JPH0792324B2 - Air separation method - Google Patents
Air separation methodInfo
- Publication number
- JPH0792324B2 JPH0792324B2 JP60292717A JP29271785A JPH0792324B2 JP H0792324 B2 JPH0792324 B2 JP H0792324B2 JP 60292717 A JP60292717 A JP 60292717A JP 29271785 A JP29271785 A JP 29271785A JP H0792324 B2 JPH0792324 B2 JP H0792324B2
- Authority
- JP
- Japan
- Prior art keywords
- amount
- waste gas
- tower
- gas
- conduit
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Fee Related
Links
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
- F25J3/04406—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
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04151—Purification and (pre-)cooling of the feed air; recuperative heat-exchange with product streams
- F25J3/04187—Cooling of the purified feed air by recuperative heat-exchange; Heat-exchange with product streams
- F25J3/04218—Parallel arrangement of the main heat exchange line in cores having different functions, e.g. in low pressure and high pressure cores
- F25J3/04224—Cores associated with a liquefaction or refrigeration cycle
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
- F25J3/04278—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using external refrigeration units, e.g. closed mechanical or regenerative refrigeration units
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
- F25J3/04333—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using quasi-closed loop internal vapor compression refrigeration cycles, e.g. of intermediate or oxygen enriched (waste-)streams
- F25J3/04351—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using quasi-closed loop internal vapor compression refrigeration cycles, e.g. of intermediate or oxygen enriched (waste-)streams of nitrogen
-
- F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
- F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
- F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
- F25J3/00—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification
- F25J3/02—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream
- F25J3/04—Processes or apparatus for separating the constituents of gaseous or liquefied gaseous mixtures involving the use of liquefaction or solidification by rectification, i.e. by continuous interchange of heat and material between a vapour stream and a liquid stream for air
- F25J3/04248—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion
- F25J3/04333—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using quasi-closed loop internal vapor compression refrigeration cycles, e.g. of intermediate or oxygen enriched (waste-)streams
- F25J3/04351—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using quasi-closed loop internal vapor compression refrigeration cycles, e.g. of intermediate or oxygen enriched (waste-)streams of nitrogen
- F25J3/04357—Generation of cold for compensating heat leaks or liquid production, e.g. by Joule-Thompson expansion using quasi-closed loop internal vapor compression refrigeration cycles, e.g. of intermediate or oxygen enriched (waste-)streams of nitrogen and comprising a gas work expansion loop
-
- 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
- F25J2270/00—Refrigeration techniques used
- F25J2270/14—External refrigeration with work-producing gas expansion loop
-
- 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
- F25J2270/42—Quasi-closed internal or closed external nitrogen refrigeration cycle
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】 〔発明の利用分野〕 本発明は、空気から製品ガスを分離し、採取する空気分
離方法に関する。Description: FIELD OF THE INVENTION The present invention relates to an air separation method for separating product gas from air and collecting the product gas.
空気を原料ガスとし、この原料空気から窒素，酸素，ア
ルゴン等の製品ガスを分離し、採取するものは、種々の
ものが知られている。この中で、産業用等のように大量
に製品ガスを採取するものとしては、精留塔を用いた精
留分離によるものが最も一般的である。There are various known sources for separating product gases such as nitrogen, oxygen, and argon from the source air by using air as the source gas. Among these, the most common method for collecting a large amount of product gas for industrial use is by rectification separation using a rectification column.
ところで、精留塔を用いて空気分離するに際し、製品ガ
スを液体（すなわち、液体窒素，液体酸素等）として採
取する必要がある場合がある。このような場合、液体と
して採取する製品ガスを多くするため、液化回路が設置
されている。液化回路が設置された空気分離装置の例を
第２図に示す。第２図において、原料空気は導管10を経
て熱交換器１に供給され、ここで廃ガス等との熱交換に
よって深冷分離に必要十分な温度まで冷却される。冷却
された原料空気は複式精留塔２の下塔2aに吹込まれ、下
塔2a内部で酸素と窒素の液化温度差を利用した精留分離
がなされる。この結果、下塔2aの上部には純度の高い窒
素（気体窒素および液体窒素）が分離され、下塔2aの底
部には酸素富化された液体空気が分離される。この液体
空気は、導管12を経て精留塔２の上塔2bに供給され、同
様の精留分離作用によって、上塔2bの上部には窒素分の
多い廃ガスが分離され、上塔2bの下部には純度の高い酸
素（気体酸素および液体酸素）が分離される。この例に
おいて、採取する製品ガスは、液体窒素および液体酸素
である。液体酸素は、精留塔２の上塔2b底部から導管22
によって抜出される。液体窒素は、精留塔２の下塔2a上
部から直接抜出しても良いが、この例では昇圧し液化し
た後採取するようになっている。すなわち、下塔2a上部
の高純度窒素は、導管15から抜出され、熱交換器１で原
料空気と熱交換後導管16を経て昇圧機３に供給され、昇
圧される。また、下塔2a上部の高純度窒素は、導管23か
ら抜出され、熱交換器５で温度回復され、導管24を通っ
て昇圧機３によって昇圧される。昇圧後の高純度窒素
は、導管17を通って予冷器８に導かれ、ここで昇圧によ
って上昇した温度が下げられる。予冷器８を通過した高
純度窒素は、導管18を通って液化器７に導かれ、冷媒と
の熱交換によって液化される。液化された窒素、すなわ
ち液体窒素は、導管19,20によって、製品ガスとして抜
出される。また、この液体窒素の一部は、導管21を通っ
て、精留塔２の下塔2aに供給される。なお、第２図にお
いて13,14は導管である。また、４は冷媒（例えば窒素
を用いる）を圧縮（昇圧）する昇圧機、５は熱交換機、
６は寒冷発生用の膨張タービン、25〜29は冷媒の循環経
路を構成する導管であり、これらによって循環寒冷発生
手段が構成される。By the way, when performing air separation using a rectification column, it may be necessary to collect product gas as liquid (namely, liquid nitrogen, liquid oxygen, etc.). In such a case, a liquefaction circuit is installed in order to increase the amount of product gas collected as a liquid. FIG. 2 shows an example of an air separation device provided with a liquefaction circuit. In FIG. 2, the raw material air is supplied to the heat exchanger 1 via the conduit 10, and is cooled to a temperature sufficient for deep-separation by heat exchange with waste gas and the like. The cooled raw material air is blown into the lower tower 2a of the double rectification tower 2, and rectification separation is performed inside the lower tower 2a by utilizing the difference in liquefaction temperature between oxygen and nitrogen. As a result, high-purity nitrogen (gaseous nitrogen and liquid nitrogen) is separated in the upper part of the lower column 2a, and oxygen-enriched liquid air is separated in the lower part of the lower column 2a. This liquid air is supplied to the upper tower 2b of the rectification tower 2 via the conduit 12, and the same rectification separation action separates waste gas rich in nitrogen in the upper part of the upper tower 2b, and Highly pure oxygen (gaseous oxygen and liquid oxygen) is separated in the lower part. In this example, the product gases sampled are liquid nitrogen and liquid oxygen. Liquid oxygen is supplied from the bottom of the upper tower 2b of the rectification tower 2 to the conduit 22.
Is extracted by. Liquid nitrogen may be directly withdrawn from the upper part of the lower column 2a of the rectification column 2, but in this example, it is collected after being pressurized and liquefied. That is, the high-purity nitrogen in the upper portion of the lower tower 2a is extracted from the conduit 15, is heat-exchanged with the raw material air in the heat exchanger 1, is supplied to the booster 3 via the conduit 16, and is pressurized. The high-purity nitrogen in the upper part of the lower tower 2a is extracted from the conduit 23, the temperature is recovered in the heat exchanger 5, and the pressure is increased by the booster 3 through the conduit 24. The pressurized high-purity nitrogen is introduced into the precooler 8 through the conduit 17, where the temperature raised by the pressurization is lowered. The high-purity nitrogen that has passed through the precooler 8 is guided to the liquefier 7 through the conduit 18 and is liquefied by heat exchange with the refrigerant. Liquefied nitrogen, i.e. liquid nitrogen, is withdrawn as product gas via conduits 19,20. Further, a part of this liquid nitrogen is supplied to the lower column 2a of the rectification column 2 through the conduit 21. In FIG. 2, 13 and 14 are conduits. Further, 4 is a booster that compresses (pressurizes) a refrigerant (for example, nitrogen is used), 5 is a heat exchanger,
Reference numeral 6 is an expansion turbine for generating cold, and 25 to 29 are conduits that constitute a circulation path of the refrigerant, and these constitute a circulating cold generating means.
このような設備で、製品量の比率、すなわち酸素と窒素
の採取比率を変化させる場合、次のような操作が必要と
なる。When changing the ratio of the product amount, that is, the sampling ratio of oxygen and nitrogen in such equipment, the following operation is required.
（１） 液体窒素を増量する場合 導管20から抜出される液体窒素を増量することによって
目的が達成されるが、反面導管21を通って精留塔下塔へ
供給する液体窒素の量が減少する。この結果、精留塔２
で処理されるガス量が減少するため、この不足分は原料
空気量を増加することで対処する。(1) When increasing the amount of liquid nitrogen Although the purpose is achieved by increasing the amount of liquid nitrogen withdrawn from the conduit 20, the amount of liquid nitrogen supplied to the lower rectification column through the conduit 21 is decreased. As a result, the rectification tower 2
Since the amount of gas treated in 1 is reduced, this shortage is dealt with by increasing the amount of raw material air.
（２） 液体窒素を減量する場合 導管20から抜出される液体窒素を減量することで達成で
きるが、精留塔２の下塔に供給される液体窒素量が増加
する。これにより、塔内を下降する液化ガス量が増加
し、下降液と上昇ガスとの比が悪化して安定な精留が困
難となる。これを防ぐには、上昇ガスの量を増加させれ
ば良く、原料空気の下塔への供給量を増加することで対
処できる。(2) When reducing the amount of liquid nitrogen Although it can be achieved by reducing the amount of liquid nitrogen withdrawn from the conduit 20, the amount of liquid nitrogen supplied to the lower column of the rectification column 2 increases. As a result, the amount of liquefied gas that descends in the tower increases, the ratio of the descending liquid to the ascending gas deteriorates, and stable rectification becomes difficult. This can be prevented by increasing the amount of rising gas, which can be dealt with by increasing the amount of feed air supplied to the lower tower.
さて、原料空気を増加させることは、大量の空気を処理
する必要があるため、装置自体が大型化することにな
る。特に、空気を昇圧する昇圧機，昇圧された空気中の
二酸化炭素，水分等を除去する吸着塔などの前処理設備
の大型化が避けられない。もちろん、大型の設備を運転
すると運転コストがアップすることは当然である。Now, increasing the amount of raw material air requires a large amount of air to be treated, and thus the size of the apparatus itself increases. In particular, it is inevitable to increase the size of pretreatment equipment such as a booster for boosting air and an adsorption tower for removing carbon dioxide, moisture, etc. in the boosted air. Of course, operating large equipment naturally increases operating costs.
本発明の目的は、原料空気量の増加を少なくして液体製
品採取量の増減運転を行うことのできる空気分離方法を
提供することである。An object of the present invention is to provide an air separation method capable of increasing / decreasing the amount of raw material air and increasing / decreasing the liquid product sampling amount.
本発明は、原料空気を精留塔に供給して製品ガスとそれ
以外のガスとに分離し、精留塔で分離された窒素を液化
手段によって液化し、該液化された製品ガスを採取する
空気分離方法において、精留塔で分離された廃ガスを前
記液化手段での液化のための冷媒として活用すると共
に、該冷媒の一部を必要に応じ精留塔に供給する如く構
成したことを特徴とする。According to the present invention, raw material air is supplied to a rectification tower to separate it into a product gas and other gases, the nitrogen separated in the rectification tower is liquefied by a liquefying means, and the liquefied product gas is collected. In the air separation method, the waste gas separated in the rectification tower is used as a refrigerant for liquefaction in the liquefaction means, and a part of the refrigerant is supplied to the rectification tower as needed. Characterize.
以下、本発明を具体的な実施例に基づき詳細に説明す
る。Hereinafter, the present invention will be described in detail based on specific examples.
第１図は、本発明の一実施例を示すシステムフローシー
トである。第１図において、40は空気を昇圧（圧縮）す
る昇圧機、45は昇圧された空気中の水分，二酸化炭素，
炭化水素等の不純物を除去する不純物除去設備である。
30〜32は導管である。その他の機器は、第２図の場合と
同様であるので、その説明は省略する。FIG. 1 is a system flow sheet showing an embodiment of the present invention. In FIG. 1, 40 is a booster that boosts (compresses) air, and 45 is water, carbon dioxide, etc. in the boosted air.
This is an impurity removal facility that removes impurities such as hydrocarbons.
30 to 32 are conduits. The other devices are the same as those shown in FIG. 2, and therefore their explanations are omitted.
第１図において、二酸化炭素，水分等を除去された原料
空気は、導管10から熱交換機１に導かれ、熱交換によっ
て約−170℃まで冷却される。この冷却原料空気は、導
管11によって精留塔２の下塔2aに供給され、精留がなさ
れる。すなわち、下塔2aにおいて、その上部に高純度の
窒素が分離され、その底部には酸素富化された液体空気
が分離される。この液体空気は、導管12に導かれ、低圧
の上塔2bに供給され、上塔2bの底部（下部）に高純度酸
素（液体酸素および気体酸素）が分離される。この例で
は、液体酸素も採取しているので、導管22から製品ガス
の一つである液体酸素が採取される。下塔2aの上部に分
離された窒素は、導管15,23から抜出され、夫々熱交換
機1,5によって常温まで温度回復され、夫々導管16,24に
よって昇圧機３に導かれる。昇圧機３で昇圧した窒素
は、導管17,予冷器8,導管18を経て、液化器に導かれ、
液化される。液化器７で液化された高純度の液体窒素
は、導管19,20から製品ガスとして採取される。また、
一部の液体窒素は、導管21に導かれて下塔2aの上部に供
給される。これらの系で必要な寒冷は、昇圧機4,熱交換
器5,膨張タービン６および導管26〜29で構成される循環
式の寒冷発生手段から供給される。精留塔２の上塔2bで
分離され廃ガス（窒素富化の廃ガス）の一部は導管13,
熱交換器1,導管14を介して常温まで回復され、系外へ排
気される。また、廃ガスの一部は、導管32を介して導管
28内の冷媒と合流し、冷媒の一部となる。このようにす
ることにより、図示しない液体窒素タンク等から供給す
る冷媒（例えば窒素）の量を減らすことができる。ま
た、この冷媒の一部は、必要に応じ導管27から分岐した
導管30により抜出され、液化器７で液化され、導管31を
通って精留塔下塔2aに供給される。In FIG. 1, raw material air from which carbon dioxide, water and the like have been removed is introduced from a conduit 10 to a heat exchanger 1 and cooled to about -170 ° C by heat exchange. This cooling raw material air is supplied to the lower tower 2a of the rectification tower 2 through the conduit 11 and rectified. That is, in the lower tower 2a, high-purity nitrogen is separated in the upper part and oxygen-enriched liquid air is separated in the bottom. This liquid air is guided to the conduit 12 and supplied to the low pressure upper tower 2b, and high-purity oxygen (liquid oxygen and gaseous oxygen) is separated at the bottom (lower part) of the upper tower 2b. In this example, since liquid oxygen is also collected, liquid oxygen, which is one of the product gases, is collected from the conduit 22. The nitrogen separated in the upper part of the lower tower 2a is withdrawn from the conduits 15 and 23, the temperature is restored to room temperature by the heat exchangers 1 and 5, and is introduced into the booster 3 by the conduits 16 and 24, respectively. The nitrogen pressurized by the booster 3 is led to the liquefier via the conduit 17, the precooler 8 and the conduit 18.
Liquefied. The high-purity liquid nitrogen liquefied in the liquefier 7 is collected from the conduits 19 and 20 as a product gas. Also,
Part of the liquid nitrogen is guided to the conduit 21 and supplied to the upper part of the lower tower 2a. The cold required in these systems is supplied from a circulating cold generating means composed of the booster 4, the heat exchanger 5, the expansion turbine 6 and the conduits 26 to 29. Part of the waste gas (nitrogen-enriched waste gas) separated in the upper tower 2b of the rectification tower 2 is introduced into the conduit 13,
It is restored to room temperature via the heat exchanger 1 and the conduit 14, and is discharged to the outside of the system. In addition, a part of the waste gas is piped through the pipe 32.
It merges with the refrigerant in 28 and becomes part of the refrigerant. By doing so, the amount of the refrigerant (for example, nitrogen) supplied from the liquid nitrogen tank or the like (not shown) can be reduced. A part of this refrigerant is withdrawn from the conduit 27 through a conduit 30 branched as required, liquefied in the liquefier 7, and supplied to the lower rectification column 2a through the conduit 31.
第１図に示す実施例において、液体窒素の増減運転（液
体窒素と液体酸素の採取比率変更運転）は、次のように
行なわれる。In the embodiment shown in FIG. 1, the liquid nitrogen increase / decrease operation (liquid nitrogen and liquid oxygen sampling ratio changing operation) is performed as follows.
（１） 液体窒素を増量する場合 導管20から抜出す液体窒素の量を増加させれば良い。こ
の場合、導管21を通って下塔2aに戻る液体窒素の量が減
少するため、この減少分に見合って、冷媒の一部を導管
30から抜出し、それを液化器７で液化後導管31によって
下塔2aに供給する。この冷媒の一部抜出しによる冷媒の
不足分は、導管32からの窒素富化廃ガスの増量でまかな
う。したがって、液体窒素を増量したことによって、直
ちに原料空気を増加することを必要としない。もっと
も、原料空気を増加しない場合の液体窒素の増量には限
界があり、液体窒素の採取量を更に増量させる場合に
は、原料空気の増加が必要となる。しかし、この場合で
あっても、原料空気の増加量は、従来方法によりも格段
に低くおさえることができる。(1) When increasing the amount of liquid nitrogen The amount of liquid nitrogen extracted from the conduit 20 may be increased. In this case, the amount of liquid nitrogen returning to the lower tower 2a through the conduit 21 is reduced, so that a part of the refrigerant is piped in proportion to the reduced amount.
After being liquefied in the liquefier 7, it is supplied to the lower tower 2a through a conduit 31. The shortage of the refrigerant due to the partial withdrawal of the refrigerant is covered by the increase of the nitrogen-rich waste gas from the conduit 32. Therefore, it is not necessary to immediately increase the raw material air by increasing the amount of liquid nitrogen. However, there is a limit to the increase in the amount of liquid nitrogen when the amount of raw material air is not increased, and it is necessary to increase the amount of raw material air when the amount of collected liquid nitrogen is further increased. However, even in this case, the amount of increase in the raw material air can be suppressed significantly lower than in the conventional method.
（２） 液体窒素を減量する場合 導管20から抜出す量を減少させれば良い。この場合、導
管21を通って下塔2aに戻る液体窒素の量が増加するた
め、不安定な運転になる。これを防ぐために、下塔2aに
戻る他の液化ガス，すなわち導管30から抜出される冷媒
の量を減らすことで対処できる。冷媒の抜出し量の減少
に見合って、導管13を通って系外へ排出される廃ガスの
量を増量する。このようにすることによって、原料空気
の増加をせずとも、液体窒素の減量ができる。(2) When reducing the amount of liquid nitrogen The amount taken out from the conduit 20 should be reduced. In this case, the amount of liquid nitrogen returning to the lower tower 2a through the conduit 21 increases, resulting in unstable operation. In order to prevent this, it can be dealt with by reducing the amount of other liquefied gas returning to the lower tower 2a, that is, the amount of refrigerant withdrawn from the conduit 30. The amount of waste gas discharged to the outside of the system through the conduit 13 is increased in proportion to the decrease in the amount of refrigerant taken out. By doing so, the amount of liquid nitrogen can be reduced without increasing the raw material air.
なお、液体酸素の増減運転も同様の考えで実現できる。
例えば、液体酸素の増量の場合、導管22から抜出す量を
増加すれば良いが、そのためには上塔2bで処理されるガ
スの量を増加することが必要となる。このため、液体窒
素を増量させる場合と同様に、導管30から冷媒の一部を
抜出し、液化器７で液化して下塔2aに供給する。この供
給されたガスは、下塔2aで精留に使用された後液体空気
の一部となって導管12を通り上塔2bへ供給される。これ
により、上塔2bでの処理量が増加し、液体酸素の増量を
達成できる。もちろん、この場合も、原料空気の増加な
しでは限度があることは当然である。しかし、原料空気
の増加量を低くおさえることができる。The liquid oxygen increasing / decreasing operation can be realized by the same idea.
For example, in the case of increasing the amount of liquid oxygen, the amount taken out from the conduit 22 may be increased, but for that purpose, it is necessary to increase the amount of gas treated in the upper column 2b. Therefore, as in the case of increasing the amount of liquid nitrogen, a part of the refrigerant is withdrawn from the conduit 30, liquefied by the liquefier 7 and supplied to the lower tower 2a. The supplied gas is used for rectification in the lower tower 2a and then becomes a part of liquid air to be supplied to the upper tower 2b through the conduit 12. As a result, the treatment amount in the upper tower 2b is increased, and the amount of liquid oxygen can be increased. Of course, even in this case, there is a limit without increasing the raw material air. However, the amount of increase in the raw material air can be kept low.
上述した実施例によれば、液体窒素，液体酸素の採取量
並びに採取比率を変更することができる。しかも、この
場合、原料空気の増量は非常に低くおさえることができ
る。また、このような種々の採取量の変更を行なう運転
を行なっても、安定した運転を継続することができる。According to the above-described embodiment, it is possible to change the collection amount and the collection ratio of liquid nitrogen and liquid oxygen. Moreover, in this case, the increase of the raw material air can be suppressed to a very low level. Further, even when such an operation of changing the various sampling amounts is performed, stable operation can be continued.
以上説明したように本発明によれば、原料空気量の増加
を少なくして液体製品ガスの採取量の増減運転を行うこ
とができる。このため、機器の大型化を極力おさえるこ
とができ、経済的である。As described above, according to the present invention, the increase / decrease operation of the liquid product gas sampling amount can be performed while suppressing the increase of the raw material air amount. Therefore, the size of the device can be suppressed as much as possible, which is economical.
第１図は本発明の一実施例を示す図、第２図は従来の例
を示す図である。 １……熱交換器、２……精留塔、2a……下塔、2b……上
塔、３……昇圧機、４……昇圧機、５……熱交換器、６
……膨張タービン、７……液化器、８……予冷器、10〜
32……導管FIG. 1 is a diagram showing an embodiment of the present invention, and FIG. 2 is a diagram showing a conventional example. 1 ... Heat exchanger, 2 ... Fractionation tower, 2a ... Lower tower, 2b ... Upper tower, 3 ... Booster, 4 ... Booster, 5 ... Heat exchanger, 6
...... Expansion turbine, 7 …… Liquefier, 8 …… Precooler, 10〜
32 ... conduit
───────────────────────────────────────────────────── フロントページの続き (72)発明者 岡部 道昌 山口県下松市大字東豊井794番地 株式会 社日立製作所笠戸工場内 (56)参考文献 特開 昭48−38887（ＪＰ，Ａ) 特公 昭49−39754（ＪＰ，Ｂ１) 実公 昭49−41481（ＪＰ，Ｙ１) ─────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Michimasa Okabe 794 Azuma Higashitoyoi, Shimomatsu City, Yamaguchi Prefecture Inside the Kasado Plant, Hitachi Ltd. (56) References JP-A-48-38887 (JP, A) Public 49-39754 (JP, B1) Actual Public 49-41481 (JP, Y1)
Claims (1)
スとを分離して発生し、 上記廃ガスの一部を供給される循環寒冷発生手段により
この供給された廃ガスを冷媒として寒冷を発生するとも
に冷媒として循環される廃ガスの一部を上記精留塔に戻
し、 上記廃ガスの残りを大気放出し、 上記製品ガスを上記冷媒と熱交換して液化し、 液化された製品ガスを、製品採取する採取分流と上記精
留塔に戻す戻り分流とに２分流し、 上記採取分流より採取される製品採取量を増加するとき
は、上記精留塔から上記循環寒冷発生手段に供給される
廃ガス量および上記循環寒冷発生手段から上記精留塔に
戻される廃ガス量を増加させ、 上記採取分流より採取される製品採取量を減少するとき
は、上記循環寒冷発生手段から上記精留塔に戻される廃
ガス量を減少させるともに上記大気放出される廃ガス量
を増加させる ことを特徴とする空気分離方法。1. A refrigeration tower separates a product gas and a waste gas from raw material air to generate the waste gas, and a circulating cold generating means to which a part of the waste gas is supplied cools the waste gas supplied as a refrigerant. A part of the waste gas that is generated and is circulated as a refrigerant is returned to the rectification column, the rest of the waste gas is released into the atmosphere, and the product gas is heat-exchanged with the refrigerant to be liquefied and the liquefied product When the gas is divided into a collecting branch stream for product collection and a return branch stream returning to the rectification tower for two minutes, and when the amount of product collected from the collecting branch stream is increased, the gas is collected from the rectification tower to the circulating cold generation means. When increasing the amount of waste gas supplied and the amount of waste gas returned from the circulating cold generating means to the rectification column and decreasing the amount of product collected from the sampling diversion, Waste gas returned to the rectification tower Air separation method characterized by increasing both waste gas quantity of the atmospheric discharge reduces.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60292717A JPH0792324B2 (en) | 1985-12-27 | 1985-12-27 | Air separation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP60292717A JPH0792324B2 (en) | 1985-12-27 | 1985-12-27 | Air separation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS62155486A JPS62155486A (en) | 1987-07-10 |
| JPH0792324B2 true JPH0792324B2 (en) | 1995-10-09 |
Family
ID=17785400
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60292717A Expired - Fee Related JPH0792324B2 (en) | 1985-12-27 | 1985-12-27 | Air separation method |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPH0792324B2 (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JP2810819B2 (en) * | 1992-02-28 | 1998-10-15 | 日本エア・リキード株式会社 | Nitrogen production method and apparatus |
| US7712331B2 (en) * | 2006-06-30 | 2010-05-11 | Air Products And Chemicals, Inc. | System to increase capacity of LNG-based liquefier in air separation process |
Family Cites Families (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5439343B2 (en) * | 1971-09-21 | 1979-11-27 | ||
| JPS4941481U (en) * | 1972-07-11 | 1974-04-11 | ||
| JPS525698B2 (en) * | 1972-08-26 | 1977-02-16 |
-
1985
- 1985-12-27 JP JP60292717A patent/JPH0792324B2/en not_active Expired - Fee Related
Also Published As
| Publication number | Publication date |
|---|---|
| JPS62155486A (en) | 1987-07-10 |
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