vapor stream to ambient temperature, compressing the heated vapor stream followed by cooling in an after-cooler, cooling the compressed vapor stream by heat exchange against said vapor stream as it leaves the low-pressure column, condensing the cooled vapor stream to liquid in an auxiliary low-pressure column reboiler, flashing the condensed liquid stream to the pressure of the low-pressure column to form a stream of a gas and liquid mixture, returning the flashed stream to a second intermediate level of the low-pressure column.
Claim 11
Dependent Claim
21 words
The method of claim 8 wherein the second intermediate level is the same tray or higher than the first intermediate level.
Claim 12
Dependent Claim
17 words
The method of claim 8 wherein crude argon is produced in addition to ultra high purity oxygen.
Claim 13
Dependent Claim
26 words
The method of claim 10 wherein the oxygen-rich vapor stream is removed at the same location that a feed to an argon sidearm column is withdrawn.
Claim 14
Dependent Claim
27 words
The method of claim 8 wherein the vapor stream is compressed to a pressure such that it will condense when in indirect heat exchange with boiling oxygen.
Claim 15
Dependent Claim
31 words
The method of claim 12 wherein the vapor stream is compressed to about 32 to 46 psia when in indirect heat exchange with boiling oxygen at about 20 to 27 psia.
References Cited (Backward Citations)
US2530602A
Cited
US2502282A
Cited
US2559132A
Cited
US2603956A
Cited
US2817216A
Cited
US3363427A
Cited
US3370435A
Cited
US3813890A
Cited
US3751933A
Cited
US3969481A
Cited
US4137056A
Cited
US4433990A
Cited
US4433989A
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1989-10-06 | 1990-04-07 | 1990-10-07 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1993-10-06 | 1994-04-07 | 1994-10-07 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1997-10-06 | 1998-04-07 | 1998-10-07 | $7700.00 | Window Closed / Lapsed |