CN115839600B - Cryogenic air separation plant - Google Patents

Cryogenic air separation plant Download PDF

Info

Publication number
CN115839600B
CN115839600B CN202310147318.1A CN202310147318A CN115839600B CN 115839600 B CN115839600 B CN 115839600B CN 202310147318 A CN202310147318 A CN 202310147318A CN 115839600 B CN115839600 B CN 115839600B
Authority
CN
China
Prior art keywords
liquid
tower
oxygen
outlet
nitrogen
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.)
Active
Application number
CN202310147318.1A
Other languages
Chinese (zh)
Other versions
CN115839600A (en
Inventor
范小华
钱宏青
殷黎航
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.)
Zhongke Fuhai Hangzhou Gas Engineering Technology Co ltd
Original Assignee
Zhongke Fuhai Hangzhou Gas Engineering Technology Co 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 Zhongke Fuhai Hangzhou Gas Engineering Technology Co ltd filed Critical Zhongke Fuhai Hangzhou Gas Engineering Technology Co ltd
Priority to CN202310147318.1A priority Critical patent/CN115839600B/en
Publication of CN115839600A publication Critical patent/CN115839600A/en
Application granted granted Critical
Publication of CN115839600B publication Critical patent/CN115839600B/en
Active legal-status Critical Current
Anticipated expiration legal-status Critical

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
    • F25J3/04006—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
    • F25J3/04084—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 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
    • F25J3/04151—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
    • F25J3/042—Division of the main heat exchange line in consecutive sections having different functions having an intermediate feed connection
    • 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
    • F25J3/0446—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 heat generated by mixing two different phases
    • 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
    • F25J3/04642—Recovering noble gases from air
    • F25J3/04648—Recovering noble gases from air argon
    • F25J3/04654—Producing crude argon in a crude argon column
    • F25J3/04666—Producing crude argon in a crude argon column as a parallel working rectification column of the low pressure column in a dual pressure main column system
    • F25J3/04672—Producing crude argon in a crude argon column as a parallel working rectification column of the low pressure column in a dual pressure main column system having a top condenser
    • F25J3/04678—Producing crude argon in a crude argon column as a parallel working rectification column of the low pressure column in a dual pressure main column system having a top condenser cooled by oxygen enriched liquid from high pressure column bottoms
    • 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
    • F25J3/04642—Recovering noble gases from air
    • F25J3/04648—Recovering noble gases from air argon
    • F25J3/04721—Producing pure argon, e.g. recovered from a crude argon column
    • F25J3/04727—Producing pure argon, e.g. recovered from a crude argon column using an auxiliary pure argon column for nitrogen rejection
    • 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
    • F25J2200/04—Processes or apparatus using separation by rectification in a dual pressure main column system
    • F25J2200/06—Processes or apparatus using separation by rectification in a dual pressure main column system in a classical double column flow-sheet, 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
    • F25J2235/00—Processes or apparatus involving steps for increasing the pressure or for conveying of liquid process streams
    • F25J2235/50—Processes or apparatus involving steps for increasing the pressure or for conveying of liquid process streams the fluid being 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
    • F25J2245/00—Processes or apparatus involving steps for recycling of process streams
    • F25J2245/42—Processes or apparatus involving steps for recycling of process streams the recycled stream being nitrogen

Landscapes

  • Engineering & Computer Science (AREA)
  • Physics & Mathematics (AREA)
  • Mechanical Engineering (AREA)
  • Thermal Sciences (AREA)
  • General Engineering & Computer Science (AREA)
  • Separation By Low-Temperature Treatments (AREA)

Abstract

The application provides a cryogenic air separation device which comprises a main tower and a mixing tower, wherein a liquid oxygen outlet is arranged on a main condensing evaporator of the main tower, a first liquid oxygen branch used for being communicated with the mixing tower is arranged on the liquid oxygen outlet, a liquid nitrogen outlet is arranged on a lower tower of the main tower, and a first liquid nitrogen branch used for being communicated with the mixing tower is arranged on the liquid nitrogen outlet so as to extract part of liquid oxygen and liquid nitrogen from the main tower and send the liquid oxygen and the liquid nitrogen into the mixing tower; and a reboiler is arranged at the bottom of the mixing tower to heat the mixed liquid at the bottom of the mixing tower to vaporize the mixed liquid, so that 80-98% of oxygen-enriched products with pressure are obtained at the top of the mixing tower. The cryogenic air separation plant can directly produce the pressurized oxygen-enriched product in the cold box, the working pressure of the mixing tower is also obtained by pressurizing the pressurized oxygen-enriched product by the liquid oxygen pump, an oxygen compressor is not required to be arranged outside, the total cost of the plant is reduced, and the fire hazard is avoided; meanwhile, the medium at the evaporation side of the reboiler is oxygen-enriched liquid, so that hydrocarbon is not easy to accumulate, and oxygen-enriched evaporation is safer under the same hydrocarbon content.

Description

Cryogenic air separation plant
Technical Field
The application relates to the technical field of high-purity oxygen preparation, in particular to a cryogenic air separation plant.
Background
The air separation device separates oxygen, nitrogen, argon and other gases from the air by a cryogenic method according to the principle that boiling points of different components in the air are different; the non-ferrous smelting industry also has the requirement of oxygen-enriched air separation, but the conventional cryogenic air separation can not directly produce an oxygen-enriched product with pressure (2-6 bar) in a cold box of a cryogenic air separation device while producing pure oxygen and liquid argon, but the pressurized air is required to be doped into the pure oxygen product outside the cold box, so that the pure oxygen and the liquid argon reach the required oxygen-enriched purity (80% -98%) after being mixed, but the energy consumption of the whole process route is higher; while the existing oxygen-enriched air separation device can directly produce the pressurized oxygen-enriched product from the cold box, pure oxygen and liquid argon products cannot be simultaneously extracted due to the specificity of the oxygen-enriched air separation device.
Disclosure of Invention
The invention aims to provide a cryogenic air separation plant, which can directly produce pressurized oxygen enrichment in a cold box and reduce the energy consumption of the plant.
The invention provides a cryogenic air separation plant, which comprises a main tower and a mixing tower; the main tower comprises an upper tower, a lower tower and a main condensing evaporator arranged between the upper tower and the lower tower; the bottom of the main condensation evaporator is provided with a liquid oxygen outlet, the liquid oxygen outlet is used for extracting liquid oxygen, the liquid oxygen outlet is provided with a first liquid oxygen branch, the first liquid oxygen branch is communicated with a feed inlet of the mixing tower, and a liquid oxygen pump is arranged on the first liquid oxygen branch; the top of the lower tower is provided with a liquid nitrogen outlet, the liquid nitrogen outlet is used for extracting liquid nitrogen, the liquid nitrogen outlet is provided with a first liquid nitrogen branch, and the first liquid nitrogen branch is communicated with a feed inlet of the mixing tower; the tower bottom of the mixing tower is provided with a reboiler, the tower top of the mixing tower is provided with an oxygen-enriched product outlet, the tower bottom of the mixing tower is provided with an oxygen-enriched liquid outlet, and the oxygen-enriched liquid outlet is communicated with an oxygen-enriched liquid reflux port at the bottom of the upper tower.
Further, the cryogenic air separation plant also comprises a mixing tower heat exchanger; the mixing tower heat exchanger comprises a cold flow channel, the first liquid oxygen branch and the first liquid nitrogen branch are respectively communicated with an inlet of the cold flow channel, an outlet of the cold flow channel is communicated with a feed inlet of the mixing tower, and the mixing tower heat exchanger is used for heating and rewarming liquid oxygen and liquid nitrogen flowing through the cold flow channel to a preset temperature.
Further, the cryogenic air separation plant also comprises a main heat exchanger and a subcooler; the outlet of the oxygen-enriched product is communicated with an oxygen-enriched channel of the main heat exchanger, and the outlet of the oxygen-enriched channel of the main heat exchanger is communicated with a pressurized oxygen-enriched product conveying pipeline; the top of the upper tower is provided with a low-pressure nitrogen outlet, the low-pressure nitrogen outlet is sequentially communicated with a low-pressure nitrogen channel of the subcooler and a low-pressure nitrogen channel of the main heat exchanger, and the low-pressure nitrogen channel of the main heat exchanger is used for being communicated with a low-pressure nitrogen product conveying pipeline; the top of the upper tower is provided with a dirty nitrogen outlet which is communicated with a dirty nitrogen channel of the subcooler, and the outlet of the dirty nitrogen channel of the subcooler is provided with a first nitrogen branch and a second nitrogen branch; the first nitrogen branch is communicated with a first polluted nitrogen channel of the main heat exchanger and then is communicated with a polluted nitrogen conveying pipeline; the second nitrogen branch is communicated with a second polluted nitrogen channel of the main heat exchanger and then is communicated with a polluted nitrogen conveying pipeline for regeneration of the purification system.
Further, the cryogenic air separation plant also comprises a feeding unit, wherein the feeding unit comprises an air compressor, a precooling system, a purifying system, an air booster and an expander; the air compressor, the precooling system and the purifying system are connected in sequence, and a first air branch and a second air branch are arranged at an outlet of the purifying system; the first air branch is sequentially connected with a first air channel of the main heat exchanger and a raw material feeding port of the lower tower; the second air branch is communicated with the air booster and is connected to the boosting end of the expander through the final-stage outlet of the air booster; the outlet of the pressurizing end is provided with a third air branch and a fourth air branch, and the third air branch is sequentially connected with the second air channel of the main heat exchanger, the first throttle valve and the raw material feeding port of the lower tower; the fourth air branch is sequentially connected with the third air channel of the main heat exchanger, the expansion end of the expander, the fourth air channel of the main heat exchanger and the raw material feeding port of the lower tower.
Further, the air supercharger is provided with a middle pumping port; the middle pumping port is sequentially connected with a fifth air channel of the main heat exchanger, the reboiler, a heat flow channel of the mixing tower heat exchanger and a raw material feeding port of the lower tower.
Further, the liquid oxygen outlet of the main condensation evaporator is divided into two paths, wherein one path is the first liquid oxygen branch, and the other path is the second liquid oxygen branch; the second liquid oxygen branch is communicated with a liquid oxygen channel of the subcooler, and an outlet of the liquid oxygen channel is communicated with a liquid oxygen product conveying pipeline.
Further, the cryogenic air separation plant also comprises a liquid nitrogen liquid separator; the liquid nitrogen outlet at the top of the lower tower is divided into three paths, namely the first liquid nitrogen branch, the second liquid nitrogen branch and the third liquid nitrogen branch in sequence; the second liquid nitrogen branch is sequentially connected with a liquid nitrogen channel of the subcooler, a second throttle valve and an inlet of the liquid nitrogen gas-liquid separator; the bottom of the liquid nitrogen gas-liquid separator is provided with a liquid nitrogen product outlet which is used for being communicated with a liquid nitrogen product conveying pipeline, the top of the liquid nitrogen gas-liquid separator is provided with a flash evaporation nitrogen outlet, and the flash evaporation nitrogen outlet is communicated with a nitrogen reflux port of the upper tower; the third liquid nitrogen branch is communicated with a liquid nitrogen channel of the main heat exchanger through a liquid nitrogen pump, and an outlet of the liquid nitrogen channel of the main heat exchanger is communicated with a nitrogen product conveying pipeline.
Further, the cryogenic air separation plant also comprises a crude argon column and a fine argon column; an argon fraction outlet is formed in the middle of the upper tower and is sequentially communicated with the crude argon tower and the refined argon tower; the bottom of the crude argon tower and the bottom of the refined argon tower are respectively provided with a liquid argon outlet, the liquid argon outlet of the crude argon tower is communicated with the crude argon reflux port of the upper tower through a crude argon conveying pump, and the liquid argon outlet of the refined argon tower is used for being communicated with a liquid argon product conveying channel.
Further, a crude argon condenser is arranged at the top of the crude argon tower; the bottom of the refined argon tower is provided with a pure argon evaporator, and the top of the refined argon tower is provided with a pure argon condenser; the bottom of the lower tower is provided with an oxygen-enriched liquid air outlet which is sequentially communicated with the subcooler and the pure argon evaporator and then is divided into two paths: one path is communicated with the upper tower through the pure argon condenser, and the other path is communicated with the upper tower after passing through the crude argon condenser.
Further, a liquid air outlet is formed in the middle of the lower tower, the liquid air outlet is sequentially communicated with a liquid air channel of the subcooler and a liquid air return port of the upper tower, and a throttle valve is arranged on a pipeline between the liquid air channel of the subcooler and the liquid air return port of the upper tower.
Compared with the prior art, the invention has the beneficial effects that:
the invention provides a cryogenic air separation device which comprises a main tower and a mixing tower, wherein the main tower is core equipment of the cryogenic air separation device and comprises an upper tower, a lower tower and a main condensing evaporator, the main condensing evaporator is arranged between the upper tower and the lower tower, the lower tower is provided with a raw material feeding port, and raw material air can enter the lower tower through the raw material feeding port to be rectified so as to separate out various components, such as liquid oxygen, liquid nitrogen and argon fractions; the main tower is provided with a liquid oxygen outlet for extracting liquid oxygen from the main tower and a liquid nitrogen outlet for extracting liquid nitrogen, the liquid oxygen outlet is arranged at the bottom of the main condensing evaporator, the liquid oxygen outlet is provided with a first liquid oxygen branch, the first liquid oxygen branch is communicated with a feed inlet of the mixing tower, and the first liquid oxygen branch is provided with a liquid oxygen pump so as to extract part of liquid oxygen from the main tower and send the liquid oxygen into the mixing tower after being pressurized by the liquid oxygen pump; the liquid nitrogen outlet is arranged at the top of the lower tower, and is provided with a first liquid nitrogen branch which is used for being communicated with a feed inlet of the mixing tower so as to extract part of liquid nitrogen from the main tower and send the liquid nitrogen into the mixing tower; the bottom of the mixing tower is provided with a reboiler, the mixed liquid of liquid oxygen and liquid nitrogen falls into the bottom of the mixing tower through a tower filler in the mixing tower and is heated and vaporized by the reboiler, so that 80-98% of the oxygen-enriched product with pressure is obtained at the top of the mixing tower, the working pressure of the mixing tower is the pressure required by the oxygen-enriched product, and the oxygen-enriched product with pressure can be pumped out through an oxygen-enriched product outlet at the top of the mixing tower.
The cryogenic air separation device innovatively introduces a pure liquid oxygen and pure liquid nitrogen mixing tower process route, and can directly produce a pressurized oxygen-enriched product in a cold box on the basis of maintaining a conventional cryogenic air separation argon adding and extracting system; meanwhile, the working pressure of the mixing tower is pressurized to the required pressure by the liquid oxygen pump, and the working pressure of the mixing tower is the pressure required by the oxygen-enriched product with pressure, so that an oxygen compressor is not required to be arranged outside, the total cost of the device is reduced, and the fire hazard caused by adopting an oxygen turbine compressor is avoided; meanwhile, because the medium at the evaporation side of the reboiler is oxygen-enriched liquid, compared with a pure liquid oxygen environment under the same pressure, hydrocarbon is less likely to accumulate, and the oxygen-enriched evaporation is safer under the same hydrocarbon content in an impure oxygen environment.
Drawings
In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present invention, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.
Fig. 1 is a schematic structural diagram of a cryogenic air separation plant according to an embodiment of the present invention.
Reference numerals:
1-air compressor, 2-precooling system, 3-purification system, 4-air booster, 5-expander, 6-main heat exchanger, 7-mixing tower, 8-reboiler, 9-subcooler, 10-main tower, 11-main condensing evaporator, 12-upper tower, 13-lower tower, 14-crude argon tower, 15-refined argon tower, 16-pure argon evaporator, 17-crude argon condenser, 18-pure argon condenser.
Detailed Description
The following description of the embodiments of the present invention will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the invention are shown.
The components of the embodiments of the present invention generally described and illustrated in the figures herein may be arranged and designed in a wide variety of different configurations. Thus, the following detailed description of the embodiments of the invention, as presented in the figures, is not intended to limit the scope of the invention, as claimed, but is merely representative of selected embodiments of the invention.
All other embodiments, which can be made by those skilled in the art based on the embodiments of the invention without making any inventive effort, are intended to be within the scope of the invention.
In the description of the present invention, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present invention and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present invention. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.
In the description of the present invention, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present invention will be understood in specific cases by those of ordinary skill in the art.
A cryogenic air separation plant according to some embodiments of the present application is described below with reference to fig. 1.
The application provides a cryogenic air separation plant, as shown in figure 1, comprising a feed unit, a main heat exchanger 6, a main column 10, a mixing column 7, a subcooler 9, a crude argon column 14 and a fine argon column 15.
The main tower 10 is a core device of a cryogenic air separation plant, and comprises an upper tower 12, a lower tower 13 and a main condensation evaporator 11, wherein the main condensation evaporator 11 is arranged between the upper tower 12 and the lower tower 13, the lower tower 13 is provided with a raw material feed port, and raw material air can enter the lower tower 13 for rectification through the raw material feed port after being processed by a feed unit and cooled by the main heat exchanger 6, so as to separate various components, such as liquid oxygen, liquid nitrogen and argon fractions.
The feeding unit comprises an air compressor 1, a pre-cooling system 2, a purifying system 3, an air booster 4 and an expander 5, wherein the air compressor 1 is communicated with a raw material air conveying pipeline, and an outlet of the air compressor 1 is sequentially connected with the pre-cooling system 2 and the purifying system 3, so that raw material air is compressed by the air compressor 1 and then sequentially subjected to pre-cooling and purifying by the pre-cooling system 2 and the purifying system 3.
The raw material air is divided into two paths after being purified, namely, a first air branch and a second air branch are arranged at an outlet of the purifying system 3: the first air branch is sequentially communicated with a first air channel of the main heat exchanger 6 and a raw material feed inlet of the lower tower 13, so that air in the first air branch enters the lower tower 13 after being cooled by the main heat exchanger 6; the second air branch communicates with the air booster 4 and is connected via a final outlet of the air booster 4 to the charging end of the expander 5.
The outlet of the pressurizing end of the expander 5 is also divided into two paths, namely a third air branch and a fourth air branch, wherein the third air branch is sequentially communicated with the second air channel of the main heat exchanger 6, the first throttle valve and the raw material feeding port of the lower tower 13, so that the pressurized raw material air enters the lower tower 13 after being cooled by the main heat exchanger 6; the fourth air branch is sequentially communicated with the third air channel of the main heat exchanger 6, the expansion end of the expander 5, the fourth air channel of the main heat exchanger 6 and the raw material feed inlet of the lower tower 13, so that the pressurized raw material air is cooled to a certain temperature by the main heat exchanger 6, then is discharged out of the main heat exchanger 6 and enters the expansion end of the collision, is further cooled to a preset temperature close to the saturation temperature by the main heat exchanger 6 after being expanded, and then enters the lower tower 13.
The air booster 4 is also provided with a middle pumping port which is communicated with a fifth air channel of the main heat exchanger 6, a reboiler 8 at the bottom of the mixing tower 7, a heat flow channel of the heat exchanger and a raw material inlet of the lower tower 13 in sequence through pipelines; the middle pumping air of the incoming air booster 4 is cooled by the main heat exchanger 6 and then enters the reboiler 8 at the bottom of the mixing tower 7 as a heat source, kettle liquid (mixed liquid of liquid oxygen and liquid nitrogen) at the bottom of the mixing tower 7 is heated and vaporized, and enters the hot flow channel of the mixing tower heat exchanger after exiting from the reboiler 8, exchanges heat with the liquid oxygen and the liquid nitrogen in the cold flow channel of the mixing tower heat exchanger, and finally enters the lower tower 13.
The main column 10 is provided with a liquid oxygen outlet for extracting liquid oxygen from the inside of the main column 10, a liquid nitrogen outlet for extracting liquid nitrogen, and an argon fraction outlet for extracting an argon fraction.
Wherein the liquid oxygen outlet is arranged at the bottom of the main condensation evaporator 11 of the main tower 10, and the liquid oxygen outlet is divided into two paths, namely, the liquid oxygen outlet is provided with a first liquid oxygen branch and a second liquid oxygen branch.
The first liquid oxygen branch is used for being communicated with a feed inlet of the mixing tower 7 so as to extract part of liquid oxygen from the main tower 10 and send the part of liquid oxygen into the mixing tower 7 to participate in the preparation of the pressurized oxygen-enriched product.
The second liquid oxygen branch is communicated with the liquid oxygen channel of the subcooler 9, and then is communicated with an external liquid oxygen product conveying pipeline, so that the liquid oxygen in the liquid oxygen branch is cooled and then taken as a liquid oxygen product to be sent out of the cold box through the liquid oxygen product conveying pipeline, for example, the liquid oxygen product is sent into a liquid oxygen storage tank for storage.
The liquid nitrogen outlet is arranged at the top of the lower tower 13 and is divided into three paths, namely a first liquid nitrogen branch, a second liquid nitrogen branch and a third liquid nitrogen branch in sequence.
The first liquid nitrogen branch is used for being communicated with a feed inlet of the mixing tower 7 so as to extract part of liquid nitrogen from the main tower 10 and send the liquid nitrogen into the mixing tower 7 to participate in the preparation of the pressurized oxygen-enriched product together with liquid oxygen from the first liquid oxygen branch.
The second liquid nitrogen branch is sequentially communicated with a liquid nitrogen channel of the subcooler 9, a second throttle valve and an inlet of the liquid nitrogen gas-liquid separator, so that the liquid nitrogen in the branch is throttled to be sent into the liquid nitrogen gas-liquid separator for gas-liquid separation after being subcooled by the subcooler 9.
The bottom of the liquid nitrogen liquid separator is provided with a liquid nitrogen product outlet for extracting a liquid nitrogen product, and the liquid nitrogen product outlet is communicated with a liquid nitrogen product conveying pipeline so as to convey the liquid nitrogen product out of the cold box; the top of the liquid nitrogen liquid separator is provided with a flash nitrogen outlet which is communicated with a nitrogen reflux port at the top of the upper tower 12 to send the flash nitrogen to the top of the upper tower 12.
The third nitrogen branch is communicated with a liquid nitrogen channel of the main heat exchanger 6 through a liquid nitrogen pump, and an outlet of the liquid nitrogen channel is communicated with a nitrogen product conveying pipeline, so that the liquid nitrogen in the branch is pressurized by the liquid nitrogen pump and then heated and gasified by the main heat exchanger 6 to be used as product nitrogen, and the product nitrogen is sent out of the cold box through the nitrogen product conveying pipeline.
Regarding the preparation of the pressurized oxygen-enriched product, specifically, the cryogenic air separation plant further comprises a mixing tower heat exchanger comprising a hot flow channel and a cold flow channel which can perform heat exchange, as described above, the evacuated air in the incoming air supercharger 4 flows through the main heat exchanger 6, the reboiler 8 at the bottom of the mixing tower 7, the hot flow channel and then flows into the lower tower 13, and the evacuated air is used as a heat source to heat the fluid flowing through the cold flow channel in the mixing tower heat exchanger.
The first liquid oxygen branch is provided with a liquid oxygen pump, and the first liquid oxygen branch and the first liquid nitrogen branch are respectively communicated with the inlet of the cold flow channel, specifically, the first liquid oxygen branch and the first liquid nitrogen branch are converged and then connected to the inlet of the cold flow channel; the outlet of the cold flow channel is communicated with the feed inlet of the mixing tower 7, so that part of liquid oxygen pumped from the bottom of the main condensation evaporator 11 is pressurized by a liquid oxygen pump, is mixed with liquid nitrogen from the top of the lower tower 13, is heated and rewuped to a slightly cooled preset temperature by an independent heat exchanger (i.e. a mixing tower heat exchanger), and is sent into the mixing tower 7.
The working pressure of the mixing tower 7 is pressurized to the required pressure by a liquid oxygen pump, the mixed liquid of liquid oxygen and liquid nitrogen falls into the bottom of the mixing tower 7 through a tower inner filler in the mixing tower 7, and is heated and gasified by a reboiler 8 at the bottom of the mixing tower 7 (the heat of the reboiler 8 is provided by the medium-pumped air of the air-air booster 4 as described above), so that 80-98% of oxygen-enriched product is obtained at the top of the mixing tower 7, the working pressure of the mixing tower 7 is the required pressure of the oxygen-enriched product, and the oxygen-enriched product with pressure can be pumped out through an oxygen-enriched product outlet at the top of the mixing tower 7.
Preferably, an oxygen-enriched product outlet at the top of the mixing tower 7 is communicated with an oxygen-enriched channel of the main heat exchanger 6, and the outlet of the oxygen-enriched channel is used for being communicated with a pressurized oxygen-enriched product conveying pipeline so as to heat and rewire the pressurized oxygen-enriched product to a preset temperature through the main heat exchanger 6 and then send out of the cold box through the pressurized oxygen-enriched product conveying pipeline.
Preferably, the bottom of the mixing tower 7 is provided with an oxygen-enriched liquid outlet, the bottom of the upper tower 12 is provided with an oxygen-enriched liquid reflux port, and the oxygen-enriched liquid outlet is communicated with the oxygen-enriched liquid reflux port so as to be capable of extracting a small part of the oxygen-enriched liquid from the bottom of the mixing tower 7 and recycling the oxygen-enriched liquid back to the upper tower 12, thereby reducing the risk of hydrocarbon accumulation.
In the embodiment of the present application, preferably, the top of the upper tower 12 is further provided with a low-pressure nitrogen outlet, the low-pressure nitrogen outlet is used for extracting low-pressure nitrogen from the top of the upper tower 12, the low-pressure nitrogen outlet is sequentially communicated with a low-pressure nitrogen channel of the subcooler 9 and a low-pressure nitrogen channel of the main heat exchanger 6, an outlet of the low-pressure nitrogen channel is used for being communicated with a low-pressure nitrogen product conveying pipeline, and the extracted low-pressure nitrogen is sent out of the cold box as a low-pressure nitrogen product through the low-pressure nitrogen product conveying pipeline after being reheated by the subcooler 9 and the main heat exchanger 6.
In this embodiment, preferably, the top of the upper tower 12 is provided with a dirty nitrogen outlet, the dirty nitrogen outlet is communicated with a dirty nitrogen channel of the subcooler 9, and the outlet of the dirty nitrogen channel of the subcooler 9 is provided with a first nitrogen branch and a second nitrogen branch; the first nitrogen branch is communicated with a first polluted nitrogen channel of the main heat exchanger 6 and then is communicated with a polluted nitrogen conveying pipeline; the second nitrogen branch is communicated with a second polluted nitrogen channel of the main heat exchanger 6 and then is communicated with a polluted nitrogen conveying pipeline for regeneration of the purification system. The dirty nitrogen extracted from the upper tower 12 is heated and rewarmed through the subcooler 9 and the main heat exchanger 6, and the dirty nitrogen is divided into two paths, one path is sent out of the cold box through a dirty nitrogen conveying pipeline, the other path is used for regenerating the molecular sieve of the purification system 3, and the other path is independently sent out of the cold box through a dirty nitrogen conveying pipeline for regenerating the purification system.
In this embodiment, preferably, the middle part of the lower tower 13 is provided with a liquid-air outlet, the upper tower 12 is provided with a liquid-air return port, and the liquid-air outlet of the lower tower 13 is sequentially communicated with a liquid-air channel of the subcooler 9, a throttle valve and the liquid-air return port of the upper tower 12 through pipelines; so that the liquid space can be extracted from the lower tower 13 through the liquid space outlet of the lower tower 13, and the extracted liquid space is throttled into the upper tower 12 after being supercooled by the cooler 9.
In this embodiment, preferably, an oxygen vent is reserved in the bottom of the upper column 12.
In this embodiment, the cryogenic air separation plant preferably further comprises a crude argon column 14 and a fine argon column 15, wherein an argon fraction outlet is arranged in the middle of the upper column 12 and is sequentially communicated with the crude argon column 14 and the fine argon column 15; specifically, the argon fraction outlet of the upper column 12 is communicated with the argon fraction inlet of the crude argon column 14, and the crude argon outlet of the crude argon column 14 is communicated with the crude argon inlet of the refined argon column 15, so that the argon fraction extracted from the upper column 12 sequentially enters the crude argon column 14 and the refined argon column 15 for purification, crude liquid argon is obtained at the bottom of the crude argon column 14, and pure liquid argon is obtained at the bottom of the refined argon column 15.
The bottom of the crude argon column 14 is provided with a liquid argon outlet, and the liquid argon outlet of the crude argon column 14 is communicated with a crude argon reflux port of the upper column 12 through a crude argon conveying pump, so that crude liquid argon at the bottom of the crude argon column 14 can be refluxed to the upper column 12 through the crude argon conveying pump.
The bottom of the refined argon tower 15 is also provided with a liquid argon outlet, and the liquid argon outlet of the refined argon tower 15 is communicated with a liquid argon storage tank through a liquid argon product conveying channel, so that pure liquid argon at the bottom of the refined argon tower 15 can be used as a liquid argon product to be sent into the liquid argon storage tank for collection.
In this embodiment, preferably, the top of the crude argon column 14 is provided with a crude argon condenser 17, the bottom of the refined argon column 15 is provided with a pure argon condenser 18, and the bottom of the refined argon column 15 is provided with a pure argon evaporator 16; the bottom of the lower tower 13 is provided with an oxygen-enriched liquid space, and the bottom of the lower tower 13 is provided with an oxygen-enriched liquid space outlet so as to be capable of extracting the oxygen-enriched liquid space from the bottom of the lower tower 13; the oxygen-enriched liquid air outlet is sequentially communicated with an oxygen-enriched liquid air channel of the subcooler 9 and the pure argon evaporator 16 at the bottom of the refined argon tower 15, so that the oxygen-enriched liquid air at the bottom of the lower tower 13 flows into the pure argon evaporator 16 at the bottom of the refined argon tower 15 after being subcooled by the cooler 9.
The outlet of the pure argon evaporator 16 is divided into two paths, wherein one path is sequentially communicated with the pure argon condenser 18 and the upper tower 12, and the other path is sequentially communicated with the crude argon condenser 17 and the upper tower 12; the oxygen-enriched liquid from the pure argon evaporator 16 is divided into two paths, wherein one path flows into the pure argon condenser 18 to provide a cold source for the pure argon condenser 18 and enters the upper tower 12 after being evaporated; the other path flows into the crude argon condenser 17 to provide a cold source for the crude argon condenser 17 and enters the upper tower 12 after evaporation.
The cryogenic air separation device innovatively introduces a pure liquid oxygen and pure liquid nitrogen mixing tower process route, and can directly produce a pressurized oxygen-enriched product in a cold box and produce a byproduct liquid argon product with high extraction rate on the basis of maintaining a conventional cryogenic air separation argon adding system.
Meanwhile, the working pressure of the mixing tower is pressurized to the required pressure by the liquid oxygen pump, and the working pressure of the mixing tower is the pressure required by the oxygen-enriched product with pressure, so that an oxygen compressor is not required to be arranged outside, the total cost of the device is reduced, and the fire hazard caused by adopting an oxygen turbine compressor is avoided.
Meanwhile, the reboiler of the mixing tower uses the medium pumped air as a heat source, and the evaporation side medium of the reboiler is oxygen-enriched liquid, so that the saturation temperature is lower than that of pure liquid oxygen, and the pressure corresponding to the required medium pumped air is lower, thereby saving energy and reducing consumption to a certain extent.
Meanwhile, because the medium at the evaporation side of the reboiler is oxygen-enriched liquid, compared with a pure liquid oxygen environment under the same pressure, hydrocarbon is less likely to accumulate, and the oxygen-enriched evaporation is safer under the same hydrocarbon content in an impure oxygen environment.
Meanwhile, liquid oxygen is pressurized by the liquid oxygen pump and enters the mixing tower after being reset to a saturated state by the independently arranged mixing tower heat exchanger, so that the enthalpy required by vaporization of unit liquid oxygen is reduced, and the amount of the middle-pumping air used as a heat source is reduced as much as possible.
Meanwhile, after the medium-pressure evacuated gas is condensed into liquid air through a reboiler of the mixing tower, the liquid air is cooled to saturation temperature after being subjected to heat exchange with pressurized liquid oxygen through an independent mixing tower heat exchanger, so that the gasification rate of the liquid air after entering the lower tower is greatly reduced, the high-pressure liquid air quantity required to be liquefied by the main heat exchanger is reduced, the positive-flow air quantity directly entering the bottom of the lower tower is increased, the heat exchange temperature difference of the main heat exchanger is optimized, and the rectification efficiency of the integral cold box is also improved.
Meanwhile, compared with a conventional oxygen-enriched air separation device, the upper tower of the cryogenic air separation device can still produce pure liquid oxygen, so that argon fractions can be extracted from the middle and lower sections of the upper tower, liquid argon products with high extraction rate can be obtained, and the market demands of peripheral high values are met.
Meanwhile, because the oxygen-enriched product is directly compressed in the cold box for heat exchange and rewarming, the overall heat exchange temperature field is more uniformly distributed, even for the device with a slightly large liquid quantity, single expansion refrigeration can be adopted, and the air after expansion enters the main heat exchanger for further cooling and then enters the lower tower, so that compared with the air after expansion directly enters the lower tower, the overall heat exchange loss is small, the energy consumption is low, and the device extraction rate is higher; compared with the conventional high-low temperature expansion, the single expansion of the method has low cost and lower failure rate.
Finally, it should be noted that: the above embodiments are only for illustrating the technical solution of the present invention, and not for limiting the same; although the invention has been described in detail with reference to the foregoing embodiments, it will be understood by those of ordinary skill in the art that: the technical scheme described in the foregoing embodiments can be modified or some or all of the technical features thereof can be replaced by equivalents; such modifications and substitutions do not depart from the spirit of the invention.

Claims (5)

1. The cryogenic air separation plant is characterized by comprising a main tower and a mixing tower;
the main tower comprises an upper tower, a lower tower and a main condensing evaporator arranged between the upper tower and the lower tower;
the bottom of the main condensation evaporator is provided with a liquid oxygen outlet, the liquid oxygen outlet is used for extracting liquid oxygen, the liquid oxygen outlet is provided with a first liquid oxygen branch, the first liquid oxygen branch is communicated with a feed inlet of the mixing tower, and a liquid oxygen pump is arranged on the first liquid oxygen branch;
the top of the lower tower is provided with a liquid nitrogen outlet, the liquid nitrogen outlet is used for extracting liquid nitrogen, the liquid nitrogen outlet is provided with a first liquid nitrogen branch, and the first liquid nitrogen branch is communicated with a feed inlet of the mixing tower;
the tower bottom of the mixing tower is provided with a reboiler, the tower top of the mixing tower is provided with an oxygen-enriched product outlet, the tower bottom of the mixing tower is provided with an oxygen-enriched liquid outlet, and the oxygen-enriched liquid outlet is communicated with an oxygen-enriched liquid reflux port at the bottom of the upper tower;
the cryogenic air separation plant also comprises a mixing tower heat exchanger;
the mixing tower heat exchanger comprises a cold flow channel, the first liquid oxygen branch and the first liquid nitrogen branch are respectively communicated with an inlet of the cold flow channel, an outlet of the cold flow channel is communicated with a feed inlet of the mixing tower, and the mixing tower heat exchanger is used for heating and rewarming liquid oxygen and liquid nitrogen flowing through the cold flow channel to a preset temperature;
the cryogenic air separation plant also comprises a main heat exchanger, a subcooler and a feeding unit, wherein the feeding unit comprises an air compressor, a precooling system, a purifying system, an air booster and an expander;
the air compressor, the precooling system and the purifying system are connected in sequence, and a first air branch and a second air branch are arranged at an outlet of the purifying system;
the first air branch is sequentially connected with a first air channel of the main heat exchanger and a raw material feeding port of the lower tower; the second air branch is communicated with the air booster and is connected to the boosting end of the expander through the final-stage outlet of the air booster;
the outlet of the pressurizing end is provided with a third air branch and a fourth air branch, and the third air branch is sequentially connected with the second air channel of the main heat exchanger, the first throttle valve and the raw material feeding port of the lower tower;
the fourth air branch is sequentially connected with the third air channel of the main heat exchanger, the expansion end of the expander, the fourth air channel of the main heat exchanger and the raw material feed inlet of the lower tower;
the air booster is provided with a middle pumping port;
the middle pumping port is sequentially connected with a fifth air channel of the main heat exchanger, the reboiler, a heat flow channel of the mixing tower heat exchanger and a raw material feeding port of the lower tower;
the cryogenic air separation plant also comprises a crude argon tower and a fine argon tower;
an argon fraction outlet is formed in the middle of the upper tower and is sequentially communicated with the crude argon tower and the refined argon tower;
the liquid argon outlets of the crude argon tower and the refined argon tower are respectively provided with a liquid argon outlet, the liquid argon outlet of the crude argon tower is communicated with the crude argon reflux port of the upper tower through a crude argon conveying pump, and the liquid argon outlet of the refined argon tower is communicated with a liquid argon product conveying channel;
a crude argon condenser is arranged at the top of the crude argon tower;
the bottom of the refined argon tower is provided with a pure argon evaporator, and the top of the refined argon tower is provided with a pure argon condenser;
the bottom of the lower tower is provided with an oxygen-enriched liquid air outlet which is sequentially communicated with the subcooler and the pure argon evaporator and then is divided into two paths:
one path is communicated with the upper tower through the pure argon condenser, and the other path is communicated with the upper tower after passing through the crude argon condenser.
2. The cryogenic air separation plant of claim 1 wherein the oxygen-enriched product outlet is in communication with an oxygen-enriched channel of the main heat exchanger, the outlet of the oxygen-enriched channel of the main heat exchanger being for communication with a pressurized oxygen-enriched product delivery conduit;
the top of the upper tower is provided with a low-pressure nitrogen outlet, the low-pressure nitrogen outlet is sequentially communicated with a low-pressure nitrogen channel of the subcooler and a low-pressure nitrogen channel of the main heat exchanger, and the low-pressure nitrogen channel of the main heat exchanger is used for being communicated with a low-pressure nitrogen product conveying pipeline;
the top of the upper tower is provided with a dirty nitrogen outlet which is communicated with a dirty nitrogen channel of the subcooler, and the outlet of the dirty nitrogen channel of the subcooler is provided with a first nitrogen branch and a second nitrogen branch;
the first nitrogen branch is communicated with a first polluted nitrogen channel of the main heat exchanger and then is communicated with a polluted nitrogen conveying pipeline; the second nitrogen branch is communicated with a second polluted nitrogen channel of the main heat exchanger and then is communicated with a polluted nitrogen conveying pipeline for regeneration of the purification system.
3. The cryogenic air separation plant of claim 1 wherein the liquid oxygen outlet of the main condensing evaporator is split into two paths, one of which is the first liquid oxygen branch and the other is the second liquid oxygen branch;
the second liquid oxygen branch is communicated with a liquid oxygen channel of the subcooler, and an outlet of the liquid oxygen channel is communicated with a liquid oxygen product conveying pipeline.
4. The cryogenic air separation plant of claim 1 further comprising a liquid nitrogen liquid separator;
the liquid nitrogen outlet at the top of the lower tower is divided into three paths, namely the first liquid nitrogen branch, the second liquid nitrogen branch and the third liquid nitrogen branch in sequence;
the second liquid nitrogen branch is sequentially connected with a liquid nitrogen channel of the subcooler, a second throttle valve and an inlet of the liquid nitrogen gas-liquid separator; the bottom of the liquid nitrogen gas-liquid separator is provided with a liquid nitrogen product outlet which is used for being communicated with a liquid nitrogen product conveying pipeline, the top of the liquid nitrogen gas-liquid separator is provided with a flash evaporation nitrogen outlet, and the flash evaporation nitrogen outlet is communicated with a nitrogen reflux port of the upper tower;
the third liquid nitrogen branch is communicated with a liquid nitrogen channel of the main heat exchanger through a liquid nitrogen pump, and an outlet of the liquid nitrogen channel of the main heat exchanger is communicated with a nitrogen product conveying pipeline.
5. The cryogenic air separation plant of claim 1 wherein a liquid air outlet is provided in the middle of the lower tower, the liquid air outlet is in communication with the liquid air passage of the subcooler and the liquid air return port of the upper tower in sequence, and a throttle valve is provided on a pipeline between the liquid air passage of the subcooler and the liquid air return port of the upper tower.
CN202310147318.1A 2023-02-22 2023-02-22 Cryogenic air separation plant Active CN115839600B (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
CN202310147318.1A CN115839600B (en) 2023-02-22 2023-02-22 Cryogenic air separation plant

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
CN202310147318.1A CN115839600B (en) 2023-02-22 2023-02-22 Cryogenic air separation plant

Publications (2)

Publication Number Publication Date
CN115839600A CN115839600A (en) 2023-03-24
CN115839600B true CN115839600B (en) 2023-05-05

Family

ID=85580042

Family Applications (1)

Application Number Title Priority Date Filing Date
CN202310147318.1A Active CN115839600B (en) 2023-02-22 2023-02-22 Cryogenic air separation plant

Country Status (1)

Country Link
CN (1) CN115839600B (en)

Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103062990A (en) * 2013-01-24 2013-04-24 成都深冷液化设备股份有限公司 Novel liquid air separation device and process

Family Cites Families (7)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US6182471B1 (en) * 1999-06-28 2001-02-06 Praxair Technology, Inc. Cryogenic rectification system for producing oxygen product at a non-constant rate
FR2895068B1 (en) * 2005-12-15 2014-01-31 Air Liquide AIR SEPARATION METHOD BY CRYOGENIC DISTILLATION
EP3101374A3 (en) * 2015-06-03 2017-01-18 Linde Aktiengesellschaft Method and installation for cryogenic decomposition of air
CN205373261U (en) * 2015-12-29 2016-07-06 中国空分设备有限公司 Low positive pressure of low high extraction percentage of liquid flows large -scale interior compression air separation system of inflation
CN107940896B (en) * 2017-11-02 2019-06-18 河南大学 A kind of device and method using heat pump techniques production oxygen rich air and high pressure, high purity nitrogen
CN109186179B (en) * 2018-09-30 2023-09-19 苏州制氧机股份有限公司 Full-rectification argon extraction oxygen-enriched air separation device and process
CN211316726U (en) * 2019-11-26 2020-08-21 河南开元空分集团有限公司 Air separation plant with double-pump internal pressure and synergistic tower

Patent Citations (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN103062990A (en) * 2013-01-24 2013-04-24 成都深冷液化设备股份有限公司 Novel liquid air separation device and process

Also Published As

Publication number Publication date
CN115839600A (en) 2023-03-24

Similar Documents

Publication Publication Date Title
US6336345B1 (en) Process and apparatus for low temperature fractionation of air
EP3719427A1 (en) Cryogenic distillation method and apparatus for producing pressurized air by means of expander booster in linkage with nitrogen expander for braking
US9360250B2 (en) Process and apparatus for the separation of air by cryogenic distillation
CN113405318A (en) Device for producing pure nitrogen by using single rectifying tower and using method thereof
CN216716763U (en) Device for producing pure nitrogen by using single rectifying tower
CN102901322B (en) Pressure nitrogen and the method and apparatus of pressure oxygen is obtained by Cryogenic air separation
CA3122855A1 (en) Apparatus and method for separating air by cryogenic distillation
CN104185767B (en) For the method and apparatus producing two strands of partial air flow purified
CN201885514U (en) Device with subcooler and single tower for preparing high-purity nitrogen
CN101915495A (en) Full liquid-air separation unit using liquefied natural gas cold energy and method thereof
CN115839600B (en) Cryogenic air separation plant
CN114413570B (en) Double-tower floor type nitrogen making device
CN216115003U (en) Small air separation device for preparing low-pressure low-purity oxygen and medium-pressure nitrogen
CN111542723B (en) Method for producing air product based on cryogenic rectification process and air separation system
CN201876055U (en) Full-liquid air separation device using cold energy of liquefied natural gas
CN103003652A (en) Oxygen vaporization method and system
CN112781321B (en) Air separation device with nitrogen liquefier and method
US20040244416A1 (en) Method for separating air by cryogenic distillation and installation therefor
CN115839601B (en) Liquid space division and krypton-xenon pre-concentration integrated equipment
CN114413569B (en) Double-tower nitrogen production device and method
CN114017990B (en) Small air separation device for preparing low-pressure low-purity oxygen and medium-pressure nitrogen
CN1789868A (en) Air separating method by utilizing liquefied natural gas
US6490884B2 (en) Process and device for production of oxygen and nitrogen
CN204027204U (en) Liquid nitrogen is assisted rectifying air separation plant
CN114183997B (en) Device and method for preparing low-pressure nitrogen

Legal Events

Date Code Title Description
PB01 Publication
PB01 Publication
SE01 Entry into force of request for substantive examination
SE01 Entry into force of request for substantive examination
GR01 Patent grant
GR01 Patent grant