JP2686050B2 - High-purity nitrogen gas production equipment - Google Patents
High-purity nitrogen gas production equipmentInfo
- Publication number
- JP2686050B2 JP2686050B2 JP7014413A JP1441395A JP2686050B2 JP 2686050 B2 JP2686050 B2 JP 2686050B2 JP 7014413 A JP7014413 A JP 7014413A JP 1441395 A JP1441395 A JP 1441395A JP 2686050 B2 JP2686050 B2 JP 2686050B2
- Authority
- JP
- Japan
- Prior art keywords
- liquid nitrogen
- nitrogen
- air
- storage means
- passage
- 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
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- Separation By Low-Temperature Treatments (AREA)
Description
【発明の詳細な説明】
【０００１】
【産業上の利用分野】この発明は、高純度窒素ガス製造
装置に関するものである。
【０００２】
【従来の技術】従来の窒素ガスの製造装置は、圧縮機で
圧縮された圧縮空気を熱交換するための熱交換器の冷媒
の冷却用に、膨脹タービンを用い、これを精留塔内に溜
る液体空気（深冷液化分離により低沸点の窒素はガスと
して取り出され、残部が酸素リッチな液体空気となって
溜る）から蒸発したガスの圧力で駆動するようになって
いる。ところが、膨脹タービンは回転速度が極めて大
（数万回／分）であり、負荷変動に対する追従運転が困
難であり、特別に養成した運転員が必要である。また、
このものは高速回転するため機械構造上高精度が要求さ
れ、かつ、高価であり、機構が複雑なため特別に養成し
た保全要員が必要という難点を有している。すなわち、
膨脹タービンは高速回転部を有するため、上記のような
諸問題を生じるのであり、このような高速回転部を有す
る膨脹タービンの除去に対して強い要望があった。
【０００３】
【発明が解決しようとする課題】このような要望に対し
て、この発明者は、膨脹タービンの発生寒冷に代え、液
体窒素貯蔵タンクから精留塔に対して液体窒素を寒冷と
して供給する高純度窒素ガス製造装置を提案している
（特願昭５９−４１２３号）。この装置は、上記液体窒
素貯槽がバックアップラインの液体窒素源ともなってい
ることから、従来のバックアップ源が精留塔等に対する
保全作業の容易化等を考慮して、精留塔とは別置されて
いるという技術常識に従って、液体窒素貯槽を精留塔と
は別置にしている。しかし、この装置では、液体窒素貯
槽に貯留されている液体窒素の気化物が上記貯槽の上部
から大気中に放出されるため、ロスが多い。また、精留
塔に対する真空断熱と、液体窒素貯槽に対する真空断熱
とをそれぞれ分けて行う必要があることから、設置作業
が煩雑になるとともに、設置場所も広くなるという難点
がある。さらに、精留塔と液体窒素貯槽とを連結する配
管として真空断熱配管を用いる必要がある。
【０００４】この発明は、このような事情に鑑みなされ
たもので、精留塔と液体窒素貯槽とは別個に設置される
ものという従来の技術常識を打破すると同時に、設置作
業の簡略化、設置スペースの狭小化および構造の簡単化
をその目的とする。
【０００５】
【課題を解決するための手段】上記の目的を達成するた
め、この発明の高純度窒素ガス製造装置は、外部より取
り入れた空気を圧縮する空気圧縮手段と、この空気圧縮
手段によって圧縮された圧縮空気中の炭酸ガスと水とを
除去する除去手段と、この除去手段を経た圧縮空気を超
低温に冷却する熱交換手段と、この熱交換手段により超
低温に冷却された圧縮空気の一部を液化して内部に溜め
窒素のみを気体として保持する精留塔と、液体窒素を貯
蔵する液体窒素貯蔵手段と、この液体窒素貯蔵手段内の
液体窒素を圧縮空気液化用の寒冷源として上記精留塔に
導く液体窒素導入通路と、上記精留塔内に保持されてい
る気化窒素を取り出す窒素ガス取出通路とを備え、真空
保冷函内に、上記精留塔と液体窒素貯蔵手段とを、液体
窒素貯蔵手段の冷気を精留塔が利用可能に位置決め配設
したという構成をとる。
【０００６】
【作用】この発明の高純度窒素ガス製造装置は、上記の
ように、液体窒素貯槽から精留塔へ寒冷となる液体窒素
を供給し、これを装置全体の寒冷として用いる。したが
って、膨脹タービンを使用する必要がなくなり、膨脹タ
ービンの使用に基づく弊害が生じない。またこの発明で
は、上記のように、真空保冷函中に精留塔と液体窒素貯
蔵手段と液体窒素導入通路を収容している。そのため、
装置を停止状態からスタートアップさせる時には、液体
窒素貯槽によって、精留塔が予冷された状態となってい
ることから、スタートアップ時間を短縮することができ
る。また、同一の真空保冷函中に精留塔と液体窒素貯蔵
手段と液体窒素導入通路が収容されていることから、全
体の設置スペースが小さくてすむという効果を奏するう
え、各別に断熱材を用いて保冷するという手間が不要と
なる。また、従来、精留塔と液体窒素貯槽とを連結して
いた真空断熱配管が不要となることから、装置全体の構
造が簡単となるとともに、設備費も少なくてすむように
なる。
【０００７】つぎに、この発明を実施例に基づいて詳し
く説明する。
【０００８】
【実施例】図１はこの発明の一実施例を示している。図
において、９は空気圧縮機、１０はドレン分離器、１１
はフロン冷却器、１２は２個１組の吸着筒である。吸着
筒１２は内部にモレキュラーシーブが充填されていて空
気圧縮機９により圧縮された空気中のＨ2 ０およびＣＯ
2 を吸着除去する作用をする。８はＨ2 ０およびＣＯ2
が吸着除去された圧縮空気を送る圧縮空気供給通路であ
る。１３は第１の熱交換器であり、除去手段（吸着筒）
１２によりＨ2 ０およびＣＯ2 が吸着除去された圧縮空
気が送り込まれる。１４は第２の熱交換器であり、第１
の熱交換器１３を経た圧縮空気が送り込まれる。１５は
塔頂部が凝縮器２１ａを有する分縮器部２１になってお
り、それより下が塔部２２になっている精留塔であり、
第１および第２の熱交換器１３，１４により超低温に冷
却され圧縮空気供給通路１７を経て送り込まれる圧縮空
気をさらに冷却し、その一部を液化し液体空気１８とし
て塔部２２の底部に溜め、窒素のみを気体状態で塔部２
２の上部天井部に溜めるようになっている。２３は液体
窒素貯蔵手段（槽）であり、内部の液体窒素（高純度
品）を液体窒素導入通路２４ａを経由させて精留塔１５
の塔部２２の上部側に送入し、塔部２２内に供給される
圧縮空気の寒冷源にする。液体窒素貯蔵手段２３には通
路３６から液体窒素の充填が行われる。精留塔１５は熱
交換器１３，１４ならびに液体窒素貯蔵手段２３と共に
真空保冷函（図２参照）３７に収容されている。なお、
図２では図示の都合上、後記の膨脹弁１９ａ付きの通路
１９等を省略している。この場合、両熱交換器１３，１
４は真空保冷函３７外に配置することも可能である。ま
た、精留塔１５は仕切板２０によって分縮器部２１と塔
部２２とに区切られており、上記分縮器部２１内の凝縮
器２１ａには、塔部２２の上部に溜る窒素ガスの一部が
第１の還流液用通路２１ｂを介して送入される。この分
縮器部２１内は、塔部２２内よりも減圧状態になってお
り、塔部２２の底部の貯留液体空気（Ｎ2 ５０〜７０
％，Ｏ2 ３０〜５０％）１８が膨脹弁１９ａ付き通路１
９を経て送り込まれ、気化して内部温度を液体窒素の沸
点以下の温度に冷却するようになっている。この冷却に
より、凝縮器２１ａ内に送入された窒素ガスが液化す
る。２５は液面計であり、分縮器部２１内の液体空気の
液面に応じてバルブ２６を制御し液体窒素貯蔵手段２３
からの液体窒素の供給量を制御する。精留塔１５の塔部
２２の上部側の部分には、上記分縮器部２１の凝縮器２
１ａで生成した液体窒素が第２の還流液用通路２１ｃを
通って流下供給されるとともに、液体窒素貯蔵手段２３
から液体窒素が液体窒素導入通路２４ａを経て供給さ
れ、これらが液体窒素溜２１ｄを経て塔部２２内を下方
に流下し、塔部２２の底部から上昇する圧縮空気と向流
的に接触し冷却してその一部を液化するようになってい
る。この過程で圧縮空気中の高沸点成分は液化されて塔
部２２の底部に溜り、低沸点成分の窒素ガスが塔部２２
の上部に溜る。２７は精留塔１５の塔部２２の上部天井
部に溜った窒素ガスを製品窒素ガスとして取り出す窒素
ガス取出通路で、超低温の窒素ガスを第２および第１の
熱交換器１４，１３内に案内し、そこに送り込まれる圧
縮空気と熱交換させて常温にしメイン通路２８に送り込
む作用をする。この場合、精留塔１５の塔部２２内にお
ける最上部には、窒素ガスとともに、沸点の低いＨｅ
（−２６９℃），Ｈ2 （−２５３℃）等が溜りやすいた
め、窒素ガス取出通路２７は、塔部２２の最上部よりか
なり下側に開口しており、Ｈｅ，Ｈ2 の混在しない純窒
素ガスのみを製品窒素ガスとして取り出すようになって
いる。液体窒素貯蔵手段２３の頂部は圧力調整弁３８付
きの気化窒素抜出通路３９により窒素ガス取出通路２７
に接続され、かつ、凝縮器２１ａは上記Ｈｅ，Ｈ2 等を
外気へ逃がすためのガス抜き通路４０を備えている。２
９は分縮器部２１内の気化液体空気を第２および第１の
熱交換器１４，１３に送り込む通路、２９ａはその保圧
弁である。３０はバックアップ通路であり、精留塔１５
からメイン通路２８に流れる製品窒素ガスの不足分を補
うべく、液体窒素貯蔵手段２３内の液体窒素を蒸発器３
１により蒸発させてメイン通路２８に常時一定量供給さ
せる機能と、空気圧縮系ラインが故障したとき、消費窒
素ガスの全量を供給させる機能を備えている。この場
合、バックアップ通路３０の流量調整は、蒸発器３１の
下流部に配置された圧力調整弁３５のそれにより行われ
る。３２は不純物分析計であり、メイン通路２８に送り
出される製品窒素ガスの純度を分析し、純度の低いとき
は、弁３４，３４ａを作動させて製品窒素ガスを矢印Ｂ
のように外部に逃気する作用をする。
【０００９】この装置は、つぎのようにして製品窒素ガ
スを製造する。すなわち、空気圧縮機９により空気を圧
縮し、ドレン分離器１０により圧縮された空気中の水分
を除去してフロン冷却器１１により冷却し、その状態で
吸着筒１２に送り込み、空気中のＨ2 ０およびＣＯ2 を
吸着除去する。ついで、Ｈ2 ０およびＣＯ2 が吸着除去
された圧縮空気を、精留塔１５から窒素ガス取出通路２
７を経て送り込まれる製品窒素ガス等によって冷やされ
ている第１，第２の熱交換器１３，１４に送り込んで超
低温に冷却し、その状態で精留塔１５の塔部２２の下部
内に投入する。ついで、この投入圧縮空気を、液体窒素
貯蔵手段２３から液体窒素導入通路２４ａを経由して精
留塔１５の塔部２２内に送り込まれた液体窒素および液
体窒素溜め２１ｄからの溢流液体窒素と接触させて冷却
し、一部を液化して塔部２２の底部に液体空気１８とし
て溜める。この過程において、窒素と酸素の沸点の差
（酸素の沸点−１８３℃，窒素の沸点−１９６℃）によ
り、圧縮空気中の高沸点成分である酸素が液化し、窒素
が気体のまま残る。ついで、この気体のまま残った窒素
を窒素ガス取出通路２７から取り出して第２および第１
の熱交換器１４，１３に送り込み、常温近くまで昇温さ
せメイン通路２８から製品窒素ガスとして送り出す。こ
の場合、精留塔１５の塔部２２内は、空気圧縮機９の圧
縮力および液体窒素の蒸気圧により高圧になっているた
め、窒素ガス取出通路２７から取り出される製品窒素ガ
スの圧力も高い。したがって、この製品窒素ガスをパー
ジ用ガス等として用いるようなときには有利となる。ま
た、圧力がこのように高いため、同一径のパイプでは多
量のガスを輸送できるようになるし、輸送量を一定にし
たときには小径のパイプを用いることができるようにな
り、設備費の節約を実現しうるようになる。他方、精留
塔１５の塔部２２の下部に溜った液体空気１８について
は、これを分縮器部２１内に送り込み凝縮機２１ａを冷
却させる。この冷却により、精留塔１５の塔部２２の上
部から第１の還流液用通路２１ｂを通って凝縮器２１ａ
に送入された窒素ガスが液化して精留塔塔部２２内の還
流液となり、第２の還流液用通路２１ｃを経て精留塔１
５の塔部２２に戻る。そして、凝縮器２１ａを冷却し終
えた液体空気１８は、気化し通路２９により第２および
第１の熱交換器１４，１３に送られその熱交換器１４，
１３を冷やしたのち、空中に放出される。なお、液体窒
素貯蔵手段２３から液体窒素導入通路２４ａを経由して
精留塔１５の塔部２２内に送り込まれた液体窒素は、圧
縮空気液化用の寒冷源として作用し、それ自身は気化し
て窒素ガス取出通路２７から製品窒素ガスの一部として
取り出される。このように、液体窒素貯蔵手段２３の液
体窒素は、圧縮空気液化用の寒冷源としての作用を終え
たのち、廃棄されるのではなく、圧縮空気を原料とする
高純度窒素ガスと合体して製品化されるのであり、無駄
なく利用される。また、液体窒素貯蔵手段２３の頂部に
溜る気化窒素は気化窒素抜出通路３９から窒素ガス取出
通路２７に導かれるので、エネルギの無駄な消費が防止
される。
【００１０】
【発明の効果】この発明の高純度窒素ガス製造装置は、
膨脹タービンを用いず、それに代えて何ら回転部をもた
ない液体窒素貯槽のような液体窒素貯蔵手段を用いるた
め、装置全体として回転部がなくなり故障が全く生じな
いうえ、膨脹タービンの使用時の弊害（製品窒素ガスの
取り出し量の変化に応じて迅速に寒冷量を制御すること
ができない）が生じず、純度の高い製品窒素ガスを製造
することができるようになる。そのうえ、この発明の高
純度窒素ガス製造装置は、上記のように、液体窒素貯槽
から精留塔へ寒冷となる液体窒素を供給し、これを装置
全体の寒冷として用いる。したがって、膨脹タービンを
使用する必要がなくなり、膨脹タービンの使用に基づく
弊害が生じない。またこの発明では、上記のように、真
空保冷函中に精留塔と液体窒素貯蔵手段と液体窒素導入
通路とを収容している。そのため、装置を停止状態から
スタートアップさせる時には、液体窒素貯槽によって、
精留塔が予冷された状態となっていることから、スター
トアップ時間を短縮することができる。また、同一の真
空保冷函中に精留塔と液体窒素貯蔵手段と液体窒素導入
通路とが収容されていることから、全体の設置スペース
が小さくてすむという効果を奏するうえ、各別に断熱材
を用いて保冷するという手間が不要となる。また、従
来、精留塔と液体窒素貯槽とを連結していた真空断熱配
管が不要となることから、装置全体の構造が簡単となる
とともに、設備費も少なくてすむようになる。しかも、
この発明では、真空保冷函内に精留塔と液体窒素貯蔵手
段と液体窒素導入通路とを収容し、かつ、精留塔と液体
窒素貯蔵手段とを、液体窒素貯蔵手段の冷気を精留塔が
利用可能に位置決め配設しているため、真空保冷函の表
面積が縮小し、かつ断熱層が増加する。これにより、液
体窒素の使用量が減少する。そのうえ、精留塔と液体窒
素貯蔵手段とが、互いに熱輻射（熱侵入）を遮断する効
果があり、この遮断により、精留塔と液体窒素貯蔵手段
との間の空間が熱侵入により昇温することが殆どなくな
る。このため、上記空間に面した精留塔の部分も熱侵入
による昇温が殆どなく、その結果、精留塔の寒冷として
必要な液体窒素量がさらに少なくて済む。また、上記空
間に面した精留塔の部分への熱侵入が殆どないため、精
留塔内での蒸留面積（蒸留が有効に作用する面積）の低
下が少なくなり、蒸留効率が上昇して製品窒素ガスの純
度が上がる。Description: BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a high-purity nitrogen gas producing apparatus. A conventional nitrogen gas producing apparatus uses an expansion turbine for cooling a refrigerant of a heat exchanger for exchanging heat of compressed air compressed by a compressor, and rectifying this. The gas is driven by the pressure of the gas evaporated from the liquid air accumulated in the column (nitrogen having a low boiling point is taken out as a gas by the cryogenic liquefaction separation, and the rest is accumulated as oxygen-rich liquid air). However, the rotation speed of the expansion turbine is extremely high (tens of thousands of rotations / minute), so that it is difficult to follow the load fluctuation, and a specially trained operator is required. Also,
Since this machine rotates at high speed, it requires high precision in terms of mechanical structure, is expensive, and has a complicated mechanism, which requires specially trained maintenance personnel. That is,
Since the expansion turbine has a high-speed rotating part, the above-mentioned various problems occur, and there has been a strong demand for the removal of the expansion turbine having such a high-speed rotating part. In response to such a demand, the inventor of the present invention supplies liquid nitrogen as cold to the rectification column from the liquid nitrogen storage tank, instead of generating cold from the expansion turbine. Has proposed a high-purity nitrogen gas production apparatus (Japanese Patent Application No. 59-4123). In this device, since the liquid nitrogen storage tank also serves as a liquid nitrogen source for the backup line, the conventional backup source is installed separately from the rectification tower in consideration of facilitating maintenance work for the rectification tower and the like. The liquid nitrogen storage tank is installed separately from the rectification tower according to the common general knowledge that However, in this device, since the vaporized product of liquid nitrogen stored in the liquid nitrogen storage tank is released into the atmosphere from the upper portion of the storage tank, there are many losses. Further, since it is necessary to separately perform vacuum heat insulation for the rectification tower and vacuum heat insulation for the liquid nitrogen storage tank, there is a problem that the installation work becomes complicated and the installation place becomes wide. Furthermore, it is necessary to use vacuum heat insulation piping as piping for connecting the rectification column and the liquid nitrogen storage tank. The present invention has been made in view of the above circumstances, and breaks down the conventional common general knowledge that a rectification tower and a liquid nitrogen storage tank are installed separately, and simplifies and installs the installation work. Its purpose is to narrow the space and simplify the structure. In order to achieve the above object, the high-purity nitrogen gas producing apparatus of the present invention comprises an air compression means for compressing the air taken in from the outside, and the air compression means. Removing means for removing carbon dioxide gas and water in the compressed air thus compressed, heat exchanging means for cooling the compressed air having passed through this removing means to an ultralow temperature, and part of the compressed air cooled to an ultralow temperature by this heat exchanging means A rectification column that liquefies the liquid nitrogen and retains only nitrogen as a gas inside, liquid nitrogen storage means that stores liquid nitrogen, and liquid nitrogen in the liquid nitrogen storage means as the cold source for liquefying compressed air as described above. A liquid nitrogen introduction passage leading to the distillation column and a nitrogen gas extraction passage for taking out the vaporized nitrogen held in the rectification column are provided, and the rectification column and the liquid nitrogen storage means are provided in a vacuum cool box. Liquid nitrogen The cold air in the storage means is positioned and arranged so that the rectification tower can use it. As described above, the high-purity nitrogen gas producing apparatus of the present invention supplies cold liquid nitrogen from the liquid nitrogen storage tank to the rectification column and uses it as cold for the entire apparatus. Therefore, it is not necessary to use the expansion turbine, and the harmful effect due to the use of the expansion turbine does not occur. Further, in the present invention, as described above, the rectification column, the liquid nitrogen storage means, and the liquid nitrogen introduction passage are housed in the vacuum cool box. for that reason,
When the apparatus is started up from the stopped state, the rectification column is precooled by the liquid nitrogen storage tank, so that the start-up time can be shortened. Further, since the rectification column, the liquid nitrogen storage means, and the liquid nitrogen introduction passage are housed in the same vacuum cool box, the effect is that the entire installation space can be reduced, and a separate heat insulating material is used. There is no need to keep it cool. Further, since the vacuum heat insulating pipe that conventionally connects the rectification column and the liquid nitrogen storage tank is not required, the structure of the entire apparatus is simplified and the equipment cost is reduced. Next, the present invention will be described in detail based on embodiments. FIG. 1 shows an embodiment of the present invention. In the figure, 9 is an air compressor, 10 is a drain separator, and 11
Is a Freon cooler, and 12 is a set of two adsorption tubes. The adsorption cylinder 12 is filled with molecular sieve inside, and contains H 2 O and CO in the air compressed by the air compressor 9.
It acts to adsorb and remove 2 . 8 is H 2 0 and CO 2
Is a compressed air supply passage for sending the compressed air that has been adsorbed and removed. 13 is a first heat exchanger, which is a removing means (adsorption cylinder)
Compressed air from which H 2 0 and CO 2 have been adsorbed and removed by 12 is fed. 14 is a second heat exchanger, the first
Compressed air that has passed through the heat exchanger 13 is sent. Reference numeral 15 is a rectification column having a condenser 21 having a condenser 21a at the top and a column 22 below the condenser.
The compressed air that has been cooled to an ultra-low temperature by the first and second heat exchangers 13 and 14 and is sent through the compressed air supply passage 17 is further cooled, and a part of it is liquefied and stored as liquid air 18 at the bottom of the tower section 22. , Tower part 2 in the gaseous state with nitrogen only
It is designed to be stored in the upper ceiling of No.2. Reference numeral 23 is a liquid nitrogen storage means (tank), and the liquid nitrogen (high-purity product) therein is passed through the liquid nitrogen introduction passage 24a to pass through the rectification column 15.
The compressed air supplied to the upper part of the tower part 22 is supplied to the inside of the tower part 22 as a cold source. The liquid nitrogen storage means 23 is filled with liquid nitrogen from the passage 36. The rectification column 15 is housed in a vacuum cool box (see FIG. 2) 37 together with the heat exchangers 13 and 14 and the liquid nitrogen storage means 23. In addition,
In FIG. 2, a passage 19 having an expansion valve 19a described later is omitted for convenience of illustration. In this case, both heat exchangers 13, 1
4 can be arranged outside the vacuum cool box 37. Further, the rectification column 15 is divided into a dephlegmator section 21 and a tower section 22 by a partition plate 20, and the condenser 21a in the dephlegmator section 21 has a nitrogen gas accumulated in the upper part of the column section 22. Is partially sent through the first reflux liquid passage 21b. The inside of the dephlegmator section 21 is in a reduced pressure state as compared with the inside of the tower section 22, and the stored liquid air (N 2 50 to 70) at the bottom of the tower section 22.
%, O 2 30 to 50%) 18 is the passage 1 with the expansion valve 19a
It is sent via 9 and vaporized to cool the internal temperature to a temperature below the boiling point of liquid nitrogen. By this cooling, the nitrogen gas fed into the condenser 21a is liquefied. A liquid level gauge 25 controls the valve 26 according to the liquid level of the liquid air in the partial condenser 21 to control the liquid nitrogen storage means 23.
Controls the supply of liquid nitrogen from. In the upper part of the tower section 22 of the rectification tower 15, the condenser 2 of the partial condenser section 21 is provided.
The liquid nitrogen generated in 1a is supplied downwardly through the second reflux liquid passage 21c, and the liquid nitrogen storage means 23 is also provided.
Liquid nitrogen is supplied from the column via the liquid nitrogen introducing passage 24a, flows downward in the tower 22 via the liquid nitrogen reservoir 21d, and comes into contact with compressed air rising from the bottom of the tower 22 countercurrently to cool it. Then, a part of it is liquefied. In this process, the high boiling point component in the compressed air is liquefied and accumulated at the bottom of the tower section 22, and the nitrogen gas of the low boiling point component is collected in the tower section 22.
Collect at the top of the. Reference numeral 27 denotes a nitrogen gas extraction passage for taking out nitrogen gas accumulated in the upper ceiling portion of the tower portion 22 of the rectification tower 15 as product nitrogen gas. Ultra-low temperature nitrogen gas is introduced into the second and first heat exchangers 14 and 13. It guides and heat-exchanges with the compressed air sent therein to bring it to room temperature and sends it into the main passage 28. In this case, at the uppermost part in the column part 22 of the rectification column 15, together with nitrogen gas, He having a low boiling point is formed.
(−269 ° C.), H 2 (−253 ° C.), etc. are likely to accumulate, so the nitrogen gas extraction passage 27 is opened considerably below the uppermost part of the tower section 22, and a pure He and H 2 mixture is not present. Only nitrogen gas is taken out as product nitrogen gas. At the top of the liquid nitrogen storage means 23, a vaporized nitrogen withdrawal passage 39 with a pressure adjusting valve 38 is used to provide a nitrogen gas takeout passage 27
The condenser 21a is provided with a gas vent passage 40 for letting out He, H 2 and the like to the outside air. 2
Reference numeral 9 is a passage for sending the vaporized liquid air in the dephlegmator 21 to the second and first heat exchangers 14 and 13, and 29a is a pressure holding valve thereof. 30 is a backup passage, and the rectification tower 15
Liquid nitrogen in the liquid nitrogen storage means 23 to compensate for the shortage of product nitrogen gas flowing from the main passage 28 to the evaporator 3.
It has a function of evaporating by 1 and constantly supplying a constant amount to the main passage 28, and a function of supplying the entire amount of nitrogen gas consumed when the air compression system line fails. In this case, the flow rate of the backup passage 30 is adjusted by that of the pressure adjusting valve 35 arranged downstream of the evaporator 31. An impurity analyzer 32 analyzes the purity of the product nitrogen gas sent to the main passage 28. When the purity is low, the valves 34 and 34a are operated to move the product nitrogen gas to the arrow B.
Like to escape to the outside. This apparatus produces product nitrogen gas as follows. That is, air is compressed by the air compressor 9, water in the air compressed by the drain separator 10 is removed and cooled by the Freon cooler 11, and then sent to the adsorption cylinder 12 in that state to remove H 2 in the air. 0 and CO 2 are removed by adsorption. Then, the compressed air from which H 2 0 and CO 2 have been adsorbed and removed is passed from the rectification column 15 to the nitrogen gas extraction passage 2
The product sent through 7 is sent to the first and second heat exchangers 13 and 14 that are cooled by nitrogen gas or the like to be cooled to an ultra-low temperature, and in that state, it is put into the lower part of the tower part 22 of the rectification tower 15. To do. Next, this input compressed air is used as the liquid nitrogen sent from the liquid nitrogen storage means 23 into the tower portion 22 of the rectification tower 15 via the liquid nitrogen introduction passage 24a and the liquid nitrogen overflowed from the liquid nitrogen reservoir 21d. They are brought into contact with each other and cooled, and a part thereof is liquefied and stored as liquid air 18 at the bottom of the tower section 22. In this process, due to the difference in boiling point between nitrogen and oxygen (boiling point of oxygen-183 ° C., boiling point of nitrogen-196 ° C.), oxygen, which is a high-boiling point component in the compressed air, is liquefied and nitrogen remains as a gas. Then, the nitrogen remaining as the gas is taken out from the nitrogen gas taking-out passage 27 to obtain the second and first nitrogen.
To the heat exchangers 14 and 13 to raise the temperature to near room temperature and send it out from the main passage 28 as product nitrogen gas. In this case, since the inside of the tower section 22 of the rectification tower 15 is at a high pressure due to the compressive force of the air compressor 9 and the vapor pressure of liquid nitrogen, the pressure of the product nitrogen gas taken out from the nitrogen gas take-out passage 27 is also high. . Therefore, it is advantageous when this product nitrogen gas is used as a purging gas or the like. Also, since the pressure is so high, a large amount of gas can be transported with a pipe of the same diameter, and a pipe with a small diameter can be used when the transport amount is constant, which saves equipment costs. It will be possible. On the other hand, the liquid air 18 collected in the lower part of the tower section 22 of the rectification tower 15 is sent into the dephlegmator section 21 to cool the condenser 21a. By this cooling, the condenser 21a is passed from the upper portion of the tower portion 22 of the rectification tower 15 through the first reflux liquid passage 21b.
The nitrogen gas sent to the liquefaction is liquefied and becomes a reflux liquid in the rectification column section 22, and the rectification column 1 is passed through the second reflux liquid passage 21c.
Return to tower 22 of No. 5. Then, the liquid air 18 that has finished cooling the condenser 21a is vaporized and sent to the second and first heat exchangers 14 and 13 through the passage 29, and the heat exchangers 14 and 13 are
After cooling 13, it is released into the air. The liquid nitrogen sent from the liquid nitrogen storage means 23 into the tower portion 22 of the rectification tower 15 via the liquid nitrogen introduction passage 24a acts as a cold source for liquefying the compressed air and vaporizes itself. And is taken out as a part of the product nitrogen gas from the nitrogen gas taking-out passage 27. As described above, the liquid nitrogen in the liquid nitrogen storage means 23 is not discarded after being used as a cold source for liquefying compressed air, but is combined with high-purity nitrogen gas using compressed air as a raw material. It is commercialized and used without waste. Further, since the vaporized nitrogen accumulated on the top of the liquid nitrogen storage means 23 is guided from the vaporized nitrogen extraction passage 39 to the nitrogen gas extraction passage 27, wasteful consumption of energy is prevented. The high-purity nitrogen gas producing apparatus of the present invention comprises:
Since the expansion turbine is not used and liquid nitrogen storage means such as a liquid nitrogen storage tank that does not have any rotating part is used instead of the expanding turbine, the rotating part disappears as a whole of the device and no failure occurs. The adverse effect (the amount of cold cannot be quickly controlled according to the change in the amount of product nitrogen gas taken out) does not occur, and the product nitrogen gas with high purity can be manufactured. In addition, the high-purity nitrogen gas producing apparatus of the present invention supplies liquid nitrogen, which becomes cold, from the liquid nitrogen storage tank to the rectification column as described above, and uses this as cold for the entire apparatus. Therefore, it is not necessary to use the expansion turbine, and the harmful effect due to the use of the expansion turbine does not occur. Further, in the present invention, as described above, the rectification column, the liquid nitrogen storage means, and the liquid nitrogen introduction passage are housed in the vacuum cool box. Therefore, when starting the device from the stopped state, the liquid nitrogen storage tank
Since the rectification column is precooled, the start-up time can be shortened. In addition, since the rectification column, the liquid nitrogen storage means, and the liquid nitrogen introduction passage are housed in the same vacuum cool box, the effect is that the entire installation space can be reduced, and a heat insulating material is provided for each. There is no need to use it to keep it cool. Further, since the vacuum heat insulating pipe that conventionally connects the rectification column and the liquid nitrogen storage tank is not required, the structure of the entire apparatus is simplified and the equipment cost is reduced. Moreover,
In this invention, the rectification column, the liquid nitrogen storage means, and the liquid nitrogen introduction passage are housed in the vacuum cool box, and the rectification column and the liquid nitrogen storage means are cooled by the rectification column. Are used so that the surface area of the vacuum insulation box is reduced and the heat insulation layer is increased. This reduces the amount of liquid nitrogen used. Moreover, the rectification column and the liquid nitrogen storage means have an effect of blocking heat radiation (heat intrusion) from each other, and due to this blocking, the space between the rectification column and the liquid nitrogen storage means is heated by the heat intrusion. There is almost nothing to do. Therefore, the portion of the rectification column facing the space is hardly heated by the heat intrusion, and as a result, the amount of liquid nitrogen required for cooling the rectification column is further reduced. Further, since there is almost no heat intrusion into the portion of the rectification column facing the above space, the reduction of the distillation area (area where distillation effectively works) in the rectification column is reduced, and the distillation efficiency is increased. The purity of the product nitrogen gas increases.
【図面の簡単な説明】
【図１】この発明の一実施例の構成図である。
【図２】精留塔と液体窒素貯蔵手段と液体窒素導入通路
を真空保冷函に収容した部分の構成図である。
【符号の説明】
９ 空気圧縮機
１２ 吸着筒
１３，１４ 熱交換器
１５ 精留塔
１９ 液体空気取入通路
１９ａ 膨脹弁
２１ 分縮器部
２１ａ 凝縮器
２１ｂ 第１の還流液用通路
２１ｃ 第２の還流液用通路
２２ 塔部
２３ 液体窒素貯蔵手段
２４ａ 液体窒素導入通路
２７ 窒素ガス取出通路
３７ 真空保冷函
３９ 気化窒素抜出通路BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is a configuration diagram of an embodiment of the present invention. FIG. 2 is a configuration diagram of a portion in which a rectification column, a liquid nitrogen storage means, and a liquid nitrogen introduction passage are housed in a vacuum cool box. [Explanation of Codes] 9 Air Compressor 12 Adsorption Tubes 13 and 14 Heat Exchanger 15 Fractionation Tower 19 Liquid Air Intake Passage 19a Expansion Valve 21 Divider 21a Condenser 21b First Reflux Passage 21c Second For recirculating liquid 22 Tower 23 Liquid nitrogen storage means 24a Liquid nitrogen introduction passage 27 Nitrogen gas extraction passage 37 Vacuum cool box 39 Vaporized nitrogen extraction passage
Claims (1)
と、この空気圧縮手段によって圧縮された圧縮空気中の
炭酸ガスと水とを除去する除去手段と、この除去手段を
経た圧縮空気を超低温に冷却する熱交換手段と、この熱
交換手段により超低温に冷却された圧縮空気の一部を液
化して内部に溜め窒素のみを気体として保持する精留塔
と、液体窒素を貯蔵する液体窒素貯蔵手段と、この液体
窒素貯蔵手段内の液体窒素を圧縮空気液化用の寒冷源と
して上記精留塔に導く液体窒素導入通路と、上記精留塔
内に保持されている気化窒素を取り出す窒素ガス取出通
路とを備え、真空保冷函内に、上記精留塔と液体窒素貯
蔵手段とを、液体窒素貯蔵手段の冷気を精留塔が利用可
能に位置決め配設したことを特徴とする高純度窒素ガス
製造装置。(57) [Claims] Air compression means for compressing air taken in from the outside, removal means for removing carbon dioxide gas and water in the compressed air compressed by the air compression means, and heat for cooling the compressed air passing through this removal means to an ultralow temperature An exchange means, a rectification column for liquefying a part of the compressed air cooled to an ultra-low temperature by this heat exchange means and retaining only nitrogen as a gas inside, a liquid nitrogen storage means for storing liquid nitrogen, and A liquid nitrogen introduction passage for guiding liquid nitrogen in the liquid nitrogen storage means to the rectification tower as a cold source for liquefying compressed air, and a nitrogen gas extraction passage for taking out the vaporized nitrogen held in the rectification tower are provided. In the vacuum cool box, the above rectification tower and liquid nitrogen storage
The rectification tower can use the cold air of the liquid nitrogen storage means as the storage means.
A high-purity nitrogen gas production device characterized by being positioned and arranged effectively.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7014413A JP2686050B2 (en) | 1995-01-31 | 1995-01-31 | High-purity nitrogen gas production equipment |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP7014413A JP2686050B2 (en) | 1995-01-31 | 1995-01-31 | High-purity nitrogen gas production equipment |
Related Parent Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP60299435A Division JPH0823470B2 (en) | 1985-12-28 | 1985-12-28 | High-purity nitrogen gas production equipment |
Related Child Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP8293016A Division JPH09105579A (en) | 1996-11-05 | 1996-11-05 | High purity nitrogen gas manufacturing apparatus |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07270063A JPH07270063A (en) | 1995-10-20 |
| JP2686050B2 true JP2686050B2 (en) | 1997-12-08 |
Family
ID=11860357
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP7014413A Expired - Fee Related JP2686050B2 (en) | 1995-01-31 | 1995-01-31 | High-purity nitrogen gas production equipment |
Country Status (1)
| Country | Link |
|---|---|
| JP (1) | JP2686050B2 (en) |
Families Citing this family (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| CN110411148A (en) * | 2019-07-05 | 2019-11-05 | 苏州市兴鲁空分设备科技发展有限公司 | A kind of space division system |
Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS515499A (en) * | 1974-07-03 | 1976-01-17 | Hitachi Ltd | Hoshaseikigasuno bunrikaishusochi |
| JPS5239100A (en) * | 1975-09-22 | 1977-03-26 | Hitachi Ltd | The enriched extraction of 85kr from the bottom liquid of a column still |
| JPS60147086A (en) * | 1984-01-11 | 1985-08-02 | 大同酸素株式会社 | Method and device for manufacturing high-purity nitrogen gas |
| JPS62158976A (en) * | 1985-12-28 | 1987-07-14 | 大同ほくさん株式会社 | Production unit for high-purity nitrogen gas |
-
1995
- 1995-01-31 JP JP7014413A patent/JP2686050B2/en not_active Expired - Fee Related
Patent Citations (4)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS515499A (en) * | 1974-07-03 | 1976-01-17 | Hitachi Ltd | Hoshaseikigasuno bunrikaishusochi |
| JPS5239100A (en) * | 1975-09-22 | 1977-03-26 | Hitachi Ltd | The enriched extraction of 85kr from the bottom liquid of a column still |
| JPS60147086A (en) * | 1984-01-11 | 1985-08-02 | 大同酸素株式会社 | Method and device for manufacturing high-purity nitrogen gas |
| JPS62158976A (en) * | 1985-12-28 | 1987-07-14 | 大同ほくさん株式会社 | Production unit for high-purity nitrogen gas |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07270063A (en) | 1995-10-20 |
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