EP0029656A1
Expired / Lapsed
EP
⏱️ 0.0 years remaining
Method and cryogenic plant for producing gaseous oxygen
Assignee: Air Products and Chemicals Inc
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Filing: 1980-10-22
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Granted: —
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Expires: 2000-10-22
Abstract
Abstract A method of producing gaseous oxygen comprises the steps of fractionating dry compressed air in a distillation system (9) having a high pressure column (8) operating at between 4 and 8 bars gauge and a low pressure column (15) operating at between 0.3 and 2 bars gauge. Liquid oxygen is withdrawn from the bottom of the low pressure column (8) through line (40) is pressurized by static head and/or a pump (41) and is evaporated in vessel (43) against a stream (27) of substantially pure nitrogen which has been removed from the top of the high pressure column (8) and compressed to such a pressure that it is at least partly liquified by the evaporation of the oxygen. At least part of the liquified nitrogen formed in vessel (43) is expanded and is returned to the high pressure column (8) as reflux.
Inventors
- 👤 Alan Theobald
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-11-07 16:06
CPC Classifications
F; F25; F25J; F25J3/00; F25J3/02; F25J3/04; F25J3/04006; F25J3/04078; F25J3/04103; F25J3/0409; F25J3/04151; F25J3/04157; F25J3/04187; F25J3/04193; F25J3/04206; F25J3/04212; F25J3/04218; F25J3/04224; F25J3/04248; F25J3/04284; F25J3/04309; F25J3/04333; F25J3/04351; F25J3/04406; F25J3/04412; F25J2205/00; F25J2205/02; F25J2205/24; F25J2205/30; F25J2205/32; F25J2205/34; F25J2250/00; F25J2250/30; F25J2250/42; F25J2250/50
Claims Analysis
Total Claims: 8
Claim 1
Independent Claim
120 words
A method of producing gaseous oxygen which method comprises the steps of fractionating dry compressed air in a distillation system having a high pressure column operating at between 4 and 8 bars gauge and a low pressure column operating at between 0.3 and 2 bars gauge, and wherein liquid oxygen is withdrawn from the bottom of said low pressure column, is pressurized and is evaporated against a stream of substantially pure nitrogen which has been removed from the top of said high pressure column warmed in a heat exchanger, compressed, cooled in said heat exchanger, at least partly liquified by the evaporation of said oxygen, and, at least in part, expanded and returned to said high pressure column as reflux.
Claim 2
Independent Claim
120 words
A method of producing gaseous oxygen which method comprises the steps of fractionating dry compressed air in a distillation system having a high pressure column operating at between 4 and 8 bars gauge and a low pressure column operating at between 0.3 and 2 bars gauge, and wherein liquid oxygen is withdrawn from the bottom of said low pressure column, is pressurized and is evaporated against a stream of substantially pure nitrogen which has been removed from the top of said high pressure column warmed in a heat exchanger, compressed, cooled in said heat exchanger, at least partly liquified by the evaporation of said oxygen, and, at least in part, expanded and returned to said high pressure column as reflux.
Claim 3
Dependent Claim
18 words
A method as claimed in Claim 1, wherein the pressure of said oxygen is raised by a pump.
Claim 4
Dependent Claim
26 words
A method according to Claim 1 or 2, wherein said low pressure column is raised so that its bottom is at least 15m above ground level.
Claim 5
Dependent Claim
23 words
A method according to Claim 1, 2 or 3, wherein -said high pressure column is operated at between 4.5 and 7 bars gauge.
Claim 6
Independent Claim
21 words
A method according to any preceding Claim, wherein said low pressure column is operated at between 0.5 and 2.0 bars gauge.
Claim 7
Dependent Claim
205 words
A cryogenic plant for producing gaseous oxygen which plant comprises a high pressure column (8) and a low pressure column (15) for distilling air, an evaporator (43), a pipe (40) for conveying, in use, liquid oxygen from the bottom of said low pressure column (15) to said evaporator (43), means (41) to ensure that, in use, the pressure of liquid oxygen at said evaporator (43) is higher than the pressure of liquid oxygen leaving.said low pressure column (15), a pipe (44) for carrying gaseous oxygen from said evaporator (43), a heat exchanger (6), a pipe (33) for conveying gaseous nitrogen from said high pressure column (8) to said heat exchanger (33), a compressor (34), a pipe for conveying gaseous nitrogen from said heat exchanger to said compressor, a pipe for conveying compressed gaseous nitrogen to said heat exchanger (34), a pipe (36) for conveying compressed gaseous nitrogen from said heat exchanger (33) to a heat exchanger (38) within said evaporator (43), an expansion valve (49), a pipe for conveying liquid nitrogen from said heat exchanger (38) within said evaporator (43) to said expansion valve (49), and a pipe for carrying expanded liquid nitrogen from said expansion valve to the top of said high pressure column.
Claim 8
Dependent Claim
205 words
A cryogenic plant for producing gaseous oxygen which plant comprises a high pressure column (8) and a low pressure column (15) for distilling air, an evaporator (43), a pipe (40) for conveying, in use, liquid oxygen from the bottom of said low pressure column (15) to said evaporator (43), means (41) to ensure that, in use, the pressure of liquid oxygen at said evaporator (43) is higher than the pressure of liquid oxygen leaving.said low pressure column (15), a pipe (44) for carrying gaseous oxygen from said evaporator (43), a heat exchanger (6), a pipe (33) for conveying gaseous nitrogen from said high pressure column (8) to said heat exchanger (33), a compressor (34), a pipe for conveying gaseous nitrogen from said heat exchanger to said compressor, a pipe for conveying compressed gaseous nitrogen to said heat exchanger (34), a pipe (36) for conveying compressed gaseous nitrogen from said heat exchanger (33) to a heat exchanger (38) within said evaporator (43), an expansion valve (49), a pipe for conveying liquid nitrogen from said heat exchanger (38) within said evaporator (43) to said expansion valve (49), and a pipe for carrying expanded liquid nitrogen from said expansion valve to the top of said high pressure column.
References Cited (Backward Citations)
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