JPH0128311B2 - - Google Patents
Info
- Publication number
- JPH0128311B2 JPH0128311B2 JP56005795A JP579581A JPH0128311B2 JP H0128311 B2 JPH0128311 B2 JP H0128311B2 JP 56005795 A JP56005795 A JP 56005795A JP 579581 A JP579581 A JP 579581A JP H0128311 B2 JPH0128311 B2 JP H0128311B2
- Authority
- JP
- Japan
- Prior art keywords
- nitrogen
- air
- natural gas
- lower column
- column
- 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
Links
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims description 151
- 229910052757 nitrogen Inorganic materials 0.000 claims description 75
- 239000003949 liquefied natural gas Substances 0.000 claims description 20
- 239000007788 liquid Substances 0.000 claims description 15
- 238000000034 method Methods 0.000 claims description 14
- 238000001816 cooling Methods 0.000 claims description 7
- 230000006835 compression Effects 0.000 claims description 5
- 238000007906 compression Methods 0.000 claims description 5
- VNWKTOKETHGBQD-UHFFFAOYSA-N methane Chemical compound C VNWKTOKETHGBQD-UHFFFAOYSA-N 0.000 claims description 4
- 239000007789 gas Substances 0.000 claims description 2
- 239000003345 natural gas Substances 0.000 claims description 2
- 238000000926 separation method Methods 0.000 claims description 2
- 238000005057 refrigeration Methods 0.000 claims 2
- 239000000047 product Substances 0.000 description 9
- XKRFYHLGVUSROY-UHFFFAOYSA-N Argon Chemical compound [Ar] XKRFYHLGVUSROY-UHFFFAOYSA-N 0.000 description 8
- 230000001172 regenerating effect Effects 0.000 description 8
- QVGXLLKOCUKJST-UHFFFAOYSA-N atomic oxygen Chemical compound [O] QVGXLLKOCUKJST-UHFFFAOYSA-N 0.000 description 6
- 239000001301 oxygen Substances 0.000 description 6
- 229910052760 oxygen Inorganic materials 0.000 description 6
- 239000003507 refrigerant Substances 0.000 description 6
- 238000007796 conventional method Methods 0.000 description 5
- 229910052786 argon Inorganic materials 0.000 description 4
- 239000002994 raw material Substances 0.000 description 4
- 229910001873 dinitrogen Inorganic materials 0.000 description 3
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 2
- MYMOFIZGZYHOMD-UHFFFAOYSA-N Dioxygen Chemical compound O=O MYMOFIZGZYHOMD-UHFFFAOYSA-N 0.000 description 2
- 238000010586 diagram Methods 0.000 description 2
- 150000002829 nitrogen Chemical class 0.000 description 2
- 239000002912 waste gas Substances 0.000 description 2
- 239000006227 byproduct Substances 0.000 description 1
- 229910002092 carbon dioxide Inorganic materials 0.000 description 1
- 239000001569 carbon dioxide Substances 0.000 description 1
- 230000001351 cycling effect Effects 0.000 description 1
- 230000000694 effects Effects 0.000 description 1
- NBVXSUQYWXRMNV-UHFFFAOYSA-N fluoromethane Chemical compound FC NBVXSUQYWXRMNV-UHFFFAOYSA-N 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
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
- F25J3/04048—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of cold gaseous streams, e.g. intermediate or oxygen enriched (waste) streams
- F25J3/0406—Providing pressurised feed air or process streams within or from the air fractionation unit by compression of cold gaseous streams, e.g. 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
- F25J3/04151—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
- F25J3/04254—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
- F25J3/04266—The cryogenic component does not participate in the fractionation and being liquefied hydrocarbons
- F25J3/04272—The cryogenic component does not participate in the fractionation and being liquefied hydrocarbons and comprising means for reducing the risk of pollution of hydrocarbons into the air 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
- F25J3/04248—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
- F25J3/04406—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
Landscapes
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Mechanical Engineering (AREA)
- Thermal Sciences (AREA)
- General Engineering & Computer Science (AREA)
- Environmental & Geological Engineering (AREA)
- Separation By Low-Temperature Treatments (AREA)
Description
【発明の詳細な説明】
本発明は、液化天然ガス（以下LNGという）
の寒冷を利用して電力消費量の低減化を図る空気
の液化分離方法に関するものである。[Detailed Description of the Invention] The present invention relates to liquefied natural gas (hereinafter referred to as LNG)
The present invention relates to a method for liquefying and separating air, which uses the cold temperature of air to reduce power consumption.
従来よりLNGの寒冷を空気液化分離装置に与
えて動力の低減化を図る方法は種々提案されてお
り、一部実施されているがLNGの冷熱は一般に
下部塔上部に発生する高純度窒素を液化する際に
利用されていた。このため、原料空気量が多く従
つて、これを圧縮するに要する動力が大きくな
り、満足できるものではなかつた。例えば、これ
を第１図によつて説明すると、管１より圧縮機２
に導びかれた原料空気は５Kg/cm2に圧縮されて再
生式熱交換器３に入り、分離低温ガスによつて冷
却されかつ水分炭酸ガス等の不純物を除去した
後、管４より下部塔５下部に供給される。下部塔
５に供給された原料空気は精溜され、上部に窒素
が又底部に酸素リツチの液体空気が生成される
が、このうち液体空気は管６を通り弁７で膨張し
た後、上部塔８にフイードされ、精溜される。次
に下部塔５中部より液体窒素が管９より導出され
弁１０にて膨張した後、管１１より上部塔８上部
に供給されると共に下部塔５上部からは管１２を
介して製品液体窒素が採取される。又管１３より
窒素が導出され、管１４に一部を分岐した後管１
５を経て再生式熱交換器３を流れ、原料空気を冷
却して加温されて管１６より第１冷却器１７に導
入される。第１冷却器１７は、第２冷却器１８と
共にLNGの冷熱をフロン等の冷媒を介して冷却
するもので冷媒は熱交換器１９においてLNGと
熱交換して管２０を流れ第１、２各冷却器１７，
１８を冷却し、循環ポンプ２１により熱交換器１
９に戻るサイクルが形成される。第１冷却器１７
で冷却された前記窒素は前記管１４に分岐された
後、過冷器２２、第２熱交換器２４、第１熱交換
器２３を経た分岐窒素流れと合流し、管２５より
窒素圧縮機の低圧段２６に吸入され圧縮される。
この圧縮窒素はついで管２７を介して第２冷却器
１８に入り冷却された後、後記する未凝縮窒素と
合流して管２８より窒素圧縮機の高圧段２９に入
り更に圧縮される。窒素圧縮機で約60Kg/cm2に圧
縮された窒素は、管３０と管３１に２分され管３
０の窒素流れはLNG熱交換器３２で冷却された
後、前記第１熱交換器２３を通つた管３１の窒素
流れと合流して第２熱交換器２４に導入される。
第２熱交換器２４で更に冷却された窒素は弁３３
で膨張された後気液分離器３４に導入され、液体
窒素と未凝縮窒素に分離される。このうち液体窒
素は管３５より導出され過冷器２２、管３６を通
り弁３７で膨張されて下部塔５に導入され、又未
凝縮窒素は気液分離器３４の頂部から抜き出さ
れ、第２、第１各熱交換器２４，２３を逆流して
前記第２冷却器１８を出た窒素流れに合流され
る。 Various methods have been proposed and some have been implemented to reduce power by applying cold LNG to the air liquefaction separation equipment, but the cold heat of LNG is generally used to liquefy high-purity nitrogen generated at the top of the lower column. It was used when For this reason, the amount of raw material air is large, and the power required to compress it becomes large, which is not satisfactory. For example, to explain this using FIG. 1, from the pipe 1 to the compressor 2
The raw material air led to the 5 is supplied to the lower part. The raw air supplied to the lower column 5 is rectified to produce nitrogen-rich liquid air at the top and oxygen-rich liquid air at the bottom.The liquid air passes through a pipe 6 and expands at a valve 7, and then passes through the upper column. 8 and is distilled. Next, liquid nitrogen is led out from the middle of the lower column 5 through a pipe 9, expanded at a valve 10, and then supplied to the upper part of the upper column 8 through a pipe 11, and product liquid nitrogen is passed from the upper part of the lower column 5 through a pipe 12. collected. Further, nitrogen is led out from the pipe 13, and a part of the nitrogen is branched into the pipe 14, and then the pipe 1
5 and flows through the regenerative heat exchanger 3, the raw air is cooled and heated, and then introduced into the first cooler 17 through the pipe 16. The first cooler 17, together with the second cooler 18, cools the cold energy of LNG through a refrigerant such as fluorocarbon. cooler 17,
18, and the circulation pump 21 cools the heat exchanger 1.
A cycle back to 9 is formed. First cooler 17
After being branched into the pipe 14, the nitrogen cooled in It is sucked into the low pressure stage 26 and compressed.
This compressed nitrogen then enters the second cooler 18 through a pipe 27 and is cooled, and then joins with uncondensed nitrogen (described later), enters the high pressure stage 29 of the nitrogen compressor through a pipe 28, and is further compressed. Nitrogen compressed to approximately 60Kg/cm 2 by a nitrogen compressor is divided into two pipes 30 and 31, and pipe 3
After being cooled in the LNG heat exchanger 32, the nitrogen stream at 0 is combined with the nitrogen stream in the tube 31 passing through the first heat exchanger 23 and introduced into the second heat exchanger 24.
Nitrogen further cooled in the second heat exchanger 24 is transferred to the valve 33
After being expanded, it is introduced into a gas-liquid separator 34, where it is separated into liquid nitrogen and uncondensed nitrogen. Among them, liquid nitrogen is led out from the pipe 35, passes through the subcooler 22 and the pipe 36, is expanded by the valve 37, and is introduced into the lower column 5, and uncondensed nitrogen is extracted from the top of the gas-liquid separator 34, and is introduced into the lower column 5. 2. It flows back through the first heat exchangers 24 and 23 and is combined with the nitrogen flow exiting the second cooler 18.
次に上部塔８では精溜により上部に窒素が下部
に酸素が分離されるが酸素は凝縮部より液体酸素
として管３８より採取され、窒素は頂部より管３
９を介して導出された後再生式熱交換器３を流
れ、該器３内を冷却すると共に原料空気が残して
いた水分、炭酸ガスを同伴して管４０より系外に
放出される。又、LNGは管４１よりLNG熱交換
器３２に供給され該器３２内を流れる窒素に寒冷
を与えた後管４２を介して冷媒との熱交換器１９
に導入されて冷媒を冷却し、天然ガスとして管４
３より供給される。 Next, in the upper column 8, nitrogen is separated into the upper part and oxygen is separated into the lower part by rectification.The oxygen is collected as liquid oxygen from the condensing part through the pipe 38, and the nitrogen is collected from the top through the pipe 38.
After being led out through air 9, the air flows through the regenerative heat exchanger 3, cooling the inside of the vessel 3, and is discharged out of the system through a pipe 40, accompanied by moisture and carbon dioxide gas left behind in the raw material air. Further, LNG is supplied from a pipe 41 to an LNG heat exchanger 32, and after cooling the nitrogen flowing inside the vessel 32, it is transferred to a heat exchanger 19 with a refrigerant via a pipe 42.
The refrigerant is introduced into the pipe 4 as natural gas to cool the refrigerant.
Supplied from 3.
以上に説明した従来方法においては、下部塔５
の高純度窒素をサイクルさせる過程でLNGの寒
冷により液化して採取しており、このため原料空
気量は製品酸素を生産するに要する量よりも多く
必要になる。例えば、製品酸素を9000m3/h、製
品窒素を9600m3/h生産する場合、従来54500Nm3/
ｈの原料空気が必要であつた。 In the conventional method explained above, the lower column 5
The high-purity nitrogen is collected by liquefying it by cooling the LNG during the cycling process, so the amount of feed air required is greater than the amount required to produce the product oxygen. For example, when producing 9000 m 3 /h of oxygen product and 9600 m 3 /h of nitrogen product, conventional production of 54500Nm 3 /h
h of raw material air was required.
本発明は、前記同様の製品を生産するに要する
原料空気量を減少せしめて動力の低減化を図るこ
とを目的としたものでその特徴は前記サイクル窒
素ガスに上部塔頂部より取り出した低圧窒素を冷
却かつ圧縮してフイードするようにしたものであ
る。以下に本発明の実施例を第２図により説明す
るが、第１図と同一個所は同一番号を付し説明を
省略する。 The purpose of the present invention is to reduce the amount of feed air required to produce the same product as described above, thereby reducing power consumption. It is designed to be cooled and compressed before being fed. An embodiment of the present invention will be described below with reference to FIG. 2, where the same parts as in FIG. 1 are given the same numbers and the explanation will be omitted.
第２図において、下部塔５上部の製品液体窒素
を採取する管１２に管５１を連設し、液体窒素の
一部が管５１、弁５２を経て上部塔８頂部の高純
度窒素部５３に送られ、精溜されて管５４より高
純度窒素が導出される。この窒素は再生式熱交換
器３に入つて該器３を冷却しほぼ常温まで加温さ
れた後、管５５を経て高純度窒素冷却器５６に導
入される。高純度窒素冷却器５６は前記第１、２
冷却器１７，１８と同様LNG熱交換器１９を流
れるLNGの冷熱によつて冷却されるもので冷媒
回路２０に管を連設し、冷却器１７，１８および
５６とLNG熱交換器１９とを冷媒が循環するよ
う構成される。高純度窒素冷却器５６で冷却され
た窒素はついで低圧圧縮機５７に吸引されて下部
塔圧力まで圧縮された後、下部塔５上部より管１
３により導出され、管１５、再生式熱交換器３を
経て管１６を流れる窒素にフイードされる。この
合流窒素は第１冷却器１７に流れて冷却された
後、以後は第１図で説明したと同様の工程を経て
液化された後、下部塔５上部に供給される。 In FIG. 2, a pipe 51 is connected to the pipe 12 that collects the product liquid nitrogen from the upper part of the lower column 5, and a part of the liquid nitrogen passes through the pipe 51 and the valve 52 to the high-purity nitrogen section 53 at the top of the upper column 8. The nitrogen gas is sent and rectified, and high-purity nitrogen is led out from the pipe 54. This nitrogen enters the regenerative heat exchanger 3, cools the vessel 3, warms it to approximately room temperature, and then is introduced into the high purity nitrogen cooler 56 through the pipe 55. The high-purity nitrogen cooler 56
Like the coolers 17 and 18, they are cooled by the cold heat of LNG flowing through the LNG heat exchanger 19, and a pipe is connected to the refrigerant circuit 20 to connect the coolers 17, 18, and 56 to the LNG heat exchanger 19. The refrigerant is configured to circulate. The nitrogen cooled by the high-purity nitrogen cooler 56 is then sucked into the low-pressure compressor 57 and compressed to the lower column pressure.
3 and is fed to the nitrogen flowing through the pipe 15 and the regenerative heat exchanger 3 through the pipe 16. After this combined nitrogen flows into the first cooler 17 and is cooled, it is thereafter liquefied through the same steps as explained in FIG. 1 and then supplied to the upper part of the lower column 5.
ここで、この種の装置において液体酸素を9000
m3／ｈ、液体窒素を9600m3/h製品として採取する
場合、循環窒素を形成するために精溜塔から抜き
出す窒素量は29000m3/hである。従来はこの窒素
は下部塔５で生成される窒素ですべてまかなつて
いたが本発明方法ではこのうちの一部、例えば製
品窒素量に見合う量だけ上部塔８頂部で生成する
窒素でまかなわれる。即ち、前記精溜塔からの抜
出窒素量29000m3/hのうち、下部塔５の管１３よ
り19400m3/h導出してそのうちの7000m3/hを管１
４に分岐し、残部の12400m3/hが管１５を経て再
生式熱交換器３で加温され、循環窒素の主流れが
形成される。次に不足分9600m3/hは上部塔８頂
部より管５４を介して導出され、再生式熱交換器
３で加温された後、冷却器５６を経て圧縮機５７
で下部塔５より導出された前記窒素主流れと見合
う圧力まで加圧されて該主流れにフイードされ
る。 Here, in this type of equipment, liquid oxygen is
m 3 /h, if liquid nitrogen is taken as 9600 m 3 /h product, the amount of nitrogen withdrawn from the rectification column to form circulating nitrogen is 29000 m 3 /h. Conventionally, this nitrogen was entirely covered by the nitrogen produced in the lower column 5, but in the method of the present invention, a portion of this, for example, an amount corresponding to the amount of product nitrogen, is covered by the nitrogen produced at the top of the upper column 8. . That is, of the 29,000 m 3 /h of nitrogen extracted from the rectification column, 19,400 m 3 /h is drawn out from the pipe 13 of the lower column 5, and 7,000 m 3 /h of that is transferred to the pipe 1.
4, and the remaining 12400 m 3 /h is heated via pipe 15 in regenerative heat exchanger 3 to form the main flow of circulating nitrogen. Next, the shortfall of 9,600 m 3 /h is led out from the top of the upper column 8 through a pipe 54, heated in a regenerative heat exchanger 3, and then passed through a cooler 56 to a compressor 57.
It is pressurized to a pressure corresponding to the nitrogen main stream discharged from the lower column 5 and fed to the main stream.
以上のように本発明方法によると、原料空気量
を9500m3/h減少し、45000Nm3/hとすることがで
き、従つて空気圧縮機２における空気量減少によ
る動力低減と、窒素圧縮機５７において9600m3/
ｈの窒素を低温圧縮する動力増加とを相殺し、低
温圧縮がもたらす効果分の動力が節減できる。例
えば前記した条件で空気を５Kg/cm2に圧縮した場
合、従来法によると54500Nm3/hの原料空気を圧
縮するに要する動力は4500KWHである。これに
対し本発明方法によると、原料空気45000Nm3/h
圧縮するに要する動力が3720KWH、9600m3/hの
窒素を−132℃の低温圧縮により4.6Kg/cm2Gまで
圧縮するに要する動力が550KWHであるから合
計4270KWHですみ、約５％の動力節減ができ
る。 As described above, according to the method of the present invention, the amount of feed air can be reduced by 9,500 m 3 /h to 45,000 Nm 3 /h, and therefore the power is reduced by reducing the amount of air in the air compressor 2, and the nitrogen compressor 57 9600m 3 /
This offsets the increase in power for compressing nitrogen at low temperature in h, and the power for the effect brought about by low-temperature compression can be saved. For example, when air is compressed to 5Kg/cm 2 under the above conditions, the power required to compress 54500Nm 3 /h of raw air according to the conventional method is 4500KWH. On the other hand, according to the method of the present invention, the raw air is 45000Nm 3 /h.
The power required for compression is 3720KWH, and the power required to compress 9600m 3 /h of nitrogen to 4.6Kg/cm 2 G by low-temperature compression at -132℃ is 550KWH, so the total amount is 4270KWH, which is a power saving of approximately 5%. Can be done.
又、本発明方法によると副産物としてアルゴン
を採取する場合に効果をもたらす特徴がある。即
ち、従来法によると廃ガス中の酸素分は約6.5％
であるのに対し、本発明方法によると約1.7％で
あり、従つて廃ガス中に逃げるアルゴンが少くな
る。又、下部塔および上部塔上部の精溜条件も従
来法に比して有利となり、これはアルゴン収率の
向上をもたらすので原料空気量の減少にかかわら
ず従来法より多いアルゴンを採取することができ
る。 Furthermore, the method of the present invention has a feature that is effective when collecting argon as a by-product. In other words, according to the conventional method, the oxygen content in the waste gas is approximately 6.5%.
In contrast, according to the method of the present invention, it is about 1.7%, and therefore less argon escapes into the waste gas. In addition, the rectification conditions at the top of the lower column and the upper column are more advantageous than in the conventional method, which improves the argon yield, making it possible to collect more argon than in the conventional method despite the reduction in the amount of feed air. can.
以上の説明から明らかなように、本発明の特徴
はサイクル窒素ガスを形成する窒素ガスの一部を
上部塔で生成する高純度窒素を低温圧縮してまか
なうようにしたものであり、従つてこれを逸脱し
ない範囲においての設計変更が可能である。例え
ば上部塔頂部の窒素を過冷器２２を経て第１、２
熱交換器２３，２４を逆流する窒素流れの回路を
通した後、加圧して下部塔５より導出し、再生式
熱交換器３、冷却器１７を流れるサイクル窒素の
冷却器１７の前で合流せしめる方法でもよい。
又、サイクル窒素系によつて液化された窒素は、
弁３７を介して全量、下部塔５に導入されている
が製品窒素を管３６より分岐して採取し、残部を
下部塔５に導入することもできる。 As is clear from the above description, the feature of the present invention is that a part of the nitrogen gas forming the cycle nitrogen gas is supplied by low-temperature compression of high-purity nitrogen produced in the upper column. Design changes are possible within the range. For example, the nitrogen at the top of the upper column is passed through the subcooler 22 to the first and second
After passing through the circuit of the nitrogen flow counterflowing through the heat exchangers 23 and 24, it is pressurized and led out from the lower column 5, and is combined before the cooler 17 with the cycle nitrogen flowing through the regenerative heat exchanger 3 and the cooler 17. It may also be a method of coercion.
In addition, the nitrogen liquefied by the cycle nitrogen system is
Although the entire amount is introduced into the lower column 5 via the valve 37, the product nitrogen may be branched off from the pipe 36 and collected, and the remainder may be introduced into the lower column 5.
第１図は従来例を示す系統図、第２図は本発明
の実施例の系統図である。
２は圧縮機、３は再生式熱交換器、５は下部
塔、８は上部塔、１７，１８は冷却器、１９は熱
交換器、２２は過冷器、２３，２４は熱交換器、
３２はLNG熱交換器、３４は気液分離器、５６
は高純度窒素冷却器、５７は低圧圧縮機である。
FIG. 1 is a system diagram showing a conventional example, and FIG. 2 is a system diagram of an embodiment of the present invention. 2 is a compressor, 3 is a regenerative heat exchanger, 5 is a lower column, 8 is an upper column, 17 and 18 are coolers, 19 is a heat exchanger, 22 is a subcooler, 23 and 24 are heat exchangers,
32 is an LNG heat exchanger, 34 is a gas-liquid separator, 56
is a high-purity nitrogen cooler, and 57 is a low-pressure compressor.
Claims (1)
た窒素を液化天然ガスの寒冷を利用した冷却と、
圧縮、膨張により液化した後、前記下部塔に導入
するよう構成された窒素液化サイクルを有する空
気の液化精溜法において、前記下部塔より導出す
る液体窒素の一部を上部塔頂部に供給し、精溜し
て高純度窒素を得ると共に、該高純度窒素を低温
下で下部塔圧力まで圧縮した後、前記下部塔より
導出して窒素液化サイクルを形成する窒素にフイ
ードすることにより該窒素液化サイクルを形成す
る窒素の一部を、上部塔頂部より導出する窒素で
まかなうようにしたことを特徴とする液化天然ガ
スの寒冷を利用した空気の液化分離方法。 ２ 前記上部塔頂部より導出される高純度窒素が
原料空気と熱交換して加温された後、液化天然ガ
スの寒冷を利用して冷却され、かつ圧縮されて窒
素液化サイクルにフイードされることを特徴とす
る特許請求の範囲第１項記載の液化天然ガスの寒
冷を利用した空気の液化分離方法。 ３ 前記上部塔頂部より導出される高純度窒素
を、窒素液化サイクルの圧縮ガスと熱交換した後
圧縮し、下部塔より導出されて原料空気との熱交
換によつて加温された窒素に合流させて窒素液化
サイクルにフイードすることを特徴とする特許請
求の範囲第１項記載の液化天然ガスの寒冷を利用
した空気の液化分離方法。 ４ 前記窒素液化サイクルで得られた液体窒素の
一部を製品として採取し、残部を下部塔へ導入す
ることを特徴とする特許請求の範囲第１項又は第
２項又は第３項記載の液化天然ガスの寒冷を利用
した空気の液化分離方法。[Claims] 1. Cooling nitrogen extracted from the lower column of the rectification column of the air liquefaction separation device using the cooling of liquefied natural gas;
In an air liquefaction rectification method having a nitrogen liquefaction cycle configured to be introduced into the lower column after being liquefied by compression and expansion, a part of the liquid nitrogen derived from the lower column is supplied to the top of the upper column, The nitrogen liquefaction cycle is performed by rectifying to obtain high-purity nitrogen, compressing the high-purity nitrogen to the pressure of the lower column at low temperature, and then feeding it to the nitrogen that is led out from the lower column to form the nitrogen liquefaction cycle. A method for liquefying and separating air using the cooling of liquefied natural gas, characterized in that a part of the nitrogen forming the liquefied natural gas is supplied by nitrogen extracted from the top of the upper column. 2. After the high-purity nitrogen derived from the top of the upper column is heated by exchanging heat with the feed air, it is cooled using the refrigeration of liquefied natural gas, compressed, and fed into the nitrogen liquefaction cycle. A method for liquefying and separating air using cooling of liquefied natural gas according to claim 1. 3. The high-purity nitrogen drawn out from the top of the upper column is compressed after exchanging heat with the compressed gas of the nitrogen liquefaction cycle, and merged with the nitrogen drawn out from the lower column and heated by heat exchange with the feed air. 2. A method for liquefying and separating air using refrigeration of liquefied natural gas according to claim 1, wherein the liquefied natural gas is fed into a nitrogen liquefaction cycle. 4. Liquefaction according to claim 1, 2, or 3, characterized in that a part of the liquid nitrogen obtained in the nitrogen liquefaction cycle is collected as a product, and the remainder is introduced into the lower column. A method for liquefying and separating air using the cold of natural gas.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP579581A JPS57120077A (en) | 1981-01-17 | 1981-01-17 | Air liquified separation utilizing chilling of liquified natural gas |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP579581A JPS57120077A (en) | 1981-01-17 | 1981-01-17 | Air liquified separation utilizing chilling of liquified natural gas |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPS57120077A JPS57120077A (en) | 1982-07-26 |
| JPH0128311B2 true JPH0128311B2 (en) | 1989-06-01 |
Family
ID=11621008
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP579581A Granted JPS57120077A (en) | 1981-01-17 | 1981-01-17 | Air liquified separation utilizing chilling of liquified natural gas |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JPS57120077A (en) |
Families Citing this family (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| 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 |
| US8601833B2 (en) | 2007-10-19 | 2013-12-10 | Air Products And Chemicals, Inc. | System to cold compress an air stream using natural gas refrigeration |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5214238A (en) * | 1975-07-24 | 1977-02-03 | Arita Kosei | Sheath heater terminal mouth closing |
| JPS5382687A (en) * | 1976-12-28 | 1978-07-21 | Nippon Oxygen Co Ltd | Air liquefaction rectifying method |
-
1981
- 1981-01-17 JP JP579581A patent/JPS57120077A/en active Granted
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS5214238A (en) * | 1975-07-24 | 1977-02-03 | Arita Kosei | Sheath heater terminal mouth closing |
| JPS5382687A (en) * | 1976-12-28 | 1978-07-21 | Nippon Oxygen Co Ltd | Air liquefaction rectifying method |
Also Published As
| Publication number | Publication date |
|---|---|
| JPS57120077A (en) | 1982-07-26 |
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