JP2020099868A - Control method of nitrogen gas separation device and nitrogen gas separation device - Google Patents

Control method of nitrogen gas separation device and nitrogen gas separation device Download PDF

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JP2020099868A
JP2020099868A JP2018239674A JP2018239674A JP2020099868A JP 2020099868 A JP2020099868 A JP 2020099868A JP 2018239674 A JP2018239674 A JP 2018239674A JP 2018239674 A JP2018239674 A JP 2018239674A JP 2020099868 A JP2020099868 A JP 2020099868A
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牧治 小林
Makiharu Kobayashi
牧治 小林
晃一 杉本
Koichi Sugimoto
晃一 杉本
拓人 中島
Takuto Nakajima
拓人 中島
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Kuraray Co Ltd
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Abstract

To provide a control method of a nitrogen gas separation device capable of providing product gas of a desirable concentration and flow rate in a short time.SOLUTION: Raw material gas including nitrogen gas and oxygen gas is supplied to at least two bases of adsorption towers 3A, 3B in which adsorbent is filled, under pressure, oxygen gas in the raw material is adsorbed onto the adsorbent, thereby, intermediate product gas containing nitrogen gas provided from the raw material gas is introduced to a product tank 4, oxygen concentration in the intermediate product gas at an outlet of the intermediate product gas on the product tank 4 or oxygen concentration in the intermediate product gas flowing-out to a channel L9 from the product tank 4 is measured, a flow rate of the intermediate product gas flowing through the channel L9 is measured, a product gas is made by mixing gas for mixing which contains oxygen gas into the intermediate product gas after measuring the oxygen concentration and after measuring flow rate, the intermediate product gas flowing through the channel L9, and mixing flow rate of the gas for mixing to be mixed to the intermediate product gas is controlled in accordance with the measured oxygen concentration and the measured flow rate.SELECTED DRAWING: Figure 1

Description

本発明は、窒素ガス分離装置の制御方法および窒素ガス分離装置に関する。 The present invention relates to a method for controlling a nitrogen gas separation device and a nitrogen gas separation device.

近年、窒素ガスは金属の熱処理、半導体の製造、化学プラントの防爆シール等に用いる工業用ガスから食品保存用の充填ガスに至るまで多岐にわたる分野で使用されており、その使用量も年々増大している。この窒素ガスの製造方法として、速度分離型の吸着剤である分子ふるい炭素を充填した吸着槽に原料ガスである高圧の空気を送入し、前記吸着剤に酸素ガスを吸着させて窒素ガスを分離するいわゆる圧力変動吸着(Pressure Swing Adsorption:PSA)式製造方法が用いられている。この圧力変動吸着式製造方法は、所定濃度以上の高純度の窒素ガスを得るために使用されてきた。 In recent years, nitrogen gas has been used in a wide variety of fields from industrial gas used for heat treatment of metals, semiconductor manufacturing, explosion-proof seals of chemical plants, etc. to filling gas for food storage, and the amount used has increased year by year. ing. As a method for producing this nitrogen gas, high-pressure air that is a raw material gas is fed into an adsorption tank filled with molecular sieving carbon that is a velocity separation type adsorbent, and oxygen gas is adsorbed to the adsorbent to generate nitrogen gas. A so-called pressure swing adsorption (PSA) type manufacturing method of separating is used. This pressure fluctuation adsorption manufacturing method has been used to obtain high-purity nitrogen gas having a predetermined concentration or higher.

しかし、近年では、窒素ガスの濃度を任意に設定することが求められており、例えば、従来よりも低い濃度の窒素ガスを安定的に供給することが求められている。このような、低純度の窒素ガスを得る方法としては、特許文献1に記載されたものが知られている。 However, in recent years, it has been required to arbitrarily set the concentration of nitrogen gas, and for example, it is required to stably supply nitrogen gas having a lower concentration than in the past. As a method for obtaining such low-purity nitrogen gas, the method described in Patent Document 1 is known.

特許文献1の窒素ガス分離方法では、製品槽内の酸素ガス濃度を計測し、その酸素ガス濃度が目標の濃度よりも低濃度であれば製品槽に原料ガスを所定時間送入する。そして、所定時間経過後に、製品槽内の酸素ガス濃度を計測し、その酸素ガス濃度が目標の濃度に達していなければ、さらに、製品槽に原料ガスを注入し、製品槽内の酸素ガス濃度が目標の濃度になるまで注入と計測が繰り返し行われる。一方、製品槽内の酸素ガス濃度が目標の濃度よりも高濃度になれば原料ガスの注入を停止する。 In the nitrogen gas separation method of Patent Document 1, the oxygen gas concentration in the product tank is measured, and if the oxygen gas concentration is lower than the target concentration, the raw material gas is fed into the product tank for a predetermined time. Then, after the lapse of a predetermined time, the oxygen gas concentration in the product tank is measured, and if the oxygen gas concentration does not reach the target concentration, further, the raw material gas is injected into the product tank, and the oxygen gas concentration in the product tank is increased. The injection and measurement are repeated until the concentration reaches the target concentration. On the other hand, when the oxygen gas concentration in the product tank becomes higher than the target concentration, the injection of the raw material gas is stopped.

特開平5−200226号公報JP-A-5-200226

特許文献1の窒素ガス分離方法では、製品槽に原料ガスを送入し、製品槽内の窒素ガスと原料ガスとの混合後の酸素ガス濃度を計測し、その酸素ガス濃度が目標の濃度に達しているか否かを検出し、目標の濃度に達していなければ、さらに、原料ガスを製品槽に送入する必要があるため、目標の酸素ガス濃度に到達するのに長い時間を要する。そのため、製品槽内の酸素ガス濃度のぶれが大きい場合や、目標の酸素ガス濃度である目標残存酸素濃度が変わると、製品槽内の酸素ガス濃度が目標の濃度に達するのに大きく時間を費やしてしまう。 In the nitrogen gas separation method of Patent Document 1, the raw material gas is fed into the product tank, the oxygen gas concentration after mixing the nitrogen gas and the raw material gas in the product tank is measured, and the oxygen gas concentration becomes the target concentration. It is necessary to detect whether or not it has reached the target concentration, and if the target concentration has not been reached, it is necessary to further feed the raw material gas into the product tank, so that it takes a long time to reach the target oxygen gas concentration. Therefore, when the fluctuation of the oxygen gas concentration in the product tank is large, or when the target residual oxygen concentration, which is the target oxygen gas concentration, changes, it takes a long time for the oxygen gas concentration in the product tank to reach the target concentration. Will end up.

そこで、本発明は、上記の課題に基づいてなされたものであり、その目的は、短時間に所望の濃度及び流量の製品ガスを得ることができる窒素ガス分離装置の制御方法を提供することを目的とする。 Therefore, the present invention has been made based on the above problems, and an object thereof is to provide a method for controlling a nitrogen gas separation device capable of obtaining a product gas having a desired concentration and flow rate in a short time. To aim.

本発明に係る窒素ガス分離装置の制御方法は、吸着剤が充填された2基以上の吸着塔に窒素ガスと酸素ガスとを含む原料ガスを加圧下で供給し、各吸着塔が吸着工程、均圧工程、脱着工程、均圧工程を繰り返し、前記原料ガス中の酸素ガスを前記吸着剤に吸着させることにより、前記原料ガスから得られた窒素ガスを含む中間製品ガスを製品槽に導入し、前記製品槽における中間製品ガスの出口における中間製品ガス中の酸素濃度又は製品槽から流路に流出した中間製品ガス中の酸素濃度を計測し、前記流路を流れる中間製品ガスの流量を計測し、前記流路を流れる中間製品ガスであって前記酸素濃度が計測され且つ前記流量が計測された後の中間製品ガスに酸素ガスを含む混合用ガスを混合して製品ガスとし、前記中間製品ガスに混合する前記混合用ガスの混合流量は、前記計測された酸素濃度及び前記計測された流量に応じて制御される。 A method for controlling a nitrogen gas separation device according to the present invention is to supply a raw material gas containing nitrogen gas and oxygen gas under pressure to two or more adsorption towers filled with an adsorbent, and each adsorption tower performs an adsorption step, By repeating the pressure equalization step, the desorption step, and the pressure equalization step, and adsorbing the oxygen gas in the raw material gas to the adsorbent, an intermediate product gas containing nitrogen gas obtained from the raw material gas is introduced into the product tank. Measuring the oxygen concentration in the intermediate product gas at the outlet of the intermediate product gas in the product tank or the oxygen concentration in the intermediate product gas flowing out from the product tank to the flow path, and measuring the flow rate of the intermediate product gas flowing in the flow path. The intermediate product gas flowing through the flow path is mixed with a mixing gas containing oxygen gas into the intermediate product gas after the oxygen concentration is measured and the flow rate is measured to obtain a product gas. The mixing flow rate of the mixing gas mixed with the gas is controlled according to the measured oxygen concentration and the measured flow rate.

この構成によれば、中間製品ガスに混合する混合用ガスの混合流量は、混合用ガスと混合される前の中間製品ガス中の酸素濃度と、混合用ガスと混合される前の中間製品ガスの流量と、に応じて制御される。すなわち、混合後に製品ガス中の酸素濃度が所望の濃度および流量に達しているか否か検知して、検知結果に応じてさらに混合用ガスの混合流量を調整する方法と異なり、所望の濃度および流量の製品ガスを短時間に得ることができる。さらに、製品槽において濃度が平準化された後の中間製品ガスに基づいて混合用ガスの混合流量が制御されるため、混合流量の変動を小さくすることができる。 According to this configuration, the mixing flow rate of the mixing gas mixed with the intermediate product gas is the oxygen concentration in the intermediate product gas before being mixed with the mixing gas and the intermediate product gas before being mixed with the mixing gas. And the flow rate of That is, unlike the method of detecting whether or not the oxygen concentration in the product gas has reached a desired concentration and flow rate after mixing, and further adjusting the mixing flow rate of the mixing gas according to the detection result, the desired concentration and flow rate are different. The product gas can be obtained in a short time. Furthermore, since the mixing flow rate of the mixing gas is controlled based on the intermediate product gas whose concentration has been leveled in the product tank, fluctuations in the mixing flow rate can be reduced.

上記構成において、前記混合流量は、下記の式(1)により算出されてもよい。前記混合流量=(製品ガス目標残存酸素濃度−中間製品ガス中の酸素濃度)÷(混合用ガス酸素濃度−製品ガス目標残存酸素濃度)×中間製品ガスの流量・・・(1)。 In the above configuration, the mixed flow rate may be calculated by the following equation (1). Mixing flow rate=(product gas target residual oxygen concentration−oxygen concentration in intermediate product gas)÷(mixing gas oxygen concentration−product gas target residual oxygen concentration)×flow rate of intermediate product gas (1).

この構成によれば、混合流量は、中間製品ガス中の酸素濃度と中間製品ガスの流量に基づいて式(1)により一意的に算出されるので、所望の濃度および流量の製品ガスが作られる混合用ガスの混合流量を得ることができる。そのため、所望の濃度および流量の窒素ガスを安定的かつ短時間に得ることができる。 According to this configuration, the mixing flow rate is uniquely calculated by the equation (1) based on the oxygen concentration in the intermediate product gas and the flow rate of the intermediate product gas, so that the product gas having a desired concentration and flow rate is produced. The mixing flow rate of the mixing gas can be obtained. Therefore, nitrogen gas having a desired concentration and flow rate can be stably obtained in a short time.

混合用ガス酸素濃度は、混合用ガス中の酸素ガスの濃度を意味し、例えば、混合用ガスとして空気が使用されるため、既知の値である。製品ガス目標残存酸素濃度は、混合後の製品ガス中の酸素ガスの所望の濃度を意味し、ユーザのニーズに応じて適宜設定される。そのため、計測値である中間製品ガスの流量と中間製品ガス中の酸素濃度に基づいて、所望の濃度および流量の製品ガスが作られる混合用ガスの混合流量を一意的に算出することができる。 The mixing gas oxygen concentration means the concentration of oxygen gas in the mixing gas, and is a known value because, for example, air is used as the mixing gas. The target residual oxygen concentration of product gas means a desired concentration of oxygen gas in the product gas after mixing, and is appropriately set according to the needs of the user. Therefore, it is possible to uniquely calculate the mixing flow rate of the mixing gas that produces the product gas having a desired concentration and flow rate, based on the measured value of the flow rate of the intermediate product gas and the oxygen concentration in the intermediate product gas.

上記式(1)は、混合前の中間製品ガス中の酸素ガスの体積流量と混合用ガス中の酸素ガスの体積流量を足し合わせた流量は、混合後の製品ガス中の酸素ガスの体積流量に等しいという下記の式(2)から導かれる。 The above formula (1) is obtained by adding the volume flow rate of oxygen gas in the intermediate product gas before mixing and the volume flow rate of oxygen gas in the mixing gas to obtain the volume flow rate of oxygen gas in the product gas after mixing. It is derived from the following equation (2) that is equal to.

(中間製品ガスの流量×中間製品ガス中の酸素濃度)+(混合流量×混合用ガス酸素濃度)=(中間製品ガスの流量+混合流量)×製品ガス目標残存酸素濃度・・・(2)。 (Flow rate of intermediate product gas x oxygen concentration in intermediate product gas) + (mixing flow rate x oxygen concentration for mixing gas) = (flow rate of intermediate product gas + mixing flow rate) x target residual oxygen concentration of product gas (2) ..

上記構成において、前記混合用ガスは、原料ガス源から前記原料ガスの一部を分流させることによって前記中間製品ガスに混合されてもよい。 In the above configuration, the mixing gas may be mixed with the intermediate product gas by branching a part of the raw material gas from a raw material gas source.

この構成によれば、原料ガスの一部を混合用ガスとして使用することができるので、別途、混合用ガスを用意する必要がなくなる。そのため、製造コストを低減することができる。 According to this configuration, a part of the raw material gas can be used as the mixing gas, so that it is not necessary to separately prepare the mixing gas. Therefore, the manufacturing cost can be reduced.

上記構成において、前記混合用ガスは、前記原料ガス源とは別の供給源から供給されることによって前記中間製品ガスに混合されてもよい。 In the above configuration, the mixing gas may be mixed with the intermediate product gas by being supplied from a supply source different from the source gas source.

この構成によれば、原料ガス源から原料ガスの一部を分流させることによる原料ガスの吸着塔における圧力低下が生じないので、吸着塔内の圧力を確保しやすくなる。 According to this configuration, the pressure in the adsorption tower of the raw material gas due to the partial diversion of the raw material gas from the raw material gas source does not occur, so that the pressure in the adsorption tower is easily secured.

本発明に係る窒素ガス分離装置は、吸着剤が充填され、原料ガスが導入される第1吸着塔と、吸着剤が充填され、原料ガスが導入される第2吸着塔と、前記第1吸着塔及び第2吸着塔において吸着工程、均圧工程、脱着工程、均圧工程を繰り返し行うための制御を行う制御部と、前記第1吸着塔及び第2吸着塔において原料ガスから得られた窒素ガスを含む中間製品ガスが導入される製品槽と、前記製品槽における中間製品ガスの出口又は前記製品槽から流出した中間製品ガスが流れる流路に配置され、中間製品ガス中の酸素濃度を計測する酸素濃度計と、前記流路での中間製品ガスの流量を計測する流量計と、前記流路における前記酸素濃度計及び前記流量計の設置位置よりも下流側の部位に、酸素ガスを含む混合用ガスを導入する混合用ガス供給部と、を備える。前記制御部は、前記流量計による計測流量及び前記酸素濃度計による計測濃度に応じて、前記混合用ガス供給部によって中間製品ガスに混合する混合用ガスの混合流量を制御する。 The nitrogen gas separation device according to the present invention comprises: a first adsorption tower in which an adsorbent is filled and a raw material gas is introduced; a second adsorption tower in which an adsorbent is filled and a raw material gas is introduced; A control unit for controlling the adsorption step, the pressure equalization step, the desorption step, and the pressure equalization step repeatedly in the tower and the second adsorption tower; and nitrogen obtained from the raw material gas in the first adsorption tower and the second adsorption tower. It is arranged in the product tank into which the intermediate product gas containing gas is introduced and the outlet of the intermediate product gas in the product tank or the flow path of the intermediate product gas flowing out of the product tank, and measures the oxygen concentration in the intermediate product gas. An oxygen concentration meter, a flow meter for measuring the flow rate of the intermediate product gas in the flow channel, and a portion of the flow channel downstream of the installation positions of the oxygen concentration meter and the flow meter, containing oxygen gas. A mixing gas supply unit for introducing a mixing gas. The control unit controls the mixing flow rate of the mixing gas mixed with the intermediate product gas by the mixing gas supply unit according to the measured flow rate of the flow meter and the measured concentration of the oxygen concentration meter.

この構成によれば、中間製品ガスに混合する混合用ガスの混合流量は、混合用ガスと混合される前の中間製品ガス中の酸素ガスの計測濃度と、混合用ガスと混合される前の中間製品ガスの計測流量に応じて制御されるので、混合後に製品ガス中の酸素濃度が所望の濃度および流量に達しているか否か検知して、検知結果に応じてさらに混合用ガスの混合流量を調整する方法と異なり、所望の濃度および流量の製品ガスを短時間に得ることができる。さらに、製品槽において濃度および流量が平準化された後の中間製品ガスが流量計および酸素濃度計によって計測される。そのため、流量計および酸素濃度計による計測流量および計測濃度の変動が小さくなるので、混合流量の変動を小さくすることができる。 According to this configuration, the mixing flow rate of the mixing gas mixed with the intermediate product gas is the measured concentration of oxygen gas in the intermediate product gas before being mixed with the mixing gas, and the mixing gas before mixing with the mixing gas. Since it is controlled according to the measured flow rate of the intermediate product gas, it is detected whether the oxygen concentration in the product gas has reached the desired concentration and flow rate after mixing, and the mixing flow rate of the mixing gas is further detected according to the detection result. In contrast to the method of adjusting, the product gas having a desired concentration and flow rate can be obtained in a short time. Further, the intermediate product gas after the concentration and the flow rate are leveled in the product tank is measured by the flow meter and the oximeter. Therefore, the fluctuations in the measured flow rate and the measured concentration by the flow meter and the oxygen concentration meter are reduced, and thus the fluctuations in the mixed flow rate can be reduced.

上記構成において、前記制御部は、下記の式(1)により前記混合流量を算出する演算部を有してもよい。前記混合流量=(製品ガス目標残存酸素濃度−中間製品ガス中の酸素濃度)÷(混合用ガス酸素濃度−製品ガス目標残存酸素濃度)×中間製品ガスの流量・・・(1)。 In the above configuration, the control unit may include a calculation unit that calculates the mixed flow rate by the following equation (1). Mixing flow rate=(product gas target residual oxygen concentration−oxygen concentration in intermediate product gas)÷(mixing gas oxygen concentration−product gas target residual oxygen concentration)×flow rate of intermediate product gas (1).

この構成によれば、混合流量は、中間製品ガス中の酸素濃度と中間製品ガスの流量に基づいて式(1)により一意的に算出されるので、所望の濃度および流量の製品ガスが作られる混合用ガスの混合流量を得ることができる。そのため、所望の濃度および流量の窒素ガスを安定的かつ短時間に得ることができる。 According to this configuration, the mixing flow rate is uniquely calculated by the equation (1) based on the oxygen concentration in the intermediate product gas and the flow rate of the intermediate product gas, so that the product gas having a desired concentration and flow rate is produced. The mixing flow rate of the mixing gas can be obtained. Therefore, nitrogen gas having a desired concentration and flow rate can be stably obtained in a short time.

混合用ガス酸素濃度は、混合用ガス中の酸素ガスの濃度を意味し、例えば、混合用ガスとして空気が使用されるため、既知の値である。製品ガス目標残存酸素濃度は、混合後の製品ガス中の酸素ガスの所望の濃度を意味し、ユーザのニーズに応じて適宜設定される。そのため、流量計によって計測された中間製品ガスの流量と酸素濃度計によって計測された中間製品ガス中の酸素濃度に基づいて、所望の濃度および流量の製品ガスが作られる混合用ガスの混合流量を一意的に算出することができる。 The mixing gas oxygen concentration means the concentration of oxygen gas in the mixing gas, and is a known value because, for example, air is used as the mixing gas. The target residual oxygen concentration of product gas means a desired concentration of oxygen gas in the product gas after mixing, and is appropriately set according to the needs of the user. Therefore, based on the flow rate of the intermediate product gas measured by the flow meter and the oxygen concentration in the intermediate product gas measured by the oxygen concentration meter, the mixing flow rate of the mixing gas at which the desired concentration and flow rate of the product gas is produced is set. It can be calculated uniquely.

上記式(1)は、混合前の中間製品ガス中の酸素ガスの体積流量と混合用ガス中の酸素ガスの体積流量を足し合わせた流量は、混合後の製品ガス中の酸素ガスの体積流量に等しいという下記の式(2)から導かれる。 The above formula (1) is obtained by adding the volume flow rate of oxygen gas in the intermediate product gas before mixing and the volume flow rate of oxygen gas in the mixing gas to obtain the volume flow rate of oxygen gas in the product gas after mixing. It is derived from the following equation (2) that is equal to.

(中間製品ガスの流量×中間製品ガス中の酸素濃度)+(混合流量×混合用ガス酸素濃度)=(中間製品ガスの流量+混合流量)×製品ガス目標残存酸素濃度・・・(2)。 (Flow rate of intermediate product gas x oxygen concentration in intermediate product gas) + (mixing flow rate x oxygen concentration for mixing gas) = (flow rate of intermediate product gas + mixing flow rate) x target residual oxygen concentration of product gas (2) ..

本発明によれば、短時間に所望の濃度及び流量の製品ガスを得ることができる。 According to the present invention, a product gas having a desired concentration and flow rate can be obtained in a short time.

本発明の第1実施形態に係る窒素ガス分離装置の構成を示す図である。It is a figure which shows the structure of the nitrogen gas separation apparatus which concerns on 1st Embodiment of this invention. 本発明の第2実施形態に係る窒素ガス分離装置の構成を示す図である。It is a figure which shows the structure of the nitrogen gas separation apparatus which concerns on 2nd Embodiment of this invention. 本発明の第3実施形態に係る窒素ガス分離装置の構成を示す図である。It is a figure which shows the structure of the nitrogen gas separation apparatus which concerns on 3rd Embodiment of this invention.

以下、本発明の各実施形態について、図面を参照しながら説明する。但し、以下で参照する各図は、説明の便宜上、本発明の実施形態に係る窒素ガス分離装置10を説明するために必要となる主要な構成要素を簡略化して示したものである。したがって、本発明の各実施形態に係る窒素ガス分離装置10は、本明細書が参照する各図に示されていない任意の構成要素を備え得る。以下、図1を参照しながら、第1実施形態の窒素ガス分離装置10について説明する。 Hereinafter, each embodiment of the present invention will be described with reference to the drawings. However, for convenience of description, the respective drawings referred to below are simplified illustrations of main components necessary for explaining the nitrogen gas separation device 10 according to the embodiment of the present invention. Therefore, the nitrogen gas separation device 10 according to each embodiment of the present invention may include any component not shown in the drawings referred to in the present specification. Hereinafter, the nitrogen gas separation device 10 of the first embodiment will be described with reference to FIG. 1.

窒素ガス分離装置10は、窒素ガスと酸素ガスとを含む原料ガスから窒素ガスを分離して、窒素ガスを含む中間製品ガスを生成し、この中間製品ガスに混合用ガスを混合することによって製品ガスを得るものである。原料ガスとしては、例えば、空気を使用することができるが、これに限定されるものではなく、少なくとも窒素ガスと酸素ガスを含むガスであればよい。混合用ガスとしては、例えば、空気を使用することができるが、これに限定されるものではなく、少なくとも酸素ガスを含むガスであればよい。 The nitrogen gas separator 10 separates nitrogen gas from a raw material gas containing nitrogen gas and oxygen gas to generate an intermediate product gas containing nitrogen gas, and mixes the intermediate product gas with a mixing gas to produce a product. You get gas. As the raw material gas, for example, air can be used, but it is not limited to this, and any gas containing at least nitrogen gas and oxygen gas may be used. As the gas for mixing, for example, air can be used, but the gas is not limited to this, and any gas containing at least oxygen gas may be used.

窒素ガス分離装置10は、原料ガス供給部2と、第1吸着塔3Aと、第2吸着塔3Bと、中間製品ガス排出ラインL3と、製品槽4と、製品ガス排出ラインL9と、酸素濃度計21と、流量計22と、制御部20と、を備える。 The nitrogen gas separation device 10 includes a raw material gas supply unit 2, a first adsorption tower 3A, a second adsorption tower 3B, an intermediate product gas discharge line L3, a product tank 4, a product gas discharge line L9, and an oxygen concentration. A meter 21, a flow meter 22, and a controller 20 are provided.

原料ガス供給部2は、原料ガス圧縮機1と、原料ガス圧縮機1の吐出口に接続された原料ガス供給ラインL1と、原料ガス供給ラインL1と第1吸着塔3Aの入口とを接続する第1吸着塔入口ラインL1Aと、原料ガス供給ラインL1と第2吸着塔3Bの入口とを接続する第2吸着塔入口ラインL1Bと、を有する。 The raw material gas supply unit 2 connects the raw material gas compressor 1, the raw material gas supply line L1 connected to the discharge port of the raw material gas compressor 1, the raw material gas supply line L1 and the inlet of the first adsorption tower 3A. It has a first adsorption tower inlet line L1A and a second adsorption tower inlet line L1B connecting the source gas supply line L1 and the inlet of the second adsorption tower 3B.

原料ガス圧縮機1は、原料ガス源7の原料ガスを吸入口から吸い込み、吸い込んだ原料ガスを加圧して吐出口から吐出し、原料ガス供給ラインL1および第1及び第2吸着塔入口ラインL1A、L1Bを介して第1及び第2吸着塔3A、3Bに原料ガスを供給する。尚、原料ガスとして空気が使用される場合は、原料ガス圧縮機1の吸入口付近の空間にある空気が原料ガス源7になる。空気以外のガスを原料ガスとする場合は、例えば、容器に入れられた原料ガスが原料ガス源7になる。この場合は、原料ガス源7の容器と原料ガス圧縮機1の吸入口とが管により接続される。尚、原料ガス圧縮機1の代わりに、昇圧機やブロワを用いてもよい。 The raw material gas compressor 1 sucks the raw material gas of the raw material gas source 7 from the suction port, pressurizes the sucked raw material gas and discharges it from the discharge port, and the raw material gas supply line L1 and the first and second adsorption tower inlet lines L1A. , L1B to supply the raw material gas to the first and second adsorption towers 3A and 3B. When air is used as the source gas, the air in the space near the suction port of the source gas compressor 1 becomes the source gas source 7. When gas other than air is used as the source gas, for example, the source gas contained in the container serves as the source gas source 7. In this case, the container of the source gas source 7 and the suction port of the source gas compressor 1 are connected by a pipe. A booster or a blower may be used instead of the raw material gas compressor 1.

第1吸着塔入口ラインL1A上には、第1吸気バルブCV1が設けられている。第2吸着塔入口ラインL1Bには、第2吸気バルブCV3が設けられている。さらに、第1吸着塔入口ラインL1Aと第2吸着塔入口ラインL1Bとを接続する第1均圧ラインL7が設けられている。第1均圧ラインL7上には、第1均圧バルブCV7が設けられている。第1及び第2吸着塔入口ラインL1A、L1Bには、原料ガス排出ラインL2が接続されている。 A first intake valve CV1 is provided on the first adsorption tower inlet line L1A. A second intake valve CV3 is provided in the second adsorption tower inlet line L1B. Furthermore, the 1st pressure equalization line L7 which connects the 1st adsorption tower inlet line L1A and the 2nd adsorption tower inlet line L1B is provided. A first pressure equalizing valve CV7 is provided on the first pressure equalizing line L7. A source gas discharge line L2 is connected to the first and second adsorption tower inlet lines L1A and L1B.

原料ガス排出ラインL2は、第1吸着塔入口ラインL1A上における第1吸気バルブCV1の下流側に接続された第1排出ラインL2Aと、第2吸着塔入口ラインL1B上における第2吸気バルブCV3の下流側に接続された第2排出ラインL2Bと、第1排出ラインL2Aと第2排出ラインL2Bとの合流点に接続された排出合流ラインL2Cと、を有する。 The source gas discharge line L2 includes a first discharge line L2A connected to the downstream side of the first intake valve CV1 on the first adsorption tower inlet line L1A and a second intake valve CV3 on the second adsorption tower inlet line L1B. It has a second discharge line L2B connected to the downstream side, and a discharge merge line L2C connected to the merge point of the first discharge line L2A and the second discharge line L2B.

第1吸着塔3A及び第2吸着塔3Bは、酸素ガスを吸着する吸着剤が充填されている。第1吸着塔3A及び第2吸着塔3Bは、原料ガスが供給されると、原料ガス中の酸素ガスが吸着剤に吸着して、窒素ガスを高純度に含む中間製品ガスを生成する。 第1及び第2吸着塔3A、3B内に充填される吸着剤としては、酸素ガスを吸着できるものであればいずれのものでもよく、例えば、分子篩炭素を使用することができる。 The first adsorption tower 3A and the second adsorption tower 3B are filled with an adsorbent that adsorbs oxygen gas. When the raw material gas is supplied to the first adsorption tower 3A and the second adsorption tower 3B, oxygen gas in the raw material gas is adsorbed by the adsorbent to generate an intermediate product gas containing nitrogen gas with high purity. The adsorbent filled in the first and second adsorption towers 3A, 3B may be any adsorbent capable of adsorbing oxygen gas, and for example, molecular sieve carbon can be used.

分子篩炭素とは、多数の細孔を備える木炭、石炭、コークス、やし殻、樹脂、ピッチなどの原料を高温で炭化し、細孔径を約3〜5オングストロームに調整した木質系、石炭系、樹脂系、ピッチ系などの吸着剤である。このような分子篩炭素は、窒素ガスよりも酸素ガスを吸着しやすい性質を有しており、空気等の窒素ガスと酸素ガスとを含む混合気体から、酸素ガスを選択的に吸着する性質を有する。また、分子篩炭素は、高圧条件下において酸素ガスの吸着能が増大する。そのため、分子篩炭素は、第1及び第2吸着塔3A、3B内を加圧することにより酸素ガスを多く吸着することができ、その後、第1及び第2吸着塔3A、3B内を減圧することにより酸素ガスを脱着させることができる。 The molecular sieve carbon is a wood-based or coal-based material in which raw materials such as charcoal, coal, coke, coconut shell, resin, and pitch having a large number of pores are carbonized at a high temperature to adjust the pore diameter to about 3 to 5 angstroms. It is an adsorbent of resin type and pitch type. Such molecular sieve carbon has a property of adsorbing oxygen gas more easily than nitrogen gas, and has a property of selectively adsorbing oxygen gas from a mixed gas containing nitrogen gas such as air and oxygen gas. .. In addition, molecular sieve carbon has an increased oxygen gas adsorption capacity under high pressure conditions. Therefore, the molecular sieve carbon can adsorb a large amount of oxygen gas by pressurizing the inside of the first and second adsorption towers 3A and 3B, and then depressurizing the inside of the first and second adsorption towers 3A and 3B. Oxygen gas can be desorbed.

第1及び第2吸着塔3A、3Bにおいて生成された中間製品ガスは、中間製品ガス排出ラインL3を通して製品槽4に供給される。中間製品ガス排出ラインL3は、第1及び第2吸着塔3A、3Bの出口と製品槽4の入口とを接続している。中間製品ガス排出ラインL3は、第1吸着塔3Aの出口に接続された第1吸着塔出口ラインL3Aと、第2吸着塔3Bの出口に接続された第2吸着塔出口ラインL3Bと、第1吸着塔出口ラインL3Aと第2吸着塔出口ラインL3Bとの合流点と製品槽4の入口とを接続する製品槽合流ラインL3Cと、を有する。 The intermediate product gas generated in the first and second adsorption towers 3A and 3B is supplied to the product tank 4 through the intermediate product gas discharge line L3. The intermediate product gas discharge line L3 connects the outlets of the first and second adsorption towers 3A and 3B and the inlet of the product tank 4. The intermediate product gas discharge line L3 includes a first adsorption tower outlet line L3A connected to the outlet of the first adsorption tower 3A, a second adsorption tower outlet line L3B connected to the outlet of the second adsorption tower 3B, and a first adsorption tower outlet line L3B. It has a product tank merging line L3C that connects the merging point of the adsorption tower outlet line L3A and the second adsorption tower outlet line L3B and the inlet of the product tank 4.

第1吸着塔出口ラインL3Aには、第1取出バルブCV5が設けられている。第2吸着塔出口ラインL3Bには、第2取出バルブCV6が設けられている。さらに、第1吸着塔出口ラインL3Aにおける第1取出バルブCV5の上流側と、第2吸着塔出口ラインL3Bにおける第2取出バルブCV6の上流側と、を接続する第2均圧ラインL8が設けられている。第2均圧ラインL8には、第2均圧バルブCV8が設けられている。さらに、第2均圧ラインL8における第2均圧バルブCV8を挟む部位を接続するようにパージ流量調節ラインL5が設けられている。パージ流量調節ラインL5には、パージ流量調節器5が設けられている。 A first extraction valve CV5 is provided in the first adsorption tower outlet line L3A. A second extraction valve CV6 is provided in the second adsorption tower outlet line L3B. Further, a second pressure equalizing line L8 that connects the upstream side of the first extraction valve CV5 in the first adsorption tower outlet line L3A and the upstream side of the second extraction valve CV6 in the second adsorption tower outlet line L3B is provided. ing. A second pressure equalizing valve CV8 is provided in the second pressure equalizing line L8. Further, a purge flow rate adjusting line L5 is provided so as to connect the portions of the second pressure equalizing line L8 that sandwich the second pressure equalizing valve CV8. A purge flow rate controller 5 is provided in the purge flow rate adjustment line L5.

製品槽4は、供給された中間製品ガスを適宜貯留する一次貯留空間を有する容器によって構成されており、製品槽4内に貯留された中間製品ガスの濃度を平準化するものである。 The product tank 4 is configured by a container having a primary storage space that appropriately stores the supplied intermediate product gas, and is for equalizing the concentration of the intermediate product gas stored in the product tank 4.

製品ガス排出ラインL9は、製品槽4に接続されている。製品ガス排出ラインL9は、製品槽4において濃度が平準化された後の中間製品ガスが流出する流路である。製品ガス排出ラインL9は、製品槽4から流出した中間製品ガスが流れる流路の一例である。 The product gas discharge line L9 is connected to the product tank 4. The product gas discharge line L9 is a flow path through which the intermediate product gas whose concentration has been leveled in the product tank 4 flows out. The product gas discharge line L9 is an example of a flow path through which the intermediate product gas flowing out from the product tank 4 flows.

製品ガス排出ラインL9には、酸素濃度計21、流量計22および中間製品ガス流量調節バルブCV9が配置されている。中間製品ガス流量調節バルブCV9は、製品槽4の出口から流出した中間製品ガスの流量を調節するものである。製品槽4から流出する中間製品ガスの流量は、ユーザのニーズに応じて適宜設定される。 An oxygen concentration meter 21, a flow meter 22, and an intermediate product gas flow rate control valve CV9 are arranged in the product gas discharge line L9. The intermediate product gas flow rate control valve CV9 controls the flow rate of the intermediate product gas flowing out from the outlet of the product tank 4. The flow rate of the intermediate product gas flowing out from the product tank 4 is appropriately set according to the needs of the user.

製品ガス排出ラインL9における酸素濃度計21、流量計22及び中間製品ガス流量調節バルブCV9の下流側の部位17には、混合用ガスを供給する混合用ガス供給部6が接続されている。 A mixing gas supply unit 6 that supplies a mixing gas is connected to the downstream side portion 17 of the oxygen concentration meter 21, the flow meter 22, and the intermediate product gas flow rate control valve CV9 in the product gas discharge line L9.

混合用ガス供給部6は、混合用ガス圧縮機9と、混合用ガス圧縮機9の吐出口に接続された混合用ガス供給ラインL10と、混合用ガス供給ラインL10上に配置された混合用ガス流量制御バルブ23と、を有する。 The mixing gas supply unit 6 includes a mixing gas compressor 9, a mixing gas supply line L10 connected to a discharge port of the mixing gas compressor 9, and a mixing gas arranged on the mixing gas supply line L10. And a gas flow control valve 23.

混合用ガス圧縮機9は、混合用ガス源8の混合用ガスを吸入口から吸い込み、吸い込んだ混合用ガスを加圧して吐出口から吐出し、混合用ガス供給ラインL10を介して製品ガス排出ラインL9の部位17に混合用ガスを供給する。製品ガス排出ラインL9の部位17に供給された混合用ガスは、中間製品ガスと混合されて製品ガスとなり、製品ガス供給ラインL9を通じてユーザに提供される。尚、混合用ガスとして空気が使用される場合は、混合用ガス圧縮機9の吸入口付近の空間にある空気が混合用ガス源8になる。空気以外のガスを混合用ガスとする場合は、例えば、容器に入れられた混合用ガスが混合用ガス源8になる。この場合は、混合用ガス源8の容器と混合用ガス圧縮機9の吸入口とが管により接続される。尚、混合用ガス圧縮機9の代わりに、昇圧機やブロワを用いてもよい。混合用ガス源8は、原料ガス源とは別の供給源の一例である。 The mixing gas compressor 9 sucks the mixing gas of the mixing gas source 8 from the suction port, pressurizes the sucked mixing gas and discharges it from the discharge port, and discharges the product gas through the mixing gas supply line L10. The mixed gas is supplied to the portion 17 of the line L9. The mixing gas supplied to the portion 17 of the product gas discharge line L9 is mixed with the intermediate product gas to become the product gas, which is provided to the user through the product gas supply line L9. When air is used as the mixing gas, the air in the space near the suction port of the mixing gas compressor 9 becomes the mixing gas source 8. When a gas other than air is used as the mixing gas, for example, the mixing gas contained in the container serves as the mixing gas source 8. In this case, the container of the mixing gas source 8 and the suction port of the mixing gas compressor 9 are connected by a pipe. A booster or a blower may be used instead of the mixing gas compressor 9. The mixing gas source 8 is an example of a supply source different from the source gas source.

混合用ガス流量制御バルブ23は、製品ガス排出ラインL9の部位17において中間製品ガスに混合される混合用ガスの混合流量を調節するものである。 The mixing gas flow rate control valve 23 adjusts the mixing flow rate of the mixing gas mixed with the intermediate product gas at the portion 17 of the product gas discharge line L9.

酸素濃度計21は、製品ガス排出ラインL9上における中間製品ガス流量調節バルブCV9の上流側に配置されている。酸素濃度計21は、製品ガス排出ラインL9を流れる中間製品ガス中の酸素ガスの濃度を計測する。酸素濃度計21の計測原理は、特に、限定されることはない。酸素濃度計21は、中間製品ガスの単位体積当たりに占める酸素ガスの体積、すなわち、体積百分率を算出することができるものであればいずれのものでもよい。尚、酸素濃度計21は、中間製品ガスの単位質量当たりに占める酸素ガスの質量、すなわち、質量百分率を算出するものであってもよい。この場合、算出された質量百分率は、後述する制御部20の演算部20Aによって窒素ガスの密度と酸素ガスの密度から体積百分率に変換するようにする。酸素濃度計21は、制御部20と接続されており、計測された計測濃度を示す情報を制御部20の演算部20Aに送信するように構成されている。 The oxygen concentration meter 21 is arranged upstream of the intermediate product gas flow rate control valve CV9 on the product gas discharge line L9. The oxygen concentration meter 21 measures the concentration of oxygen gas in the intermediate product gas flowing through the product gas discharge line L9. The measurement principle of the oxygen concentration meter 21 is not particularly limited. The oxygen concentration meter 21 may be any as long as it can calculate the volume of oxygen gas per unit volume of the intermediate product gas, that is, the volume percentage. The oxygen concentration meter 21 may calculate the mass of oxygen gas per unit mass of the intermediate product gas, that is, the mass percentage. In this case, the calculated mass percentage is converted from the density of the nitrogen gas and the density of the oxygen gas into the volume percentage by the calculation unit 20A of the control unit 20 described later. The oxygen concentration meter 21 is connected to the control unit 20 and is configured to transmit information indicating the measured concentration measured to the calculation unit 20A of the control unit 20.

尚、酸素濃度計21は、製品槽4における中間製品ガスの出口に配置され、製品槽4の出口における中間製品ガス中の酸素ガスの濃度を計測するようにしてもよい。製品槽4において酸素濃度計21が配置される出口は、製品ガス排出ラインL9の接続端だけでなく、製品槽4における製品ガス排出ラインL9の接続端の周囲も含む。 The oxygen concentration meter 21 may be arranged at the outlet of the intermediate product gas in the product tank 4 to measure the concentration of oxygen gas in the intermediate product gas at the outlet of the product tank 4. The outlet where the oximeter 21 is arranged in the product tank 4 includes not only the connection end of the product gas discharge line L9 but also the periphery of the connection end of the product gas discharge line L9 in the product tank 4.

流量計22は、製品ガス排出ラインL9上における酸素濃度計21と中間製品ガス流量調節バルブCV9との間に配置されている。流量計22は、中間製品ガスの流量を計測する。流量計22の計測原理は、特に、限定されることはない。流量計22は、単位時間当たりにある面を通過する中間製品ガスの体積の量、すなわち、体積流量(立方メートル毎秒)を算出することができるものであればいずれのものでもよい。尚、流量計22は、単位時間当たりにある面を通過する中間製品ガスの質量、すなわち、質量流量(キログラム毎秒)を算出するものであってもよい。この場合は、酸素濃度計21によって算出された体積百分率を後述する制御部20の演算部20Aにおいて質量百分率に変換してもよく、または、質量百分率を算出する酸素濃度計21を用いてもよい。流量計22は、制御部20と接続されており、計測された計測流量を示す情報を制御部20の後述する演算部20Aに送信するように構成されている。尚、流量計22は、製品ガス排出ラインL9上における酸素濃度計21の上流側に配置されてもよい。 The flow meter 22 is arranged on the product gas discharge line L9 between the oxygen concentration meter 21 and the intermediate product gas flow rate control valve CV9. The flow meter 22 measures the flow rate of the intermediate product gas. The measurement principle of the flow meter 22 is not particularly limited. The flow meter 22 may be any one capable of calculating the volume of the intermediate product gas passing through a surface per unit time, that is, the volume flow rate (cubic meter per second). The flowmeter 22 may calculate the mass of the intermediate product gas passing through a surface per unit time, that is, the mass flow rate (kilogram per second). In this case, the volume percentage calculated by the oxygen concentration meter 21 may be converted into a mass percentage in the calculation unit 20A of the control unit 20 described later, or the oxygen concentration meter 21 that calculates the mass percentage may be used. .. The flow meter 22 is connected to the control unit 20 and is configured to transmit information indicating the measured measured flow rate to a later-described calculation unit 20A of the control unit 20. The flowmeter 22 may be arranged upstream of the oxygen concentration meter 21 on the product gas discharge line L9.

制御部20は、バルブCV1〜CV8に接続されており、第1及び第2吸着塔3A、3Bにおいて吸着工程、均圧工程、脱着工程および均圧工程を繰り返し行うことができるようにバルブCV1〜CV8の開閉を制御する。 The control unit 20 is connected to the valves CV1 to CV8, and the valves CV1 to CV1 so that the adsorption step, the pressure equalizing step, the desorption step, and the pressure equalizing step can be repeatedly performed in the first and second adsorption towers 3A and 3B. Controls the opening and closing of CV8.

また、制御部20は、酸素濃度計21、流量計22および混合用ガス流量制御バルブ23に接続されており、酸素濃度計21による計測濃度と流量計22による計測流量とに基づいて中間製品ガスに混合する混合用ガスの混合流量を制御する。 Further, the control unit 20 is connected to the oxygen concentration meter 21, the flow meter 22, and the mixing gas flow rate control valve 23, and based on the concentration measured by the oxygen concentration meter 21 and the flow rate measured by the flow meter 22, the intermediate product gas. The mixing flow rate of the mixing gas to be mixed with is controlled.

具体的には、制御部20は、流量計22による計測流量と酸素濃度計21による計測濃度とに応じて混合用ガスの混合流量を算出する演算部20Aと、演算部20Aによって算出された混合流量の混合用ガスが混合用ガス供給ラインL10を流れるように開度を調節する指令を混合用ガス流量制御バルブ23に送出する指令部20Bと、混合用ガスの混合流量を算出するための下記の式(1)を記憶する記憶部20Cと、を有する。 Specifically, the control unit 20 calculates the mixing flow rate of the mixing gas in accordance with the flow rate measured by the flow meter 22 and the concentration measured by the oxygen concentration meter 21, and the mixing unit calculated by the calculation unit 20A. A command unit 20B for sending to the mixing gas flow rate control valve 23 a command for adjusting the opening so that the flow rate of the mixing gas flows through the mixing gas supply line L10, and the following for calculating the mixing flow rate of the mixing gas: And a storage unit 20C that stores the equation (1).

演算部20Aは、酸素濃度計21から受信した計測濃度を示す情報と流量計22から受信した計測流量を示す情報とに基づいて、下記の式(1)から中間製品ガスに混合する混合用ガスの混合流量を算出する。 The calculation unit 20A uses the mixing gas mixed with the intermediate product gas according to the following formula (1) based on the information indicating the measured concentration received from the oxygen concentration meter 21 and the information indicating the measured flow rate received from the flow meter 22. Calculate the mixed flow rate of.

混合流量=(製品ガス目標残存酸素濃度−中間製品ガス中の酸素濃度)÷(混合用ガス酸素濃度−製品ガス目標残存酸素濃度)×中間製品ガスの流量・・・(1)。 Mixing flow rate=(product gas target residual oxygen concentration−oxygen concentration in intermediate product gas)÷(mixing gas oxygen concentration−product gas target residual oxygen concentration)×flow rate of intermediate product gas (1).

混合用ガス酸素濃度は、混合用ガス中の酸素ガスの濃度を意味し、例えば、混合用ガスとして空気が使用されるため、既知の値である。製品ガス目標残存酸素濃度は、混合後の製品ガス中の酸素ガスの所望の濃度を意味し、ユーザのニーズに応じて設定(例えば、95%)される。そのため、流量計22によって計測された中間製品ガスの流量と、酸素濃度計21によって計測された中間製品ガス中の酸素ガスの濃度と、を上記(1)の式に入力することにより、所望の濃度および流量の製品ガスが作られる混合用ガスの混合流量を一意的に算出することができる。混合用ガス酸素濃度と製品ガス目標残存酸素濃度は、記憶部20Cに記憶される。混合用ガス酸素濃度と製品ガス目標残存酸素濃度が変更されると、記憶部20Cに記憶された混合用ガス酸素濃度と製品ガス目標残存酸素濃度は更新される。 The mixing gas oxygen concentration means the concentration of oxygen gas in the mixing gas, and is a known value because, for example, air is used as the mixing gas. The product gas target residual oxygen concentration means a desired concentration of oxygen gas in the product gas after mixing, and is set (for example, 95%) according to the needs of the user. Therefore, by inputting the flow rate of the intermediate product gas measured by the flow meter 22 and the concentration of the oxygen gas in the intermediate product gas measured by the oxygen concentration meter 21 into the equation (1), the desired value can be obtained. It is possible to uniquely calculate the mixing flow rate of the mixing gas from which the product gas having the concentration and the flow rate is produced. The mixed gas oxygen concentration and the product gas target residual oxygen concentration are stored in the storage unit 20C. When the mixing gas oxygen concentration and the product gas target residual oxygen concentration are changed, the mixing gas oxygen concentration and the product gas target remaining oxygen concentration stored in the storage unit 20C are updated.

上記式(1)は、混合前の中間製品ガス中の酸素ガスの体積流量と混合用ガス中の酸素ガスの体積流量を足し合わせた流量は、混合後の製品ガス中の酸素ガスの体積流量に等しいという下記の式(2)から導かれる。 The above formula (1) is obtained by adding the volume flow rate of oxygen gas in the intermediate product gas before mixing and the volume flow rate of oxygen gas in the mixing gas to obtain the volume flow rate of oxygen gas in the product gas after mixing. It is derived from the following equation (2) that is equal to.

(中間製品ガスの流量×中間製品ガス中の酸素濃度)+(混合流量×混合用ガス酸素濃度)=(中間製品ガスの流量+混合流量)×製品ガス目標残存酸素濃度・・・(2)。 (Flow rate of intermediate product gas x oxygen concentration in intermediate product gas) + (mixing flow rate x oxygen concentration for mixing gas) = (flow rate of intermediate product gas + mixing flow rate) x target residual oxygen concentration of product gas (2) ..

次に、上記のように構成された窒素ガス分離装置10の動作およびその制御方法を説明する。 Next, the operation of the nitrogen gas separation device 10 configured as described above and its control method will be described.

窒素ガス分離装置10は、第1及び第2吸着塔3A、3Bにおいて、それぞれ、吸着工程、均圧工程、脱着工程、均圧工程を繰り返し行うように、バルブCV1〜CV8の開閉制御を行う。尚、以下の説明では、均圧工程の終了直後を初期状態として説明していく。 The nitrogen gas separation device 10 controls the opening and closing of the valves CV1 to CV8 so that the adsorption step, the pressure equalizing step, the desorption step, and the pressure equalizing step are repeated in the first and second adsorption towers 3A and 3B, respectively. In the following description, the state immediately after the end of the pressure equalizing step will be described as the initial state.

まず、最初に、第1吸着塔3Aにおいて吸着工程が行われるとともに、第2吸着塔3Bにおいて脱着工程が行われる。吸着工程は、原料ガスから窒素ガスを分離して窒素ガスを含む中間製品ガスを生成する工程である。脱着工程は、吸着剤に吸着している酸素ガスを吸着剤から脱着することによって吸着剤を再生する工程である。 First, the adsorption step is first performed in the first adsorption tower 3A, and the desorption step is performed in the second adsorption tower 3B. The adsorption step is a step of separating nitrogen gas from the raw material gas to generate an intermediate product gas containing nitrogen gas. The desorption step is a step of regenerating the adsorbent by desorbing the oxygen gas adsorbed on the adsorbent from the adsorbent.

第1吸着塔3Aの吸着工程と第2吸着塔3Bの脱着工程は、第1吸気バルブCV1と第1取出バルブCV5と第2排出バルブCV4とを開き、第1及び第2均圧バルブCV7、CV8を閉じることによって開始される。 In the adsorption process of the first adsorption tower 3A and the desorption process of the second adsorption tower 3B, the first intake valve CV1, the first extraction valve CV5 and the second discharge valve CV4 are opened, and the first and second pressure equalizing valves CV7, Started by closing CV8.

第1吸着塔3Aの吸着工程では、まず、原料ガス源7から原料ガス供給ラインL1および第1吸着塔入口ラインL1Aを通して第1吸着塔3Aに原料ガスが供給される。第1吸着塔3Aに供給された原料ガスは、原料ガス中の酸素ガスが吸着剤に吸着されることにより、原料ガスから窒素ガスが分離して窒素ガスを含む中間製品ガスが生成される。第1吸着塔3Aにおいて生成した中間製品ガスは、第1吸着塔出口ラインL3Aおよび製品槽合流ラインL3Cを通して製品槽4に供給される。 In the adsorption step of the first adsorption tower 3A, first, the raw material gas is supplied from the raw material gas source 7 to the first adsorption tower 3A through the raw material gas supply line L1 and the first adsorption tower inlet line L1A. In the raw material gas supplied to the first adsorption tower 3A, the oxygen gas in the raw material gas is adsorbed by the adsorbent, whereby nitrogen gas is separated from the raw material gas and an intermediate product gas containing nitrogen gas is generated. The intermediate product gas generated in the first adsorption tower 3A is supplied to the product tank 4 through the first adsorption tower outlet line L3A and the product tank joining line L3C.

一方、第2吸着塔3Bの脱着工程では、第2吸着塔入口ラインL1B、第2排出ラインL2B、排出合流ラインL2Cを介して第2吸着塔3B内の原料ガスが第2吸着塔3B内の圧力よりも低い外部へ圧力差によって排出される。これにより、第2吸着塔3B内の圧力が減圧され、吸着剤に吸着していた酸素ガスが吸着剤から脱着する。脱着した酸素ガスは、原料ガスとともに第1吸着塔3Bから排出される。これにより、第1吸着塔3B内の吸着剤が再生される。 On the other hand, in the desorption process of the second adsorption tower 3B, the raw material gas in the second adsorption tower 3B is stored in the second adsorption tower 3B through the second adsorption tower inlet line L1B, the second discharge line L2B, and the discharge merging line L2C. It is discharged by the pressure difference to the outside lower than the pressure. As a result, the pressure in the second adsorption tower 3B is reduced, and the oxygen gas adsorbed on the adsorbent is desorbed from the adsorbent. The desorbed oxygen gas is discharged from the first adsorption tower 3B together with the raw material gas. As a result, the adsorbent in the first adsorption tower 3B is regenerated.

第1吸着塔3Aの吸着工程と第2吸着塔3Bの脱着工程とが所定時間行われると、第1吸着塔3A内のガスを第2吸着塔3Bへ移動させる均圧工程が開始される。均圧工程は、第1吸気バルブCV1と第1取出バルブCV5と第2排出バルブCV4とを閉じ、第1及び第2均圧バルブCV7、CV8を開くことによって開始される。 When the adsorption step of the first adsorption tower 3A and the desorption step of the second adsorption tower 3B are performed for a predetermined time, a pressure equalization step of moving the gas in the first adsorption tower 3A to the second adsorption tower 3B is started. The pressure equalization process is started by closing the first intake valve CV1, the first extraction valve CV5, and the second discharge valve CV4, and opening the first and second pressure equalization valves CV7, CV8.

均圧工程では、第1吸着塔3A内に充満していたガスが第1均圧ラインL7および第2均圧ラインL8を通じて第2吸着塔3Bに移動する。 In the pressure equalization step, the gas filled in the first adsorption tower 3A moves to the second adsorption tower 3B through the first pressure equalization line L7 and the second pressure equalization line L8.

均圧工程が終了すると、第1吸着塔3Aの脱着工程と第2吸着塔3Bの吸着工程が行われる。第1吸着塔3Aの脱着工程と第2吸着塔3Bの吸着工程は、第1排出バルブCV2と第2吸気バルブCV3と第2取出バルブCV6とを開き、第1及び第2均圧バルブCV7、CV8を閉じることによって開始される。 When the pressure equalization process is completed, the desorption process of the first adsorption tower 3A and the adsorption process of the second adsorption tower 3B are performed. In the desorption process of the first adsorption tower 3A and the adsorption process of the second adsorption tower 3B, the first discharge valve CV2, the second intake valve CV3, and the second extraction valve CV6 are opened, and the first and second pressure equalizing valves CV7, Started by closing CV8.

第1吸着塔3Aの脱着工程では、第1吸着塔入口ラインL1A、第1排出ラインL2A、および、排出合流ラインL2Cを通して第1吸着塔3A内の原料ガスが第1吸着塔3A内の圧力よりも低い外部へ圧力差によって排出される。これにより、第1吸着塔3A内の圧力が減圧され、吸着剤に吸着していた酸素ガスが吸着剤から脱着する。脱着した酸素ガスは、原料ガスとともに第1吸着塔3Aから排出される。これにより、第1吸着塔3A内の吸着剤が再生される。 In the desorption process of the first adsorption tower 3A, the raw material gas in the first adsorption tower 3A passes through the first adsorption tower inlet line L1A, the first discharge line L2A, and the discharge merge line L2C from the pressure in the first adsorption tower 3A. Is also discharged outside due to the pressure difference. As a result, the pressure in the first adsorption tower 3A is reduced, and the oxygen gas adsorbed by the adsorbent is desorbed from the adsorbent. The desorbed oxygen gas is discharged from the first adsorption tower 3A together with the raw material gas. As a result, the adsorbent in the first adsorption tower 3A is regenerated.

一方、第2吸着塔3Bの吸着工程では、原料ガス源7から原料ガス供給ラインL1および第2吸着塔入口ラインL1Bを通して原料ガスが第2吸着塔3Bに供給される。このとき、原料ガス中の酸素ガスが吸着剤に吸着し、原料ガスから窒素ガスが分離して窒素ガスを含む中間製品ガスが生成される。第2吸着塔3Bにおいて生成した中間製品ガスは、第2吸着塔出口ラインL3Bと製品槽合流ラインL3Cとを通して製品槽4に供給される。 On the other hand, in the adsorption step of the second adsorption tower 3B, the raw material gas is supplied from the raw material gas source 7 to the second adsorption tower 3B through the raw material gas supply line L1 and the second adsorption tower inlet line L1B. At this time, oxygen gas in the raw material gas is adsorbed by the adsorbent, nitrogen gas is separated from the raw material gas, and an intermediate product gas containing nitrogen gas is generated. The intermediate product gas generated in the second adsorption tower 3B is supplied to the product tank 4 through the second adsorption tower outlet line L3B and the product tank joining line L3C.

第1吸着塔3Aの脱着工程および第2吸着塔3Bの吸着工程が所定時間行われると、第2吸着塔3B内のガスを第1吸着塔3Aに移動させる均圧工程が行われる。均圧工程は、第2吸気バルブCV3と第2取出バルブCV6と第1排出バルブCV2とを閉じ、第1及び第2均圧バルブCV7、CV8を開くことによって開始される。 When the desorption process of the first adsorption tower 3A and the adsorption process of the second adsorption tower 3B are performed for a predetermined time, a pressure equalization process of moving the gas in the second adsorption tower 3B to the first adsorption tower 3A is performed. The pressure equalization process is started by closing the second intake valve CV3, the second extraction valve CV6, and the first discharge valve CV2, and opening the first and second pressure equalization valves CV7, CV8.

均圧工程では、第2吸着塔3B内に充満していたガスが第1均圧ラインL7および第2均圧ラインL8を通じて第1吸着塔3Aに移動する。 In the pressure equalization step, the gas filled in the second adsorption tower 3B moves to the first adsorption tower 3A through the first pressure equalization line L7 and the second pressure equalization line L8.

均圧工程が終了すると、第1吸着塔3Aの吸着工程と第2吸着塔3Bの脱着工程が行われる。以後、第1及び第2吸着塔3A、3Bにおいて上記のサイクルが繰り返される。 When the pressure equalization step is completed, the adsorption step of the first adsorption tower 3A and the desorption step of the second adsorption tower 3B are performed. After that, the above cycle is repeated in the first and second adsorption towers 3A and 3B.

吸着工程を経て製品槽4に流入する中間製品ガス中の酸素ガスの濃度は、吸着剤の吸着能力の低下により、吸着工程の初期と吸着工程の後期とでばらつきがある。しかしながら、製品槽4に流入した中間製品ガスは、製品槽4内において一時的に貯留されることにより、製品槽4内の中間製品ガス中の酸素ガスの濃度は平準化される。 The concentration of oxygen gas in the intermediate product gas flowing into the product tank 4 through the adsorption step varies between the initial stage of the adsorption step and the latter stage of the adsorption step due to the lowering of the adsorption capacity of the adsorbent. However, the intermediate product gas flowing into the product tank 4 is temporarily stored in the product tank 4, so that the oxygen gas concentration in the intermediate product gas in the product tank 4 is leveled.

製品槽4内に一時的に貯留された中間製品ガスは、中間製品ガス流量調節バルブCV9の開放により、製品槽4から製品ガス排出ラインL9に流出する。このとき、製品槽4から製品ガス排出ラインL9に流出する中間製品ガスの流量が中間製品ガス流量調節バルブCV9によって調節される。 The intermediate product gas temporarily stored in the product tank 4 flows out from the product tank 4 to the product gas discharge line L9 by opening the intermediate product gas flow rate control valve CV9. At this time, the flow rate of the intermediate product gas flowing from the product tank 4 to the product gas discharge line L9 is adjusted by the intermediate product gas flow rate adjusting valve CV9.

製品槽4から製品ガス排出ラインL9に流出した中間製品ガスは、酸素濃度計21によって濃度が計測され、さらに流量計22によって流量が計測される。このとき、計測された計測濃度を示す情報と計測流量を示す情報が制御部20の演算部20Aに常時送信される。 The concentration of the intermediate product gas flowing out from the product tank 4 to the product gas discharge line L9 is measured by the oxygen concentration meter 21, and the flow rate is measured by the flow meter 22. At this time, the information indicating the measured concentration and the information indicating the measured flow rate are constantly transmitted to the arithmetic unit 20A of the control unit 20.

酸素濃度計21および流量計22によって計測された後の中間製品ガスは、混合用ガス源8から混合用ガス供給ラインL10を介して製品ガス排出ラインL9の部位17に供給された混合用ガスと混合される。このとき、混合用ガスの混合流量は、中間製品ガスに混合されたときに、所望の濃度および流量の製品ガスが作られるように制御部20によって制御される。制御は、中間製品ガスが製品槽4から製品ガス排出ラインL9に流出している間、常時行われる。すなわち、非常に短い間隔で制御が繰り返し行われる。 The intermediate product gas measured by the oxygen concentration meter 21 and the flow meter 22 is mixed with the mixing gas supplied from the mixing gas source 8 to the part 17 of the product gas discharge line L9 through the mixing gas supply line L10. Mixed. At this time, the mixing flow rate of the mixing gas is controlled by the control unit 20 so that the product gas having a desired concentration and flow rate is produced when mixed with the intermediate product gas. The control is always performed while the intermediate product gas is flowing from the product tank 4 to the product gas discharge line L9. That is, the control is repeatedly performed at very short intervals.

具体的には、まず、制御部20の演算部20Aは、中間製品ガスに混合する混合用ガスの混合流量を算出するための上記の式(1)を記憶部20Cから読み出し、記憶部20Cに記憶された混合用ガス酸素濃度と製品ガス目標残存酸素濃度を式(1)に当て嵌める。次いで、演算部20Aは、受信した計測濃度と計測流量を式(1)に当て嵌めることによって混合流量を算出する。 Specifically, first, the arithmetic unit 20A of the control unit 20 reads the above equation (1) for calculating the mixing flow rate of the mixing gas mixed with the intermediate product gas from the storage unit 20C, and stores it in the storage unit 20C. The stored mixed gas oxygen concentration and the product gas target residual oxygen concentration are applied to the equation (1). Next, the calculation unit 20A calculates the mixed flow rate by applying the received measured concentration and measured flow rate to the equation (1).

混合流量が算出されると、指令部20Bは、算出された混合流量の混合用ガスが混合用ガス供給ラインL10を流れるように開度を調節する指令を混合用ガス流量制御バルブ23に送出する。混合用ガス流量制御バルブ23は、指令部20Bからの指令を受け取ると、前記指令に基づいて開度を調節する。これにより、算出された混合流量の混合用ガスが中間製品ガスに混合され、その結果、中間製品ガスと混合用ガスは、所望の濃度および流量の製品ガスとなり、製品ガス供給ラインL9を通してユーザに提供される。 When the mixing flow rate is calculated, the command unit 20B sends a command to the mixing gas flow rate control valve 23 to adjust the opening so that the mixing gas having the calculated mixing flow rate flows through the mixing gas supply line L10. .. When receiving the command from the command unit 20B, the mixing gas flow control valve 23 adjusts the opening degree based on the command. As a result, the mixing gas having the calculated mixing flow rate is mixed with the intermediate product gas, and as a result, the intermediate product gas and the mixing gas become the product gas having a desired concentration and flow rate, and the product gas is supplied to the user through the product gas supply line L9. Provided.

制御部20は、指令部20Bが混合用ガス流量制御バルブ23に指令を送出した後、受信した計測濃度と計測流量に基づいて上記と同様に混合用ガスの混合流量を算出して混合用ガス流量制御バルブ23に指令を送出する。このような制御が非常に短い間隔で繰り返し行われる。 After the command unit 20B sends a command to the mixing gas flow rate control valve 23, the control unit 20 calculates the mixing flow rate of the mixing gas in the same manner as above based on the received measured concentration and the measured flow rate, and then the mixing gas. A command is sent to the flow control valve 23. Such control is repeatedly performed at very short intervals.

尚、制御の方法は、常時制御以外の方法で行われてもよい。例えば、制御の方法は、中間製品ガスが製品槽4から製品ガス排出ラインL9に流出している間、常時制御よりも長い間隔を空けて繰り返し行う方法でもよく、断続的に行う方法でもよい。また、制御の方法は、1回だけ行うようにしてもよい。 The control method may be a method other than the constant control. For example, as a control method, while the intermediate product gas is flowing from the product tank 4 to the product gas discharge line L9, a method may be repeatedly performed with a longer interval than the regular control, or may be an intermittent method. The control method may be performed only once.

上記窒素ガス分離装置10の制御方法では、中間製品ガスに混合する混合用ガスの混合流量は、混合用ガスと混合される前の中間製品ガス中の酸素濃度と、混合用ガスと混合される前の中間製品ガスの流量に応じて制御される。すなわち、混合後に製品ガス中の酸素濃度が所望の濃度および流量に達しているか否か検知して、検知結果に応じてさらに混合用ガスの混合流量を調整する方法と異なり、所望の濃度および流量の製品ガスを短時間に得ることができる。 In the control method of the nitrogen gas separation device 10, the mixing flow rate of the mixing gas mixed with the intermediate product gas is the oxygen concentration in the intermediate product gas before being mixed with the mixing gas, and the mixing gas. It is controlled according to the flow rate of the previous intermediate product gas. That is, unlike the method of detecting whether or not the oxygen concentration in the product gas has reached a desired concentration and flow rate after mixing, and further adjusting the mixing flow rate of the mixing gas according to the detection result, the desired concentration and flow rate are different. The product gas can be obtained in a short time.

上記窒素ガス分離装置10の制御方法では、製品槽4において濃度が平準化された後の中間製品ガスに基づいて混合用ガスの混合流量が制御されるため、混合流量の変動が小さい。 In the control method of the nitrogen gas separation device 10 described above, the mixing flow rate of the mixing gas is controlled based on the intermediate product gas after the concentration in the product tank 4 is leveled, so that the fluctuation of the mixing flow rate is small.

上記窒素ガス分離装置10の制御方法では、中間製品ガスに混合する混合用ガスの混合流量は、中間製品ガス中の酸素ガスの濃度と中間製品ガスの流量に基づいて上記の式(1)により一意的に算出されるので、所望の濃度および流量の製品ガスが作られる混合用ガスの混合流量が得られる。そのため、例えば、製品槽4から製品ガス排出ラインL9に流出する中間製品ガスの流量の変動が大きい場合や、第1及び第2吸着塔3A、3Bで生成される中間製品ガス中の酸素ガスの濃度のばらつきが大きい場合であっても、所望の濃度および流量の窒素ガスを安定的かつ短時間に得ることができる。 In the control method of the nitrogen gas separation device 10 described above, the mixing flow rate of the mixing gas mixed with the intermediate product gas is determined by the above formula (1) based on the concentration of oxygen gas in the intermediate product gas and the flow rate of the intermediate product gas. Since it is uniquely calculated, the mixing flow rate of the mixing gas that produces the desired concentration and flow rate of the product gas is obtained. Therefore, for example, when the fluctuation of the flow rate of the intermediate product gas flowing from the product tank 4 to the product gas discharge line L9 is large, or when the oxygen gas in the intermediate product gas generated in the first and second adsorption towers 3A and 3B is Even if there is a large variation in concentration, nitrogen gas having a desired concentration and flow rate can be stably obtained in a short time.

上記窒素ガス分離装置10では、混合用ガスは、原料ガス源7とは別の供給源である混合用ガス源8から供給されることによって中間製品ガスに混合されるので、原料ガス源7から原料ガスの一部を分流させることによって混合用ガスを中間製品ガスに混合する場合(後述の第2、3実施形態)と比べて、原料ガスの第1及び第2吸着塔3A、3Bにおける圧力低下が生じないので、第1及び第2吸着塔3A、3B内の圧力が確保されやすい。 In the nitrogen gas separation device 10, the mixing gas is mixed with the intermediate product gas by being supplied from the mixing gas source 8 which is a supply source different from the source gas source 7, Compared with the case where the mixing gas is mixed with the intermediate product gas by dividing a part of the raw material gas (second and third embodiments described later), the pressure of the raw material gas in the first and second adsorption towers 3A, 3B Since the decrease does not occur, the pressure in the first and second adsorption towers 3A and 3B is easily secured.

以上に説明した窒素ガス分離装置10およびその制御方法は、本発明の一実施形態であり、その具体的構成については、本発明の趣旨を逸脱しない範囲で適宜変更可能である。以下、本発明の第2実施形態の窒素ガス分離装置およびその制御方法について説明する。第2実施形態において上記第1実施形態と対応する要素は、上記第1実施形態と同様の符号を付して、その説明が省略される。 The nitrogen gas separation device 10 and the control method thereof described above are one embodiment of the present invention, and the specific configuration thereof can be appropriately changed without departing from the spirit of the present invention. Hereinafter, a nitrogen gas separation apparatus and a control method thereof according to the second embodiment of the present invention will be described. In the second embodiment, elements corresponding to those in the first embodiment are designated by the same reference numerals as those in the first embodiment, and description thereof will be omitted.

上記第1実施形態の窒素ガス分離装置10の制御方法では、原料ガス源7とは別の供給源である混合用ガス源8から混合用ガスを中間製品ガスに混合したが、第2実施形態の窒素ガス分離装置100は、図2に示すように、混合用ガス源8及び混合用ガス圧縮機9を省略している点、混合用ガス供給ラインL10が原料ガス供給ラインL1から分岐している点で、上記第1実施形態と相違している。すなわち、第2実施形態の窒素ガス分離装置100では、原料ガス源7から原料ガスの一部が分流して中間製品ガスに混合用ガスとして混合される。その他の構成および制御方法については上記第1実施形態と同一なので、第1実施形態と同様の符号を付して、その説明を省略する。 In the control method of the nitrogen gas separation device 10 of the first embodiment, the mixing gas is mixed with the intermediate product gas from the mixing gas source 8 which is a supply source different from the raw material gas source 7, but the second embodiment As shown in FIG. 2, the nitrogen gas separation device 100 of FIG. 2 omits the mixing gas source 8 and the mixing gas compressor 9, and the mixing gas supply line L10 is branched from the raw material gas supply line L1. This is different from the first embodiment in that That is, in the nitrogen gas separation apparatus 100 of the second embodiment, a part of the raw material gas is branched from the raw material gas source 7 and mixed with the intermediate product gas as a mixing gas. Since other configurations and control methods are the same as those in the first embodiment, the same reference numerals as those in the first embodiment are used, and the description thereof will be omitted.

第2実施形態の窒素ガス分離装置100では、原料ガスの一部を混合用ガスとして使用することができるので、別途、混合用ガスや混合用ガス圧縮機9を用意する必要がない。そのため、製造コストを低減することができる。 In the nitrogen gas separation apparatus 100 of the second embodiment, a part of the raw material gas can be used as a mixing gas, so that it is not necessary to separately prepare a mixing gas or a mixing gas compressor 9. Therefore, the manufacturing cost can be reduced.

次に、第3実施形態の窒素ガス分離装置200およびその制御方法について説明する。 Next, the nitrogen gas separation apparatus 200 of the third embodiment and its control method will be described.

第3実施形態の窒素ガス分離装置200は、第1及び第2吸着塔3A、3Bの脱着工程において、第1及び第2吸着塔3A、3B内の原料ガスを排出する真空ポンプ24を更に備える点で、上記第2実施形態と相違する。その他の構成および制御方法については、第2実施形態と同一なので、第2実施形態と対応する要素については、第2実施形態と同様の符号を付して、その説明を省略する。 The nitrogen gas separation apparatus 200 of the third embodiment further includes a vacuum pump 24 that discharges the raw material gas in the first and second adsorption towers 3A and 3B in the desorption process of the first and second adsorption towers 3A and 3B. This point is different from the second embodiment. Since other configurations and control methods are the same as those in the second embodiment, elements corresponding to those in the second embodiment are designated by the same reference numerals as those in the second embodiment, and the description thereof will be omitted.

第3実施形態の窒素ガス分離装置200では、図3に示すように、排出合流ラインL2C上に設置された真空ポンプ24によって第1及び第2吸着塔3A、3B内の原料ガスが脱着工程において吸引されることによって第1及び第2吸着塔3A、3Bの外部へ排出される。 In the nitrogen gas separation apparatus 200 of the third embodiment, as shown in FIG. 3, the raw material gas in the first and second adsorption towers 3A and 3B is desorbed by the vacuum pump 24 installed on the discharge joining line L2C. By being sucked, it is discharged to the outside of the first and second adsorption towers 3A and 3B.

第3実施形態の窒素ガス分離装置200では、脱着工程において真空ポンプ24によって第1及び第2吸着塔3A、3B内の原料ガスが吸引されるので、脱着工程における第1及び第2吸着塔3A、3B内の原料ガスを圧力差によって排出する第1及び第2実施形態と比べて、第1及び第2吸着塔3A、3B内の圧力を低減することができる。そのため、より多くの酸素ガスを吸着剤から脱着させることができるので、より十分に吸着剤を再生させることができる。 In the nitrogen gas separation device 200 of the third embodiment, since the raw material gas in the first and second adsorption towers 3A and 3B is sucked by the vacuum pump 24 in the desorption step, the first and second adsorption towers 3A in the desorption step. It is possible to reduce the pressure in the first and second adsorption towers 3A and 3B as compared with the first and second embodiments in which the raw material gas in 3B is discharged by a pressure difference. Therefore, since more oxygen gas can be desorbed from the adsorbent, the adsorbent can be regenerated more sufficiently.

3A 第1吸着塔
3B 第2吸着塔
4 製品槽
6 混合用ガス供給部
7 原料ガス源
8 別の供給源
10 窒素ガス分離装置
17 部位
20 制御部
20A 演算部
21 酸素濃度計
22 流量計
L9 流路
3A 1st adsorption tower 3B 2nd adsorption tower 4 Product tank 6 Mixing gas supply part 7 Raw material gas source 8 Another supply source 10 Nitrogen gas separation device 17 parts 20 Control part 20A Calculation part 21 Oxygen concentration meter 22 Flowmeter L9 flow Road

Claims (6)

吸着剤が充填された2基以上の吸着塔に窒素ガスと酸素ガスとを含む原料ガスを加圧下で供給し、各吸着塔が吸着工程、均圧工程、脱着工程、均圧工程を繰り返し、前記原料ガス中の酸素ガスを前記吸着剤に吸着させることにより、前記原料ガスから得られた窒素ガスを含む中間製品ガスを製品槽に導入し、
前記製品槽における中間製品ガスの出口における中間製品ガス中の酸素濃度又は製品槽から流路に流出した中間製品ガス中の酸素濃度を計測し、
前記流路を流れる中間製品ガスの流量を計測し、
前記流路を流れる中間製品ガスであって前記酸素濃度が計測され且つ前記流量が計測された後の中間製品ガスに酸素ガスを含む混合用ガスを混合して製品ガスとし、
前記中間製品ガスに混合する前記混合用ガスの混合流量は、前記計測された酸素濃度及び前記計測された流量に応じて制御される、窒素ガス分離装置の制御方法。
A raw material gas containing nitrogen gas and oxygen gas is supplied under pressure to two or more adsorption towers filled with an adsorbent, and each adsorption tower repeats an adsorption step, a pressure equalization step, a desorption step, and a pressure equalization step, By adsorbing oxygen gas in the raw material gas to the adsorbent, an intermediate product gas containing nitrogen gas obtained from the raw material gas is introduced into a product tank,
Measuring the oxygen concentration in the intermediate product gas at the outlet of the intermediate product gas in the product tank or the oxygen concentration in the intermediate product gas flowing out from the product tank to the flow path,
Measuring the flow rate of the intermediate product gas flowing through the flow path,
An intermediate product gas flowing through the flow path is mixed with a mixing gas containing oxygen gas in the intermediate product gas after the oxygen concentration is measured and the flow rate is measured, to obtain a product gas,
A method for controlling a nitrogen gas separation device, wherein a mixing flow rate of the mixing gas mixed with the intermediate product gas is controlled according to the measured oxygen concentration and the measured flow rate.
前記混合流量は、下記の式(1)により算出される請求項1に記載の窒素ガス分離装置の制御方法。
前記混合流量=(製品ガス目標残存酸素濃度−中間製品ガス中の酸素濃度)÷(混合用ガス酸素濃度−製品ガス目標残存酸素濃度)×中間製品ガスの流量・・・(1)
The method for controlling a nitrogen gas separator according to claim 1, wherein the mixed flow rate is calculated by the following equation (1).
Mixing flow rate=(product gas target residual oxygen concentration−oxygen concentration in intermediate product gas)÷(mixing gas oxygen concentration−product gas target residual oxygen concentration)×intermediate product gas flow rate (1)
前記混合用ガスは、原料ガス源から前記原料ガスの一部を分流させることによって前記中間製品ガスに混合される、請求項1又は請求項2に記載の窒素ガス分離装置の制御方法。 The method for controlling a nitrogen gas separation device according to claim 1, wherein the gas for mixing is mixed with the intermediate product gas by branching a part of the raw material gas from a raw material gas source. 前記混合用ガスは、前記原料ガス源とは別の供給源から供給されることによって前記中間製品ガスに混合される、請求項1又は請求項2に記載の窒素ガス分離装置の制御方法。 The method for controlling a nitrogen gas separation device according to claim 1 or 2, wherein the mixed gas is mixed with the intermediate product gas by being supplied from a supply source different from the source gas source. 吸着剤が充填され、原料ガスが導入される第1吸着塔と、
吸着剤が充填され、原料ガスが導入される第2吸着塔と、
前記第1吸着塔及び第2吸着塔において吸着工程、均圧工程、脱着工程、均圧工程を繰り返し行うための制御を行う制御部と、
前記第1吸着塔及び第2吸着塔において原料ガスから得られた窒素ガスを含む中間製品ガスが導入される製品槽と、
前記製品槽における中間製品ガスの出口又は前記製品槽から流出した中間製品ガスが流れる流路に配置され、中間製品ガス中の酸素濃度を計測する酸素濃度計と、
前記流路での中間製品ガスの流量を計測する流量計と、
前記流路における前記酸素濃度計及び前記流量計の設置位置よりも下流側の部位に、酸素ガスを含む混合用ガスを導入する混合用ガス供給部と、を備え、
前記制御部は、前記流量計による計測流量及び前記酸素濃度計による計測濃度に応じて、前記混合用ガス供給部によって中間製品ガスに混合する混合用ガスの混合流量を制御する、窒素ガス分離装置。
A first adsorption tower in which an adsorbent is filled and a raw material gas is introduced;
A second adsorption tower in which an adsorbent is filled and a raw material gas is introduced;
A control unit that performs control for repeatedly performing an adsorption step, a pressure equalization step, a desorption step, and a pressure equalization step in the first adsorption tower and the second adsorption tower;
A product tank into which an intermediate product gas containing nitrogen gas obtained from a raw material gas is introduced in the first adsorption tower and the second adsorption tower,
An oxygen concentration meter for measuring the oxygen concentration in the intermediate product gas, which is disposed in the outlet of the intermediate product gas in the product tank or the flow path of the intermediate product gas flowing out from the product tank,
A flow meter for measuring the flow rate of the intermediate product gas in the flow path,
At a site downstream of the installation position of the oxygen concentration meter and the flow meter in the flow path, a mixing gas supply unit for introducing a mixing gas containing oxygen gas,
The control unit controls the mixing flow rate of the mixing gas mixed with the intermediate product gas by the mixing gas supply unit according to the measurement flow rate of the flow meter and the measurement concentration of the oxygen concentration meter. ..
前記制御部は、下記の式(1)により前記混合流量を算出する演算部を有する請求項5に記載の窒素ガス分離装置。
前記混合流量=(製品ガス目標残存酸素濃度−中間製品ガス中の酸素濃度)÷(混合用ガス酸素濃度−製品ガス目標残存酸素濃度)×中間製品ガスの流量・・・(1)

The said control part is a nitrogen gas separation apparatus of Claim 5 which has a calculating part which calculates the said mixed flow volume by following formula (1).
Mixing flow rate=(product gas target residual oxygen concentration−oxygen concentration in intermediate product gas)÷(mixing gas oxygen concentration−product gas target residual oxygen concentration)×intermediate product gas flow rate (1)

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Publication number Priority date Publication date Assignee Title
JPH02307507A (en) * 1989-05-19 1990-12-20 Tokico Ltd Gas separator
JPH05200226A (en) * 1992-01-27 1993-08-10 Kanebo Ltd Separation of nitrogen gas
JPH05305214A (en) * 1992-04-28 1993-11-19 Kanebo Ltd Separation of oxygen gas
JP2013117346A (en) * 2011-12-02 2013-06-13 Osaka Gas Co Ltd Industrial furnace apparatus
JP2015024349A (en) * 2013-07-24 2015-02-05 クラレケミカル株式会社 Nitrogen gas concentration system

Patent Citations (5)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
JPH02307507A (en) * 1989-05-19 1990-12-20 Tokico Ltd Gas separator
JPH05200226A (en) * 1992-01-27 1993-08-10 Kanebo Ltd Separation of nitrogen gas
JPH05305214A (en) * 1992-04-28 1993-11-19 Kanebo Ltd Separation of oxygen gas
JP2013117346A (en) * 2011-12-02 2013-06-13 Osaka Gas Co Ltd Industrial furnace apparatus
JP2015024349A (en) * 2013-07-24 2015-02-05 クラレケミカル株式会社 Nitrogen gas concentration system

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