US3273349A - Variable demand air rectification plant with recycle - Google Patents

Variable demand air rectification plant with recycle Download PDF

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US3273349A
US3273349A US432722A US43272265A US3273349A US 3273349 A US3273349 A US 3273349A US 432722 A US432722 A US 432722A US 43272265 A US43272265 A US 43272265A US 3273349 A US3273349 A US 3273349A
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nitrogen
plant
product
waste nitrogen
liquid
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US432722A
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Litvin Milton
Allen V Muska
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Airco Inc
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Air Reduction Co Inc
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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
    • F25J3/04218—Parallel arrangement of the main heat exchange line in cores having different functions, e.g. in low pressure and high pressure cores
    • F25J3/04224—Cores associated with a liquefaction or refrigeration cycle
    • 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
    • F25J3/04333—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using quasi-closed loop internal vapor compression refrigeration cycles, e.g. of intermediate or oxygen enriched (waste-)streams
    • F25J3/04351—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using quasi-closed loop internal vapor compression refrigeration cycles, e.g. of intermediate or oxygen enriched (waste-)streams of nitrogen
    • 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
    • F25J3/04472—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 the cold from cryogenic liquids produced within the air fractionation unit and stored in internal or intermediate storages
    • F25J3/04496—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 the cold from cryogenic liquids produced within the air fractionation unit and stored in internal or intermediate storages for compensating variable air feed or variable product demand by alternating between periods of liquid storage and liquid assist
    • F25J3/04503—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 the cold from cryogenic liquids produced within the air fractionation unit and stored in internal or intermediate storages for compensating variable air feed or variable product demand by alternating between periods of liquid storage and liquid assist by exchanging "cold" between at least two different cryogenic liquids, e.g. independently from the main heat exchange line of the air fractionation and/or by using external alternating storage systems
    • F25J3/04509—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 the cold from cryogenic liquids produced within the air fractionation unit and stored in internal or intermediate storages for compensating variable air feed or variable product demand by alternating between periods of liquid storage and liquid assist by exchanging "cold" between at least two different cryogenic liquids, e.g. independently from the main heat exchange line of the air fractionation and/or by using external alternating storage systems within the cold part of the air fractionation, i.e. exchanging "cold" within the fractionation and/or main heat exchange line
    • 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
    • F25J2250/30—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
    • F25J2250/42—One fluid being nitrogen
    • 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
    • F25J2250/30—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
    • F25J2250/50—One fluid being oxygen

Definitions

  • This invention relates to the economic design of an air rectification process including the utilization of the refrigeration capacity of a stored liquid product of said process.
  • this invention relates to an economic design of an air rectification process, saving a substantial part of the power consumption needed to supply the required refrigeration including storage of liquefied product of said process, in which the refrigeration capacity is re covered from the liquefied product as a result of heat exchange with recycled nitrogen.
  • the stored liquefied product meets peak demands, which peak demands may exceed the steady supply capacity of the air rectification process.
  • the stored liquefied product may be oxygen, as shown in the drawing to be discussed hereinafter, or some other liquefied product of the process, such as nitrogen. Further description will be made in terms of product oxygen, although this invention is not limited to such stored product.
  • liquid product for example oxygen
  • a heat exchanger where it is gasified.
  • This pumping controls the operation of a variable capacity compressor.
  • Nitrogen for example clean waste nitrogen, emanating from an air separation process is compressed by the variable capacity compressor and condensed as a result of counter-current heat transfer with the gasifying oxygen.
  • the nitrogen just liquefied as a result of heat exchange with the vaporizing oxygen, is stored and fed at a steady rate to the air separation process to be used in any manner desired, for example as reflux to the low pressure column.
  • the gaseous nitrogen stream recovers the refrigeration capacity of the gasifying oxygen product before the product leaves the system.
  • the dis- 3,273,349 Patented Sept. 20, 1966 closed process can be utilized most effectively where there is a large customer requirement for the product, be it nitrogen or oxygen or some other product, during periods of peak operation, as will be apparent from the more detailed description in connection with the drawing that follows.
  • the drawing shows schematically an air separation plant and an external process and equipment therefor.
  • the drawing shows liquid oxygen storage; however, as stated earlier, other liquefied products, such as liquid nitrogen, could be utilized in the same manner as is described hereinafter.
  • the air separation plant unit 1 is steady state in its production of liquid and gaseous products; that is, for substantial periods of time it produces at a particular constant percent of capacity no matter what the customers demands are. Of course, from time .to time that percentage of capacity production may be altered. Said air separation plant unit 1 supplies oxygen gas product, at 2, as a unit sup-ply base load to the customer. The steady state air separation plant unit 1 also produces liquid oxygen which is stored at 3 to fulfill the surge requirements of the customer. Of course, liquid nitrogen may be stored at 3, this description of the process shown in the drawing being written in terms of oxygen storage only for purposes of illustration.
  • Clean waste nitrogen gas emanates from the air separation plant unit at 4 in one pass of a multiple pass exchanger.
  • the scavenging stream 5 usually exhausts to the atmosphere.
  • the description is made with particular reference to the stream in pass 4 being clean waste nitrogen, other forms of nitrogen exhausted from the plant may be utilized.
  • the product liquid oxygen stored in the storage vessel 3 is vaporized in a heat exchanger 7 to satisfy surge gas demands of a customer, conserving the refrigeration value of the liquid oxygen by vaporizing said liquid oxygen against clean warm waste nitrogen gas 4 running countercurrently.
  • the clean waste nitrogen 4 when it leaves the air separation plant is at atmospheric pressure and is warm. A typical operating temperature of said clean waste nitrogen would be 86 F.
  • the clean waste nitrogen gas 4, after being compressed in the variable capacity gas compressor 9 is passed countercurrently to the vaporizing oxygen through pass 15 of heat exchanger apparatus 7.
  • the clean warm Waste nitrogen gas transfers its heat in the heat exchanger to the cold liquid oxygen in the adjacent pass 16, gasifying said liquid oxygen.
  • the nitrogen gas is condensed as a result of the heat exchange with the cold liquid oxygen.
  • the liquid oxygen is pumped to the heat exchanger 7 from the liquid storage vessel 3 by a pump 6 in response to the variable surge demands of the gas customer.
  • the pump 6 may be linked through a motor drive interlock control 8 to the variable capacity nitrogen compressor 9.
  • the nitrogen gas in line 4 is compressed by the compressor 9 when product oxygen is pumped by pump 6, as a result of inter-lock control 8.
  • the liquefied waste nitrogen is discharged from the heat exchanger 7 and passes through a throttle valve control 17, at lower pressure, into a liquefied nitrogen storage vessel 11.
  • the liquid nitrogen undergoes a Joule-Thomson expansion in which some liquid is vaporized.
  • This cold vapor, plus other cold vapor resulting from the effects on the liquid nitrogen of heat leak into the storage vessel 11, is vented from the storage vessel through valve 14, as determined by storage pressure control mechanism 18, and passed countercurrently through pass 19 in heat exchange relationship in exchanger 7 to the warm waste nitrogen gas stream in pass 15.
  • variable capacity compressor is linked to the gasified oxygen supply line 13 by a temperature capacity control 22.
  • This control adjusts the speed of the compressor 9, so that adequate waste nitrogen is supplied to the exchanger 7 to vaporize all of the liquid oxygen in pass 16 of the exchanger.
  • Pressure control 21 maintains the pass 15 of exchanger 7 at the proper pressure needed for the transfer of heat between the three exchanger fluids. This pressure controller maintains this pressure by control of throttling valve 17, as above.
  • the proposed process functions according to the product demanded by the customer.
  • the refrigeration capacity of the liquid product is conserved by, in effect, transferring said refrigeration capacity to a waste nitrogen stream which is reintroduced back into the air separation plant.
  • the refrigeration supply to the air separation process is evened out.
  • the process described above is external to the air separation plant unit 1 and is therefore independent of the particular cycle or process used in the air separation plant, since all that is required is that the air separation plant discharge some amount and form of nitrogen which discharge is standard. Therefore, the process described above can be used with all types of air separation processes or plants.
  • this invention is not limited to th storage of liquefied oxygen product and a clean waste nitrogen stream emanating from an air separation plant.
  • oxygen product and clean waste nitrogen are used in this description only for purposes of illustration of the invention.
  • other stored liquefied products than oxygen such as nitrogen
  • other streams emanating from an air separation plant than clean waste nitrogen such as a scavenging stream of nitrogen which is then purified
  • this invention is not limited to any method, process or apparatus described hereinbefore, except as set forth in the following claims.
  • a process for supply of gaseous oxygen from an air separation plant so as to meet varying demands comprising the steps of passing gaseous oxygen product at a substantially steady state from the plant to a source of demand, storing liquid oxygen product from said plant, vaporizing said liquid product in a vaporizer in response to demand, compressing waste nitrogen from said plant, cooling substantially all of said compressed waste nitrogen by heat exchange with said liquid oxygen product being vaporized, throttling said compressed and cooled waste nitrogen to liquefy it, controllably applying said liquefied waste nitrogen to said plant to provide refrigeration therefor, and passing vapors from said liquified nitrogen in heat exchange with the compressed nitrogen stream and then into mixture with the waste nitrogen before said waste nitrogen is compressed.
  • a process for supply of gas product from an air separation plant so as to meet varying demands comprising the steps of passing a gas product stream at a substantially steady state from the plant to a source of demand, storing liquid products from said plant, vaporizing it in a vaporizer in response to the demand, compressing a nitrogen gas stream from said plant, cooling substantially all of said last-mentioned compressed gas by heat exchange with said liquid product being vaporized throttling said compressed and cooled nitrogen to liquefy it, controllably supplying said liquefied nitrogen stream to said plant to provide refrigeration therefor, passing said vaporized product on to the source of demand, and directing vapors emanating from said liquefied nitrogen in heat exchange with the nitrogen gas stream before said stream is compressed.

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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)

Description

Sept. 20, 1966 M- LITVIN ET AL 3,273,349
VARIABLE DEMAND AIR RECTIFICATION PLANT WITH RECYCLE Filed Feb. 15, 1965 2 GAS PRODUCT GAS SUPPLY [UNIT SUPPLY BASE LOAD T0 CUSTOMQR d I AIRSEPARATION V A W PLANT UNIT V wvw-+ l LIQUEFIED NITROGEN STORAGE \CLEAN WASTE NITROGEN \SCAVENGING STREAM- WASTE NITROGEN TO ATMOSPHERE ALLEN V. MUS/(A Emmy/kw 2Q OM7 ATTORNEY United States Patent 3,273,349 VARIABLE DEMAND AIR RECTIFICATION PLANT WITH RECYCLE Milton Litvin, New York, N.Y., and Allen V. Muska,
Berkeley Heights, N.J., assignors to Air Reduction Company, Incorporated, New York, N.Y., a corporation of New York Filed Feb. 15, 1965, Ser. No. 432,722
3 Claims. (CI. 6250) This invention relates to the economic design of an air rectification process including the utilization of the refrigeration capacity of a stored liquid product of said process.
More specifically, this invention relates to an economic design of an air rectification process, saving a substantial part of the power consumption needed to supply the required refrigeration including storage of liquefied product of said process, in which the refrigeration capacity is re covered from the liquefied product as a result of heat exchange with recycled nitrogen. The stored liquefied product meets peak demands, which peak demands may exceed the steady supply capacity of the air rectification process.
Most often it is proposed to store a product, for example, oxygen, of an air separation plant in gaseous form. In the usual air separation plant that supplies a customer by pipeline, the customers steady gas demand is supplied directly from the producing unit, While high customer demand is supplied by high pressure gaseous storage. Liquid storage has not generally been used in this service, in spite, of the lower capital investment in comparison to gaseous storage. This is due to the fact that considerable power is needed to make liquid by refrigerating the gas. This refrigeration has been lost when the liquid is vaporized and put into the pipeline for supply to the customer. It is therefore an object of this invention to make the cheaper liquid storage attractive by utilizing the refrigeration capacity of the liquefied product in an efficient and effective manner within the air separation plant.
It is further an object of this invention to provide an economic air separation process in which product gas flow surges demanded by the customer on the process are evened out.
It is further an object of this invention to effectively conserve the refrigeration eifect captured within a liquefied product of an air rectification process for use within the process so as to provide for economic use of power.
These and other objects and advantages of this invention will become apparent in connection with the more detailed disclosure set forth hereinbelow.
The stored liquefied product may be oxygen, as shown in the drawing to be discussed hereinafter, or some other liquefied product of the process, such as nitrogen. Further description will be made in terms of product oxygen, although this invention is not limited to such stored product.
In general, liquid product, for example oxygen, produced by an air separation process, is pumped through a heat exchanger, where it is gasified. This pumping controls the operation of a variable capacity compressor. Nitrogen, for example clean waste nitrogen, emanating from an air separation process is compressed by the variable capacity compressor and condensed as a result of counter-current heat transfer with the gasifying oxygen. The nitrogen, just liquefied as a result of heat exchange with the vaporizing oxygen, is stored and fed at a steady rate to the air separation process to be used in any manner desired, for example as reflux to the low pressure column. Effectively, the gaseous nitrogen stream recovers the refrigeration capacity of the gasifying oxygen product before the product leaves the system. The dis- 3,273,349 Patented Sept. 20, 1966 closed process can be utilized most effectively where there is a large customer requirement for the product, be it nitrogen or oxygen or some other product, during periods of peak operation, as will be apparent from the more detailed description in connection with the drawing that follows.
The drawing shows schematically an air separation plant and an external process and equipment therefor. The drawing shows liquid oxygen storage; however, as stated earlier, other liquefied products, such as liquid nitrogen, could be utilized in the same manner as is described hereinafter.
The air separation plant unit 1 is steady state in its production of liquid and gaseous products; that is, for substantial periods of time it produces at a particular constant percent of capacity no matter what the customers demands are. Of course, from time .to time that percentage of capacity production may be altered. Said air separation plant unit 1 supplies oxygen gas product, at 2, as a unit sup-ply base load to the customer. The steady state air separation plant unit 1 also produces liquid oxygen which is stored at 3 to fulfill the surge requirements of the customer. Of course, liquid nitrogen may be stored at 3, this description of the process shown in the drawing being written in terms of oxygen storage only for purposes of illustration.
Clean waste nitrogen gas emanates from the air separation plant unit at 4 in one pass of a multiple pass exchanger. The scavenging stream 5 usually exhausts to the atmosphere. Although the description is made with particular reference to the stream in pass 4 being clean waste nitrogen, other forms of nitrogen exhausted from the plant may be utilized. In the air separation plant 1 and external process of the drawing, the product liquid oxygen stored in the storage vessel 3 is vaporized in a heat exchanger 7 to satisfy surge gas demands of a customer, conserving the refrigeration value of the liquid oxygen by vaporizing said liquid oxygen against clean warm waste nitrogen gas 4 running countercurrently.
The clean waste nitrogen 4 when it leaves the air separation plant is at atmospheric pressure and is warm. A typical operating temperature of said clean waste nitrogen would be 86 F. The clean waste nitrogen gas 4, after being compressed in the variable capacity gas compressor 9 is passed countercurrently to the vaporizing oxygen through pass 15 of heat exchanger apparatus 7. The clean warm Waste nitrogen gas transfers its heat in the heat exchanger to the cold liquid oxygen in the adjacent pass 16, gasifying said liquid oxygen. The nitrogen gas is condensed as a result of the heat exchange with the cold liquid oxygen. The liquid oxygen is pumped to the heat exchanger 7 from the liquid storage vessel 3 by a pump 6 in response to the variable surge demands of the gas customer. The pump 6 may be linked through a motor drive interlock control 8 to the variable capacity nitrogen compressor 9. (The nitrogen gas in line 4 is compressed by the compressor 9 when product oxygen is pumped by pump 6, as a result of inter-lock control 8.) The liquefied waste nitrogen is discharged from the heat exchanger 7 and passes through a throttle valve control 17, at lower pressure, into a liquefied nitrogen storage vessel 11. In passing through the throttle valve 17, the liquid nitrogen undergoes a Joule-Thomson expansion in which some liquid is vaporized. This cold vapor, plus other cold vapor resulting from the effects on the liquid nitrogen of heat leak into the storage vessel 11, is vented from the storage vessel through valve 14, as determined by storage pressure control mechanism 18, and passed countercurrently through pass 19 in heat exchange relationship in exchanger 7 to the warm waste nitrogen gas stream in pass 15. Thus, a portion of the heat in said waste nitrogen gas stream in pass 15 is removed as a result of heat exchange with the cold gas in pass 19, adding to the saving of the refrigeration capacity originally taken from the gasifying oxygen. More efficient and complete liquefying of the waste nitrogen gas and conserving of refrigeration and thus power is effected. The cold vented gas from storage container 11 is thus warmed in exchanger 7 and then combined in gaseous form with the clean warm waste nitrogen gas emanating in line 4 from the air separation plant unit 1. The liquefied waste nitrogen storage vessel 11 discharges through a flow control valve 20 nitrogen liqued which is used in the air separation plant, for example, as reflux to the low pressure or so-called oxygen column.
The variable capacity compressor is linked to the gasified oxygen supply line 13 by a temperature capacity control 22. This control adjusts the speed of the compressor 9, so that adequate waste nitrogen is supplied to the exchanger 7 to vaporize all of the liquid oxygen in pass 16 of the exchanger. Pressure control 21 maintains the pass 15 of exchanger 7 at the proper pressure needed for the transfer of heat between the three exchanger fluids. This pressure controller maintains this pressure by control of throttling valve 17, as above.
In a typical operation, the following process conditions will occur in the heat exchanger.
Warm end T=86 I Mass flow ratios: Waste nitrogen to flash recycle to liquid 0xygen= 1.07 0.257 1.0 lb. waste nitrogen liquefied per lb. liquid oxygen=0.813.
The proposed process functions according to the product demanded by the customer. The refrigeration capacity of the liquid product is conserved by, in effect, transferring said refrigeration capacity to a waste nitrogen stream which is reintroduced back into the air separation plant. As a result of the liquefication of the clean waste nitrogen gas and then subsequent storage thereof, the refrigeration supply to the air separation process is evened out.
The process described above is external to the air separation plant unit 1 and is therefore independent of the particular cycle or process used in the air separation plant, since all that is required is that the air separation plant discharge some amount and form of nitrogen which discharge is standard. Therefore, the process described above can be used with all types of air separation processes or plants.
As stated previously, this invention is not limited to th storage of liquefied oxygen product and a clean waste nitrogen stream emanating from an air separation plant. As stated previously, oxygen product and clean waste nitrogen are used in this description only for purposes of illustration of the invention. It should be understood that other stored liquefied products than oxygen (such as nitrogen) and other streams emanating from an air separation plant than clean waste nitrogen (such as a scavenging stream of nitrogen which is then purified) can be utilized according to the invention described hereinbefore. Furthermore, this invention is not limited to any method, process or apparatus described hereinbefore, except as set forth in the following claims.
We claim:
1. A process for supply of gaseous oxygen from an air separation plant so as to meet varying demands comprising the steps of passing gaseous oxygen product at a substantially steady state from the plant to a source of demand, storing liquid oxygen product from said plant, vaporizing said liquid product in a vaporizer in response to demand, compressing waste nitrogen from said plant, cooling substantially all of said compressed waste nitrogen by heat exchange with said liquid oxygen product being vaporized, throttling said compressed and cooled waste nitrogen to liquefy it, controllably applying said liquefied waste nitrogen to said plant to provide refrigeration therefor, and passing vapors from said liquified nitrogen in heat exchange with the compressed nitrogen stream and then into mixture with the waste nitrogen before said waste nitrogen is compressed.
2. A process for supply of gas product from an air separation plant so as to meet varying demands, comprising the steps of passing a gas product stream at a substantially steady state from the plant to a source of demand, storing liquid products from said plant, vaporizing it in a vaporizer in response to the demand, compressing a nitrogen gas stream from said plant, cooling substantially all of said last-mentioned compressed gas by heat exchange with said liquid product being vaporized throttling said compressed and cooled nitrogen to liquefy it, controllably supplying said liquefied nitrogen stream to said plant to provide refrigeration therefor, passing said vaporized product on to the source of demand, and directing vapors emanating from said liquefied nitrogen in heat exchange with the nitrogen gas stream before said stream is compressed.
3. A process as set forth in claim 2, the gaseous product stream and liquid products being oxygen.
References Cited by the Examiner UNITED STATES PATENTS 3,058,314 10/1962 Gardner 6252 X 3,058,315 10/1962 Schuftan 62-52 3,195,316 7/1965 Maher et al. 6252 LLOYD 1,. KING, Primary Examiner.

Claims (1)

1. A PROCESS FOR SUPPLY OF GASEOUS OXYGEN FROM AN AIR SEPARATION PLANT SO AS TO MEET VARYING DEMANDS COMPRISING THE STEPS OF PASSING GASEOUS OXYGEN PRODUCT AT A SUBSTANTIALLY STEADY STATE FROM THE PLANT TO A SOURCE OF DEMAND, STORING LIQUID OXYGEN PRODUCT FROM SAID PLANT, VAPORIZING SAID LIQUID PRODUCT IN A VAPORIZER IN RESPONSE TO DEMAND, COMPRESSING WASTE NITROGEN FROM SAID PLANT, COOLING SUBSTANTIALLY ALL OF SAID COMPRESSED WASTE NITROGEN BY HEAT EXCHANGE WITH SAID LIQUID OXYGEN PRODUCT BEING VAPORIZED, THROTTLING SAID COMPRESSED AND COOLED WASTE NITROGEN TO LIQUEFY IT, CONTROLLABLY APPLYING SAID LIQUEFIED WASTE NITROGEN TO SAID PLANT TO PROVIDE REFRIGERATION THEREFOR, AND PASSING VAPORS FROM SAID LIQUIDFIED NITROGEN IN HEAT EXCHANGE WITH THE COMPRESSED NITROGEN STREAM AND THEN INTO MIXTURE WITH THE WASTE NITROGEN BEFORE SAID WASTE NITROGEN IS COMPRESSED.
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Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3319434A (en) * 1966-03-14 1967-05-16 Air Reduction Low temperature refrigeration and gas storage
US3397548A (en) * 1965-04-30 1968-08-20 Sulzer Ag Method for supplying a gaseous product to meet a variable demand
US3485053A (en) * 1966-03-25 1969-12-23 Air Liquide Process for the production of a gas with a variable output by controlling the degree of refrigeration in the liquefaction of stored gas
US4838912A (en) * 1985-07-11 1989-06-13 Leybold Ag Method and apparatus for the purification and recirculation of gases
US5265429A (en) * 1992-02-21 1993-11-30 Praxair Technology, Inc. Cryogenic air separation system for producing gaseous oxygen
US5467603A (en) * 1993-07-08 1995-11-21 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude High-pressure gas supply installation
US6584998B1 (en) * 2000-03-31 2003-07-01 Innovative Engineered Solutions, Llc Apparatus and method for regulating gas flow
US20180299195A1 (en) * 2017-04-12 2018-10-18 Nick J. Degenstein Method for controlling production of high pressure gaseous oxygen in an air separation unit

Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3058314A (en) * 1957-08-12 1962-10-16 British Oxygen Co Ltd Process and apparatus for the low temperature separation of air
US3058315A (en) * 1959-12-14 1962-10-16 British Oxygen Co Ltd Process for supplying a gaseous product to meet a fluctuating demand
US3195316A (en) * 1963-08-02 1965-07-20 Chicago & Bridge & Iron Compan Methane liquefaction system

Patent Citations (3)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3058314A (en) * 1957-08-12 1962-10-16 British Oxygen Co Ltd Process and apparatus for the low temperature separation of air
US3058315A (en) * 1959-12-14 1962-10-16 British Oxygen Co Ltd Process for supplying a gaseous product to meet a fluctuating demand
US3195316A (en) * 1963-08-02 1965-07-20 Chicago & Bridge & Iron Compan Methane liquefaction system

Cited By (9)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3397548A (en) * 1965-04-30 1968-08-20 Sulzer Ag Method for supplying a gaseous product to meet a variable demand
US3319434A (en) * 1966-03-14 1967-05-16 Air Reduction Low temperature refrigeration and gas storage
US3485053A (en) * 1966-03-25 1969-12-23 Air Liquide Process for the production of a gas with a variable output by controlling the degree of refrigeration in the liquefaction of stored gas
US4838912A (en) * 1985-07-11 1989-06-13 Leybold Ag Method and apparatus for the purification and recirculation of gases
US5265429A (en) * 1992-02-21 1993-11-30 Praxair Technology, Inc. Cryogenic air separation system for producing gaseous oxygen
US5467603A (en) * 1993-07-08 1995-11-21 L'air Liquide, Societe Anonyme Pour L'etude Et L'exploitation Des Procedes Georges Claude High-pressure gas supply installation
US6584998B1 (en) * 2000-03-31 2003-07-01 Innovative Engineered Solutions, Llc Apparatus and method for regulating gas flow
US20180299195A1 (en) * 2017-04-12 2018-10-18 Nick J. Degenstein Method for controlling production of high pressure gaseous oxygen in an air separation unit
US10359231B2 (en) * 2017-04-12 2019-07-23 Praxair Technology, Inc. Method for controlling production of high pressure gaseous oxygen in an air separation unit

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