US3798917A - Fractionation of air to obtain oxygen of about seventy percent purity - Google Patents

Fractionation of air to obtain oxygen of about seventy percent purity Download PDF

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US3798917A
US3798917A US00137887A US13788771A US3798917A US 3798917 A US3798917 A US 3798917A US 00137887 A US00137887 A US 00137887A US 13788771 A US13788771 A US 13788771A US 3798917 A US3798917 A US 3798917A
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column
air
liquid
oxygen
condensed
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F Juncker
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Messer Griesheim GmbH
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    • 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
    • F25J3/04193—Division of the main heat exchange line in consecutive sections having different functions
    • F25J3/04206—Division of the main heat exchange line in consecutive sections having different functions including a so-called "auxiliary vaporiser" for vaporising and producing a gaseous product
    • F25J3/04212—Division of the main heat exchange line in consecutive sections having different functions including a so-called "auxiliary vaporiser" for vaporising and producing a gaseous product and simultaneously condensing vapor from a column serving as reflux within the or another column
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    • 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
    • F25J3/04193—Division of the main heat exchange line in consecutive sections having different functions
    • F25J3/04206—Division of the main heat exchange line in consecutive sections having different functions including a so-called "auxiliary vaporiser" for vaporising and producing a gaseous product
    • 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
    • F25J3/0423—Subcooling of liquid process streams
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    • 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
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    • 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
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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    • 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
    • F25J3/04303—Lachmann expansion, i.e. expanded into oxygen producing or low pressure column
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    • 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
    • F25J3/04309—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 nitrogen
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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    • 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
    • F25J3/04424—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 without thermally coupled high and low pressure columns, i.e. a so-called split columns
    • 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
    • F25J3/0443—A main column system not otherwise provided, e.g. a modified double column flowsheet
    • 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
    • F25J3/04763—Start-up or control of the process; Details of the apparatus used
    • F25J3/04769—Operation, control and regulation of the process; Instrumentation within the process
    • F25J3/04854—Safety aspects of operation
    • F25J3/0486—Safety aspects of operation of vaporisers for oxygen enriched liquids, e.g. purging of liquids
    • 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
    • F25J2200/00—Processes or apparatus using separation by rectification
    • F25J2200/90—Details relating to column internals, e.g. structured packing, gas or liquid distribution
    • 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
    • F25J2205/02—Processes or apparatus using other separation and/or other processing means using simple phase separation in a vessel or drum
    • 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
    • F25J2205/60—Processes or apparatus using other separation and/or other processing means using adsorption on solid adsorbents, e.g. by temperature-swing adsorption [TSA] at the hot or cold end
    • 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
    • F25J2215/00—Processes characterised by the type or other details of the product stream
    • F25J2215/50—Oxygen or special cases, e.g. isotope-mixtures or low purity O2
    • 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
    • F25J2250/00—Details related to the use of reboiler-condensers
    • F25J2250/02—Bath type boiler-condenser using thermo-siphon effect, e.g. with natural or forced circulation or pool boiling, i.e. core-in-kettle heat exchanger
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
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    • 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
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    • F25J2250/20—Boiler-condenser with multiple exchanger cores in parallel or with multiple re-boiling or condensing streams
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    • 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
    • F25J2250/00—Details related to the use of reboiler-condensers
    • F25J2250/30—External or auxiliary boiler-condenser in general, e.g. without a specified fluid or one fluid is not a primary air component or an intermediate fluid
    • F25J2250/40—One fluid being air
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    • F25J2250/50—One fluid being oxygen

Definitions

  • ABSTRACT Oxygen of approximately 70% purity is obtained by a two-stage rectification process in which air is cooled against the fractionation products, part of the cooled air is liquefied against evaporating oxygen product,
  • This invention relates to a process of obtaining oxygen of approximately 70 percent purity by two-stage rectification of air in a medium-pressure column and a low-pressure column and by work-performing expansion of a process stream to the pressure of the lowpressure column, in which process the incoming air is cooled against fractionation products and is divided into at least two streams, one of which is conducted directly into the lower part of the medium-pressure column and another into the low-pressure column.
  • Refrigeration for the condensation of the nitrogen is available in particular as a result of the evaporating oxygen product. Since the pressure of the evaporating oxygen product cannot be lowered without limit unless it is withdrawn from the plant by a vacuum pump, the evaporation temperature of the oxygen product is also fixed.
  • Theobject of the present invention is to provide a method which is at least as favorable with respect to the consumption of energy as the known methods but operates with well-proven, ordinary apparatus components and without expenditure for special apparatus.
  • the advantages of sliding evaporation of the oxygen product without use of a special column are to be utilized, and the method is to require compression of the inlet air to a single pressure level and no recycling.
  • oxygen of approximately percent purity is obtained by a two-stage rectification process in which the incoming air is cooled against the fractionation products and divided into at least two streams, one of which is conducted directly into the lower part of the first or medium-pressure column and the other stream is condensed againstevaporating liquid impure oxygen withdrawn from the second or lowpressure column.
  • the condensed air stream is further cooled to a low temperature, expanded, evaporated against the vapor of the top of the medium-pressure column and thereupon conducted into the low-pressure column.
  • the top of the medium-pressure column is cooled by the crude oxygen from the bottom of that column and a process gas stream is expanded with the performance of work to the pressure of the low-pressure column.
  • FIG. 3 is a flow sheet of still another embodiment in Y which a gaseous intermediate fraction is withdrawn DESCRIPTION OF THE PREFERRED EMBODIMENTS:
  • air compressed to about 3.5 ata passes at room temperature through line 5 into heat exchangers 6 and 7 and into gas-phase filter 8 in which hydrocarbons contained in the air and traces of carbon dioxide which were not frozen-out in heat exchangers 6 and 7 are retained.
  • the air is cooledin heat exchangers 6 and 7 to close to the dew point.
  • gas-phase filter 8 After gas-phase filter 8 the air is divided into two streams. About 20 percent of the incoming air flows through line 10 into heat exchanger 7 and is warmed somewhat therein. If desired, this air can in part also bypass heat exchanger 7 via valve 1 lb. Via bypass line 11a, a part of the reheated air can be fed through regulating heat exchanger 12 so that the air finally enters turbine 13 with a temperature of about l68C and is there expanded to 1.32 ata, the pressure of lowpressure column 2. The air cooled by the workperforming expansion then, flows through line 14 into low-pressure column 2.
  • the other stream constituting about 80 percent of the incoming air, flowsthrough air precondenser 16 and is then divided into second and third streams.
  • the second stream constituting about 50 percent of the total air, passes through line 9 directly into mediumpressure column 1. This air is fed above the bottom liquid pool in column 1 and provides vapor upflow therein.
  • the third stream passes through line into air condenser 17 in which it condenses.
  • a small part of the condensed air passes via line 18 into medium-pressure column 1 and there fortifies the reflux.
  • the main quantity of the condensed air which continues through line I5 is cooled to about -1 89C in subcooler 4 and split into streams of approximately equal size in lines 19 and 20.
  • the stream flowing through line 19 is expanded in throttle valve 21a into the upper part of low-pressure I column 2.
  • the stream in line 20 is expanded in throttle valve 21b to the pressure of low-pressure column 2 and y is evaporated in condenser 3,. whereby it assists in cooling vapor from the top of medium-pressure column 1.
  • the evaporated air combines with the expanded air from turbine 13 in line 14 and is introduced together with the latter into the lower third of low-pressure column 2.
  • Medium-pressure column 1 fractionates the air fed thereto into nitrogen and crude oxygen which is obtained in the bottom of column 1 in liquid form containing about 41 percent oxygen.
  • the nitrogen is withdrawn in gaseous form by line 22 from the top of medium-pressure column 1 and is condensed in condenser 3.
  • a part of the condensed nitrogen passes through line 23 as reflux back into medium-pressure column 1.
  • the balance of the condensed nitrogen passes through line 24 into nitrogen subcooler 25 and then is introduced via throttle valve 26 as reflux into low-pressure column
  • Liquid crude oxygen is withdrawn from the bottom of medium-pressure column 1 through line 27 and subcooled in cooler 4; it is then expanded in throttle valve 28 and evaporated in condenser 3, whereby nitrogen vapor from the top of medium-pressure column 1 is condensed.
  • the crude oxygen then flows through line'27 into low-pressure column 2 above the liquid pool in the bottom and produces a gaseous upflow' in column 2.
  • Low-pressure column 2 effects the final fractionation. From its top, through line 29 there escapes gaseous nitrogen which after flowing through subcoolers 25 and 4, air precondenser l6, regulating heat exchanger 12 and heat exchangers 7 and 6, leaves the plant at room temperature.
  • Subcooler 25 is provided with bypass line 30 and regulating valve 31 for the gaseous nitrogen flowing from low-pressure column 2 through line 29.
  • liquid oxygen of about percent purity is withdrawn through line 32 and expanded to nearly atmospheric pressure in throttle valve 33. Thereupon, it passes into condenser 3 where it partially evaporates, thus taking up about one-third of the heat necessary for its evaporation. This heat is withdrawn from the vapor from the top of medium-pressure column 1. Separation of this oxygen stream into phases then takes place in separator 34.
  • the liquid phase is withdrawn through line 35 and is pumped by circulating pump 36 through oxygen filter 37 where any-hydrocarbons still present in the liquid are retained by adsorption.
  • the impure liquid oxygen can, to be sure, be evaporated only to the extent of about one-third in condenser 3 since with evaporation it becomes warmer and warmer due to the enrichment of oxygen in the remaining liquid, but the unevaporated portion can' be evapo rated against the incoming air in line 15.
  • the air in line 15 is thus condensed and refrigeration originally in the impure liquid oxygen can now be given off near the top of medium-pressure column 1 by re-evaporation of condensed air introduced through line 18.
  • the impure liquid oxygen could be evaporated completely in condenser 3 only if the pressure of medium-pressure column 1 were increased.
  • the turbo-compressor (not shown) for the air flowing into the plant would then require more energy.
  • the incoming air is divided into only two streams.
  • the stream which in the process of FIG. 1 was expanded with the performance of work in turbine 13 is eliminated.
  • a partial stream of the nitrogen withdrawn in gaseous form by line 22 from the top of medium-pressure column 1 is passed into line 40, heated in air precondenser l6 andheat exchangers 12 and 7, and expanded with the performance of work in turbine 41.
  • the expanded, cooled nitrogen flows through line 42 and is combined with the nitrogen withdrawn through line 29 from the top of low-pressure column 2.
  • bypassline l la and valve 1112 are also provided up-stream of turbine 41.
  • the process for obtaining oxygen of approximately 70 percent purity by the two-stage rectification of air and by the expansion of a process gas stream with the performance of work which comprises cooling the incoming air by indirect heat exchange with the products of rectification, dividing the cooled air into at least two unfractionated streams, discharging one of said unfractionated streams into the lower part of the first medium-pressure column, condensing another of said unfractionated streams by indirect heat exchange with evaporating liquid oxygen of approximately 70 percent purity withdrawn from the second low-pressure column, sub-cooling and then expanding thus condensed unfractionated air which is then evaporated by indirect heat exchange with the top vapor of said first column, discharging thus evaporated unfractionated air into the lower part of said second column, and evaporating the bottom liquid of said first column by indirect heat ex- 4.
  • the process of claim 1 wherein the liquid oxygen of approximately percent purity withdrawn from the second column is partially evaporated by indirect heat exchange with top vapor of the first column prior to completion of evaporation by indirect heat exchange with the air stream

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  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Separation By Low-Temperature Treatments (AREA)
US00137887A 1970-05-12 1971-04-27 Fractionation of air to obtain oxygen of about seventy percent purity Expired - Lifetime US3798917A (en)

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DE2022953A DE2022953C3 (de) 1970-05-12 1970-05-12 Verfahren zum Gewinnen von un reinem, etwa 70 %igem Sauerstoff

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JP (1) JPS5146078B1 (de)
AU (1) AU2838771A (de)
BE (1) BE766516A (de)
DE (1) DE2022953C3 (de)
ES (1) ES390769A1 (de)
FR (1) FR2092141A1 (de)
GB (1) GB1288173A (de)
LU (1) LU63113A1 (de)
NL (1) NL7106072A (de)
ZA (1) ZA713053B (de)

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US20060169000A1 (en) * 2005-01-14 2006-08-03 Frederic Judas Process and apparatus for the separation of air by cryogenic distillation

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US2584985A (en) * 1948-04-08 1952-02-12 Hydrocarbon Research Inc Production of oxygen by rectification of air involving precooling the air
US2648205A (en) * 1948-03-30 1953-08-11 Hydrocarbon Research Inc Rectification of mixed gases
US2822675A (en) * 1954-04-23 1958-02-11 Air Liquide Production of gaseous oxygen under pressure
US2873583A (en) * 1954-05-04 1959-02-17 Union Carbide Corp Dual pressure cycle for air separation
US2918802A (en) * 1956-09-27 1959-12-29 Air Liquide Process of separation of air into its elements
US3113854A (en) * 1960-08-25 1963-12-10 Air Prod & Chem Method and apparatus for separating gaseous mixtures
US3209548A (en) * 1962-02-27 1965-10-05 Air Liquide Process for the manufacture of oxygen-enriched air
US3210951A (en) * 1960-08-25 1965-10-12 Air Prod & Chem Method for low temperature separation of gaseous mixtures
US3260056A (en) * 1962-01-12 1966-07-12 Linde Ag Regenerative heat exchange in low temperature gas fractionation
US3312074A (en) * 1964-05-06 1967-04-04 Hydrocarbon Research Inc Air separation plant
US3563046A (en) * 1968-01-05 1971-02-16 Hydrocarbon Research Inc Air separatiin process

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DE10343498A1 (de) * 2003-02-07 2005-05-04 Univ Leipzig Verfahren zur Feststellung wenigstens eines Zustandsparameters eines Dichtungssystems sowie Dichtungssystem
US20070241510A1 (en) * 2006-04-12 2007-10-18 Dileo Anthony Filter seating monitor

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US2648205A (en) * 1948-03-30 1953-08-11 Hydrocarbon Research Inc Rectification of mixed gases
US2584985A (en) * 1948-04-08 1952-02-12 Hydrocarbon Research Inc Production of oxygen by rectification of air involving precooling the air
US2822675A (en) * 1954-04-23 1958-02-11 Air Liquide Production of gaseous oxygen under pressure
US2873583A (en) * 1954-05-04 1959-02-17 Union Carbide Corp Dual pressure cycle for air separation
US2918802A (en) * 1956-09-27 1959-12-29 Air Liquide Process of separation of air into its elements
US3113854A (en) * 1960-08-25 1963-12-10 Air Prod & Chem Method and apparatus for separating gaseous mixtures
US3210951A (en) * 1960-08-25 1965-10-12 Air Prod & Chem Method for low temperature separation of gaseous mixtures
US3260056A (en) * 1962-01-12 1966-07-12 Linde Ag Regenerative heat exchange in low temperature gas fractionation
US3209548A (en) * 1962-02-27 1965-10-05 Air Liquide Process for the manufacture of oxygen-enriched air
US3312074A (en) * 1964-05-06 1967-04-04 Hydrocarbon Research Inc Air separation plant
US3563046A (en) * 1968-01-05 1971-02-16 Hydrocarbon Research Inc Air separatiin process

Cited By (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20060169000A1 (en) * 2005-01-14 2006-08-03 Frederic Judas Process and apparatus for the separation of air by cryogenic distillation
US7546748B2 (en) * 2005-01-14 2009-06-16 Air Liquide Process & Construction, Inc. Process and apparatus for the separation of air by cryogenic distillation
US20080245102A1 (en) * 2005-11-17 2008-10-09 Frederic Judas Process and Apparatus for the Separation of Air by Cryogenic Distillation

Also Published As

Publication number Publication date
FR2092141A1 (de) 1972-01-21
AU2838771A (en) 1972-11-09
ZA713053B (en) 1972-01-26
SU403206A3 (de) 1973-10-19
DE2022953C3 (de) 1973-09-27
NL7106072A (de) 1971-11-16
LU63113A1 (de) 1971-08-31
BE766516A (fr) 1971-09-16
DE2022953A1 (de) 1971-11-18
JPS5146078B1 (de) 1976-12-07
DE2022953B2 (de) 1973-03-22
ES390769A1 (es) 1973-06-01
GB1288173A (de) 1972-09-06

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