US4006001A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Production of intermediate purity oxygen by plural distillation
Assignee: Linde GmbH
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Filing: 1975-01-20
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Granted: 1977-02-01
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Expires: 1995-01-20
Abstract
Abstract In a process for the production of oxygen of intermediate purity by a two-stage low-temperature rectification of air in two distinct and spaced apart rectifying columns, wherein an oxygen-rich liquid fraction is withdrawn from the sump of a low-pressure column, conveyed by means of a pump to a condenser located at the head of a high-pressure column, and vaporized at that location in indirect heat exchange with condensing nitrogen The improvement wherein said liquid fraction evaporating in the condenser in the head of the high-pressure column is withdrawn in its entirety as product oxygen, whereby the pressure in the high-pressure column is lowered as compared to a process where some of the product oxygen is recycled to the low pressure column.
Inventors
- 👤 Eugen Schonpflug
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-06 19:28
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/04; F25J3/04763; F25J3/04866; F25J3/04872; F25J3/04878; F25J3/04006; F25J3/04078; F25J3/0409; F25J3/04151; F25J3/04187; F25J3/04193; F25J3/04206; F25J3/04212; F25J3/04406; F25J3/04412; F25J2215/00; F25J2215/50; F25J2235/00; F25J2235/50; F25J2250/00; F25J2250/10
Claims Analysis
Total Claims: 4
Claim 1
Independent Claim
253 words
A low-temperature separation process for the production from air of oxygen of intermediate purity containing about 35 to 95% by volume oxygen, comprising: a. subjecting air to low temperature rectification in a first distillation column operating under superatmospheric pressure to obtain a bottoms fraction enriched in oxygen and first overhead vapor enriched in nitrogen; b. passing said bottoms fraction to a second distillation column operating at a pressure lower than said first column, said second and first columns being spaced apart and distinct from one another, and further distilling said bottoms fraction to obtain a bottoms liquid product of intermediate purity oxygen and a second overhead fraction enriched in nitrogen; c. passing a portion of said first overhead fraction enriched with nitrogen from said first column into the bottom of said second column in indirect heat exchange relationship with said bottom liquid product of intermediate purity oxygen to vaporize a portion of said intermediate purity oxygen to be used as vapor boil-up in said second column and to condense said first overhead fraction enriched in nitrogen; d. pumping a further portion of said bottoms liquid product of intermediate purity oxygen to a condenser located at the head of the first distillation column to completely vaporize said further portion and to condense a further portion of said first overhead fraction enriched in nitrogen; and e. withdrawing the entire resultant vaporized further portion of intermediate purity oxygen from said low temperature separation process, none of said vaporized further portion being recycled to the second column.
Claim 2
Dependent Claim
253 words
A low-temperature separation process for the production from air of oxygen of intermediate purity containing about 35 to 95% by volume oxygen, comprising: a. subjecting air to low temperature rectification in a first distillation column operating under superatmospheric pressure to obtain a bottoms fraction enriched in oxygen and first overhead vapor enriched in nitrogen; b. passing said bottoms fraction to a second distillation column operating at a pressure lower than said first column, said second and first columns being spaced apart and distinct from one another, and further distilling said bottoms fraction to obtain a bottoms liquid product of intermediate purity oxygen and a second overhead fraction enriched in nitrogen; c. passing a portion of said first overhead fraction enriched with nitrogen from said first column into the bottom of said second column in indirect heat exchange relationship with said bottom liquid product of intermediate purity oxygen to vaporize a portion of said intermediate purity oxygen to be used as vapor boil-up in said second column and to condense said first overhead fraction enriched in nitrogen; d. pumping a further portion of said bottoms liquid product of intermediate purity oxygen to a condenser located at the head of the first distillation column to completely vaporize said further portion and to condense a further portion of said first overhead fraction enriched in nitrogen; and e. withdrawing the entire resultant vaporized further portion of intermediate purity oxygen from said low temperature separation process, none of said vaporized further portion being recycled to the second column.
Claim 3
Dependent Claim
66 words
A process according to claim 1, further comprising passing a fraction of resultant condensed further portion of said first overhead fraction enriched in nitrogen from step (d) to the head of the second column, and passing resultant condensed first overhead fraction from step (c) also to the head of the second column, both of said condensed fractions being employed as reflux liquid in said second column.
Claim 4
Dependent Claim
20 words
A process according to claim 2, said oxygen of intermediate purity containing about 55 to 90% by volume of oxygen.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1980-02-01 | 1980-08-02 | 1981-02-01 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1984-02-01 | 1984-08-02 | 1985-02-01 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1988-02-01 | 1988-08-02 | 1989-02-01 | $7700.00 | Window Closed / Lapsed |