JP2000002481A - Method and system for producing nitrogen - Google Patents

Method and system for producing nitrogen

Info

Publication number
JP2000002481A
JP2000002481A JP10168337A JP16833798A JP2000002481A JP 2000002481 A JP2000002481 A JP 2000002481A JP 10168337 A JP10168337 A JP 10168337A JP 16833798 A JP16833798 A JP 16833798A JP 2000002481 A JP2000002481 A JP 2000002481A
Authority
JP
Japan
Prior art keywords
gas
expansion turbine
nitrogen
braking
bearing
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.)
Pending
Application number
JP10168337A
Other languages
Japanese (ja)
Inventor
Hideyuki Honda
秀幸 本田
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Japan Oxygen Co Ltd
Nippon Sanso Corp
Original Assignee
Japan Oxygen Co Ltd
Nippon Sanso Corp
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Japan Oxygen Co Ltd, Nippon Sanso Corp filed Critical Japan Oxygen Co Ltd
Priority to JP10168337A priority Critical patent/JP2000002481A/en
Publication of JP2000002481A publication Critical patent/JP2000002481A/en
Pending legal-status Critical Current

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
    • F25J3/044—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
    • F25J3/04006—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
    • 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
    • F25J3/04248—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
    • 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
    • F25J3/04375—Details relating to the work expansion, e.g. process parameter etc.
    • F25J3/04381—Details relating to the work expansion, e.g. process parameter etc. using work extraction by mechanical coupling of compression and expansion so-called companders
    • 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
    • F25J3/04763—Start-up or control of the process; Details of the apparatus used
    • F25J3/04769—Operation, control and regulation of the process; Instrumentation within the process
    • F25J3/04781—Pressure changing devices, e.g. for compression, expansion, liquid pumping
    • 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
    • F25J3/04763—Start-up or control of the process; Details of the apparatus used
    • F25J3/04866—Construction and layout of air fractionation equipments, e.g. valves, machines
    • 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
    • F25J2230/00—Processes or apparatus involving steps for increasing the pressure of gaseous process streams
    • F25J2230/20—Integrated compressor and process expander; Gear box arrangement; Multiple compressors on a common shaft
    • 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
    • F25J2230/00—Processes or apparatus involving steps for increasing the pressure of gaseous process streams
    • F25J2230/52—Processes or apparatus involving steps for increasing the pressure of gaseous process streams the fluid being oxygen enriched compared to air, e.g. "crude 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
    • F25J2240/00—Processes or apparatus involving steps for expanding of process streams
    • F25J2240/02—Expansion of a process fluid in a work-extracting turbine (i.e. isentropic expansion), e.g. of the feed stream
    • F25J2240/20—Expansion of a process fluid in a work-extracting turbine (i.e. isentropic expansion), e.g. of the feed stream the fluid being oxygen
    • F—MECHANICAL ENGINEERING; LIGHTING; HEATING; WEAPONS; BLASTING
    • F25—REFRIGERATION OR COOLING; COMBINED HEATING AND REFRIGERATION SYSTEMS; HEAT PUMP SYSTEMS; MANUFACTURE OR STORAGE OF ICE; LIQUEFACTION SOLIDIFICATION OF GASES
    • F25J—LIQUEFACTION, SOLIDIFICATION OR SEPARATION OF GASES OR GASEOUS OR LIQUEFIED GASEOUS MIXTURES BY PRESSURE AND COLD TREATMENT OR BY BRINGING THEM INTO THE SUPERCRITICAL STATE
    • F25J2250/00—Details related to the use of reboiler-condensers
    • F25J2250/02—Bath type boiler-condenser using thermo-siphon effect, e.g. with natural or forced circulation or pool boiling, i.e. core-in-kettle heat exchanger

Abstract

PROBLEM TO BE SOLVED: To compress circulation gas of high oxygen concentration in safety by providing a brake compressor coaxially with an expansion turbine and employing a gas bearing or a magnetic bearing in the shaft for coupling them. SOLUTION: An oil-free magnetic bearing 24 is employed in a shaft 23 for coupling an expansion turbine 21 and a brake compressor 22 coaxially and a generator 25 is employed as a brake for dissipating a part of driving power of the expansion turbine 21. When it is applied to a nitrogen producing system, fluid having oxygen concentration higher than that of the air is tapped from at least one position of a single rectifying column and passed through at least one reducing valve and condenser to produce circulation gas and waste gas. At least a part thereof is introduced to the expansion turbine 21 and the circulation gas is introduced to the brake compressor 22. Alternatively, a gas bearing 29 may be employed in the coupling shaft 23 of the expansion turbine 21 and the brake compressor 22.

Description

【発明の詳細な説明】DETAILED DESCRIPTION OF THE INVENTION

【０００１】[0001]

【発明の属する技術分野】本発明は、窒素製造方法に関
し、詳しくは、高い収率で窒素を製造するための循環系
を有する窒素製造装置における膨張タービン部分の構成
に関する。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a method for producing nitrogen, and more particularly, to a structure of an expansion turbine in a nitrogen producing apparatus having a circulation system for producing nitrogen with a high yield.

【０００２】[0002]

【従来の技術及び発明が解決しようとする課題】工業的
に窒素を製造する方法として、空気を原料としてこれを
圧縮，精製，冷却して液化し、その組成分をその沸点差
によって精留分離する空気液化分離方法が多く採用され
ている。比較的純度の高い窒素を製造する目的で、この
空気液化分離方法を用いた単一の精留塔をもつ装置が実
用化されている。2. Description of the Related Art As a method for producing nitrogen industrially, air is used as a raw material, which is compressed, refined, cooled and liquefied, and its components are rectified and separated by the difference in boiling points. The air liquefaction separation method is often used. For the purpose of producing nitrogen with relatively high purity, an apparatus having a single rectification column using this air liquefaction separation method has been put to practical use.

【０００３】窒素の製造は、精留塔下部に空気を導入し
て窒素を精留分離し、頂部から製品窒素ガスを採取する
プロセスが多用されているが、廃ガスの一部を精留塔下
部の圧力まで昇圧し、再び精留塔へ導入することによ
り、窒素収率を改善する方法が知られている。この方法
は、製品として窒素を採取した残りのガス、すなわち、
本来は廃ガスとして排出されるガス中には５０％以上の
窒素が含まれていることに着目したものであって、精留
塔下部から抜き出した液を気化して循環ガスとし、膨張
タービンで駆動する圧縮機で昇圧して精留塔へ循環させ
ることで精留条件を改善し、窒素収率の高いプロセスを
実現するものである。このようなプロセスは、特公平７
−９４９５３号公報や特開平５−１８７７６５号公報、
特開平９−１３２４０４号公報、米国特許第５３８５０
２４明細書、国際公開番号ＷＯ９６／２７１１１号公報
等に開示されいる。[0003] In the production of nitrogen, a process of rectifying and separating nitrogen by introducing air into the lower part of the rectification column and collecting product nitrogen gas from the top is frequently used. There is known a method of improving the nitrogen yield by increasing the pressure to the lower pressure and introducing the pressure into the rectification column again. This method is based on the remaining gas from which nitrogen is collected as a product,
Originally, we focused on the fact that the gas discharged as waste gas contained more than 50% of nitrogen. The liquid extracted from the lower part of the rectification column was vaporized into circulating gas, which was expanded by an expansion turbine. The pressure is increased by a driven compressor and circulated to a rectification column to improve rectification conditions and realize a process with a high nitrogen yield. Such a process is called
-94953 and JP-A-5-187765,
JP-A-9-132404, U.S. Pat.
24, International Publication No. WO 96/27111.

【０００４】図３は、廃ガスの一部を精留塔に循環させ
る上記方法を採用した窒素製造装置の一例を示す系統図
あって、塵埃，炭酸ガス及び水分等の不純物を除去され
た圧縮精製原料空気５７８９Ｎｍ３／ｈが、経路１を経
て主熱交換器２に導入され、低温流体と熱交換すること
によって圧縮空気の露点に近い温度まで冷却される。こ
の冷却原料空気は、経路３を経て単精留塔４の塔底より
数段上へ導入される。FIG. 3 is a system diagram showing an example of a nitrogen production apparatus employing the above-described method of circulating a part of waste gas to a rectification column, and is a compression system from which impurities such as dust, carbon dioxide and moisture are removed. Purified raw air 5789 Nm 3 / h is introduced into the main heat exchanger 2 via the path 1 and cooled to a temperature close to the dew point of the compressed air by exchanging heat with a low-temperature fluid. This cooling raw material air is introduced into the single rectification column 4 via the passage 3 several stages above the bottom.

【０００５】単精留塔４では、導入された空気が、その
組成分をその沸点差を利用して精留分離され、単精留塔
４の上部で低沸点成分である窒素分が増し、反対に塔底
では高沸点成分である酸素分が増す。塔上部の還流液
は、塔内を下降するうちに精留分離によって酸素分を増
やし、塔底に達したときに最も酸素に富む液（約４４％
Ｏ２）となる。In the single rectification column 4, the introduced air is rectified and separated by utilizing its boiling point difference by utilizing its boiling point difference, and the nitrogen content, which is a low boiling component, increases in the upper part of the single rectification column 4. On the contrary, the oxygen content, which is a high-boiling component, increases at the bottom of the column. The reflux liquid at the top of the column increases the oxygen content by rectification while descending in the column, and when it reaches the bottom of the column, a liquid rich in oxygen (about 44%)
O 2 ).

【０００６】単精留塔４の塔底液は、経路５を経て過冷
器６で過冷却され、弁７で減圧されて単精留塔上方に設
置された凝縮器８へ導入される。凝縮器８において、塔
底液と潜熱交換した単精留塔上部の窒素ガスは凝縮・液
化し、単精留塔４上部へ経路９を経て還流液として戻さ
れ、一方、塔底液はガス化し、経路１０を経て廃ガスと
して導出される。The bottom liquid of the single rectification column 4 is supercooled by a supercooler 6 via a path 5, decompressed by a valve 7, and introduced into a condenser 8 installed above the single rectification column. In the condenser 8, the nitrogen gas in the upper part of the single rectification column, which has exchanged latent heat with the bottom liquid, is condensed and liquefied and returned to the upper part of the single rectification tower 4 as a reflux liquid via the passage 9 while the bottom liquid is gaseous. And is led out as waste gas via a passage 10.

【０００７】廃ガスの一部（２７８０Ｎｍ３／ｈ）は、
経路１１に分岐して主熱交換器２で昇温された後、膨張
タービン１２を駆動して減圧し、主熱交換器２を経て排
出される。一方、経路１０から経路１３に進んだ残りの
廃ガス（１０２０Ｎｍ３／ｈ）は循環ガスとなり、前記
膨張タービン１２に連結された制動圧縮機１４で単精留
塔圧力まで昇圧され、経路１５を経て主熱交換器２へ導
入され、精留温度に近い温度まで冷却された後、経路１
６を経て再び単精留塔４へ導入され、精留分離の原料と
して使用される。Part of the waste gas (2780 Nm 3 / h)
After branching to the path 11 and being heated in the main heat exchanger 2, the pressure is reduced by driving the expansion turbine 12 and discharged through the main heat exchanger 2. On the other hand, the remaining waste gas (1020 Nm 3 / h) that has proceeded from the path 10 to the path 13 becomes a circulating gas, and the pressure is increased to the pressure of the single rectification column by the brake compressor 14 connected to the expansion turbine 12, and the path 15 After passing through the main heat exchanger 2 and cooling to a temperature close to the rectification temperature,
After passing through 6, the mixture is again introduced into the single rectification column 4 and used as a raw material for rectification separation.

【０００８】前記膨張タービン１２と制動圧縮機１４と
を連結する軸（シャフト）１７には、膨張タービン１２
を廃ガスで駆動することにより生じる駆動力の一部を消
散させるオイルポンプ等のブレーキ１８が備え付けられ
ており、これにより、プロセス系内を冷却する仕組みと
なっている。また、膨張タービンを制動力の割合に応じ
て分割するとともに、廃ガスも分割し、制動圧縮機１４
と連結した第一の膨張タービンと、ブレーキ１８と連結
した第二の膨張タービンとの２台に分けて設けることも
知られている。A shaft 17 connecting the expansion turbine 12 and the brake compressor 14 has an expansion turbine 12
Is provided with a brake 18 such as an oil pump for dissipating a part of the driving force generated by driving of the process gas with the waste gas, thereby cooling the inside of the process system. In addition, the expansion turbine is divided according to the braking force ratio, and the waste gas is also divided.
It is also known to provide two units, a first expansion turbine connected to the brake 18 and a second expansion turbine connected to the brake 18.

【０００９】一方、エネルギー散逸ブレーキとして、オ
イルブレーキ、ブロワーブレーキ、発電機ブレーキが知
られており、軸受としては、油潤滑、転がり（ローラー
又はボールベアリング）、ガスベアリング、磁気ベアリ
ングが知られている。On the other hand, oil brakes, blower brakes, and generator brakes are known as energy dissipation brakes, and oil lubrication, rolling (roller or ball bearings), gas bearings, and magnetic bearings are known as bearings. .

【００１０】制動圧縮機と一体となった膨張タービン
は、これらの組合わせで実用化されてきているが、空気
液化分離装置では、負荷能力が高く安価な油潤滑や、グ
リース等の潤滑剤を使用した転がり式軸受と、オイルポ
ンプブレーキ又はブロワーとの組合わせがほとんどであ
った。すなわち、従来は、図４に示すように、膨脹ター
ビン１２と制動圧縮機１４とを同軸で連結するシャフト
１７の軸受１９として油潤滑を採用し、制動機構として
オイルポンプ２０を採用したものがほとんどであった。[0010] An expansion turbine integrated with a braking compressor has been put to practical use in combination with these. However, in an air liquefaction / separation device, a lubricating agent such as oil lubrication or grease having a high load capacity and low cost is used. Almost all combinations of the rolling bearing used and the oil pump brake or blower were used. That is, as shown in FIG. 4, oil lubrication is conventionally used as a bearing 19 of a shaft 17 for coaxially connecting an expansion turbine 12 and a braking compressor 14, and an oil pump 20 is generally used as a braking mechanism. Met.

【００１１】また、発電機ブレーキと磁気ベアリングと
の組合わせは、磁気ベアリングが比較的最近実用化され
たベアリングであり、酸素製造用の空気分離装置でさ
え、最近のプロセス効率の観点から、エネルギー回収と
してブロワーが採用されるため、ほとんど採用例はない
と考えられる。In addition, the combination of the generator brake and the magnetic bearing is a magnetic bearing is a bearing that has been relatively recently put into practical use, and even an air separation device for producing oxygen has a problem in view of recent process efficiency. Since blowers are used for recovery, it is considered that there are almost no cases of use.

【００１２】一方、ブロワーとガスベアリングとの組合
わせは、窒素製造装置に長く使われてきたが、窒素製造
装置でのブロワーは、制動用として実用化されており、
常温での圧縮で、かつ、吐出圧力が低いまま使用されて
いた。前記図３に示した窒素製造装置のように、低温
で、吐出圧が高くなる循環圧縮に採用すると、ブロワー
側、タービン側共に低温となることから、ガスベアリン
グ部分も従来以上に低温になることが予想され、低温度
ではベアリングの保持力を生むガス粘度が低下し、採用
が危惧されていた。On the other hand, a combination of a blower and a gas bearing has been used for a long time in a nitrogen producing apparatus, but the blower in the nitrogen producing apparatus has been put to practical use for braking.
It has been used at normal temperature and with a low discharge pressure. When adopted for circulating compression in which the discharge pressure is high at a low temperature, as in the nitrogen production apparatus shown in FIG. 3, since the temperature on both the blower side and the turbine side becomes low, the temperature of the gas bearing part also becomes lower than before. At low temperatures, the gas viscosity that generates the holding power of the bearings was reduced, and there was concern about its use.

【００１３】他方、酸素濃度の高いガスを圧縮する場合
は、支燃性が高いことから、特別の保安対策が要求され
る。例えば欧州のＩＧＣ（Industrial Gases Committe
e）では、酸素サービス用ターボコンプレッサー実務コ
ードを定め、９０％以上の酸素ガスの圧縮について特別
な指針を出しており、９０％以下の濃度のガスについて
は、メーカーとユーザーとで合意すべきとしている。し
かし、４０％を超える酸素濃度のガスは、１００％の酸
素と大差ない支燃性を示すといわれている。On the other hand, when compressing a gas having a high oxygen concentration, special safety measures are required because of its high flammability. For example, European IGC (Industrial Gases Committe
e) stipulates the Code of Practice for Turbo Compressors for Oxygen Service and provides special guidelines for the compression of oxygen gas of 90% or more. For gas with a concentration of 90% or less, agreement should be reached between manufacturers and users. I have. However, it is said that a gas having an oxygen concentration of more than 40% exhibits a flammability that is not much different from that of 100% oxygen.

【００１４】空気液化分離装置では、膨張タービンの流
体は、窒素や空気といった酸素濃度の低いガスが使用さ
れてきている。また、窒素製造装置で多用されている単
精留プロセスでは収率が低く、廃ガスの酸素濃度も３５
％程度と比較的低かった。In the air liquefaction / separation apparatus, a gas having a low oxygen concentration, such as nitrogen or air, has been used as the fluid for the expansion turbine. In addition, the yield is low in the single rectification process frequently used in the nitrogen production apparatus, and the oxygen concentration of the waste gas is 35%.
% Was relatively low.

【００１５】しかしながら、前記図３で示した制動圧縮
機１４で昇圧する流体は、酸素濃度が空気より大で、５
０％近くにまで高くなり、窒素の収率を上げるほど、酸
素濃度が大きくなる。このことから、制動圧縮機１４
は、酸素濃度の観点から、酸素圧縮機として保安対策を
行うことが必要と考えられる。However, the fluid to be pressurized by the brake compressor 14 shown in FIG.
The oxygen concentration increases as the nitrogen concentration increases to near 0% and the nitrogen yield increases. From this, the braking compressor 14
It is considered necessary to take security measures as an oxygen compressor from the viewpoint of oxygen concentration.

【００１６】ところが、従来のものは、エネルギー散逸
ブレーキは、圧縮機、ポンプ、発電機、ベアリングにお
ける摩擦力と説明されており、図３に例示したように、
ポンプは一般的にオイルポンプであり、エネルギーを散
逸させるほどの摩擦力が生じるのも、一般に油潤滑軸受
と理解され、保安に対する配慮は全く為されてなく、常
用のオイルポンプブレーキや油潤滑軸受を使用した場
合、可燃性の油が酸素を多く含む圧縮流体の直近で使用
されることになる。However, in the related art, the energy-dissipating brake is described as a frictional force in a compressor, a pump, a generator, and a bearing. As illustrated in FIG.
Pumps are generally oil pumps and generate frictional force enough to dissipate energy, but they are generally understood as oil-lubricated bearings, and no consideration is given to security. Is used, the combustible oil is used in the immediate vicinity of the compressed fluid containing a large amount of oxygen.

【００１７】そこで本発明は、循環系を設けて高い収率
で窒素を製造する装置において、酸素濃度の高い循環ガ
スの圧縮を安全に行うことができる窒素製造装置及び方
法を提供することを目的としている。Accordingly, an object of the present invention is to provide an apparatus and method for producing a nitrogen gas at a high yield by providing a circulation system, which can safely compress a circulating gas having a high oxygen concentration. And

【００１８】[0018]

【課題を解決するための手段】上記目的を達成するた
め、本発明の窒素製造装置は、圧縮，精製，冷却した原
料空気を蒸留して窒素を分離する精留塔と、前記精留塔
の少なくとも一箇所から空気より酸素濃度の高い液流体
を抜出し、少なくとも一段階の減圧工程及び気化工程を
経て循環ガス及び廃ガスとし、該廃ガスの少なくとも一
部を膨張させる膨張タービンで駆動される制動圧縮機
に、前記循環ガスを精留温度付近で導入して昇圧し、冷
却後に前記精留塔に再導入する循環経路を備えた窒素製
造装置において、前記膨張タービンと同軸に前記制動圧
縮機を設けるとともに、膨張タービンと制動圧縮機とを
連結する軸の軸受をガスベアリング式又は磁気ベアリン
グ式としたことを特徴としている。In order to achieve the above object, a nitrogen production apparatus according to the present invention comprises: a rectification column for distilling compressed, purified and cooled raw air to separate nitrogen; A liquid fluid having an oxygen concentration higher than that of air is withdrawn from at least one place and subjected to at least one pressure reduction step and a vaporization step to form a circulating gas and a waste gas, and a brake driven by an expansion turbine for expanding at least a part of the waste gas In the compressor, the nitrogen gas is introduced near the rectification temperature and the pressure is increased near the rectification temperature. In addition, the present invention is characterized in that a bearing of a shaft connecting the expansion turbine and the brake compressor is a gas bearing type or a magnetic bearing type.

【００１９】さらに、本発明の窒素製造装置は、前記膨
張タービンと同軸に前記制動圧縮機を設けるとともに第
二の制動機構を設け、特に、該第二の制動機構が、制動
用発電機であることを特徴としている。さらに、前記膨
張タービンに加えて第二の膨張タービンを設け、前記廃
ガスの一部を分岐して第二の膨張タービンに導入する経
路を設けるとともに、該第二の膨張タービンと同軸に制
動発電機を設け、第二の膨張タービンと制動発電機とを
連結する軸の軸受をガスベアリング式又は磁気ベアリン
グ式としたことを特徴としている。Further, in the nitrogen production apparatus of the present invention, the braking compressor is provided coaxially with the expansion turbine, and a second braking mechanism is provided. In particular, the second braking mechanism is a braking generator. It is characterized by: Further, a second expansion turbine is provided in addition to the expansion turbine, a path for branching a part of the waste gas to be introduced into the second expansion turbine is provided, and braking power generation is performed coaxially with the second expansion turbine. And a shaft bearing connecting the second expansion turbine and the brake generator is a gas bearing type or a magnetic bearing type.

【００２０】また、本発明の窒素製造方法は、圧縮，精
製，冷却した原料空気を精留塔に導入して蒸留すること
により窒素を分離するとともに、前記精留塔の少なくと
も一箇所から空気より酸素濃度の高い液流体を抜出し、
少なくとも一段階の減圧工程及び気化工程を経て循環ガ
ス及び廃ガスとし、該廃ガスの少なくとも一部を膨張さ
せる膨張タービンで駆動される制動圧縮機に、前記循環
ガスを精留温度付近で導入して昇圧し、冷却後に前記精
留塔に循環再導入する窒素製造方法において、前記膨張
タービンの制動機構として圧縮機制動又は発電機制動を
使用し、これらの制動機構の回転軸を前記膨張タービン
と同軸とし、その軸受をオイルフリーとしたことを特徴
としている。Further, in the nitrogen production method of the present invention, the compressed, purified, and cooled raw material air is introduced into a rectification column and distilled by separating the nitrogen. Withdraw liquid fluid with high oxygen concentration,
A circulating gas and a waste gas are passed through at least one pressure reduction step and a vaporization step, and the circulating gas is introduced around a rectification temperature to a brake compressor driven by an expansion turbine that expands at least a part of the waste gas. In the nitrogen production method of circulating and reintroducing into the rectification column after cooling, a compressor brake or a generator brake is used as a braking mechanism of the expansion turbine, and a rotating shaft of these braking mechanisms is connected to the expansion turbine. It is coaxial and its bearings are oil-free.

【００２１】さらに、本発明の窒素製造方法は、前記廃
ガス中の酸素濃度が４０％以上であること、前記オイル
フリーとした軸受の回転機構が磁気ベアリングであり、
その磁気コイル部に酸素濃度が空気以下のガス又は窒素
ガスを供給すること、さらに、前記膨張タービンの制動
機構を発電機制動とし、該発電機の磁気コイル部に酸素
濃度が空気以下のガス又は窒素ガスを供給することを特
徴としている。Further, in the method for producing nitrogen according to the present invention, the oxygen concentration in the waste gas is 40% or more, and the rotation mechanism of the oil-free bearing is a magnetic bearing;
Supplying a gas or a nitrogen gas having an oxygen concentration of air or less to the magnetic coil portion, and further using a generator braking mechanism for the braking mechanism of the expansion turbine, and supplying a gas or a gas having an oxygen concentration of air or less to the magnetic coil portion of the generator. It is characterized by supplying nitrogen gas.

【００２２】[0022]

【発明の実施の形態】図１は本発明の要部である膨張タ
ービン部分の一形態例を示す説明図である。なお、窒素
製造装置の全体構成は、前記図３に示したもののほか、
前記各公報に記載された各種構成のものを適宜採用する
ことができるので、図示及び詳細な説明は省略する。DESCRIPTION OF THE PREFERRED EMBODIMENTS FIG. 1 is an explanatory view showing an example of an embodiment of an expansion turbine portion which is a main part of the present invention. The overall configuration of the nitrogen production apparatus is the same as that shown in FIG.
Since various configurations described in the above publications can be appropriately adopted, illustration and detailed description are omitted.

【００２３】図１は、膨張タービン２１と制動圧縮機２
２とを同軸で連結する軸（シャフト）２３の軸受として
オイルフリーの磁気ベアリング式軸受２４を使用すると
ともに、膨張タービン２１の駆動力の一部を消散させる
ブレーキとして発電機２５を採用したものである。FIG. 1 shows an expansion turbine 21 and a braking compressor 2
An oil-free magnetic bearing type bearing 24 is used as a bearing for a shaft 23 coaxially connecting the shaft 2 and a generator 25 as a brake for dissipating a part of the driving force of the expansion turbine 21. is there.

【００２４】すなわち、前記図３に示した窒素製造装置
に本形態例を適用した場合は、単精留塔４の少なくとも
一箇所から空気より酸素濃度の高い液流体、例えば、前
述のように、約４４％Ｏ２の塔底液を抜出し、少なくと
も一段階の減圧工程（弁７）及び気化工程（凝縮器８）
を経て経路１３の循環ガスと経路１１の廃ガスとを生成
し、生成した廃ガスの少なくとも一部を図１における膨
張タービン２１に導入し、循環ガスを図１における制動
圧縮機２２に導入することになる。That is, when this embodiment is applied to the nitrogen production apparatus shown in FIG. 3, a liquid fluid having an oxygen concentration higher than that of air from at least one portion of the single rectification column 4, for example, as described above, About 44% O 2 of the bottom liquid is withdrawn, and at least one pressure reduction step (valve 7) and vaporization step (condenser 8)
To generate the circulating gas in the path 13 and the waste gas in the path 11, at least a part of the generated waste gas is introduced into the expansion turbine 21 in FIG. 1, and the circulating gas is introduced into the brake compressor 22 in FIG. Will be.

【００２５】このように、軸受を、従来の油潤滑に代え
て磁気ベアリング式軸受２４とし、ブレーキを、従来の
オイルポンプに代えて発電機２５とすることにより、従
来のように油を使用しないため、酸素濃度の高いガスを
扱う場合における保安性を大幅に向上させることができ
る。As described above, by replacing the conventional oil lubrication with the magnetic bearing type bearing 24 and replacing the conventional oil pump with the generator 25, the oil is not used unlike the conventional oil lubrication. Therefore, security when handling a gas having a high oxygen concentration can be greatly improved.

【００２６】但し、発電機２５や磁気ベアリング式軸受
２４のコイルが酸素濃度の高い雰囲気中にさらされるこ
とになるため、この点における保安対策として、コイル
部分に空気や窒素等を供給する経路を設け、コイル部分
の酸素濃度を下げることが好ましい。この空気や窒素等
を供給する経路は、図１（Ａ）に示すように、膨張ター
ビン２１や制動圧縮機２２の経路とは別に経路２６を設
け、この経路２６に、圧縮空気や圧縮窒素、原料空気の
一部や製品窒素の一部を供給するようにしてもよく、膨
張タービン２１に導入される流体が、空気あるいはそれ
よりも酸素濃度が低いガスの場合は、図１（Ｂ）に示す
ように、膨張タービン２１の入口経路２７から分岐した
経路２８を設け、この経路２８を介してコイル部分に空
気等を供給するようにしてもよい。However, since the coils of the generator 25 and the magnetic bearing type bearing 24 are exposed to an atmosphere having a high oxygen concentration, as a security measure at this point, a path for supplying air, nitrogen, etc. to the coil portion is provided. It is preferable to provide the oxygen concentration in the coil portion. As shown in FIG. 1A, a path for supplying the air, nitrogen, or the like is provided with a path 26 separately from the paths of the expansion turbine 21 and the brake compressor 22, and the compressed air, compressed nitrogen, A part of the raw air or a part of the product nitrogen may be supplied. If the fluid introduced into the expansion turbine 21 is air or a gas having a lower oxygen concentration than that of the air, FIG. As shown, a path 28 branched from the inlet path 27 of the expansion turbine 21 may be provided, and air or the like may be supplied to the coil portion via the path 28.

【００２７】また、超高純度窒素を採取する装置では、
単精留塔の頂部より数段下から製品窒素を採取し、塔頂
からは低沸点成分を含むガスをパージガスとして導出し
ているが、この場合には、前記パージガスを、図１
（Ａ）の経路２６からコイル部分に供給するように形成
することが好ましい。In the apparatus for collecting ultra-high purity nitrogen,
Product nitrogen is sampled from several stages below the top of the single rectification column, and a gas containing a low-boiling component is led out as a purge gas from the top of the column. In this case, the purge gas is supplied as shown in FIG.
It is preferable to form so as to supply the coil portion from the path 26 of (A).

【００２８】なお、経路２６や経路２８から供給したガ
スは、導出用の経路から排出するようにしてもよく、シ
ャフト２３とコイルとの間の隙間から膨張タービン２１
側や制動圧縮機２２側に流すようにしてもよい。また、
第１の制動機構である制動圧縮機２２で十分な制動力が
得られる場合は、第２の制動機構としての発電機２５を
省くことができる。The gas supplied from the passages 26 and 28 may be exhausted from the lead-out passage, and the gas supplied from the expansion turbine 21 through the gap between the shaft 23 and the coil.
It may flow to the side or the brake compressor 22 side. Also,
When a sufficient braking force can be obtained by the braking compressor 22 as the first braking mechanism, the generator 25 as the second braking mechanism can be omitted.

【００２９】図２は、本発明の他の形態例を示すもの
で、膨張タービン２１と制動圧縮機２２とを同軸で連結
するシャフト２３の軸受としてガスベアリング式軸受２
９を採用したものである。本形態例においても、油を一
切使用していないため、制動圧縮機２２で４０％Ｏ２濃
度以上のガスを圧縮する場合の保安が保たれている。FIG. 2 shows another embodiment of the present invention, in which a gas bearing type bearing 2 is used as a bearing for a shaft 23 which connects an expansion turbine 21 and a brake compressor 22 coaxially.
9 is adopted. Also in this embodiment, since no oil is used, the security when the gas having a concentration of 40% O 2 or more is compressed by the brake compressor 22 is maintained.

【００３０】このガスベアリング式軸受２９の場合、図
に示すように、外部から経路３０を介して供給されるベ
アリングガスの圧力でシャフト２３を浮上させる静圧ベ
アリング式と、図示は省略するが、外部からガスを供給
せずに、薄い金属フィルム等を案内として軸受部に存在
するガスをシャフトの回転で巻き込んでシャフトを浮上
させる動圧ベアリング式とがあり、いずれも使用可能で
あるが、薄いフィルムは着火エネルギーが低いことか
ら、前述の循環ガスのように、酸素濃度が４０％以上の
ガスを圧縮する場合は、静圧ベアリング式のガスベアリ
ングを採用することが好ましい。また、ベアリングガス
には、空気や窒素等、任意のガスを用いることができ、
膨張タービン２１や制動圧縮機２２に導入するガスの一
部を用いることもできる。In the case of the gas bearing type bearing 29, as shown in the figure, a static pressure bearing type in which the shaft 23 floats by the pressure of the bearing gas supplied from the outside via the path 30 is omitted, although not shown. There is a dynamic pressure bearing type in which the gas existing in the bearing portion is guided by a thin metal film or the like by the rotation of the shaft and the shaft floats without supplying gas from the outside, and both can be used. Since the film has low ignition energy, when compressing a gas having an oxygen concentration of 40% or more, such as the above-mentioned circulating gas, it is preferable to employ a gas bearing of a static pressure bearing type. In addition, any gas such as air or nitrogen can be used for the bearing gas,
Part of the gas introduced into the expansion turbine 21 and the brake compressor 22 may be used.

【００３１】なお、前述のように、膨張タービンを制動
力の割合に応じて分割するとともに、廃ガスも分割し、
制動圧縮機と連結した第一の膨張タービンと、ブレーキ
と連結した第二の膨張タービンとの２台を設置する場合
でも同様である。As described above, the expansion turbine is divided according to the ratio of the braking force, and the waste gas is also divided.
The same applies to the case where two units, the first expansion turbine connected to the brake compressor and the second expansion turbine connected to the brake, are installed.

【００３２】[0032]

【発明の効果】以上説明したように、本発明によれば、
循環系を設けて高い収率で窒素を製造する装置におい
て、酸素濃度の高い循環ガスの圧縮を安全に行うことが
できる。As described above, according to the present invention,
In a device for producing nitrogen with a high yield by providing a circulation system, it is possible to safely compress a circulating gas having a high oxygen concentration.

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

【図１】 本発明の要部である膨張タービン部分の一形
態例を示す説明図である。FIG. 1 is an explanatory diagram showing an example of an embodiment of an expansion turbine portion which is a main part of the present invention.

【図２】 本発明の他の形態例を示す説明図である。FIG. 2 is an explanatory diagram showing another embodiment of the present invention.

【図３】 廃ガスの一部を精留塔に循環させる方法を採
用した窒素製造装置の一例を示す系統図である。FIG. 3 is a system diagram showing an example of a nitrogen production apparatus employing a method of circulating a part of waste gas to a rectification column.

【図４】 従来の膨張タービン部分の一構成例を示す説
明図である。FIG. 4 is an explanatory diagram showing one configuration example of a conventional expansion turbine portion.

【符号の説明】[Explanation of symbols]

２１…膨張タービン、２２…制動圧縮機、２３…シャフ
ト、２４…磁気ベアリング式軸受、２５…発電機、２９
…ガスベアリング式軸受21 ... Expansion turbine, 22 ... Brake compressor, 23 ... Shaft, 24 ... Magnetic bearing type bearing, 25 ... Generator, 29
… Gas bearing type bearing

Claims (8)

【特許請求の範囲】[Claims] 【請求項１】 圧縮，精製，冷却した原料空気を蒸留し
て窒素を分離する精留塔と、前記精留塔の少なくとも一
箇所から空気より酸素濃度の高い液流体を抜出し、少な
くとも一段階の減圧工程及び気化工程を経て循環ガス及
び廃ガスとし、該廃ガスの少なくとも一部を膨張させる
膨張タービンで駆動される制動圧縮機に、前記循環ガス
を精留温度付近で導入して昇圧し、冷却後に前記精留塔
に再導入する循環経路を備えた窒素製造装置において、
前記膨張タービンと同軸に前記制動圧縮機を設けるとと
もに、膨張タービンと制動圧縮機とを連結する軸の軸受
をガスベアリング式又は磁気ベアリング式としたことを
特徴とする窒素製造装置。1. A rectification column for distilling compressed, purified and cooled raw air to separate nitrogen, and a liquid fluid having an oxygen concentration higher than that of air is extracted from at least one portion of the rectification column. Through a decompression step and a vaporization step to a circulating gas and waste gas, to a brake compressor driven by an expansion turbine that expands at least a part of the waste gas, the circulating gas is introduced near the rectification temperature and pressure is increased, In a nitrogen production device having a circulation path for re-introducing the rectification column after cooling,
A nitrogen production apparatus, wherein the brake compressor is provided coaxially with the expansion turbine, and a bearing of a shaft connecting the expansion turbine and the brake compressor is a gas bearing type or a magnetic bearing type. 【請求項２】 前記膨張タービンと同軸に前記制動圧縮
機を設けるとともに、第二の制動機構を設けたことを特
徴とする請求項１記載の窒素製造装置。2. The nitrogen producing apparatus according to claim 1, wherein the braking compressor is provided coaxially with the expansion turbine, and a second braking mechanism is provided. 【請求項３】 前記第二の制動機構が、制動用発電機で
あることを特徴とする請求項２記載の窒素製造装置。3. The nitrogen producing apparatus according to claim 2, wherein the second braking mechanism is a braking generator. 【請求項４】 前記膨張タービンに加えて、第二の膨張
タービンを設け、前記廃ガスの一部を分岐して第二の膨
張タービンに導入する経路を設けるとともに、該第二の
膨張タービンと同軸に制動発電機を設け、第二の膨張タ
ービンと制動発電機とを連結する軸の軸受をガスベアリ
ング式又は磁気ベアリング式としたことを特徴とする請
求項１記載の窒素製造装置。4. A second expansion turbine is provided in addition to the expansion turbine, a path for branching a part of the waste gas and introducing the waste gas to the second expansion turbine is provided. 2. The nitrogen production apparatus according to claim 1, wherein a braking generator is provided coaxially, and a bearing of a shaft connecting the second expansion turbine and the braking generator is a gas bearing type or a magnetic bearing type. 【請求項５】 圧縮，精製，冷却した原料空気を精留塔
に導入して蒸留することにより窒素を分離するととも
に、前記精留塔の少なくとも一箇所から空気より酸素濃
度の高い液流体を抜出し、少なくとも一段階の減圧工程
及び気化工程を経て循環ガス及び廃ガスとし、該廃ガス
の少なくとも一部を膨張させる膨張タービンで駆動され
る制動圧縮機に、前記循環ガスを精留温度付近で導入し
て昇圧し、冷却後に前記精留塔に循環再導入する窒素製
造方法において、前記膨張タービンの制動機構として圧
縮機制動又は発電機制動を使用し、これらの制動機構の
回転軸を前記膨張タービンと同軸とし、その軸受をオイ
ルフリーとしたことを特徴とする窒素製造方法。5. A compressed, purified, and cooled raw material air is introduced into a rectification column and distilled to separate nitrogen, and a liquid fluid having a higher oxygen concentration than air is extracted from at least one portion of the rectification column. Circulating gas and waste gas through at least one pressure reduction step and vaporization step, and introducing the circulating gas at a temperature near the rectification temperature to a brake compressor driven by an expansion turbine for expanding at least a part of the waste gas. In the method for producing nitrogen in which the pressure is increased and the circulation is reintroduced into the rectification column after cooling, compressor braking or generator braking is used as a braking mechanism of the expansion turbine, and a rotation shaft of these braking mechanisms is connected to the expansion turbine. And a bearing that is oil-free. 【請求項６】 前記廃ガス中の酸素濃度が４０％以上で
あることを特徴とする請求項５記載の窒素製造方法。6. The nitrogen production method according to claim 5, wherein the oxygen concentration in the waste gas is 40% or more. 【請求項７】 前記オイルフリーとした軸受の回転機構
が磁気ベアリングであり、その磁気コイル部に酸素濃度
が空気以下のガス又は窒素ガスを供給することを特徴と
する請求項５記載の窒素製造方法。7. The nitrogen production apparatus according to claim 5, wherein the rotation mechanism of the oil-free bearing is a magnetic bearing, and a gas having an oxygen concentration of air or less or a nitrogen gas is supplied to the magnetic coil portion. Method. 【請求項８】 前記膨張タービンの制動機構を発電機制
動とし、該発電機の磁気コイル部に酸素濃度が空気以下
のガス又は窒素ガスを供給することを特徴とする請求項
５記載の窒素製造方法。8. The nitrogen production according to claim 5, wherein a braking mechanism of the expansion turbine is a generator brake, and a gas having an oxygen concentration of less than air or a nitrogen gas is supplied to a magnetic coil portion of the generator. Method.
JP10168337A 1998-06-16 1998-06-16 Method and system for producing nitrogen Pending JP2000002481A (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
JP10168337A JP2000002481A (en) 1998-06-16 1998-06-16 Method and system for producing nitrogen

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
JP10168337A JP2000002481A (en) 1998-06-16 1998-06-16 Method and system for producing nitrogen

Publications (1)

Publication Number Publication Date
JP2000002481A true JP2000002481A (en) 2000-01-07

Family

ID=15866195

Family Applications (1)

Application Number Title Priority Date Filing Date
JP10168337A Pending JP2000002481A (en) 1998-06-16 1998-06-16 Method and system for producing nitrogen

Country Status (1)

Country Link
JP (1) JP2000002481A (en)

Cited By (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100422576B1 (en) * 2001-10-09 2004-03-11 한국과학기술연구원 High accuracy turbine flowmeter using magnetic bearing
JP2007507682A (en) * 2003-10-01 2007-03-29 レール・リキード−ソシエテ・アノニム・ア・ディレクトワール・エ・コンセイユ・ドゥ・スールベイランス・プール・レテュード・エ・レクスプロワタシオン・デ・プロセデ・ジョルジュ・クロード Apparatus and method for cryogenic separation of gas mixtures
EP1801518A1 (en) * 2004-07-30 2007-06-27 Mitsubishi Heavy Industries, Ltd. Air refrigerant type cooling apparatus and air refrigerant cold system using the same
JP2009239987A (en) * 2008-03-25 2009-10-15 Taiyo Nippon Sanso Corp Expansion turbine brake
US8225619B2 (en) 2004-07-30 2012-07-24 Mitsubishi Heavy Industries, Ltd Air-refrigerant cooling apparatus with a warm gas defrost bypass pipe
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US9016083B2 (en) 2004-11-29 2015-04-28 Mitsubishi Heavy Industries, Ltd. Air refrigerant type freezing and heating apparatus

Cited By (15)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
KR100422576B1 (en) * 2001-10-09 2004-03-11 한국과학기술연구원 High accuracy turbine flowmeter using magnetic bearing
JP2007507682A (en) * 2003-10-01 2007-03-29 レール・リキード−ソシエテ・アノニム・ア・ディレクトワール・エ・コンセイユ・ドゥ・スールベイランス・プール・レテュード・エ・レクスプロワタシオン・デ・プロセデ・ジョルジュ・クロード Apparatus and method for cryogenic separation of gas mixtures
EP1801518A1 (en) * 2004-07-30 2007-06-27 Mitsubishi Heavy Industries, Ltd. Air refrigerant type cooling apparatus and air refrigerant cold system using the same
EP1801518A4 (en) * 2004-07-30 2012-03-28 Mitsubishi Heavy Ind Ltd Air refrigerant type cooling apparatus and air refrigerant cold system using the same
US8225619B2 (en) 2004-07-30 2012-07-24 Mitsubishi Heavy Industries, Ltd Air-refrigerant cooling apparatus with a warm gas defrost bypass pipe
US9016083B2 (en) 2004-11-29 2015-04-28 Mitsubishi Heavy Industries, Ltd. Air refrigerant type freezing and heating apparatus
JP2009239987A (en) * 2008-03-25 2009-10-15 Taiyo Nippon Sanso Corp Expansion turbine brake
WO2012137270A1 (en) * 2011-04-08 2012-10-11 川崎重工業株式会社 Liquefier system
CN103477174A (en) * 2011-04-08 2013-12-25 川崎重工业株式会社 Liquefier system
JP2012219711A (en) * 2011-04-08 2012-11-12 Kawasaki Heavy Ind Ltd Liquefaction system
AU2011365154B2 (en) * 2011-04-08 2015-05-21 Kawasaki Jukogyo Kabushiki Kaisha Liquefier system
CN103477174B (en) * 2011-04-08 2015-09-16 川崎重工业株式会社 Liquefaction system
US9644888B2 (en) 2011-04-08 2017-05-09 Kawasaki Jukogyo Kabushiki Kaisha Liquefier system
US20120301278A1 (en) * 2011-05-25 2012-11-29 GM Global Technology Operations LLC Engine assembly including turbocharger
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