JP2997939B2 - Recovery and utilization of evaporative gas in low-temperature storage tank - Google Patents

Recovery and utilization of evaporative gas in low-temperature storage tank

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Publication number
JP2997939B2
JP2997939B2 JP2561590A JP2561590A JP2997939B2 JP 2997939 B2 JP2997939 B2 JP 2997939B2 JP 2561590 A JP2561590 A JP 2561590A JP 2561590 A JP2561590 A JP 2561590A JP 2997939 B2 JP2997939 B2 JP 2997939B2
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Japan
Prior art keywords
gas
storage tank
low
exhaust gas
temperature storage
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Expired - Fee Related
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JP2561590A
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Japanese (ja)
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JPH03230080A (en
Inventor
和人 遠藤
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日本酸素株式会社
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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
    • F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
    • F25J3/04254—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using the cold stored in external cryogenic fluids
    • F25J3/0426—The cryogenic component does not participate in the fractionation
    • 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
    • F25J3/04157—Afterstage cooling and so-called "pre-cooling" of the feed air upstream the air purification unit and 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
    • 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
    • F25J3/04163—Hot end purification of the feed air
    • F25J3/04169—Hot end purification of the feed air by adsorption of the impurities
    • F25J3/04181—Regenerating the adsorbents
    • 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
    • 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
    • F25J3/044—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a single pressure main column system only
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
    • F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
    • F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
    • F25J3/04406—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system
    • F25J3/04412—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air using a dual pressure main column system in a classical double column flowsheet, i.e. with thermal coupling by a main reboiler-condenser in the bottom of low pressure respectively top of high pressure column
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2200/00—Processes or apparatus using separation by rectification
    • F25J2200/72—Refluxing the column with at least a part of the totally condensed overhead gas
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2205/00—Processes or apparatus using other separation and/or other processing means
    • F25J2205/30—Processes or apparatus using other separation and/or other processing means using a washing, e.g. "scrubbing" or bubble column for purification purposes
    • F25J2205/32—Processes or apparatus using other separation and/or other processing means using a washing, e.g. "scrubbing" or bubble column for purification purposes as direct contact cooling tower to produce a cooled gas stream, e.g. direct contact after cooler [DCAC]
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2205/00—Processes or apparatus using other separation and/or other processing means
    • F25J2205/30—Processes or apparatus using other separation and/or other processing means using a washing, e.g. "scrubbing" or bubble column for purification purposes
    • F25J2205/34—Processes or apparatus using other separation and/or other processing means using a washing, e.g. "scrubbing" or bubble column for purification purposes as evaporative cooling tower to produce chilled water, e.g. evaporative water chiller [EWC]
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2205/00—Processes or apparatus using other separation and/or other processing means
    • F25J2205/60—Processes or apparatus using other separation and/or other processing means using adsorption on solid adsorbents, e.g. by temperature-swing adsorption [TSA] at the hot or cold end
    • F25J2205/66—Regenerating the adsorption vessel, e.g. kind of reactivation gas
    • F25J2205/70—Heating the adsorption vessel
    • 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
    • F25J2245/40—Processes or apparatus involving steps for recycling of process streams the recycled stream being air
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • 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
    • 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
    • F25J2245/50—Processes or apparatus involving steps for recycling of process streams the recycled stream 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
    • F25J2245/90—Processes or apparatus involving steps for recycling of process streams the recycled stream being boil-off gas from storage
    • 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
    • F25J2270/00—Refrigeration techniques used
    • F25J2270/90—External refrigeration, e.g. conventional closed-loop mechanical refrigeration unit using Freon or NH3, unspecified external refrigeration
    • 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
    • F25J2290/00—Other details not covered by groups F25J2200/00 - F25J2280/00
    • F25J2290/62—Details of storing a fluid in a tank

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)

Description

【発明の詳細な説明】 〔産業上の利用分野〕 本発明は、低温貯槽内の蒸発ガスの回収方法に関し、
特に深冷分離装置に付属した低温貯槽内の蒸発ガスを回
収し利用する方法に関する。The present invention relates to a method for recovering evaporative gas in a low-temperature storage tank,
In particular, the present invention relates to a method for recovering and using evaporative gas in a low-temperature storage tank attached to a cryogenic separation device.

〔従来の技術〕[Conventional technology]

従来から、深冷分離装置の一種として空気液化分離装
置が広く用いられている。通常、中型，大型の空気液化
分離装置に付属する低温貯槽としては、貯蔵設備コスト
の関係から、低圧貯槽であることが多い。このため、低
温貯槽内で蒸発するガス、いわゆるオフガスを有効利用
するためには、加圧操作によるエネルギーを付加する
か、又は別途寒冷を用いて再液化させる熱交換器を増設
しなければ、低圧のオフガスを回収できないので、回収
コストが高くなり、一般には、大気放出されている。Conventionally, an air liquefaction separator has been widely used as a kind of cryogenic separator. Normally, low-temperature storage tanks attached to medium-sized and large-sized air liquefaction / separation apparatuses are often low-pressure storage tanks in view of the cost of storage equipment. For this reason, in order to effectively use the gas that evaporates in the low-temperature storage tank, the so-called off-gas, low pressure must be applied unless energy by pressurizing operation is added or a heat exchanger that reliquefies by using cold separately is added. Since the off-gas cannot be recovered, the recovery cost is high, and it is generally released to the atmosphere.

このような低温貯槽のオフガスを回収する方法とし
て、オフガスを空気液化分離装置の製品ガスに合流させ
て回収することが知られている。As a method for recovering the off-gas from such a low-temperature storage tank, it is known to collect the off-gas by merging it with the product gas of the air liquefaction / separation apparatus.

一方、最近の空気液化分離装置等の深冷分離装置は、
窒素をはじめとし各種製品ガスの需要増大により、原料
ガスに対する製品ガス（液化ガスも含む）の採取割合が
増加し、排ガス量が減少している。On the other hand, recent cryogenic separation equipment such as air liquefaction separation equipment,
Due to an increase in demand for various product gases such as nitrogen, the proportion of product gas (including liquefied gas) to the raw material gas is increasing, and the amount of exhaust gas is decreasing.

〔発明が解決しようとする課題〕[Problems to be solved by the invention]

従って、原料ガス中の水分や炭酸ガスを除去する吸着
設備や、原料ガスの予冷を行う冷水塔等の前処理工程の
再生や冷却に用いる再生ガスあるいは冷却ガスの量が減
少し不足してきている。冷えば、吸着器の再生ガスとし
て低圧乾燥ガスである排ガスを用いているが、排ガス量
の減少に伴い十分な再生ガス流量を確保できないため、
再生ガスを長時間流して再生する必要がでてきた。この
ように長時間かけて再生を行うと、原料ガスの吸着処理
時間も長くなるため、結果的に大型の吸着器を設置せざ
るを得なくなり、吸着剤コストや容器製作コストが高く
なり、さらに吸着器設置スペースの増大も招くという問
題がある。また、冷却ガスが減少すれば、別途冷凍機等
を用意しなければならない。Therefore, the amount of a regeneration gas or a cooling gas used for regeneration or cooling in a pretreatment process such as an adsorption facility for removing water and carbon dioxide in a source gas and a cooling water tower for pre-cooling the source gas is decreasing and becoming insufficient. . When cooled, the exhaust gas, which is a low-pressure dry gas, is used as the regeneration gas for the adsorber, but a sufficient regeneration gas flow rate cannot be secured due to the decrease in the amount of exhaust gas.
It has become necessary to regenerate by flowing a regeneration gas for a long time. If the regeneration is performed for a long time in this manner, the time required for the adsorption treatment of the raw material gas also becomes longer, and as a result, a large adsorber must be installed, and the adsorbent cost and the container production cost increase. There is a problem that the adsorber installation space also increases. If the amount of cooling gas decreases, a refrigerator or the like must be separately prepared.

一方、低温貯槽のオフガスを製品ガスに合流させるよ
うにした場合、一般に低圧貯槽のオフガスの圧力は、精
留塔から採取する製品ガスの圧力よりも低いため、両ガ
スを合流させるためには製品ガス出口系統に減圧弁を設
け、製品ガスの圧力をオフガスの圧力より低くする必要
があった。しかしながら、この方法では、製品ガス量に
対して少量のオフガスを回収するために製品ガス系統を
減圧しているが、この減圧分製品ガス運転圧力を低下さ
せることはエネルギーの有効利用上問題である。従っ
て、この方法は、多少のエネルギーロスを無視すれば中
圧以上の貯槽のオフガスの回収には利用できるが、大型
空気液化分離装置の低圧低温貯槽のオフガスを回収する
ために用いることはできなかった。On the other hand, when the off-gas of the low-temperature storage tank is combined with the product gas, the pressure of the off-gas of the low-pressure storage tank is generally lower than the pressure of the product gas collected from the rectification column. It was necessary to provide a pressure reducing valve in the gas outlet system and make the pressure of the product gas lower than the pressure of the off gas. However, in this method, the product gas system is depressurized in order to recover a small amount of offgas with respect to the product gas amount. However, lowering the product gas operating pressure by the reduced pressure is a problem in effective use of energy. . Therefore, this method can be used to recover off-gas in storage tanks at medium pressure or higher if some energy loss is ignored, but cannot be used to recover off-gas in low-pressure low-temperature storage tanks of large air liquefaction / separation devices. Was.

そこで、本発明は、低温貯槽のオフガス発生量が貯液
量と蒸発量に比例するため、小型の低温貯槽に比べてオ
フガス発生量の多いにもかかわらず低圧であるがために
利用されることのなかった中型又は大型の低温貯槽のオ
フガスを有効に利用することのできる回収利用方法及び
中圧貯槽のオフガスをエネルギーロスなしに有効に回収
利用する方法を提供することを目的としている。Therefore, the present invention is used because the amount of off-gas generation in the low-temperature storage tank is proportional to the amount of liquid storage and the amount of evaporation, and therefore the pressure is low despite the large amount of off-gas generation compared to a small-sized low-temperature storage tank. It is an object of the present invention to provide a method of recovering and utilizing an off-gas of a medium-sized or large-sized low-temperature storage tank that has not been provided, and a method of effectively recovering and utilizing an off-gas of an intermediate-pressure storage tank without energy loss.

〔課題を解決するための手段〕[Means for solving the problem]

上記した目的を達成するために、本発明の低温貯槽内
の蒸発ガスの回収方法は、前処理工程を経た原料ガスを
熱交換器で冷却し、精留塔に導入して深冷分離する深冷
分離装置に付属した低温貯槽内で蒸発するガスを回収す
るにあたり、前記低温貯槽内の蒸発ガスを捕集し、前記
深冷分離装置の精留塔内の排ガスもしくは精留塔から導
出された排ガスの少なくともいずれか一方に、好ましく
はバッファタンクを介して合流させて排ガスを増量し、
該増量した排ガスの寒冷を熱交換器で回収した後に、前
記前処理工程の再生ガスもしくは冷水塔冷却ガスの少な
くともいずれか一方に用いることを特徴としている。In order to achieve the above-mentioned object, a method for recovering evaporative gas in a low-temperature storage tank according to the present invention comprises a method of cooling a raw material gas that has undergone a pretreatment step with a heat exchanger, introducing the raw material gas into a rectification column, and performing cryogenic separation. Upon recovering the gas evaporating in the low-temperature storage tank attached to the cold separation device, the evaporating gas in the low-temperature storage tank was collected, and the gas was extracted from the exhaust gas or the rectification tower in the rectification column of the cryogenic separation device. At least one of the exhaust gas, preferably through a buffer tank to increase the amount of exhaust gas,
The method is characterized in that after the cold of the increased exhaust gas is recovered by a heat exchanger, it is used as at least one of a regeneration gas and a cooling water tower cooling gas in the pretreatment step.

〔作 用〕(Operation)

従って、貯槽内で発生したオフガスを、排ガスと合流
させて寒冷回収した上、吸着器の再生ガス又は冷水塔冷
却ガスとして利用できる。Therefore, the off-gas generated in the storage tank can be combined with the exhaust gas, collected at a low temperature, and then used as a regeneration gas for the adsorber or a cooling water tower cooling gas.

〔実施例〕〔Example〕

以下、本発明は、図面に示す実施例に基づいて、さら
に詳細に説明する。Hereinafter, the present invention will be described in more detail based on embodiments shown in the drawings.

まず、第１図は本発明を深冷液化分離法による窒素製
造装置に適用したものである。First, FIG. 1 shows the present invention applied to an apparatus for producing nitrogen by cryogenic liquefaction separation.

この窒素製造装置１は、空気を原料として窒素ガスGN
及び液化窒素LNを製品として採取するもので、原料ガス
である空気GAを、圧縮，精製，冷却して精留塔２に導入
し、液化精留分離して窒素ガスGN,液化窒素LN及び酸素
成分に富む排ガスWGに分離する。This nitrogen production apparatus 1 uses air as a raw material to produce nitrogen gas GN.
And liquefied nitrogen LN as a product. Air GA, which is a raw material gas, is compressed, refined, cooled, and introduced into the rectification tower 2, where it is liquefied and rectified and separated, and nitrogen gas GN, liquefied nitrogen LN and oxygen Separates into exhaust gas WG rich in components.

即ち、フィルター３から吸入された原料空気GAは、圧
縮機４で中圧（4kg/cm2G〜7kg/cm2G程度）に昇圧され、
熱交換器５及び冷却器６で冷却された後に気液分離器７
で凝縮水を分離して吸着設備８に導入され、該原料空気
中の水分，炭酸ガス等が除去される。吸着設備８は、切
り替え使用される一対の吸着器9a,9bを切替弁群10,10で
接続したもので、一方の吸着器9aが吸着工程にあるとき
には、他方の吸着器9bが再生工程にあり、原料空気GA
は、吸着工程にある吸着器9aを通って精製される。精製
後の原料空気GAは、管路11から保冷箱12内の主熱交換器
13に導入され、窒素ガスGN及び排ガスWGと熱交換を行い
液化点付近まで冷却されて管路14から精留塔２の下部に
導入される。That is, feed air GA sucked from the filter 3 is increased to a medium pressure (4kg / cm 2 G~7kg / cm 2 approximately G) in the compressor 4,
After being cooled by the heat exchanger 5 and the cooler 6, the gas-liquid separator 7
The condensed water is separated and introduced into the adsorption equipment 8 to remove water, carbon dioxide gas and the like in the raw material air. In the adsorption equipment 8, a pair of adsorbers 9a and 9b to be used for switching are connected by switching valve groups 10 and 10, and when one adsorber 9a is in the adsorption step, the other adsorber 9b is in the regeneration step. Yes, raw material air GA
Is purified through the adsorber 9a in the adsorption step. The purified raw material air is supplied from the pipeline 11 to the main heat exchanger in the cool box 12.
The gas is exchanged with the nitrogen gas GN and the exhaust gas WG and cooled to near the liquefaction point.

精留塔２の上部に分離した窒素ガスGNは、塔上部から
管路15に導出され、その一部が管路16を経て主熱交換器
13に導入され、常温に温度回復して採取される。窒素ガ
スGNの残部は、凝縮器18に導入されて後述の液化空気LA
との熱交換により液化し、液化窒素LNとなる。液化窒素
LNの一部は、製品液化窒素として管路19に分岐し、流量
調整弁20を経て液化窒素貯槽21に貯留される。残部の液
化窒素は、管路22から精留塔２の頂部に還流液として戻
される。The nitrogen gas GN separated at the upper part of the rectification tower 2 is led out from the upper part of the tower to a pipe 15, and a part of the nitrogen gas GN is passed through a pipe 16 to the main heat exchanger
Introduced to 13 and collected at room temperature. The remainder of the nitrogen gas GN is introduced into the condenser 18 and is liquefied air LA described later.
And liquefaction by heat exchange with LN. Liquefied nitrogen
A part of the LN branches off to a pipe 19 as product liquefied nitrogen, and is stored in a liquefied nitrogen storage tank 21 via a flow control valve 20. The remaining liquefied nitrogen is returned from line 22 to the top of rectification column 2 as reflux.

一方、精留塔２底部に分離した酸素成分に富む液化空
気LAは、塔底部から管路23に導出され、減圧弁24で管15
からの窒素ガスを凝縮器18で液化し得る圧力（温度）迄
減圧された後に凝縮器18に導入される。この液化空気LA
は、凝縮器18で前記窒素ガスGNと熱交換を行い蒸発して
排ガスWGとなり、逆止弁25を介して管路26に導出され
る。この排ガスWGは、一部が流量調整弁27を介して管路
28に分岐し、主熱交換器13の再熱回路29で中間温度まで
昇温した後にタービン流体として膨張タービン30に導入
され、ほぼ大気圧程度迄膨張して寒冷を発生する。排ガ
スWGの残部は、減圧弁31で膨張タービン導出後の膨張ガ
スと同じ圧力に減圧され、合流して主熱交換器13に導入
される。主熱交換器13で原料空気GAと熱交換を行い常温
まで温度回復した排ガスWGは、前記吸着設備８の再生ガ
スRGとして用いられた後に消音器32から外部に排出され
る。On the other hand, the liquefied air LA rich in the oxygen component separated at the bottom of the rectification column 2 is led out to the line 23 from the bottom of the column,
Is introduced into the condenser 18 after being reduced to a pressure (temperature) at which the nitrogen gas can be liquefied in the condenser 18. This liquefied air LA
Is exchanged with the nitrogen gas GN in the condenser 18 to evaporate to become exhaust gas WG, which is led out to the pipe 26 via the check valve 25. Part of the exhaust gas WG is connected to the pipeline via the flow control valve 27.
After branching to 28, the temperature is raised to the intermediate temperature in the reheating circuit 29 of the main heat exchanger 13, the gas is introduced into the expansion turbine 30 as turbine fluid, and expands to approximately atmospheric pressure to generate cold. The remaining part of the exhaust gas WG is reduced in pressure by the pressure reducing valve 31 to the same pressure as the expansion gas derived from the expansion turbine, merges and is introduced into the main heat exchanger 13. The exhaust gas WG, which has been subjected to heat exchange with the raw material air GA in the main heat exchanger 13 and recovered to a normal temperature, is discharged from the silencer 32 to the outside after being used as the regeneration gas RG of the adsorption equipment 8.

再生工程にある吸着器9bの再生は、まず、排ガスWGを
弁33から管路34を介して前記熱交換器５に導入し、圧縮
機４で圧縮されて高温となった原料空気GAと熱交換さ
せ、所定温度まで昇温する。尚、必要に応じて別途加熱
器等を設けて加熱してもよい。昇温後の排ガスWGは、管
路35から管路36を経て管路37に導入され、吸着器9bの出
口側切替弁10aから吸着器9bに導入され、吸着剤の加熱
再生を行い、切替弁10b,管路38,消音器32を経て排出さ
れる。加熱再生終了後は、排ガスWGを加熱することなく
弁39から管路36に導入し、同様に吸着器9bを逆流させて
吸着剤の冷却を行い排出する。In the regeneration of the adsorber 9b in the regeneration step, first, the exhaust gas WG is introduced from the valve 33 into the heat exchanger 5 via the pipe line 34, and the raw material air GA which has been Replace it and raise the temperature to the predetermined temperature. In addition, you may provide a heater etc. separately as needed and may heat. The exhaust gas WG after the temperature rise is introduced into the pipe 37 from the pipe 35 through the pipe 36, and is introduced into the adsorber 9b from the outlet side switching valve 10a of the adsorber 9b, and heats and regenerates the adsorbent to perform switching. It is discharged through the valve 10b, the conduit 38, and the silencer 32. After the completion of the heat regeneration, the exhaust gas WG is introduced into the pipe 36 from the valve 39 without heating, and the adsorbent 9b is similarly caused to flow backward to cool the adsorbent and discharge it.

前記液化窒素貯槽21は、周囲に断熱槽21aを配した平
底型の低圧低温貯槽であって、液化窒素LNは、その底部
の管路40から弁41を介して需要先に供給される。一方、
該液化窒素貯槽21の頂部には、オフガスOGを回収するオ
フガス回収系統42が設けられている。このオフガス回収
系統42は、貯槽頂部に連通する管路43と、該管路43に設
けられた逆止弁44,流量制御弁46とにより構成されてお
り、管路43の終端は、前記凝縮器18で蒸発した排ガスWG
を排出する管路26に接続している。このように形成する
ことにより、液化窒素貯槽21内で蒸発したオフガスOG
を、上記オフガス回収系統42を経た後排ガス系統に合流
させて排ガスWGを増量させ、該増量した排ガスWGの寒冷
を主熱交換器13で回収した上、吸着設備８の再生ガスRG
として用いることができる。The liquefied nitrogen storage tank 21 is a flat-bottom type low-pressure low-temperature storage tank having a heat insulating tank 21a disposed around the liquefied nitrogen storage tank. on the other hand,
At the top of the liquefied nitrogen storage tank 21, an off-gas recovery system 42 for recovering off-gas OG is provided. The off-gas recovery system 42 includes a pipe 43 communicating with the top of the storage tank, a check valve 44 and a flow control valve 46 provided in the pipe 43, and the end of the pipe 43 Exhaust gas WG evaporating in the vessel 18
Is connected to a conduit 26 for discharging air. By forming in this manner, the off-gas OG evaporated in the liquefied nitrogen storage tank 21
After passing through the off-gas recovery system 42, the waste gas is combined with the exhaust gas system to increase the amount of the exhaust gas WG.
Can be used as

従って、吸着設備８の再生ガス量を多くすることがで
き、吸着器9a,9bの再生を短時間で終了させることがで
きる。これにより、切り替え時間の短縮、即ち吸着運転
時間の短縮を図ることができ、吸着剤量の低減，吸着設
備８の小型化を図ることができる。さらに、オフガスOG
が有する寒冷を主熱交換器13で回収できるので、エネル
ギーコストの低減も図ることができ、設備費や運転コス
トの低減を図れる。Therefore, the amount of the regeneration gas in the adsorption equipment 8 can be increased, and the regeneration of the adsorbers 9a and 9b can be completed in a short time. As a result, the switching time can be reduced, that is, the adsorption operation time can be shortened, the adsorbent amount can be reduced, and the adsorption equipment 8 can be downsized. In addition, off-gas OG
Can be recovered by the main heat exchanger 13, so that energy costs can be reduced, and equipment costs and operation costs can be reduced.

尚、上記実施例における排ガス出口管路26の逆止弁25
とオフガス回収系統42の逆止弁44は、運転圧力の変動に
より排ガスWGが液化窒素貯槽21に逆流し、液化窒素LNの
純度を損うこと、及びオフガスOGの圧力変動が凝縮器18
及び精留塔２の運転圧力に影響を与えることを防止する
ためのもので、装置運転上、圧力変動が無視できる場合
には省略することができる。The check valve 25 of the exhaust gas outlet line 26 in the above-described embodiment is used.
The check valve 44 of the off-gas recovery system 42 detects that the exhaust gas WG flows back to the liquefied nitrogen storage tank 21 due to the fluctuation of the operating pressure, impairs the purity of the liquefied nitrogen LN, and the pressure fluctuation of the off-gas OG
And to prevent the operation pressure of the rectification column 2 from being affected, and can be omitted when the pressure fluctuation can be ignored in the operation of the apparatus.

また、第２図は貯槽21が中圧貯槽21′である場合の例
であり、オフガス回収系統42の途中にバッファタンク45
を設けた場合を示している。貯槽21′の型式及びバッフ
ァタンク45以外の構成は、前記第１図の場合と同様であ
るため同一要素には同一符号を付してその説明を省略す
る。FIG. 2 shows an example in which the storage tank 21 is a medium pressure storage tank 21 ′.
Is provided. Except for the type of the storage tank 21 'and the configuration other than the buffer tank 45, the same elements as those in FIG. 1 are denoted by the same reference numerals, and description thereof will be omitted.

上記中圧貯槽21′は運転圧（設計圧）が精留塔２の運
転圧とほぼ同圧であり、従って、平底型貯槽よりは小容
量の二重円筒耐圧容器による貯槽である。バッファタン
ク45と流量制御弁46は、吸着設備８の再生ガスRGが間欠
使用になるため、再生ガスRGの使用に合せてオフガスOG
を貯留，放出して有効利用し、再生ガス量増大を図るも
ので、オフガスOGを常時排ガスWGに合流させる場合に
は、両者を省略することができる。The medium pressure storage tank 21 'has an operating pressure (design pressure) substantially equal to the operation pressure of the rectification tower 2, and is therefore a storage tank using a double cylindrical pressure vessel having a smaller capacity than a flat bottom storage tank. The buffer tank 45 and the flow control valve 46 use the off-gas OG according to the use of the regeneration gas RG because the regeneration gas RG of the adsorption equipment 8 is used intermittently.
Is stored and released for effective use to increase the amount of regenerated gas. When the off-gas OG is constantly combined with the exhaust gas WG, both can be omitted.

上記バッファタンク45は、低温ガス貯蔵であるため、
常温ガス貯蔵に比べてガス密度が大きくなる分、容積を
小型化することができる。特に中圧排ガスの場合には、
より小型化を図れるため、圧力変動や流量変動を吸収す
る手段として効果的である。Since the buffer tank 45 is for storing low-temperature gas,
The volume can be reduced as much as the gas density is increased as compared with room temperature gas storage. Especially in the case of medium pressure exhaust gas,
Since the size can be further reduced, it is effective as a means for absorbing pressure fluctuations and flow rate fluctuations.

さらに、上記実施例では、原料空気中の不純物除去工
程として吸着設備８を用いたが、水分除去塔と炭酸ガス
除去塔に分離した工程にも同様に適用することができ
る。Further, in the above embodiment, the adsorption equipment 8 is used as the step of removing impurities in the raw material air, but the present invention can be similarly applied to a step of separating into a water removing tower and a carbon dioxide removing tower.

次に第３図は、複精留塔50を用いて酸素ガスGO,窒素
ガスGN,液化酸素LO,液化窒素LNを採取する空気液化分離
装置51に本発明を適用した例を示すもので、液化酸素LO
及び液化窒素LNを貯留するためのそれぞれの低温貯槽5
2,53が設けられている。また、この装置51には、圧縮さ
れて昇温した原料空気GAを洗浄冷却する水洗冷却塔54
と、該水洗冷却塔54に冷却水CWを供給する冷水塔55及び
冷却器56,送水ポンプ57,切替弁58等が付設されている。Next, FIG. 3 shows an example in which the present invention is applied to an air liquefaction separation device 51 that collects oxygen gas GO, nitrogen gas GN, liquefied oxygen LO, and liquefied nitrogen LN using a double rectification column 50. Liquefied oxygen LO
And low-temperature storage tanks 5 for storing liquefied nitrogen LN
2,53 are provided. The apparatus 51 also includes a washing cooling tower 54 for washing and cooling the raw material air GA that has been compressed and heated.
A cooling water tower 55 for supplying cooling water CW to the washing cooling tower 54, a cooler 56, a water pump 57, a switching valve 58, and the like are additionally provided.

上記冷水塔55は、排ガスWGの一部を利用して冷却水CW
を冷却するもので、塔下部から排ガスWGを導入するとと
もに塔頂部から冷却水CWを導入して両者を直接接触させ
ている。従って、複精留塔50から排出される排ガスWG
は、上記同様の吸着設備８の再生とこの冷却水CWの冷却
とに用いられる。The cooling water tower 55 uses cooling water CW by utilizing a part of the exhaust gas WG.
The exhaust gas WG is introduced from the bottom of the tower and the cooling water CW is introduced from the top of the tower to bring them into direct contact. Therefore, the exhaust gas WG discharged from the double rectification column 50
Is used for regeneration of the adsorption equipment 8 and cooling of the cooling water CW as described above.

圧縮機4,水洗冷却塔54,吸着設備8,主熱交換器13を経
て複精留塔50の下部塔59に導入された原料空気GAは、周
知の精留操作により、上部塔60の下部の酸素ガスGO,上
部塔底部の液化酸素LO,上部塔頂部の窒素ガスGN,主凝縮
蒸発機61で凝縮した液化窒素LNに分離し、それぞれが製
品として採取され、上部塔中段からは排ガスWGが排出さ
れる。The raw material air GA introduced into the lower tower 59 of the double rectification tower 50 via the compressor 4, the washing / cooling tower 54, the adsorption equipment 8, and the main heat exchanger 13 is supplied to the lower part of the upper tower 60 by a well-known rectification operation. Is separated into oxygen gas GO, liquefied oxygen LO at the bottom of the upper tower, nitrogen gas GN at the top of the upper tower, and liquefied nitrogen LN condensed in the main condenser evaporator 61. Is discharged.

上記排ガスWGを排出する管路62には、前記液化酸素及
び液化窒素を貯留する低温貯槽52,53の頂部に連通する
オフガス回収用の管路63,64が接続されており、貯槽内
で発生したオフガスOGを排ガスWGに合流させて排ガスWG
を増量させている。オフガス合流後の増量した排ガスWG
は、過冷器65,主熱交換器13を経て保冷箱12から管路66
に導出され、弁67を介して管路68から冷水塔55に導入さ
れる冷却用ガスCGと、弁69を介して管路70に分岐する吸
着器再生ガスRGとになる。再生ガスRGは、吸着器9a,9b
の加熱再生時には加熱器71を備えた管路72を通り、冷却
時には管路73を通って吸着器9a,9bを逆流し、管路74か
ら消音器32を経て外部に排出される。The pipe 62 for discharging the exhaust gas WG is connected to pipes 63 and 64 for off-gas recovery communicating with the tops of the low-temperature storage tanks 52 and 53 for storing the liquefied oxygen and liquefied nitrogen. The combined off-gas OG into the exhaust gas WG
Has been increased. Increased exhaust gas WG after off-gas merging
Is connected to the line 66 from the cool box 12 through the subcooler 65 and the main heat exchanger 13.
The cooling gas CG is introduced into the cooling water tower 55 from the pipe 68 via the valve 67, and the adsorber regeneration gas RG branched to the pipe 70 via the valve 69. The regeneration gas RG is supplied to the adsorbers 9a and 9b.
During regeneration by heating, the gas flows through a pipe 72 provided with a heater 71, and at the time of cooling, flows backward through the adsorbers 9a and 9b through the pipe 73, and is discharged from the pipe 74 to the outside through the muffler 32.

尚、装置各部の他の気液の流れ等は、複精留通を用い
た周知の空気液化分離装置と同様であり、各種機器の作
用も同様のため、詳細な説明を省略する。The flow of other gas and liquid in each part of the apparatus is the same as that of a known air liquefaction / separation apparatus using double rectification, and the operation of various devices is also the same.

このように吸着器の再生ガスだけでなく、冷水塔の冷
却ガスとしても排ガスを用いる場合には、排ガスを僅か
でも増量することにより、大きな効果を期待することが
できる。As described above, when the exhaust gas is used not only as the regeneration gas for the adsorber but also as the cooling gas for the cooling water tower, a great effect can be expected by increasing the exhaust gas even slightly.

上記構成の空気液化分離装置におけるオフガス回収に
よる排ガス増量効果の一例を説明する。装置の主な使用
を下表に示す。An example of the effect of increasing off-gas by off-gas recovery in the air liquefaction / separation apparatus having the above configuration will be described. The main uses of the device are shown in the table below.

上記第２表から、１時間当りに発生するそれぞれの貯
槽のオフガス量は、窒素ガス233Nm3/h,酸素ガス146Nm3/
hとなり、合計379Nm3/hのオフガスが発生していること
になる。また、吸着器の切り替え時間内における再生ガ
スの使用時間を全体の3/4とし、残りの1/4を貯留して再
生に用いるとすると、再生ガスとして使用できる量は50
5Nm3/hとなる。このオフガス量は全体の排ガス量に比べ
て少量であるが、上記実施例のごとく、冷水塔の冷却ガ
スとして排ガスを使用する装置では、吸着器再生用に用
いる排ガスは、通常2500Nm3/h程度であるので、オフガ
ス合流による再生ガス増量の効果は大きい。 It said from Table 2, the off-gas the amount of each of the storage tank to be generated per hour, nitrogen gas 233 nm 3 / h, the oxygen gas 146 nm 3 /
h, which means that a total of 379 Nm 3 / h of off-gas has been generated. Further, if the use time of the regeneration gas within the switching time of the adsorber is set to 3/4 of the whole, and the remaining 1/4 is stored and used for regeneration, the amount that can be used as the regeneration gas is 50%.
5Nm 3 / h. Although the amount of off-gas is small compared to the total amount of exhaust gas, as in the above embodiment, in an apparatus using exhaust gas as a cooling gas for a cooling water tower, the exhaust gas used for adsorber regeneration is usually about 2500 Nm 3 / h. Therefore, the effect of increasing the regeneration gas by the offgas merging is significant.

尚、上記両実施例では、オフガスを精留塔から排出さ
れた直後の排ガスに合流させたが、両者の合流位置は、
オフガスの種類や圧力，発生量あるいは装置構成等によ
り適宜に設定することが可能である。また、深冷分離装
置として、空気液化分離装置に限らず、各種のガス分離
装置，ガス精製装置等にも本発明を適用することができ
る。In each of the above embodiments, the offgas was combined with the exhaust gas immediately after being discharged from the rectification column.
It can be set as appropriate depending on the type, pressure, generation amount, or device configuration of the off-gas. In addition, the present invention can be applied to not only an air liquefaction separation device but also various gas separation devices and gas purification devices as a cryogenic separation device.

〔発明の効果〕〔The invention's effect〕

以上説明したように、本発明の低温貯槽内の蒸発ガス
の回収方法は、低温貯槽内の蒸発ガス（オフガス）を排
ガスに合流させて排ガスを増量し、該増量した排ガスの
寒冷を熱交換器で回収し、前処理工程の再生ガスもしく
は冷却ガスの少なくともいずれか一方に用いるようにし
たから、従来大気中に放出されていたオフガスから寒冷
を回収でき、エネルギーコストを低減できるとともに、
製品ガスの採取率の向上に伴う吸着器の再生ガスの不足
を、寒冷回収後のオフガスによって増量して、吸着剤の
再生時間を短縮できる。これによって、吸着器切り替え
間隔が短縮でき、吸着剤量の低減と吸着器の小型化が図
れ、設備費の低減も図れる。また、冷水塔の冷却効果を
増加でき、フレオン冷凍機の負荷を軽減することができ
る。As described above, the method for recovering evaporative gas in a low-temperature storage tank according to the present invention increases the amount of exhaust gas by merging the evaporative gas (off-gas) in the low-temperature storage tank with the exhaust gas. Because it was collected and used as at least one of the regeneration gas and the cooling gas in the pretreatment process, it was possible to recover the cold from the off-gas that was conventionally released into the atmosphere, and reduce the energy cost,
The shortage of the regeneration gas in the adsorber due to the improvement in the product gas collection rate can be increased by the off-gas after cold recovery, and the regeneration time of the adsorbent can be reduced. Thereby, the adsorber switching interval can be shortened, the adsorbent amount can be reduced, the adsorber can be downsized, and the equipment cost can be reduced. Further, the cooling effect of the cooling water tower can be increased, and the load on the Freon refrigerator can be reduced.

【図面の簡単な説明】[Brief description of the drawings]

第１図及び第２図は本発明を適用した窒素製造装置の一
例を示す系統図、第３図は同じく複精留塔を用いた空気
液化分離装置の一例を示す系統図である。 １……窒素製造装置、２……精留塔、８……吸着設備、
9a,9b……吸着器、13……主熱交換器、18……凝縮器、2
1,21′……液化窒素貯槽、42……オフガス回収系統、44
……逆止弁、45……バッファタンク、46……流量制御
弁、OG……オフガス、RG……再生ガス、WG……排ガス1 and 2 are system diagrams showing an example of a nitrogen production apparatus to which the present invention is applied, and FIG. 3 is a system diagram showing an example of an air liquefaction / separation device using a double rectification column. 1 ... Nitrogen production equipment, 2 ... Rectification tower, 8 ... Adsorption equipment,
9a, 9b: Adsorber, 13: Main heat exchanger, 18: Condenser, 2
1,21 ': Liquefied nitrogen storage tank, 42: Off-gas recovery system, 44
…… Check valve, 45 …… Buffer tank, 46 …… Flow control valve, OG… Off gas, RG… Regenerated gas, WG …… Exhaust gas

Claims (2)

(57)【特許請求の範囲】(57) [Claims] 【請求項１】前処理工程を経た原料ガスを熱交換器で冷
却し、精留塔に導入して深冷分離する深冷分離装置に付
属した低温貯槽内で蒸発するガスを回収するにあたり、
前記低温貯槽内の蒸発ガスを捕集し、前記深冷分離装置
の精留塔内の排ガスもしくは精留塔から導出された排ガ
スの少なくともいずれか一方に合流させて排ガスを増量
し、該増量した排ガスの寒冷を熱交換器で回収した後
に、前記前処理工程の再生ガスもしくは冷却ガスの少な
くともいずれか一方に用いることを特徴とする低温貯槽
内の蒸発ガスの回収利用方法。1. A method for cooling a raw material gas having passed through a pretreatment step with a heat exchanger, and introducing the raw material gas into a rectification column to perform a low-temperature separation to recover a gas evaporated in a low-temperature storage tank attached to a cryogenic separation device.
The evaporative gas in the low-temperature storage tank is collected, and combined with at least one of the exhaust gas in the rectification column or the exhaust gas derived from the rectification column of the cryogenic separation device to increase the amount of the exhaust gas, and the increased amount is added. A method for recovering and utilizing evaporative gas in a low-temperature storage tank, wherein after recovering cold of exhaust gas with a heat exchanger, the recovered gas is used as at least one of a regeneration gas and a cooling gas in the pretreatment step. 【請求項２】前記低温貯槽から捕集される蒸発ガスは、
バッファタンクを介して前記深冷分離装置の精留塔内の
排ガスもしくは精留塔から導出された排ガスの少なくと
もいずれか一方に合流させることを特徴とする請求項１
記載の低温貯槽内の蒸発ガスの回収利用方法。2. An evaporative gas collected from the low-temperature storage tank,
2. The refrigeration apparatus according to claim 1, wherein the effluent gas is combined with at least one of an exhaust gas in the rectification tower and an exhaust gas derived from the rectification tower via a buffer tank.
The method for recovering and using the evaporated gas in the low-temperature storage tank described in the above.
JP2561590A 1990-02-05 1990-02-05 Recovery and utilization of evaporative gas in low-temperature storage tank Expired - Fee Related JP2997939B2 (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP2561590A JP2997939B2 (en) 1990-02-05 1990-02-05 Recovery and utilization of evaporative gas in low-temperature storage tank

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP2561590A JP2997939B2 (en) 1990-02-05 1990-02-05 Recovery and utilization of evaporative gas in low-temperature storage tank

Publications (2)

Publication Number Publication Date
JPH03230080A JPH03230080A (en) 1991-10-14
JP2997939B2 true JP2997939B2 (en) 2000-01-11

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Application Number Title Priority Date Filing Date
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Country Link
JP (1) JP2997939B2 (en)

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* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JP5005894B2 (en) 2005-06-23 2012-08-22 エア・ウォーター株式会社 Nitrogen generation method and apparatus used therefor
CN113198394A (en) * 2021-04-20 2021-08-03 国家能源集团宁夏煤业有限责任公司 Waste heat utilization device and waste heat utilization system for intermittent regeneration waste gas

Also Published As

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