US2915882A - Separation of air - Google Patents

Separation of air Download PDF

Info

Publication number
US2915882A
US2915882A US579932A US57993256A US2915882A US 2915882 A US2915882 A US 2915882A US 579932 A US579932 A US 579932A US 57993256 A US57993256 A US 57993256A US 2915882 A US2915882 A US 2915882A
Authority
US
United States
Prior art keywords
fraction
air stream
air
compressed
oxygen fraction
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Expired - Lifetime
Application number
US579932A
Inventor
Schuftan Paul Maurice
Littlewood Anthony Duncan
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BOC Group Ltd
Original Assignee
British Oxigen Ltd
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by British Oxigen Ltd filed Critical British Oxigen Ltd
Application granted granted Critical
Publication of US2915882A publication Critical patent/US2915882A/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Images

Classifications

    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
    • F25J3/04242—Cold end purification of the feed air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04006—Providing pressurised feed air or process streams within or from the air fractionation unit
    • F25J3/04078—Providing pressurised feed air or process streams within or from the air fractionation unit providing pressurized products by liquid compression and vaporisation with cold recovery, i.e. so-called internal compression
    • F25J3/0409—Providing pressurised feed air or process streams within or from the air fractionation unit providing pressurized products by liquid compression and vaporisation with cold recovery, i.e. so-called internal compression of oxygen
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
    • F25J3/04187—Cooling of the purified feed air by recuperative heat-exchange; Heat-exchange with product streams
    • F25J3/04218—Parallel arrangement of the main heat exchange line in cores having different functions, e.g. in low pressure and high pressure cores
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
    • F25J3/04284—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams
    • F25J3/0429—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using internal refrigeration by open-loop gas work expansion, e.g. of intermediate or oxygen enriched (waste-)streams of feed air, e.g. used as waste or product air or expanded into an auxiliary column
    • F25J3/04296—Claude expansion, i.e. expanded into the main or high pressure column
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04406—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system
    • F25J3/04412—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system in a classical double column flowsheet, i.e. with thermal coupling by a main reboiler-condenser in the bottom of low pressure respectively top of high pressure column
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2205/00—Processes or apparatus using other separation and/or other processing means
    • F25J2205/24—Processes or apparatus using other separation and/or other processing means using regenerators, cold accumulators or reversible heat exchangers
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2205/00—Processes or apparatus using other separation and/or other processing means
    • F25J2205/30—Processes or apparatus using other separation and/or other processing means using a washing, e.g. "scrubbing" or bubble column for purification purposes

Definitions

  • the present invention relates to air separation and more particularly to a process of the type in which air is compressed, cooled, expanded and subjected to rectification to produce a liquid oxygen fraction and a gaseous nitrogen fraction.
  • the oxygen fraction is frequently required to be delivered in the gaseous phase under pressure and it has been proposed to pump the liquid oxygen fraction under pressure and to vaporize the liquid by heat interchange with the incoming air, the whole of the air to be separated being compressed to a uniform and relatively high pressure.
  • an air separation process of the type specified comprises establishing a major air stream and a minor air stream, compressing the major air stream only to a relatively low pressure sufficient on expansion with the performance of external work to cover the greater part of the cold requirements of the process, compressing the minor stream to a relatively high pressure, sufficient to recover by heat exchange the cold conent of the separated compressed liquid oxygen fraction, and passing the compressed minor air stream in heat exchange relationship With the compressed liquid oxygen fraction prior to the expansion of the minor air stream.
  • the whole of the major stream is expanded with the performance of external work, for example, in a turbine, while the minor stream, after being cooled by heat transfer with the compressed liquid oxygen fraction, is expanded isenthalpically.
  • the two streams after expansion are passed into a double rectification system operating in known manner to produce the required liquid oxygen fraction and a gaseous nitrogen fraction.
  • Air is drawn into the compressor 1 through a pipe 2, compressed therein to about atmospheres absolute pressure, and then passed through a vessel 3 where carbon dioxide is removed by scrubbing, into exchanger 4 where the air is cooled to a temperature of about 253 K. with simultaneous removal of water vapour, the cooling and drying agent being the separated gaseous nitrogen fraction.
  • the whole of the gaseous nitrogen fraction is shown as passing through the exchanger 4, but, if desired, only a part of this fraction may be so treated.
  • the air leaving the exchanger 4 is then split into two streams.
  • One stream is further compressed to about 80 atmospheres absolute pressure in a compressor 5 and dried in vessel 6 from which it passes through an exchanger 7 in countercurrent flow to the separated liquid V United States Patent 0 2,915,882 Patented Dec. 8, 1959' ice oxygen fraction which cools it to a temperature of about 116 K.
  • This air is further cooled in an exchanger 8' separated gaseous nitrogen fraction, leaving them at a. temperature of about 213 K. and is further cooled to about 118 K. in an exchanger 13 by the separated gas eous nitrogen fraction.
  • the gaseous nitrogen fraction leaving the top of the upper column 16 is first used to cool the liquid nitrogen: stream leaving the lower column 15 to act as reflux in: the upper column 16, in an exchanger 17 in the manner well known in the art.
  • the effluent gaseous nitrogen fraction then passes through the exchangers 8, 13, 11 or 12 and 4 as hereinbefore described in order to cool the incoming air streams.
  • a pure nitrogen fraction is required, this can be obtained from the top of the upper column 16 by withdrawing an impure nitrogen stream from a lower position in the upper column in known manner. The two nitrogen streams are then directed through separate sets of exchangers in a similar manner to that hereinbefore described.
  • the liquid oxygen fraction withdrawn from the bottom of the upper column 16 is compressed to about 20 atmospheres absolute pressure by means of a liquid pump 18, and the compressed liquid is vaporized and the resulting vapour heated in the exchanger 7 by heat exchange with the stream of air compressed to atmospheres absolute pressure as previously described.
  • Process for the separation of air to produce a compressed gaseous oxygen fraction and a gaseous nitrogen fraction which comprises the steps of compressing the air to a relatively low pressure, cooling the compressed air by heat exchange with at least a part of at least one of the separation products, dividing said cooled air into a major air stream and a minor air stream, expanding the whole of said major air stream with the production of external work, whereby an amount of cold is produced suflicient to satisfy the greater part of the cold requirements ofthe process, compressing said minor air stream to a relatively high pressure, cooling the whole of said compressed minor air stream by heat exchange with a liquid oxygen fraction pumped under pressure, whereby said liquid oxygen fraction is vaporized to produce the required compressed gaseous oxygen fraction, expanding said cooled minor air stream, subjecting said expanded major and minor air streams to rectification to separate therefrom a gaseous nitrogen fraction and a liquid oxygen fraction and pumping said liquid oxygen fraction under pressure to produce the liquid oxygen fraction which is vaporized by heat exchange with the compressed minor air stream.
  • Process for the separation of air to produce a compressed gaseous oxygen fraction and a gaseous nitrogen fraction which comprises the steps of compressing the air to a relatively low pressure, cooling the compressed air by heat exchange with at least a part of the separated gaseous nitrogen fraction, dividing said cooled air into a major air stream and a minor air stream, expand- 1 ing the whole of said major air stream with the produc tion of external work, whereby an amount of coldris pro-- dluced sufficient to satisfy the greater part of.

Description

Dec. 8, 1959 P. M. SCHUFTAN ET AL 2,915,382
SEPARATION OF AIR Filed April 23, 1956 RESSOR I nventor Attorney 2,915,882 SEPARATION or AIR Paul Maurice Schuftan, Richmond Hill, and Anthony Duncan Littlwood, Wbiidfoid Green, England, as-
ors to The British Oxygen Company Limited, a British company Application April 23, 1956, Serial No. 579,932 Claims priority, application Great Britain May 31, 1955 Claims. (Cl. 62-30) The present invention relates to air separation and more particularly to a process of the type in which air is compressed, cooled, expanded and subjected to rectification to produce a liquid oxygen fraction and a gaseous nitrogen fraction.
The oxygen fraction is frequently required to be delivered in the gaseous phase under pressure and it has been proposed to pump the liquid oxygen fraction under pressure and to vaporize the liquid by heat interchange with the incoming air, the whole of the air to be separated being compressed to a uniform and relatively high pressure.
It is an object of this invention to provide for producing a compressed gaseous oxygen fraction, an air separation process having enhanced thermodynamic efliciency as compared with other processes of this type hitherto proposed.
According to this invention, an air separation process of the type specified comprises establishing a major air stream and a minor air stream, compressing the major air stream only to a relatively low pressure sufficient on expansion with the performance of external work to cover the greater part of the cold requirements of the process, compressing the minor stream to a relatively high pressure, sufficient to recover by heat exchange the cold conent of the separated compressed liquid oxygen fraction, and passing the compressed minor air stream in heat exchange relationship With the compressed liquid oxygen fraction prior to the expansion of the minor air stream.
Preferably the whole of the major stream is expanded with the performance of external work, for example, in a turbine, while the minor stream, after being cooled by heat transfer with the compressed liquid oxygen fraction, is expanded isenthalpically. The two streams after expansion are passed into a double rectification system operating in known manner to produce the required liquid oxygen fraction and a gaseous nitrogen fraction.
The invention will now be more particularly described with reference to the accompanying drawing which shows diagrammatically one method of carrying out the invention.
Air is drawn into the compressor 1 through a pipe 2, compressed therein to about atmospheres absolute pressure, and then passed through a vessel 3 where carbon dioxide is removed by scrubbing, into exchanger 4 where the air is cooled to a temperature of about 253 K. with simultaneous removal of water vapour, the cooling and drying agent being the separated gaseous nitrogen fraction. In the drawing, the whole of the gaseous nitrogen fraction is shown as passing through the exchanger 4, but, if desired, only a part of this fraction may be so treated.
The air leaving the exchanger 4 is then split into two streams. One stream is further compressed to about 80 atmospheres absolute pressure in a compressor 5 and dried in vessel 6 from which it passes through an exchanger 7 in countercurrent flow to the separated liquid V United States Patent 0 2,915,882 Patented Dec. 8, 1959' ice oxygen fraction which cools it to a temperature of about 116 K. This air is further cooled in an exchanger 8' separated gaseous nitrogen fraction, leaving them at a. temperature of about 213 K. and is further cooled to about 118 K. in an exchanger 13 by the separated gas eous nitrogen fraction. This air stream is finally expanded in the turbine 14 to a pressure of 5.5 atmos= pheres absolute and a temperature of about 100 K. and.
is introduced into the scrubber 10 to admix With the first.
air stream.
From the scrubber 10 the liquid and vapour fractions of the cooled and expanded air are introduced into the upper and lower columns 16 and 15 respectively, of at double column system, to efiect separation into a liquid. oxygen fraction and a gaseous nitrogen fraction in known:
manner.
The gaseous nitrogen fraction leaving the top of the upper column 16 is first used to cool the liquid nitrogen: stream leaving the lower column 15 to act as reflux in: the upper column 16, in an exchanger 17 in the manner well known in the art. The effluent gaseous nitrogen fraction then passes through the exchangers 8, 13, 11 or 12 and 4 as hereinbefore described in order to cool the incoming air streams.
If a pure nitrogen fraction is required, this can be obtained from the top of the upper column 16 by withdrawing an impure nitrogen stream from a lower position in the upper column in known manner. The two nitrogen streams are then directed through separate sets of exchangers in a similar manner to that hereinbefore described.
The liquid oxygen fraction withdrawn from the bottom of the upper column 16 is compressed to about 20 atmospheres absolute pressure by means of a liquid pump 18, and the compressed liquid is vaporized and the resulting vapour heated in the exchanger 7 by heat exchange with the stream of air compressed to atmospheres absolute pressure as previously described.
By this means, a gaseous oxygen stream at a desired pressure is obtained in a highly efficient manner.
We claim:
1. Process for the separation of air to produce a compressed gaseous oxygen fraction and a gaseous nitrogen fraction which comprises the steps of compressing the air to a relatively low pressure, cooling the compressed air by heat exchange with at least a part of at least one of the separation products, dividing said cooled air into a major air stream and a minor air stream, expanding the whole of said major air stream with the production of external work, whereby an amount of cold is produced suflicient to satisfy the greater part of the cold requirements ofthe process, compressing said minor air stream to a relatively high pressure, cooling the whole of said compressed minor air stream by heat exchange with a liquid oxygen fraction pumped under pressure, whereby said liquid oxygen fraction is vaporized to produce the required compressed gaseous oxygen fraction, expanding said cooled minor air stream, subjecting said expanded major and minor air streams to rectification to separate therefrom a gaseous nitrogen fraction and a liquid oxygen fraction and pumping said liquid oxygen fraction under pressure to produce the liquid oxygen fraction which is vaporized by heat exchange with the compressed minor air stream.
2. Process for the separation of air to produce a compressed gaseous oxygen fraction and a gaseous nitrogen sufiicient to. satisfy the greater part of the cold requirements of the process, compressing said minor air stream :to a relatively high pressure, cooling the whole of said'mie nor air stream byheat exchangewith a liquid oxygen frac- .tion pumped under pressure, whereby said liquid oxy- -gen fraction is vaporized to produce the required compressed gaseous oxygen fraction,,isenthalpically expanding said cooled minor air stream, subjecting said expanded major and minor air streams to rectification to separate therefrom a gaseous nitrogen fraction and a liquid, oxygen fraction and pumping said liquid oxygen fraction under pressure to produce the liquid oxygen fraction which is vaporized by heat exchange with the compressed minor air stream.
Q3. Process for the separation of air to produce a compressed gaseous oxygen fraction and a gaseous nitrogen fraction which comprises the steps of compressing the air to a relatively low pressure, cooling the compressed air by heat exchange with at least a part of the separated gaseous nitrogen fraction, dividing said cooled air into a major air stream and a minor air stream, expand- 1 ing the whole of said major air stream with the produc tion of external work, whereby an amount of coldris pro-- dluced sufficient to satisfy the greater part of. the cold requirements of the process, compressing said minor air :stream to a relatively high pressure, cooling the whole of said minor air stream by heat exchange with a liquid oxygenfraction pumped under pressure, whereby said liquid oxygen fraction is vaporized to produce the required compressed gaseous oxygen fraction, isenthalpical- 1y expanding said cooled minor air stream, subjecting said expanded major and minor air streams to rectification to separate therefrom a gaseous nitrogen fraction and a liquid oxygen fraction and pumping said liquid oxygen fraction under pressure to produce the liquid oxygen fraction which is vaporized byheat exchange with, the compressed minor air stream.
4. Process for the separation of air to produce a com pressed gaseous oxygen fraction and a gaseous nitrogen fraction which comprises the steps of compressing, the air to a relatively low pressure, cooling the compressed .air by heat exchange with at least a part of the separated gaseous nitrogen fraction dividing said cooled'air into a major air stream and a minor air stream, furthercooling said major air stream by heat exchange with said separated gaseous nitrogen fraction, expanding the .whole of said cooled major air stream with the productionof external work, whereby an amount of cold isrproduced sufiicient to, satisfy the greater part of the cold require-,.
ments of the process, compressing said minor air stream to a relatively high pressure, cooling the whole of said compressed minor air stream by heat exchange with a liquid oxygen fraction pumped. under pressure, wherev by said liquid oxygen fraction is vaporized to produce the required compressed gaseous .oxygen fraction, isenthalpically expanding said cooled minor air stream, subjecting said expanded major and minor air streams to rectification to separate therefrom a gaseous nitrogen fraction and a liquid oxygen fraction and pumping said liquid oxygen fraction under pressure to produce the 7 liquid oxygen fraction which isvaporized by heat exchange with the compressed minor air stream. V
5. Process for the separation of air to produce a compressed gaseous oxygen fraction and-a gaseous nitrogen fraction which comprises the steps of compressing the air to a relatively low pressure, cooling the compressed air 'by heat exchange with at least a part of the separatedgaseous nitrogen fraction dividing sa'id cooled air'into a major air stream and; a minor air stream, further cooling said major air stream by heat exchange with said:
separatedgaseous nitrogen fraction, expanding the whole of said cooled major air stream with the production of external work, whereby an amount of cold is'produced'.
sufiicient to satisfy the greater part of the cold requirements of theprocess, compressing said minor air stream to 3.,I'tilfltlV6lY- high pressure, cooling the whole of said minor air stream by heat exchangewith a liquid oxygen fraction pumped under pressure, whereby said liquid oxygen fraction is vaporized to produce the required compressed gaseous oxygen fraction, further cooling said. compressed minor air stream by heat exchange with said! separated gaseous nitrogen fraction, isenthalpically ex panding said cooled-minor air stream, subjecting said expanded major and minor air streams to rectification to separate therefrom a gaseous nitrogen fraction and a: liquid oxygen fraction and pumping said liquid oxygen fraction under pressure to produce the liquid. oxygen fraction which is vaporized by heat exchange with the compressed minor air stream.
References Cited in the file of this patent UNITED STATES PATENTS 2,209,748 Schlitt July 30, 19.40 2,239,883 Bauflre et'al. Apr. 29, 1941 2,409,458 Van Nuys Oct. 15, 1946 2,411,680 Dennis Nov. 26, 1946 2,685,183 Collins Aug. 3, 1954 2,699,047 Karwat Jan. 11, 1955' 2,712,738 Wucherer July 12, 1955 FOREIGN PATENTS 4 6 9,939 Great Britain Aug. 3, 1937

Claims (1)

1. PROCESS FOR THE SEPARATION OF AIR TO PRODUCE A COMPRESSED GASEOUS OXYGEN FRACTION AND A GASEOUS NITROGEN FRACTION WHICH COMPRISES THE STEPS OF COMPRESSING THE AIR TO A RELATIVELY LOW PRESSURE, COOLING THE COMPRESSED AIR BY HEAT EXCHANGE WITH AT LEAST A PART OF AT LEAST ONE OF THE SEPARATION PRODUCTS, DIVIDING SAID COOLED AIR INTO A MAJOR AIR STREAM AND A MINOR AIR STREAM EXPANDING THE WHOLE OF SAID MAJOR AIR STREAM WITH THE PRODUCTION OF EXTERNAL WORK, WHEREBY AN AMOUNT OF COLD IS PRODUCED SUFFICIENT TO SATISFY THE GREATER PART OF THE COLD REQUIREMENTS OF THE PROCESS, COMPRESSING SAID MINOR AIR STREAM TO A RELATIVELY HIGH PRESSURE, COOLING THE WHOLE OF SAID COMPRESSED MINOR AIR STREAM BY HEAT EXCHANGE WITH A LIQUID OXYGEN FRACTION PUMPED UNDER THE PRESSURE, WHEREBY SAID LIQUID OXYGEN FRACTION IS VAPORIZED TO PRODUCE THE REQUIRED COMPRESSED GASEOUS OXYGEN FRACTION, EXPANDING SAID COOLED MINOR AIR STREAM, SUBJECTING SAID EXPANDED MAJOR AND MINOR AIR STREAMS TO RECTIFICATION TO SEPARATE THEREFROM A GASEOUS NITROGEN FRACTION AND A LIQUID OXYGEN FRACTION AND PUMPING SAID LIQUID OXYGEN FRACTION UNDER PRESSURE TO PRODUCE THE LIDUID OXYGEN FRACTION WHICH IS VAPORIZED BY HEAT EXCHANGE WITH THE COMPRESSED MINOR AIR STREAM.
US579932A 1955-05-31 1956-04-23 Separation of air Expired - Lifetime US2915882A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
GB15586/55A GB784590A (en) 1955-05-31 1955-05-31 Improvements in or relating to the cold separation of air

Publications (1)

Publication Number Publication Date
US2915882A true US2915882A (en) 1959-12-08

Family

ID=10061785

Family Applications (1)

Application Number Title Priority Date Filing Date
US579932A Expired - Lifetime US2915882A (en) 1955-05-31 1956-04-23 Separation of air

Country Status (4)

Country Link
US (1) US2915882A (en)
BE (1) BE547614A (en)
GB (1) GB784590A (en)
NL (1) NL207488A (en)

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3100696A (en) * 1957-07-04 1963-08-13 Linde Eismasch Ag Method and apparatus for separating gases
US3143406A (en) * 1957-07-04 1964-08-04 Linde Eismasch Ag System for conducting heat exchange operations in a gas separation apparatus incorporating periodically reversible regenerators
US3214925A (en) * 1960-08-13 1965-11-02 Linde Eismasch Ag System for gas separation by rectification at low temperatures
US3261168A (en) * 1961-11-03 1966-07-19 Petrocarbon Dev Ltd Separation of oxygen from air
US3383873A (en) * 1964-11-03 1968-05-21 Linde Ag Engine expansion of liquefied gas at below critical temperature and above critical pressure
US3397138A (en) * 1965-12-02 1968-08-13 Warren Petroleum Corp Gas separation employing work expansion of feed and fractionator overhead
US3416323A (en) * 1966-01-13 1968-12-17 Linde Ag Low temperature production of highly compressed gaseous and/or liquid oxygen
US3447332A (en) * 1967-07-13 1969-06-03 Genrikh Maxovich Basin Air separation employing separated nitrogen as heat exchange fluid in liquid oxygen pump jacket
US4964901A (en) * 1988-05-20 1990-10-23 Linde Aktiengesellschaft Low-temperature separation of air using high and low pressure air feedstreams
US5082482A (en) * 1989-10-09 1992-01-21 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Process and apparatus for the production of gaseous oxygen with a variable flow by air distillation
US5098456A (en) * 1990-06-27 1992-03-24 Union Carbide Industrial Gases Technology Corporation Cryogenic air separation system with dual feed air side condensers
US5108476A (en) * 1990-06-27 1992-04-28 Union Carbide Industrial Gases Technology Corporation Cryogenic air separation system with dual temperature feed turboexpansion
US5114452A (en) * 1990-06-27 1992-05-19 Union Carbide Industrial Gases Technology Corporation Cryogenic air separation system for producing elevated pressure product gas
US5148680A (en) * 1990-06-27 1992-09-22 Union Carbide Industrial Gases Technology Corporation Cryogenic air separation system with dual product side condenser
US5379598A (en) * 1993-08-23 1995-01-10 The Boc Group, Inc. Cryogenic rectification process and apparatus for vaporizing a pumped liquid product

Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
GB469939A (en) * 1936-02-03 1937-08-03 Gas Ind Company Improvements in and relating to processes and apparatus for producing gases under pressure
US2209748A (en) * 1938-08-03 1940-07-30 Air Reduction Method of separating the constituents of gaseous mixtures
US2239883A (en) * 1941-04-29 Expansion engine
US2409458A (en) * 1943-04-27 1946-10-15 Air Reduction Separation of the constituents of gaseous mixtures
US2411680A (en) * 1944-03-07 1946-11-26 Air Reduction Separation of the constituents of gaseous mixtures
US2685183A (en) * 1949-10-18 1954-08-03 Joy Mfg Co Method of and means for treating gases
US2699047A (en) * 1950-10-27 1955-01-11 Linde Eismasch Ag Process for cooling and purifying compressed gas mixtures
US2712738A (en) * 1952-01-10 1955-07-12 Linde S Eismaschinen Ag Method for fractionating air by liquefaction and rectification

Patent Citations (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US2239883A (en) * 1941-04-29 Expansion engine
GB469939A (en) * 1936-02-03 1937-08-03 Gas Ind Company Improvements in and relating to processes and apparatus for producing gases under pressure
US2209748A (en) * 1938-08-03 1940-07-30 Air Reduction Method of separating the constituents of gaseous mixtures
US2409458A (en) * 1943-04-27 1946-10-15 Air Reduction Separation of the constituents of gaseous mixtures
US2411680A (en) * 1944-03-07 1946-11-26 Air Reduction Separation of the constituents of gaseous mixtures
US2685183A (en) * 1949-10-18 1954-08-03 Joy Mfg Co Method of and means for treating gases
US2699047A (en) * 1950-10-27 1955-01-11 Linde Eismasch Ag Process for cooling and purifying compressed gas mixtures
US2712738A (en) * 1952-01-10 1955-07-12 Linde S Eismaschinen Ag Method for fractionating air by liquefaction and rectification

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3100696A (en) * 1957-07-04 1963-08-13 Linde Eismasch Ag Method and apparatus for separating gases
US3143406A (en) * 1957-07-04 1964-08-04 Linde Eismasch Ag System for conducting heat exchange operations in a gas separation apparatus incorporating periodically reversible regenerators
US3214925A (en) * 1960-08-13 1965-11-02 Linde Eismasch Ag System for gas separation by rectification at low temperatures
US3261168A (en) * 1961-11-03 1966-07-19 Petrocarbon Dev Ltd Separation of oxygen from air
US3383873A (en) * 1964-11-03 1968-05-21 Linde Ag Engine expansion of liquefied gas at below critical temperature and above critical pressure
US3397138A (en) * 1965-12-02 1968-08-13 Warren Petroleum Corp Gas separation employing work expansion of feed and fractionator overhead
US3416323A (en) * 1966-01-13 1968-12-17 Linde Ag Low temperature production of highly compressed gaseous and/or liquid oxygen
US3447332A (en) * 1967-07-13 1969-06-03 Genrikh Maxovich Basin Air separation employing separated nitrogen as heat exchange fluid in liquid oxygen pump jacket
US4964901A (en) * 1988-05-20 1990-10-23 Linde Aktiengesellschaft Low-temperature separation of air using high and low pressure air feedstreams
US5082482A (en) * 1989-10-09 1992-01-21 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude Process and apparatus for the production of gaseous oxygen with a variable flow by air distillation
US5098456A (en) * 1990-06-27 1992-03-24 Union Carbide Industrial Gases Technology Corporation Cryogenic air separation system with dual feed air side condensers
US5108476A (en) * 1990-06-27 1992-04-28 Union Carbide Industrial Gases Technology Corporation Cryogenic air separation system with dual temperature feed turboexpansion
US5114452A (en) * 1990-06-27 1992-05-19 Union Carbide Industrial Gases Technology Corporation Cryogenic air separation system for producing elevated pressure product gas
US5148680A (en) * 1990-06-27 1992-09-22 Union Carbide Industrial Gases Technology Corporation Cryogenic air separation system with dual product side condenser
US5379598A (en) * 1993-08-23 1995-01-10 The Boc Group, Inc. Cryogenic rectification process and apparatus for vaporizing a pumped liquid product

Also Published As

Publication number Publication date
GB784590A (en) 1957-10-09
BE547614A (en)
NL207488A (en)

Similar Documents

Publication Publication Date Title
US2915882A (en) Separation of air
US3214925A (en) System for gas separation by rectification at low temperatures
US2918802A (en) Process of separation of air into its elements
US3098732A (en) Liquefaction and purification of low temperature gases
US5596885A (en) Process and installation for the production of gaseous oxygen under pressure
US2850880A (en) Process and an apparatus for the separation of compressed air
US3083544A (en) Rectification of gases
US3401531A (en) Heat exchange of compressed nitrogen and liquid oxygen in ammonia synthesis feed gas production
US2048076A (en) Process for separating low boiling gas mixtures
US1664412A (en) Production of helium from natural gas
US4964901A (en) Low-temperature separation of air using high and low pressure air feedstreams
JPS61110872A (en) Manufacture of nitrogen
US3209548A (en) Process for the manufacture of oxygen-enriched air
US2827775A (en) Process for separating a compressed gas mixture
US3339370A (en) Process for the separation of nitrogen and oxygen from air by fractional distillation
US3070966A (en) Production of oxygen
US2583090A (en) Separation of natural gas mixtures
US3110155A (en) Improved process for the separation of air to produce a desired separation product in the gaseous phase under pressure
US3609984A (en) Process for producing liquefied hydrogen,helium and neon
US2559132A (en) Fractional separation of air
US3183677A (en) Liquefaction of nitrogen in regasification of liquid methane
US2915880A (en) Separation of gas mixtures
US2964914A (en) Separation of air
US2552560A (en) Process of producing oxygen
US2709348A (en) Process of and apparatus for separating gas mixtures