JP2574639B2 - Air separation method - Google Patents
Air separation methodInfo
- Publication number
- JP2574639B2 JP2574639B2 JP5303001A JP30300193A JP2574639B2 JP 2574639 B2 JP2574639 B2 JP 2574639B2 JP 5303001 A JP5303001 A JP 5303001A JP 30300193 A JP30300193 A JP 30300193A JP 2574639 B2 JP2574639 B2 JP 2574639B2
- Authority
- JP
- Japan
- Prior art keywords
- adsorption
- gas
- adsorption tank
- pressure
- adsorbent
- 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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Landscapes
- Separation Of Gases By Adsorption (AREA)
- Oxygen, Ozone, And Oxides In General (AREA)
Description
【０００１】[0001]
【産業上の利用分野】この発明は、空気から酸素ガスを
高純度で分離する空気分離方法に関するものである。BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to an air separation method for separating oxygen gas from air with high purity.
【０００２】[0002]
【従来の技術】空気から酸素を分離する方法としては多
種の方法があるが、最近では、吸着剤を用いた分離方法
が、装置の設計の容易さや、設備費の安価なことから広
く用いられている。このような、吸着剤を用いた分離方
法は、一般にＰＳＡ法と呼ばれ、複数の吸着塔内に吸着
剤を充填し、各吸着塔に対する原料空気の供給、窒素ガ
スの吸着、窒素ガスの脱着・吸着剤の再生、復圧という
操作を、弁の切替えによって回分的に交互に行うように
なっている。そして、原料空気の供給は加圧状態で行わ
れ、吸着された窒素ガスの脱着は減圧下で行われてい
る。2. Description of the Related Art There are various methods for separating oxygen from air. Recently, a separation method using an adsorbent has been widely used due to simplicity of apparatus design and low cost of equipment. ing. Such a separation method using an adsorbent is generally called a PSA method, in which a plurality of adsorption towers are filled with an adsorbent, feed air to each adsorption tower, adsorption of nitrogen gas, desorption of nitrogen gas. -The operation of regeneration and recompression of the adsorbent is performed batchwise and alternately by switching valves. The supply of the raw material air is performed in a pressurized state, and the desorption of the adsorbed nitrogen gas is performed under reduced pressure.
【０００３】[0003]
【発明が解決しようとする課題】しかしながら、上記Ｐ
ＳＡ法では、窒素ガスの吸着工程において、窒素ガスの
みが吸着剤に吸着されるのではなく、酸素ガスの一部も
吸着される。また、吸着塔の気相部にもある程度酸素ガ
スが残留する。そして、上記吸着分離工程終了後、ただ
ちに、その吸着塔内を減圧するため、吸着剤に吸着され
ていたガスと気相部のガスがそのまま排気されてしま
う。したがって、本来、製品として取り出すべき酸素ガ
スの一部が排出されてしまうため、製品の収率が低くな
るという問題を有する。また、上記吸着工程において、
吸着塔内の吸着剤層には吸着帯が形成されるが、この吸
着帯の先端が製品ガス取り出し部を超えると、窒素ガス
が未吸着のまま取り出され、製品純度が低下する一方と
なるため、それ以上吸着を続けることができない。この
ため、全ての吸着剤を完全に飽和するまで使用すること
はできず、吸着槽内に充填された吸着剤の何割かは未使
用のままで効率が悪いという問題もある。However, the above P
In the SA method, not only the nitrogen gas is adsorbed by the adsorbent but also a part of the oxygen gas in the nitrogen gas adsorption step. Oxygen gas also remains to some extent in the gas phase of the adsorption tower. Then, immediately after the completion of the adsorption separation step, the pressure inside the adsorption tower is reduced, so that the gas adsorbed by the adsorbent and the gas in the gas phase are exhausted as they are. Therefore, since a part of the oxygen gas which should be taken out as a product is originally discharged, there is a problem that the product yield is reduced. Further, in the adsorption step,
An adsorption band is formed in the adsorbent layer in the adsorption tower, but when the tip of this adsorption band exceeds the product gas take-out part, nitrogen gas is taken out without being adsorbed and the product purity is only reduced. , The adsorption cannot be continued any more. For this reason, it is not possible to use all the adsorbents until they are completely saturated, and there is also a problem that some of the adsorbents filled in the adsorption tank are unused and inefficient.
【０００４】そこで、本発明者らは、上記ＰＳＡ法の欠
点を解消すべく一連の研究を重ねた結果、吸着槽内に粒
状吸着剤を層状に溜めて徐々に流下させる一方、下から
原料ガスを吹き出して両者を向流接触させ、混合ガス中
の易吸着ガスを吸着剤に吸着させ、吸着槽外でこれを再
生して循環使用するという画期的な方法を開発し、すで
に出願している（特願平４−５６６５９、平成４年２月
８日出願）。[0004] The inventors of the present invention have conducted a series of studies to solve the above-mentioned drawbacks of the PSA method. As a result, the granular adsorbent is stored in a layered manner in the adsorption tank and gradually flows down, while the raw material gas flows from below. And developed a revolutionary method of adsorbing the easily adsorbed gas in the mixed gas to the adsorbent, regenerating it outside the adsorption tank, and circulating it. (Japanese Patent Application No. 4-56659, filed on February 8, 1992).
【０００５】この方法によれば、全ての吸着剤が完全に
飽和するまで使用することができ、しかもガスの流れを
連続化することができるため、システムとして安定した
操業を行うことができるという利点を有する。しかし、
上記の方法では、粒状吸着剤を循環移送することから通
常の吸着剤よりも硬度の高い吸着剤を用いなければなら
ないという不具合を生じる。また、吸着剤移送のために
新たな動力源が必要なため、動力コストが高くつくとい
う問題もある。According to this method, all the adsorbents can be used until they are completely saturated, and furthermore, the gas flow can be continued, so that the system can be operated stably. Having. But,
In the above-mentioned method, since the granular adsorbent is circulated and transported, there arises a problem that an adsorbent having higher hardness than a normal adsorbent must be used. Another problem is that a new power source is required for transferring the adsorbent, so that the power cost is high.
【０００６】この発明は、このような事情に鑑みなされ
たもので、吸着剤を効率よく使用することができ、しか
も少ない動力で製品として取り出す酸素ガスの収率が非
常に高い、優れた空気分離方法の提供をその目的とす
る。The present invention has been made in view of such circumstances, and has an excellent air separation in which the adsorbent can be used efficiently and the yield of oxygen gas extracted as a product with a small power is very high. Its purpose is to provide a method.
【０００７】[0007]
【課題を解決するための手段】上記の目的を達成するた
め、この発明の空気分離方法は、吸着槽を複数個設け、
下記の（Ａ）〜（Ｄ）の４工程を、各吸着槽ごとに時間
帯をずらした状態でこの順で繰り返して行う空気分離方
法であって、下記の回収工程（Ｂ）が終了した吸着槽の
上部から、減圧再生工程（Ｃ）が終了した他の吸着槽の
下部へ、両吸着槽内の圧力差によりガスを移動させる均
圧化工程を設けたという構成をとる。 （Ａ） 吸着槽内に、原料空気を導入し、原料空気に含
まれる窒素ガスを吸着剤に吸着させる吸着工程。 （Ｂ） 上記吸着工程の終了した吸着槽内に、下記
（Ｃ）の減圧再生工程にある他の吸着槽から取り出され
る排ガスの一部を導入し、吸着剤に吸着された酸素ガス
および吸着槽内の気相部に残留する酸素ガスを上記排ガ
スで置換し、酸素濃度が上記排ガスよりも高められた回
収ガスを上記吸着槽外に取り出す回収工程。 （Ｃ） 上記回収工程の終了した吸着槽内を減圧し、吸
着剤に吸着されている窒素ガスを脱着させて吸着剤を再
生するとともに、上記脱着ガスおよび気相部に残留する
ガスを排ガスとして上記吸着槽外に取り出す減圧再生工
程。 （Ｄ） 上記減圧再生工程の終了した吸着槽内に、上記
（Ａ）の吸着工程にある他の吸着槽から取り出される製
品ガスの一部を導入して復圧させる復圧工程。Means for Solving the Problems To achieve the above object, an air separation method according to the present invention is provided with a plurality of adsorption tanks,
This is an air separation method in which the following four steps (A) to (D) are repeated in this order with the time zone shifted for each adsorption tank, and the adsorption step in which the following recovery step (B) is completed A pressure equalizing step is provided from the upper part of the tank to the lower part of the other adsorption tank where the pressure reduction regeneration step (C) has been completed, in which the gas is moved by the pressure difference between the two adsorption tanks. (A) An adsorption step in which raw air is introduced into an adsorption tank and nitrogen gas contained in the raw air is adsorbed by an adsorbent. (B) A part of the exhaust gas taken out from the other adsorption tank in the reduced pressure regeneration step (C) described below is introduced into the adsorption tank after the adsorption step, and the oxygen gas adsorbed by the adsorbent and the adsorption tank A recovery step of replacing the oxygen gas remaining in the gaseous phase portion with the exhaust gas and extracting a recovery gas having an oxygen concentration higher than the exhaust gas outside the adsorption tank. (C) The pressure in the adsorption tank after the recovery step is reduced, the nitrogen gas adsorbed on the adsorbent is desorbed to regenerate the adsorbent, and the desorbed gas and the gas remaining in the gas phase are treated as exhaust gas. A reduced-pressure regeneration step of taking out of the adsorption tank. (D) A pressure recovery step in which a part of the product gas taken out from the other adsorption tank in the adsorption step (A) is introduced into the adsorption tank after the pressure reduction regeneration step has been completed to recover the pressure.
【０００８】[0008]
【作用】すなわち、この発明は、複数個の吸着槽におい
て、吸着工程（Ａ），回収工程（Ｂ），減圧再生工程
（Ｃ），復圧工程（Ｄ）の４工程を、それぞれ時間帯を
ずらした状態でこの順で繰り返し行うようにしたもので
あり、実際には各吸着槽内に固定された吸着剤が、各吸
着槽で順次ずれた状態で繰り返される工程を経ることに
よって、あたかも各吸着槽を移動しているがごとき効果
が得られる。これにより、吸着剤の粉化等を招くことな
く使用することができ、循環移送方式の利点が活かされ
欠点が解消する。しかも、減圧再生工程に先立って、吸
着槽内を、減圧再生工程にある他の吸着槽から取り出さ
れる排ガスの一部で置換し、吸着槽内に残留する酸素ガ
スを回収するようにしているため、得られる製品ガスの
収率を大幅に高めることができる。また、この発明で
は、回収工程が終了した吸着槽の上部から、減圧工程が
終了した他の吸着槽の下部に、両槽の圧力差を利用して
ガスを移動させることにより均圧化を行うようにしてい
るため、全く動力をかけることなく、回収工程終了後の
吸着槽上部に残留する酸素濃度の高いガスをさらに回収
することができる。したがって、排ガスを利用した回収
工程において、動力負担をかけて排ガスを大量に吸着槽
内に送入しなくても、上記均圧化工程において、酸素の
回収率を高めることができ、その分上記送入排ガス量を
低減できるため、動力負担を軽減することができる。そ
して、減圧再生工程に先立って、あるいはその途中に均
圧化が行われ、吸着槽内の圧力が下がるため、減圧再生
工程における排気のための動力負担も軽減することがで
きるという利点を有する。That is, according to the present invention, in a plurality of adsorption tanks, four steps of an adsorption step (A), a recovery step (B), a reduced pressure regeneration step (C), and a pressure recovery step (D) are performed in a time zone In this case, it is performed repeatedly in this order in a shifted state.In practice, the adsorbent fixed in each adsorption tank is repeated in each adsorption tank in a sequentially shifted state, as if each The effect can be obtained while moving the adsorption tank. As a result, the adsorbent can be used without causing powdering, etc., and the advantages of the circulating transfer system are utilized to eliminate the disadvantages. Moreover, prior to the decompression regeneration step, the inside of the adsorption tank is replaced with a part of the exhaust gas taken out from another adsorption tank in the decompression regeneration step, so that oxygen gas remaining in the adsorption tank is recovered. The yield of the product gas obtained can be greatly increased. Further, in the present invention, pressure equalization is performed by moving gas from the upper part of the adsorption tank after the completion of the recovery step to the lower part of the other adsorption tank after the completion of the depressurization step by utilizing the pressure difference between the two tanks. As a result, the gas having a high oxygen concentration remaining at the upper portion of the adsorption tank after the completion of the recovery step can be further recovered without applying any power. Therefore, in the recovery step using the exhaust gas, even if a large amount of the exhaust gas is not fed into the adsorption tank by applying a power load, the recovery rate of oxygen can be increased in the pressure equalization step. Since the amount of incoming exhaust gas can be reduced, the power burden can be reduced. Then, prior to or during the decompression regeneration step, pressure equalization is performed, and the pressure in the adsorption tank is reduced, so that there is an advantage that the power load for exhaust in the decompression regeneration step can be reduced.
【０００９】つぎに、この発明を詳しく説明する。Next, the present invention will be described in detail.
【００１０】この発明は、空気から酸素ガスを分離する
方法を対象とする。また、排ガスにおける窒素ガス濃度
も高いため、この窒素ガスを、製品窒素ガスとして利用
することもできる。さらに、この発明の方法は、各種混
合ガスからの特定有効ガス（例えばＨ2 、ＣＯ、ハイド
ロカーボン類等のあらゆる有効ガス）の分離に応用する
ことも可能である。また、単にガスの分離だけでなく、
分離操作を利用して、特定ガスの濃縮，回収、あるいは
有害ガスを含んだガスの浄化等に応用することもでき
る。[0010] The present invention is directed to a method of separating oxygen gas from air. Further, since the nitrogen gas concentration in the exhaust gas is high, this nitrogen gas can be used as product nitrogen gas. Further, the method of the present invention can be applied to the separation of a specific effective gas (for example, any effective gas such as H 2 , CO, and hydrocarbons) from various mixed gases. Also, not just gas separation,
By utilizing the separation operation, the present invention can be applied to concentration and recovery of a specific gas, or purification of a gas containing a harmful gas.
【００１１】また、この発明で用いる吸着剤としては、
窒素ガスを優先的に吸着するものであればどのようなも
のでもよいが、例えば、ゼオライトを用いることが好適
である。The adsorbent used in the present invention includes:
Any material may be used as long as it preferentially adsorbs nitrogen gas. For example, zeolite is preferably used.
【００１２】つぎに、実施例について説明する。Next, an embodiment will be described.
【００１３】[0013]
【実施例】図１は、この発明の一実施例に用いる装置の
基本的な構成を示している。この装置は、仕切り板２を
介して縦１列に形成された４つの吸着槽３〜６を備えて
おり、各吸着槽３〜６内には、窒素ガス吸着能を有する
吸着剤（例えばゼオライト）８が、上下に設けられた多
孔付保持板９，１０に挟持されて上下に空間をもたせた
状態で充填されている。FIG. 1 shows a basic configuration of an apparatus used in an embodiment of the present invention. This apparatus is provided with four adsorption tanks 3 to 6 formed in one vertical line via a partition plate 2, and in each of the adsorption tanks 3 to 6, an adsorbent (for example, zeolite) having a nitrogen gas adsorbing ability is provided. ) 8 is filled between the upper and lower holding plates with perforations 9 and 10 so as to have a space above and below.
【００１４】上記第１の吸着槽３の上部空間は開閉弁１
１を介して第４の吸着槽６の下部空間に接続され、第２
の吸着槽４の上部空間は開閉弁１２を介して上記第１の
吸着槽３の下部空間に接続されている。また、第３の吸
着槽５の上部空間は開閉弁１３を介して上記第２の吸着
槽４の下部空間に接続され、第４の吸着槽６の上部空間
は開閉弁１４を介して上記第３の吸着槽５の下部空間に
接続されている。The upper space of the first adsorption tank 3 is an on-off valve 1
1 is connected to the lower space of the fourth adsorption tank 6 through
The upper space of the adsorption tank 4 is connected to the lower space of the first adsorption tank 3 via an on-off valve 12. The upper space of the third adsorption tank 5 is connected to the lower space of the second adsorption tank 4 via an on-off valve 13, and the upper space of the fourth adsorption tank 6 is connected to the fourth space via an on-off valve 14. 3 is connected to the lower space of the adsorption tank 5.
【００１５】また、上記第１の吸着槽３の上部空間は開
閉弁１５を介して第２の吸着槽４の下部空間に接続さ
れ、第２の吸着槽４の上部空間は開閉弁１６を介して上
記第３の吸着槽５の下部空間に接続されている。また、
第３の吸着槽５の上部空間は開閉弁１７を介して上記第
４の吸着槽６の下部空間に接続され、第４の吸着槽６の
上部空間は開閉弁１８を介して上記第１の吸着槽３の下
部空間に接続されている。The upper space of the first adsorption tank 3 is connected to the lower space of the second adsorption tank 4 via an on-off valve 15, and the upper space of the second adsorption tank 4 is connected via an on-off valve 16. To the lower space of the third adsorption tank 5. Also,
The upper space of the third adsorption tank 5 is connected to the lower space of the fourth adsorption tank 6 via an on-off valve 17, and the upper space of the fourth adsorption tank 6 is connected to the first space via an on-off valve 18. It is connected to the lower space of the adsorption tank 3.
【００１６】一方、２０は原料空気導入配管で、開閉弁
２１〜２４を介して各吸着槽３〜６の下部空間に接続さ
れ、各吸着槽３〜６内に原料空気を導入することができ
るようになっている。なお、上記原料空気は、エアフィ
ルター（図示せず）を経由させブロア２５で加圧したの
ち上記原料空気導入配管２０に送入されるようになって
いる。On the other hand, reference numeral 20 denotes a raw material air introduction pipe, which is connected to the lower space of each of the adsorption tanks 3 to 6 through on-off valves 21 to 24, and can introduce the raw material air into each of the adsorption tanks 3 to 6. It has become. The raw air is passed through an air filter (not shown) and pressurized by a blower 25 before being fed into the raw air introduction pipe 20.
【００１７】また、２６は製品ガス取り出し配管で、開
閉弁２７〜３０を介して各吸着槽３〜６の上部空間に接
続され、各吸着槽３〜６内から、製品ガス（高純度酸素
ガス）を取り出すことができるようになっている。ただ
し、上記製品ガス取り出し配管２６には、開閉弁３２〜
３５を介して各吸着槽３〜６に連通する分岐配管３１が
設けられており、製品ガスの一部を減圧再生工程終了後
の他の吸着槽に導入して復圧工程を行うのに利用され
る。Reference numeral 26 denotes a product gas take-out pipe, which is connected to the upper space of each of the adsorption tanks 3 to 6 via on-off valves 27 to 30 and from which the product gas (high-purity oxygen gas) is supplied. ) Can be taken out. However, the product gas extraction pipe 26 has on-off valves 32 to
A branch pipe 31 communicating with each of the adsorption tanks 3 to 6 via 35 is provided, and is used to introduce a part of the product gas into another adsorption tank after the completion of the decompression and regeneration step to perform the pressure recovery step. Is done.
【００１８】さらに、３６は、開閉弁３７〜４０を介し
て、各吸着槽３〜６の下部空間に接続される排ガス取り
出し配管で、真空ポンプ４１によって各吸着槽３〜６内
が強制排気されるようになっている。なお、上記真空ポ
ンプ４１のガス取り出し側には、ブロア４２を介して分
岐配管４３が接続されており、この分岐配管４３が、開
閉弁４４〜４７を介して、各吸着槽３〜６の下部空間に
接続されている。したがって、上記真空ポンプ４１から
取り出された排ガスの一部を、上記分岐配管４３から吸
着槽３〜６内に戻すことができるようになっている。Reference numeral 36 denotes an exhaust gas take-out pipe connected to the lower space of each of the adsorption tanks 3 to 6 via on-off valves 37 to 40, and the inside of each of the adsorption tanks 3 to 6 is forcibly evacuated by the vacuum pump 41. It has become so. A branch pipe 43 is connected to the gas extraction side of the vacuum pump 41 via a blower 42. The branch pipe 43 is connected to the lower part of each of the adsorption tanks 3 to 6 via on-off valves 44 to 47. Connected to space. Therefore, a part of the exhaust gas extracted from the vacuum pump 41 can be returned from the branch pipe 43 into the adsorption tanks 3 to 6.
【００１９】この構成において、上記各開閉弁１１〜１
４，１５〜１８，２１〜２４，２７〜３０，３２〜３
５，３７〜４０，４４〜４７等を、単位時間ごとに切り
換えることにより、上記４つの吸着槽３〜６のそれぞれ
において、吸着工程（Ａ），回収工程（Ｂ），減圧再生
工程（Ｃ），復圧工程（Ｄ）を、それぞれ時間帯をずら
した状態でこの順で繰り返し、連続的に原料空気から高
純度の酸素ガスを分離して製品ガスとして取り出すこと
ができる。In this configuration, each of the on-off valves 11 to 1
4,15-18,21-24,27-30,32-3
By switching between 5, 37 to 40, 44 to 47, and the like every unit time, in each of the four adsorption tanks 3 to 6, the adsorption step (A), the recovery step (B), and the reduced pressure regeneration step (C). , The pressure recovery step (D) is repeated in this order with the time zone shifted, and high-purity oxygen gas can be continuously separated from the raw material air and taken out as a product gas.
【００２０】なお、上記吸着工程（Ａ）は、吸着剤８の
吸着能力を完全に利用できるよう、第１の吸着工程（Ａ
１）と、第２の吸着工程（Ａ２）に分けて行い、しかも
上記第２の吸着工程（Ａ２）を、さらに２段階に分けて
行うようになっている。The adsorption step (A) is performed so that the adsorption capacity of the adsorbent 8 can be used completely.
1) and the second adsorption step (A2) are performed separately, and the second adsorption step (A2) is further performed in two stages.
【００２１】また、上記回収工程（Ｂ）が終了し減圧再
生工程（Ｃ）に移行した吸着槽と、減圧再生工程（Ｃ）
が終了し復圧工程（Ｄ）に移行した吸着槽とを、一定時
間だけ連通して両吸着槽間で均圧化を行うようになって
いる。In addition, the adsorption tank which has been transferred to the reduced pressure regeneration step (C) after the completion of the recovery step (B) and the reduced pressure regeneration step (C)
Is completed, and the adsorption tank which has shifted to the pressure recovery step (D) is communicated for a certain period of time to equalize the pressure between the two adsorption tanks.
【００２２】より詳しく説明すると、上記装置では、各
吸着槽３〜６において、例えば図２および図３に示すよ
うに、各吸着槽３〜６間で完全に工程が移行する大工程
が４つあり、各大工程がそれぞれ二つのステップに分か
れて部分的に開閉弁の切り替えがなされるようになって
おり、全体として、〔ステップ１〕〜〔ステップ８〕で
示す８種類の工程がこの順で繰り返される。More specifically, in the above apparatus, in each of the adsorption tanks 3 to 6, for example, as shown in FIGS. 2 and 3, there are four large steps in which the process completely shifts between the adsorption tanks 3 to 6. Each large process is divided into two steps, and the on / off valve is partially switched. As a whole, eight types of processes shown in [Step 1] to [Step 8] are performed in this order. Is repeated.
【００２３】すなわち、まず大工程１の〔ステップ１〕
において、第１の吸着槽３は、前段階で、他の吸着槽４
から取り出される製品ガスの一部を利用した復圧がなさ
れた状態になっており（図３における〔ステップ８〕参
照）、開閉弁１２（図１参照）の開動作により、この吸
着槽３内に、その隣の第２の吸着槽４から取り出される
ガスが導入され、このガス中の主として窒素ガスが、吸
着槽３内の吸着剤８に吸着される。そして、吸着槽３の
上部空間に接続される製品ガス取り出し配管２６から、
高純度の酸素ガスが製品として取り出される。ただし、
上記吸着槽３内における吸着は、吸着帯の先端が、吸着
槽４における製品ガス取り出し部に達するまで（図４
〔ａ〕において鎖線Ｐで示すライン）を１とすると、そ
の１／２程度に吸着が進行した段階まで行われる。この
吸着工程を、便宜上「第２の吸着工程１」という。That is, first, [Step 1] of the large process 1
In the first stage, the first adsorption tank 3 is provided with another adsorption tank 4
The pressure is restored using a part of the product gas taken out of the adsorption tank 3 (see [Step 8] in FIG. 3). Then, a gas taken out from the second adsorption tank 4 adjacent thereto is introduced, and mainly nitrogen gas in this gas is adsorbed by the adsorbent 8 in the adsorption tank 3. Then, from the product gas extraction pipe 26 connected to the upper space of the adsorption tank 3,
High-purity oxygen gas is taken out as a product. However,
The adsorption in the adsorption tank 3 is performed until the tip of the adsorption band reaches the product gas extracting section in the adsorption tank 4 (FIG. 4).
Assuming that the line indicated by the dashed line P in [a] is 1, the process is performed up to the stage where the adsorption has progressed to about 1/2 of that. This adsorption step is referred to as “second adsorption step 1” for convenience.
【００２４】上記「吸着帯」とは、図４（ａ）に示すよ
うに、吸着の進行に伴って吸着剤８層に形成される吸着
領域（図においてＳで示す）をいう。そして、この吸着
帯Ｓが、ガスの通過方向に沿って徐々に上昇し、先端が
鎖線Ｐで示すように吸着剤８層の上面（製品ガス取り出
し部に相当）に達すると、本来吸着されるべき窒素ガス
等が吸着されず、そのまま上部空間に流出して製品ガス
の純度を低下させてしまう（この状態を「ガスが破過す
る」という）ので、製品ガスを取り出しているこの吸着
槽４では、それ以上吸着を行うことができない。この
〔ステップ１〕では、上記吸着帯Ｓの先端Ｐが、Ｔで示
す位置に到達するまで吸着を行う。As shown in FIG. 4A, the "adsorption band" refers to an adsorption area (indicated by S in the figure) formed in the adsorbent 8 layer as the adsorption proceeds. Then, when the adsorption band S gradually rises in the gas passing direction and reaches the upper surface (corresponding to a product gas take-out portion) of the adsorbent 8 layer as shown by the chain line P, it is originally adsorbed. The nitrogen gas or the like to be absorbed is not adsorbed and flows out to the upper space as it is to lower the purity of the product gas (this state is called "gas breakthrough"). Then, no further adsorption can be performed. In this [Step 1], suction is performed until the tip P of the suction band S reaches the position indicated by T.
【００２５】一方、第２の吸着槽４では、前段階で、上
記吸着槽３における吸着よりもさらに吸着が進行して吸
着帯Ｓの先端Ｐが製品ガス取り出し部に達する手前まで
吸着が行われた状態になっている（ステップ８参照）
が、この吸着槽５の下部空間に、原料空気導入配管２０
（図１参照）から原料空気が加圧状態で供給され、吸着
がさらに進められる。これにより、吸着帯Ｓはさらに上
昇し、図４〔ａ〕に示すように、ついには吸着槽４の吸
着剤８全体が飽和した状態となる。この工程では、吸着
槽４の上部空間には、原料空気中の、主に窒素ガスが吸
着され、酸素濃度が原料空気よりも高められたガスが取
り出される。このガスは、連通配管によって、上記第１
の吸着槽３の下部空間に導入される。この吸着工程を、
便宜上「第１の吸着工程」という。On the other hand, in the second adsorption tank 4, in the previous stage, the adsorption proceeds further than the adsorption in the adsorption tank 3, and the adsorption is performed until the leading end P of the adsorption band S reaches the product gas take-out part. (See step 8)
In the lower space of the adsorption tank 5, a raw air introduction pipe 20 is provided.
(See FIG. 1), the raw material air is supplied in a pressurized state, and the adsorption is further promoted. Thereby, the adsorption band S further rises, and as shown in FIG. 4A, the entire adsorbent 8 of the adsorption tank 4 is finally saturated. In this step, mainly nitrogen gas in the raw material air is adsorbed in the upper space of the adsorption tank 4, and a gas having an oxygen concentration higher than that of the raw material air is taken out. This gas is supplied to the first gas by the communication pipe.
Is introduced into the lower space of the adsorption tank 3. This adsorption process,
For convenience, it is referred to as “first adsorption step”.
【００２６】また、第３の吸着槽５では、前段階で、後
述する回収工程を経て、吸着剤８内には殆ど窒素ガスの
みが吸着され槽内にわずかに酸素リッチな回収ガスが残
留した状態になっているが、この吸着槽５内は、排ガス
取り出し配管３６により強制排気され減圧される。そし
て、この吸着槽５の上部空間は、上記減圧を開始すると
同時に、開閉弁１７（図１参照）の開動作により、前段
階で減圧再生工程を終了しこの〔ステップ１〕において
復圧工程に移行した吸着槽６の下部空間と連通される。
両吸着槽５，６には圧力差があるので、この圧力差によ
り、何ら動力をかけることなく吸着槽５内の上記残留回
収ガスが吸着槽６に移動し、両槽５，６内の均圧化が行
われる。In the third adsorption tank 5, in the previous stage, through a recovery step described later, almost only nitrogen gas is adsorbed in the adsorbent 8, and a slightly oxygen-rich recovered gas remains in the tank. Although in this state, the interior of the adsorption tank 5 is forcibly evacuated and reduced in pressure by an exhaust gas extraction pipe 36. Then, at the same time as the above-mentioned pressure reduction is started, the opening and closing valve 17 (see FIG. 1) opens the pressure reduction regeneration process at the previous stage in the upper space of the adsorption tank 5, and in this [Step 1], returns to the pressure recovery process. It communicates with the lower space of the adsorption tank 6 that has shifted.
Since there is a pressure difference between the two adsorption tanks 5, 6, the residual collected gas in the adsorption tank 5 moves to the adsorption tank 6 without applying any power due to the pressure difference, and the residual collection gas in the both tanks 5, 6 is equalized. Pressure is applied.
【００２７】さらに、第４の吸着槽６では、上述のよう
に、均圧操作のために第３の吸着槽５と連通され、これ
により、第３の吸着槽５から残留回収ガス（酸素リッチ
なガス）が導入される。そして、この操作と同時に、上
記第１の吸着槽３から取り出される製品ガス（高純度酸
素ガス）の一部が、上記吸着槽６の上部空間に、分岐配
管３１を介して導入される。上記２種類のガス導入のた
め、吸着槽６は徐々に復圧する。Further, in the fourth adsorption tank 6, as described above, the fourth adsorption tank 6 communicates with the third adsorption tank 5 for pressure equalizing operation. Gas) is introduced. At the same time as this operation, a part of the product gas (high-purity oxygen gas) taken out of the first adsorption tank 3 is introduced into the upper space of the adsorption tank 6 via the branch pipe 31. Due to the introduction of the above two types of gases, the adsorption tank 6 gradually recovers its pressure.
【００２８】つぎに、装置の動作は図２の〔ステップ
２〕に進み、第１の吸着槽３では、前段階である程度進
行した吸着剤８への窒素ガス吸着が一層進行し、図４
（ａ）において鎖線Ｐで示すように、吸着帯Ｓが上昇し
てその先端が吸着剤８層の上面に達する手前、すなわち
窒素ガスが破過する直前まで吸着が行われる。この吸着
工程を、便宜上「第２の吸着工程２」という。このと
き、吸着槽３の上部空間からは、製品ガスが取り出さ
れ、下部空間には、原料空気が導入されるとともに、第
２の吸着槽４から回収ガスが導入される。Next, the operation of the apparatus proceeds to [Step 2] in FIG. 2, and in the first adsorption tank 3, the nitrogen gas adsorption to the adsorbent 8 which has progressed to some extent in the previous stage further progresses.
As shown by the chain line P in (a), the adsorption is performed until the adsorption band S rises and its tip reaches the upper surface of the adsorbent 8 layer, that is, immediately before nitrogen gas breaks through. This adsorption step is referred to as “second adsorption step 2” for convenience. At this time, product gas is taken out from the upper space of the adsorption tank 3, raw air is introduced into the lower space, and recovered gas is introduced from the second adsorption tank 4.
【００２９】また、第２の吸着槽４では、前段階で吸着
剤８全体が飽和した状態になっているが、この吸着槽４
に、減圧再生工程にある第３の吸着槽５から排ガス（窒
素ガス９５％程度）の一部が、分岐配管４３を利用して
導入される。このガスを便宜上「リンスガス」という。
これにより、吸着槽４内が上記リンスガスで置換され、
前段階で吸着剤８内に一部吸着されていた酸素ガスが吸
着剤８から脱着されて気相部に追い出され、気相部に残
留するガスとともに、回収ガスとして、上記第１の吸着
槽３の下部空間に導入される。これにより、排ガスとし
て取り出すべきガスから酸素ガスを回収することがで
き、製品ガスにおける酸素の収率を高めることができ
る。In the second adsorption tank 4, the entire adsorbent 8 is saturated in the previous stage.
Then, a part of the exhaust gas (about 95% of nitrogen gas) is introduced from the third adsorption tank 5 in the decompression regeneration step using the branch pipe 43. This gas is referred to as “rinse gas” for convenience.
Thereby, the inside of the adsorption tank 4 is replaced with the rinsing gas,
Oxygen gas partially adsorbed in the adsorbent 8 in the previous stage is desorbed from the adsorbent 8 and expelled into the gas phase, and together with the gas remaining in the gas phase, as the recovered gas, the first adsorption tank 3 is introduced into the lower space. Thereby, the oxygen gas can be recovered from the gas to be taken out as the exhaust gas, and the yield of oxygen in the product gas can be increased.
【００３０】さらに、第３の吸着槽５では、前段階であ
る程度進行した減圧による吸着剤８の再生を一層進め、
吸着剤８内から脱着しうる窒素ガスを完全に脱着させ
る。このとき、前段階では、第４の吸着槽６との均圧化
を行うために開閉弁１７を開いて両吸着槽５，６間を連
通していたが、この工程では、上記開閉弁１７を閉じ、
吸着槽５内の強制排気のみを行う。そして、排ガスの一
部は、すでに述べたように、リンスガスとして、分岐配
管４３を介して上記第２の吸着槽４の下部空間に導入さ
れる。Further, in the third adsorption tank 5, the regeneration of the adsorbent 8 is further promoted by the reduced pressure which has progressed to some extent in the previous stage.
Nitrogen gas that can be desorbed from within the adsorbent 8 is completely desorbed. At this time, in the previous stage, the on-off valve 17 was opened to equalize the pressure with the fourth adsorption tank 6, and the two adsorption tanks 5 and 6 were communicated with each other. Close
Only the forced exhaust in the adsorption tank 5 is performed. As described above, a part of the exhaust gas is introduced into the lower space of the second adsorption tank 4 through the branch pipe 43 as a rinse gas.
【００３１】また、第４の吸着槽６では、前段階である
程度進行した復圧を一層進め、完全に吸着槽６内を復圧
させる。このとき、上記減圧工程と同様、前段階で行っ
た均圧化操作は行わず、吸着槽６内に、第２の吸着工程
２にある吸着槽３から取り出される製品ガスの一部のみ
が導入される。これにより、前段階およびこの工程にお
いて吸着剤８から脱着した窒素ガスが、上記製品ガスの
流入とともに下方に移動する。したがって、つぎの段階
（図２の〔ステップ３〕参照）で再びこの吸着槽４内で
窒素ガスを吸着させ上部空間から製品ガスを取り出す
際、残留窒素ガスが製品ガスに混入して製品ガスの純度
を停止させることを防止することができる。Further, in the fourth adsorption tank 6, the decompression that has progressed to some extent in the previous stage is further advanced, and the inside of the adsorption tank 6 is completely decompressed. At this time, similarly to the pressure reduction step, the pressure equalization operation performed in the previous stage is not performed, and only a part of the product gas extracted from the adsorption tank 3 in the second adsorption step 2 is introduced into the adsorption tank 6. Is done. Thus, the nitrogen gas desorbed from the adsorbent 8 in the previous stage and in this step moves downward with the inflow of the product gas. Therefore, at the next stage (see [Step 3] in FIG. 2), when the nitrogen gas is again adsorbed in the adsorption tank 4 and the product gas is taken out from the upper space, the residual nitrogen gas is mixed into the product gas and the product gas is removed. Stopping the purity can be prevented.
【００３２】つぎに、装置の動作は図２の〔ステップ
３〕に進み、上記大工程１の〔ステップ１〕で行われた
と同様の動作が、〔ステップ１〕から吸着槽３〜６を一
つずつ繰り上げた状態で行われる。すなわち、第１の吸
着槽３では第１の吸着工程が行われ、第２の吸着槽４で
は均圧化を伴う減圧再生工程が行われ、第３の吸着槽５
では均圧化を伴う復圧工程が行われ、第４の吸着槽６で
は第２の吸着工程１が行われる。そして、〔ステップ
４〕では、上記大工程１の〔ステップ２〕で行われたと
同様の動作が、〔ステップ２〕から吸着槽３〜６を一つ
ずつ繰り上げた状態で行われる。そして、図３に示すよ
うに、〔ステップ５〕，〔ステップ６〕からなる大工程
３、〔ステップ７〕，〔ステップ８〕からなる大工程４
……と、順次、吸着槽３〜６を一つずつ繰り上げなが
ら、上記一連の動作が繰り返される。Next, the operation of the apparatus proceeds to [Step 3] in FIG. 2, and the same operation as that performed in [Step 1] of the above-mentioned large process 1 is performed by removing the adsorption tanks 3 to 6 from [Step 1]. It is performed in a state where it is raised one by one. That is, the first adsorption tank 3 performs the first adsorption step, the second adsorption tank 4 performs the reduced pressure regeneration step with pressure equalization, and the third adsorption tank 5
In, a pressure recovery step involving equalization is performed, and the second adsorption step 1 is performed in the fourth adsorption tank 6. In [Step 4], the same operation as performed in [Step 2] of the large process 1 is performed in a state where the adsorption tanks 3 to 6 are moved up one by one from [Step 2]. Then, as shown in FIG. 3, a large process 3 composed of [Step 5] and [Step 6], and a large process 4 composed of [Step 7] and [Step 8].
, And the above-described series of operations is repeated while sequentially moving up the adsorption tanks 3 to 6 one by one.
【００３３】これにより、実際には、各吸着槽３〜６に
それぞれ充填保持された吸着剤８が、その場で、第２の
吸着１，第２の吸着２，第１の吸着，回収，均圧化を伴
う減圧再生，減圧再生，均圧化を伴う復圧，復圧の８工
程に繰り返し供されているにすぎないが、装置全体とし
てみれば、あたかも第１の吸着槽３から第２の吸着槽
４、第２の吸着槽４から第３の吸着槽５、第３の吸着槽
５から第４の吸着槽６、第４の吸着槽６から第１の吸着
槽３、と吸着剤８が循環移動しながら上記８つの工程を
経由しているかのような構成になっており、各工程間に
無駄がなく、非常に効率よく高純度酸素ガスを製品とし
て取り出すことができる。Thus, in practice, the adsorbent 8 charged and held in each of the adsorption tanks 3 to 6 is provided with the second adsorption 1, the second adsorption 2, the first adsorption, recovery, Although only the eight steps of pressure reduction regeneration with pressure equalization, pressure reduction regeneration, pressure reduction with pressure equalization, and pressure recovery are repeated, the overall apparatus looks as if it were from the first adsorption tank 3 to the second adsorption tank. The second adsorption tank 4, the second adsorption tank 4 to the third adsorption tank 5, the third adsorption tank 5 to the fourth adsorption tank 6, the fourth adsorption tank 6 to the first adsorption tank 3, and the adsorption. The structure is such that the agent 8 passes through the above eight steps while circulating and moving, so that high-purity oxygen gas can be taken out as a product very efficiently without waste between the steps.
【００３４】しかも、上記装置では、回収工程を設け、
他の減圧工程にある吸着槽から排出される排ガスの一部
を、吸着剤８全体が飽和した吸着槽内に導入して窒素ガ
ス分圧を高め、吸着剤８に吸着された酸素ガスを回収す
るようにしているため、従来に比べ、大幅に製品酸素ガ
スの収率を高めることができる。そして、上記のように
して酸素ガスを回収するため、排出する排ガスにおける
窒素ガスの純度を高めることができる。したがって、上
記排ガスを、製品窒素ガスとして利用することも可能で
ある。In addition, in the above-mentioned apparatus, a recovery step is provided,
Part of the exhaust gas discharged from the adsorption tank in another decompression step is introduced into the adsorption tank in which the entire adsorbent 8 is saturated, the partial pressure of nitrogen gas is increased, and the oxygen gas adsorbed by the adsorbent 8 is recovered. As a result, the yield of product oxygen gas can be greatly increased as compared with the related art. Since the oxygen gas is recovered as described above, the purity of the nitrogen gas in the exhaust gas to be discharged can be increased. Therefore, the exhaust gas can be used as product nitrogen gas.
【００３５】また、上記装置では、回収工程の終了した
吸着槽を、減圧工程の終了した他の吸着槽と連通し、両
槽間の圧力差を利用して何ら動力をかけずに均圧化を行
うようにしているため、全く動力をかけることなく、回
収工程終了後に吸着槽内に残留する酸素濃度の高いガス
を、減圧再生工程終了後の吸着槽内に導入して吸着槽内
をある程度復圧することができる。したがって、排ガス
を利用した回収工程において、多大な動力負担をかけて
排ガスを大量に吸着槽内に送入し酸素回収率を高めなく
ても、上記均圧化操作により酸素の回収率を高めること
ができるので、その分上記送入排ガス量を低減でき、動
力負担を軽減することができる。しかも、減圧再生工程
において均圧化が行われ、吸着槽内がある程度減圧され
るため、減圧再生工程における排気のための動力負担も
軽減することができる。In the above apparatus, the adsorption tank after the recovery step is communicated with the other adsorption tank after the pressure reduction step, and the pressure is equalized without using any power by utilizing the pressure difference between the two tanks. Therefore, without applying any power, the high oxygen concentration gas remaining in the adsorption tank after the recovery step is introduced into the adsorption tank after the decompression regeneration step, and the inside of the adsorption tank is reduced to some extent. The pressure can be restored. Therefore, in the recovery process using the exhaust gas, it is possible to increase the oxygen recovery rate by the pressure equalization operation without increasing the oxygen recovery rate by sending a large amount of the exhaust gas into the adsorption tank with a large power load. Therefore, the amount of exhaust gas to be sent can be reduced accordingly, and the power load can be reduced. In addition, pressure equalization is performed in the decompression regeneration step, and the pressure in the adsorption tank is reduced to some extent, so that the power load for exhaust in the decompression regeneration step can be reduced.
【００３６】さらに、従来のＰＳＡ方式の吸着塔では、
図４（ｂ）に示すように、吸着塔１００内に、下方から
原料空気を導入し、上方から製品ガスを取り出すように
しているため、何割かの吸着剤８は未使用のまま、吸着
剤８層に形成される吸着帯Ｓの先端Ｐが製品ガス取り出
し部に達して窒素ガスが破過し、吸着剤８全体が飽和に
至るまで吸着を続けることはできず経済的でなかった
が、上記実施例の装置では、すでに述べたように、窒素
ガスの破過に至るまで吸着を行う第２の吸着工程（工程
管理上、さらに２工程に分かれている）と、吸着剤８全
体が飽和にいたる第１の吸着工程とを分け、互いに連通
する二つの吸着槽（図３における３と４）でそれぞれの
工程が同時進行的に行い、かつ上記窒素ガスの破過に至
るまでの吸着工程を終えた吸着槽で、つぎには吸着剤全
体の飽和に至るまでの吸着を行うようにしている。この
ため、各吸着槽３〜６において、充填された吸着剤８全
体を飽和に至るまで利用することができ、従来と同等の
容積の吸着剤８で、処理量を増大させることができる。
また、従来よりも少ない容積で、従来と同等の処理量を
維持することができるため、吸着槽をコンパクトに設計
することができる。Further, in a conventional PSA-type adsorption tower,
As shown in FIG. 4B, the raw material air is introduced into the adsorption tower 100 from below and the product gas is taken out from above, so that some of the adsorbent 8 is not used and the adsorbent 8 is not used. Although the tip P of the adsorption zone S formed in the eight layers reaches the product gas take-out part, the nitrogen gas breaks through, and the adsorption cannot be continued until the entire adsorbent 8 reaches saturation, which is not economical. In the apparatus of the above embodiment, as described above, the second adsorbing step for adsorbing until the nitrogen gas breaks through (further divided into two steps in terms of step management), and the entire adsorbent 8 is saturated. The first adsorption step is divided into two adsorption tanks (3 and 4 in FIG. 3) communicating with each other, and the respective steps are performed simultaneously and the adsorption step until the nitrogen gas breakthrough occurs. After the adsorption tank is finished, until the entire adsorbent reaches saturation And to perform the adsorption. For this reason, in each of the adsorption tanks 3 to 6, the entire charged adsorbent 8 can be used up to saturation, and the amount of the adsorbent 8 having the same volume as the conventional one can increase the processing amount.
In addition, since the same throughput can be maintained with a smaller volume than before, the adsorption tank can be designed to be compact.
【００３７】ちなみに、上記図１の装置を用い、下記の
条件で連続的に原料空気を供給し、先の手順にしたがっ
て稼働させたところ、純度９３％の製品酸素ガスを、安
定して取り出すことができた。また、減圧再生工程にお
いて排出される排ガスは窒素ガスが９５％であった。そ
して、上記稼働により、均圧化操作を行わないで減圧再
生工程での強制排気と復圧工程における復圧とを、全く
個別に行う従来法に従って稼働させた場合に比べ、動力
負担を１５％軽減することができた。 ＜稼働条件＞ 原料空気供給量 ： １６５Ｎｍ3 ／Ｈｒ 吸着時の圧力 ： ０．１ｋｇ／ｃｍ2 Ｇ 減圧再生時の圧力 ：−５００Ｔｏｒｒ 製品酸素ガス量 ： ３０Ｎｍ3 ／Ｈｒ 酸素ガス回収率 ： ８０％By the way, by using the apparatus shown in FIG. 1 and continuously supplying raw material air under the following conditions and operating according to the above procedure, it is possible to stably take out product oxygen gas having a purity of 93%. Was completed. The exhaust gas discharged in the pressure reduction regeneration step was 95% nitrogen gas. By the above operation, the power load is reduced by 15% as compared with the case where the forced exhaust in the pressure reduction regeneration step and the pressure recovery in the pressure recovery step are operated according to the conventional method in which the pressure equalization operation is not performed and the pressure recovery step is performed completely individually. We were able to reduce. <Operating conditions> Raw material air supply: 165 Nm 3 / Hr Pressure during adsorption: 0.1 kg / cm 2 G Pressure during decompression regeneration: -500 Torr Product oxygen gas amount: 30 Nm 3 / Hr Oxygen gas recovery rate: 80%
【００３８】なお、上記実施例では、吸着剤８の吸着能
力を完全に利用するために、吸着工程を、吸着剤８全体
が飽和するまで吸着を行う第１の吸着工程と、窒素ガス
が破過する直前まで吸着を行う第２の吸着工程とに分
け、しかも４つの吸着槽３〜６の工程管理を行いやすく
するため、上記第２の吸着工程を、前半（第２の吸着工
程１）と後半（第２の吸着工程２）に分けている。しか
しながら、第２の吸着工程を必ずしもこのように２分割
する必要はない。また、吸着剤８の完全利用を重視しな
ければ、吸着工程自体を一工程で行うようにしても差し
支えはない。例えば、吸着工程を、第１と第２の２工程
に分け、第２の吸着工程についてはさらに分割すること
なく工程管理を行う場合の一例を、図５および図６に示
す。In the above embodiment, in order to make full use of the adsorbing capacity of the adsorbent 8, the adsorbing step includes the first adsorbing step in which the adsorbent 8 is adsorbed until the entire adsorbent 8 is saturated, and the nitrogen gas destruction. In order to divide the process into a second adsorption step in which adsorption is performed until immediately before passing, and to facilitate the process management of the four adsorption tanks 3 to 6, the second adsorption step is performed in the first half (second adsorption step 1). And the latter half (second adsorption step 2). However, it is not always necessary to divide the second adsorption step into two. In addition, if importance is not placed on the complete use of the adsorbent 8, the adsorption step itself may be performed in one step. For example, FIGS. 5 and 6 show an example in which the adsorption step is divided into a first step and a second step, and the step management is performed without further dividing the second adsorption step.
【００３９】また、上記実施例では、減圧再生工程，復
圧工程を、２ステップ分維持し、その前半分のステップ
において均圧化操作を行うようにしているが、減圧再生
工程，復圧工程に移行してしまってから均圧化を行うの
ではなく、工程と工程の切り替えの間に、均圧化工程を
独立して設けるようにしてもよい。In the above embodiment, the pressure reduction regeneration step and the pressure recovery step are maintained for two steps, and the pressure equalization operation is performed in the first half of the step. The pressure equalization step may be performed independently between the steps, instead of performing the pressure equalization after shifting to the step.
【００４０】さらに、上記実施例では、８工程を、４つ
の吸着槽３〜６で、順次ずらしながら繰り返し行うよう
にしているが、必ずしも吸着槽は４つに限られるもので
はない。例えば、図７に示すように、５つの吸着槽３〜
７を用い、〔ステップ１〕〜〔ステップ５〕を繰り返す
ようにすることで、各吸着槽３〜７内で、第２の吸着工
程，第１の吸着工程，回収工程，減圧再生工程を順次行
うことができる。そして、各工程を繰り返す過程で、減
圧再生工程にある吸着槽と、復圧工程にある吸着槽と
を、最初の所定時間、あるいは各工程に移行する直前の
所定時間だけ連通し、互いの均圧化を図ることができ
る。Further, in the above embodiment, the eight steps are repeated in the four adsorption tanks 3 to 6 while being shifted sequentially, but the number of adsorption tanks is not necessarily limited to four. For example, as shown in FIG.
By using [7] and repeating [Step 1] to [Step 5], the second adsorption step, the first adsorption step, the recovery step, and the reduced pressure regeneration step are sequentially performed in each of the adsorption tanks 3 to 7. It can be carried out. Then, in the process of repeating each step, the adsorption tank in the decompression regeneration step and the adsorption tank in the pressure recovery step are communicated for the first predetermined time or for a predetermined time immediately before shifting to each step, and are mutually equalized. Pressure can be achieved.
【００４１】[0041]
【発明の効果】以上のように、この発明は、複数個の吸
着槽において、吸着工程（Ａ），回収工程（Ｂ），減圧
再生工程（Ｃ），復圧工程（Ｄ）の４工程を、それぞれ
時間帯をずらした状態でこの順で繰り返し行うようにし
たものであり、実際には各吸着槽内に固定された吸着剤
が、各吸着槽で順次ずれた状態で繰り返される工程を経
ることによって、あたかも各吸着槽を移動しているがご
とき効果が得られる。これにより、吸着剤の粉化等を招
くことなく使用することができ、循環移送方式の利点が
活かされ欠点が解消する。しかも、減圧再生工程に先立
って、吸着槽内を、減圧再生工程にある他の吸着槽から
取り出される排ガスの一部で置換し、吸着槽内に残留す
る酸素ガスを回収するようにしているため、得られる製
品ガスの収率を大幅に高めることができる。また、この
発明では、回収工程が終了した吸着槽の上部から、減圧
再生工程が終了した他の吸着槽の下部に、両槽の圧力差
を利用してガスを移動させることにより均圧化を行うよ
うにしているため、全く動力をかけることなく、回収工
程終了後に吸着槽内に残留する酸素濃度の高いガスを回
収することができる。したがって、排ガスを利用した回
収工程において、動力負担をかけて排ガスを大量に吸着
槽内に送入し酸素回収率を高めなくても、上記均圧化工
程の介在によって、動力負担を軽減した状態で酸素の回
収率を高めることができるという利点を有する。そし
て、減圧再生工程に先立って、あるいはその途中に均圧
化が行われ、吸着槽内の圧力が下がるため、減圧再生工
程における排気のための動力負担も軽減することができ
るという利点を有する。As described above, according to the present invention, the four steps of the adsorption step (A), the recovery step (B), the reduced pressure regeneration step (C), and the pressure recovery step (D) are performed in a plurality of adsorption tanks. In this case, the process is repeatedly performed in this order with the time zones shifted, and in practice, the adsorbent fixed in each adsorption tank is repeated in a state in which the adsorbents are sequentially shifted in each adsorption tank. As a result, an effect can be obtained as if each adsorption tank were moved. As a result, the adsorbent can be used without causing powdering, etc., and the advantages of the circulating transfer system are utilized to eliminate the disadvantages. Moreover, prior to the decompression regeneration step, the inside of the adsorption tank is replaced with a part of the exhaust gas taken out from another adsorption tank in the decompression regeneration step, so that oxygen gas remaining in the adsorption tank is recovered. The yield of the product gas obtained can be greatly increased. Further, in the present invention, pressure equalization is performed by moving gas from the upper part of the adsorption tank after the completion of the recovery step to the lower part of the other adsorption tank after the completion of the decompression and regeneration step by utilizing the pressure difference between the two tanks. Since it is performed, it is possible to recover the gas having a high oxygen concentration remaining in the adsorption tank after the completion of the recovery step without applying any power. Therefore, in the recovery process using the exhaust gas, the load on the power is reduced by the presence of the pressure equalization process, even if a large amount of the exhaust gas is fed into the adsorption tank to increase the oxygen recovery rate by applying a power load to the recovery tank. This has the advantage that the oxygen recovery rate can be increased. Then, prior to or during the decompression regeneration step, pressure equalization is performed, and the pressure in the adsorption tank is reduced, so that there is an advantage that the power load for exhaust in the decompression regeneration step can be reduced.
【図１】この発明の一実施例に用いる装置の構成図であ
る。FIG. 1 is a configuration diagram of an apparatus used in an embodiment of the present invention.
【図２】上記実施例の工程説明図である。FIG. 2 is a process explanatory view of the above embodiment.
【図３】上記実施例の工程説明図である。FIG. 3 is a process explanatory view of the above embodiment.
【図４】（ａ）は上記実施例における吸着工程の説明
図、（ｂ）は従来のＰＳＡ方式による吸着工程の説明図
である。FIG. 4A is an explanatory view of an adsorption step in the above embodiment, and FIG. 4B is an explanatory view of an adsorption step by a conventional PSA method.
【図５】この発明の他の実施例の工程説明図である。FIG. 5 is a process explanatory view of another embodiment of the present invention.
【図６】この発明の他の実施例の工程説明図である。FIG. 6 is a process explanatory view of another embodiment of the present invention.
【図７】この発明のさらに他の実施例の工程説明図であ
る。FIG. 7 is a process explanatory view of still another embodiment of the present invention.
３〜６ 吸着槽 ８ 吸着剤 １１〜１８，２１〜２４，２７〜３０，３２〜３５，３
７〜４０，４４〜４７開閉弁 ２０ 原料空気導入配管 ２５，４２ ブロア ２６ 製品ガス取り出し配管 ３１，４３ 分岐配管 ３６ 排ガス取り出し配管 ４１ 真空ポンプ3 to 6 adsorption tank 8 adsorbent 11 to 18, 21 to 24, 27 to 30, 32 to 35, 3
7 to 40, 44 to 47 opening and closing valve 20 Raw material air introduction pipe 25, 42 Blower 26 Product gas extraction pipe 31, 43 Branch pipe 36 Exhaust gas extraction pipe 41 Vacuum pump
───────────────────────────────────────────────────── フロントページの続き (72)発明者 三歩一 敦彦 大阪府茨木市東太田１−３−1156 (72)発明者 安田 貴彦 大阪府高槻市芝生町３−22−９ (56)参考文献 特開 平７−100323（ＪＰ，Ａ) ──────────────────────────────────────────────────続 き Continued on the front page (72) Inventor Atsuhiko Mihoichi 1-3-1156 Higashiota, Ibaraki City, Osaka (72) Inventor Takahiko Yasuda 3-22-9 Shibacho, Takatsuki City, Osaka (56) References JP Hei 7-100323 (JP, A)
Claims (2)
（Ｄ）の４工程を、各吸着槽ごとに時間帯をずらした状
態でこの順で繰り返して行う空気分離方法であって、下
記の回収工程（Ｂ）が終了した吸着槽の上部から、減圧
再生工程（Ｃ）が終了した他の吸着槽の下部へ、両吸着
槽内の圧力差によりガスを移動させる均圧化工程を設け
たことを特徴とする空気分離方法。 （Ａ） 吸着槽内に、原料空気を導入し、原料空気に含
まれる窒素ガスを吸着剤に吸着させる吸着工程。 （Ｂ） 上記吸着工程の終了した吸着槽内に、下記
（Ｃ）の減圧再生工程にある他の吸着槽から取り出され
る排ガスの一部を導入し、吸着剤に吸着された酸素ガス
および吸着槽内の気相部に残留する酸素ガスを上記排ガ
スで置換し、酸素濃度が上記排ガスよりも高められた回
収ガスを上記吸着槽外に取り出す回収工程。 （Ｃ） 上記回収工程の終了した吸着槽内を減圧し、吸
着剤に吸着されている窒素ガスを脱着させて吸着剤を再
生するとともに、上記脱着ガスおよび気相部に残留する
ガスを排ガスとして上記吸着槽外に取り出す減圧再生工
程。 （Ｄ） 上記減圧再生工程の終了した吸着槽内に、上記
（Ａ）の吸着工程にある他の吸着槽から取り出される製
品ガスの一部を導入して復圧させる復圧工程。1. A method according to claim 1, wherein a plurality of adsorption tanks are provided.
This is an air separation method in which the four steps (D) are repeated in this order with the time zone shifted for each adsorption tank, and the pressure is reduced from the top of the adsorption tank after the completion of the following recovery step (B). An air separation method comprising: providing a pressure equalizing step of moving a gas by a pressure difference between both adsorption tanks to a lower part of another adsorption tank after the regeneration step (C) is completed. (A) An adsorption step in which raw air is introduced into an adsorption tank and nitrogen gas contained in the raw air is adsorbed by an adsorbent. (B) A part of the exhaust gas taken out from the other adsorption tank in the reduced pressure regeneration step (C) described below is introduced into the adsorption tank after the adsorption step, and the oxygen gas adsorbed by the adsorbent and the adsorption tank A recovery step of replacing the oxygen gas remaining in the gaseous phase portion with the exhaust gas and extracting a recovery gas having an oxygen concentration higher than the exhaust gas outside the adsorption tank. (C) The pressure in the adsorption tank after the recovery step is reduced, the nitrogen gas adsorbed on the adsorbent is desorbed to regenerate the adsorbent, and the desorbed gas and the gas remaining in the gas phase are treated as exhaust gas. A reduced-pressure regeneration step of taking out of the adsorption tank. (D) A pressure recovery step in which a part of the product gas taken out from the other adsorption tank in the adsorption step (A) is introduced into the adsorption tank after the pressure reduction regeneration step has been completed to recover the pressure.
と（Ａ２）の２工程に分かれている請求項１記載の空気
分離方法。 （Ａ１） 吸着槽内に、下記のガス（イ）および（ロ）
の少なくとも一方を導入し、上記導入ガスに含まれる窒
素ガスを吸着剤に、吸着剤全体が飽和に達するまで吸着
させる第１の吸着工程。 （イ） 原料空気 （ロ） 請求項１記載の回収工程にある他の吸着槽から
取り出される回収ガス （Ａ２） 請求項１記載の復圧工程の終了した吸着槽内
に、上記（Ａ１）の第１の吸着工程にある他の吸着槽か
ら取り出されるガスのみ、あるいはこのガスと下記のガ
ス（イ）および（ロ）の少なくとも一方とを導入して、
窒素ガスが破過する直前まで上記導入ガスに含まれる窒
素ガスを吸着剤に吸着させ高純度の酸素ガスを製品ガス
として取り出す第２の吸着工程。 （イ） 原料空気 （ロ） 請求項１記載の回収工程にある他の吸着槽から
取り出される回収ガス2. The method according to claim 1, wherein the adsorption step (A) comprises the following (A1)
The air separation method according to claim 1, wherein the air separation method is divided into two steps of (A2) and (A2). (A1) In the adsorption tank, the following gases (a) and (b)
A first adsorption step of introducing at least one of the above and adsorbing nitrogen gas contained in the introduced gas onto the adsorbent until the entire adsorbent reaches saturation. (A) Raw material air (B) Recovered gas taken out from another adsorption tank in the recovery step according to claim 1 (A2) In the adsorption tank after the pressure recovery step according to claim 1, the above-mentioned (A1) Only the gas taken out from the other adsorption tank in the first adsorption step, or this gas and at least one of the following gases (a) and (b) are introduced,
A second adsorption step in which nitrogen gas contained in the above introduced gas is adsorbed on the adsorbent until high-purity oxygen gas is taken out as product gas until immediately before nitrogen gas breaks through. (A) Raw material air (b) Recovered gas taken out from another adsorption tank in the recovery step according to claim 1
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5303001A JP2574639B2 (en) | 1993-12-02 | 1993-12-02 | Air separation method |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| JP5303001A JP2574639B2 (en) | 1993-12-02 | 1993-12-02 | Air separation method |
Publications (2)
| Publication Number | Publication Date |
|---|---|
| JPH07155525A JPH07155525A (en) | 1995-06-20 |
| JP2574639B2 true JP2574639B2 (en) | 1997-01-22 |
Family
ID=17915747
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| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| JP5303001A Expired - Fee Related JP2574639B2 (en) | 1993-12-02 | 1993-12-02 | Air separation method |
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| Country | Link |
|---|---|
| JP (1) | JP2574639B2 (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7371061B2 (en) | 2005-09-14 | 2008-05-13 | Toshiba Kikai Kabushiki Kaisha | Die clamping system |
-
1993
- 1993-12-02 JP JP5303001A patent/JP2574639B2/en not_active Expired - Fee Related
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US7371061B2 (en) | 2005-09-14 | 2008-05-13 | Toshiba Kikai Kabushiki Kaisha | Die clamping system |
Also Published As
| Publication number | Publication date |
|---|---|
| JPH07155525A (en) | 1995-06-20 |
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