Patent US4964901A successfully refreshed from Google Patents.
US4964901A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Low-temperature separation of air using high and low pressure air feedstreams
Assignee: Linde GmbH
•
Filing: 1989-05-19
•
Granted: 1990-10-23
•
Expires: 2009-05-19
Abstract
Abstract In the separation of air by a two-stage rectification column, part of the air feedstream is compressed to only the pressure of the low pressure stage and, after prepurification in a molecular sieve and cooling, is fed directly into the low pressure stage.
Inventors
- 👤 Wilhelm Rhode
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-11-07 09:20
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/04; F25J3/04151; F25J3/04163; F25J3/04169; F25J3/04248; F25J3/04284; F25J3/0429; F25J3/04303; F25J3/04406; F25J3/04412; F25J2205/00; F25J2205/60; F25J2205/62; F25J2215/00; F25J2215/50; F25J2245/00; F25J2245/40; F25J2290/00; F25J2290/12; Y; Y10; Y10S; Y10S62/00; Y10S62/939
Claims Analysis
Total Claims: 35
Claim 1
Independent Claim
75 words
A process for the low temperature separation of air comprising passing a compressed, prepurified, and cooled first air feedstream at least partially into a high pressure stage of a two-stage rectification column and passing a second compressed, prepurified, and cooled air feedstream into a low pressure stage of the rectification column, said first air feedstream having been compressed to a higher pressure than the pressure of said second air feedstream entering said low pressure stage.
Claim 2
Dependent Claim
75 words
A process for the low temperature separation of air comprising passing a compressed, prepurified, and cooled first air feedstream at least partially into a high pressure stage of a two-stage rectification column and passing a second compressed, prepurified, and cooled air feedstream into a low pressure stage of the rectification column, said first air feedstream having been compressed to a higher pressure than the pressure of said second air feedstream entering said low pressure stage.
Claim 3
Dependent Claim
43 words
A process according to claim 1, wherein the first and second air feedstreams are compressed in a first stage together and then divided into the two air feedstreams and wherein the first air feedstream is then further compressed in a second compression stage.
Claim 4
Dependent Claim
29 words
A process according to claim 2, further the comprising branching from the compressed first air feedstream a partial stream and further compressing, cooling, and work expanding said partial stream.
Claim 5
Dependent Claim
29 words
A process according to claim 3, further comprising employing the work recovered during expansion of the partial stream of the first air feedstream for compression of the partial stream.
Claim 6
Dependent Claim
30 words
A process according to claim 4, wherein the further compressed partial stream of the first air feedstream is introduced, after expansion, into the low pressure stage of the rectification column.
Claim 7
Dependent Claim
33 words
A process according to claim 5 wherein at least one of the compressed, prepurified, and cooled air feedstreams is prepurified and cooled after being compressed and before being passed to the rectification column.
Claim 8
Dependent Claim
17 words
A process according to claim 6, wherein the prepurification steps are conducted independently for each air feedstream.
Claim 9
Dependent Claim
30 words
A process according to claim 3, wherein the further compressed partial stream of the first air feedstream is introduced, after expansion, into the low pressure stage of the rectification column.
Claim 10
Dependent Claim
28 words
A process according to claim 1, further comprising branching from the compressed first air feedstream a partial stream and further compressing, cooling, and work expanding said partial stream.
Claim 11
Dependent Claim
29 words
A process according to claim 9, further comprising employing the work recovered during expansion of the partial stream of the first air feedstream for compression of the partial stream.
Claim 12
Dependent Claim
30 words
A process according to claim 10, wherein the further compressed partial stream of the first air feedstream is introduced, after expansion, into the low pressure stage of the rectification column.
Claim 13
Dependent Claim
30 words
A process according to claim 9, wherein the further compressed partial stream of the first air feedstream is introduced, after expansion, into the low pressure stage of the rectification column.
Claim 14
Dependent Claim
35 words
A process according to claim 12, wherein said partial stream of said first air feedstream, after expansion, is combined with said second air feedstream and introduced into said low pressure stage of said rectification column.
Claim 15
Dependent Claim
22 words
A process according to claim 9, wherein about 10-30% of said first air feedstream is branched off to form said partial stream.
Claim 16
Dependent Claim
33 words
A process according to claim 1, wherein at least one of the compressed, prepurified, and cooled air feedstreams is prepurified and cooled after being compressed and before being passed to the rectification column.
Claim 17
Dependent Claim
17 words
A process according to claim 15, wherein the prepurification steps are conducted independently for each air feedstream.
Claim 18
Dependent Claim
17 words
A process according to claim 1, wherein an oxygen product is recovered having a purity of 85-98%.
Claim 19
Dependent Claim
23 words
A process according to claim 1, wherein said first air feedstream is further compressed to substantially the pressure of said high pressure stage.
Claim 20
Dependent Claim
22 words
A process according to claim 1, wherein said second air feedstream is compressed to substantially the pressure of said low pressure stage.
Claim 21
Dependent Claim
29 words
A process according to claim 1, wherein during prepurification of said first air feedstream and said second air feedstream, water vapor, CO 2 , and hydrocarbons are removed therefrom.
Claim 22
Dependent Claim
34 words
A process according to claim 1, wherein a gaseous nitrogen stream removed from said low pressure stage is used to regenerate purification stages for prepurifying said first air feedstream and said second air feedstream.
Claim 23
Dependent Claim
23 words
A process according to claim 1, wherein said first air feedstream is separately prepurified prior to introduction thereof into the high pressure stage.
Claim 24
Dependent Claim
23 words
A process according to claim 1, wherein said second air feedstream is separately prepurified prior to introduction thereof into the low pressure stage.
Claim 25
Dependent Claim
40 words
A process according to claim 1, wherein said first air feedstream is separately prepurified prior to introduction thereof to the high pressure stage and said second air feedstream is separately prepurified prior to introduction thereof into the low pressure stage.
Claim 26
Dependent Claim
20 words
A process according to claim 1, wherein said first and second air feedstreams are both prepurified by molecular sieve apparatus.
Claim 27
Independent Claim
87 words
An apparatus comprising a rectification column having a high pressure stage and a low pressure stage, means for compressing an air feedstream to the pressure of the low pressure stage, means for separating said feedstream into a first air feedstream and a second air feedstream, separate means for compressing only said first air feedstream to the pressure of the high pressure stage, means for communicating said second air feedstream to the low pressure stage and means for communicating said first air feedstream to the high pressure stage.
Claim 28
Independent Claim
87 words
An apparatus comprising a rectification column having a high pressure stage and a low pressure stage, means for compressing an air feedstream to the pressure of the low pressure stage, means for separating said feedstream into a first air feedstream and a second air feedstream, separate means for compressing only said first air feedstream to the pressure of the high pressure stage, means for communicating said second air feedstream to the low pressure stage and means for communicating said first air feedstream to the high pressure stage.
Claim 29
Dependent Claim
31 words
An apparatus according to claim 26, further comprising a prepurification means for separately prepurifying only said first airstream prior to introduction of said first air feedstream into the high pressure stage.
Claim 30
Dependent Claim
32 words
An apparatus according to claim 26, further comprising a prepurification means for separately prepurifying only said second air feedstream prior to introduction of said second air feedstream into the low pressure stage.
Claim 31
Dependent Claim
51 words
An apparatus according to claim 26, further comprising a first prepurification means for separately prepurifying only said first air feedstream prior to introduction thereof into the high pressure stage and a second prepurification means for separately prepurifying only said second air feedstream prior to introduction thereof into the low pressure stage.
Claim 32
Dependent Claim
21 words
An apparatus according to claim 29, wherein said first prepurification means and said second prepurification means are both molecular sieve apparatus.
Claim 33
Dependent Claim
32 words
An apparatus according to claim 26, further comprising branching means for branching off a partial stream from said first air feedstream downstream from said separate means for compressing said first air feedstream.
Claim 34
Dependent Claim
72 words
An apparatus according to claim 31, further comprising a compressor means for further compressing said partial stream of said first air feedstream, cooling means for cooling the further compressed partial stream of said first air feedstream, expansion means for expanding the further compressed, cooled partial stream, and means for communicating said expansion means with said low pressure stage so as to deliver the resultant expanded partial stream to said low pressure stage.
Claim 35
Dependent Claim
16 words
An apparatus according to claim 32, wherein said compression means and expansion means are mechanically coupled.
References Cited (Backward Citations)
US2666303A
Cited
US2873583A
Cited
US2846853A
Cited
US2915882A
Cited
US3280574A
Cited
US3699695A
Cited
US3500651A
Cited
US3760596A
Cited
GB2180923A
Cited
US4731102A
Cited
US4704147A
Cited
DE3643359A1
Cited
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1993-10-22 | 1994-04-23 | 1994-10-23 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1997-10-22 | 1998-04-23 | 1998-10-23 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 2001-10-22 | 2002-04-23 | 2002-10-23 | $7700.00 | Window Closed / Lapsed |