TW201536673A - Method and system for purifying helium gas - Google Patents

Abstract

Provided are a method and a system by which rarefied helium gas is industrially and efficiently purified with small-scale equipment to a high degree. In each of the adsorption towers (2a, 2b, 2c) for concentration of a first pressure swing adsorption device (1), an adsorption step, a depressurization step, a desorption step, and a pressurization step are successively performed to adsorb impurity gases contained in the rarefied helium gas onto an adsorbent and to discharge concentrated helium gas, which has remained unadsorbed onto the adsorbent. A passageway for introducing the concentrated helium gas into each of the multiple adsorption towers (102a, 102b, 102c) for reconcentration of a second pressure swing adsorption device (101) is connected to a passageway for discharging the concentrated helium gas from the first pressure swing adsorption device (1). In each of the adsorption towers for reconcentration, an adsorption step, a depressurization step, a desorption step, and a pressurization step are successively performed to adsorb impurity gases contained in the concentrated helium gas onto an adsorbent and to discharge reconcentrated helium gas, which has remained unadsorbed onto the adsorbent.

Description

Helium purification method and purification system

The present invention relates to a method and system for obtaining high-purity helium by purifying a helium gas containing an impurity gas, and is particularly suitable for purification in the case where the raw material helium gas is a thin helium gas having a low radon concentration.

For example, helium gas used as a cooling liquid for MRI (Magnetic Resonance Imaging), a porous base material forming step at the time of optical fiber production, or a wire drawing step, is only used in the United States or the Middle East. The form of by-products of overseas natural gas, such as countries, is produced in small quantities. Moreover, at present, the supply of suffocating gas is tight in the world, and the price of suffocating gas continues to rise. Furthermore, it is generally believed that the need for radon in the manufacturing industries of emerging countries with Asia as the center will increase in the future. However, the stable supply of suffocating gas in the future is worrying. In this way, helium is more resourceful and more expensive, so it is useful to recover helium from the equipment for reuse. Therefore, it is desirable to recover and purify the diluted helium gas mixed with an impurity gas such as a large amount of air to a high purity.

In the past, a cryogenic separation method in which an impurity gas is liquefied by liquid nitrogen or the like and separated from helium gas is known as a method of purifying the lean helium gas into a high purity (see Patent Document 1). In addition, a pressure swing adsorption method (PSA method) in which an impurity gas is adsorbed to an adsorbent by a pressure swing adsorption device and is separated from helium gas is known (see Patent Document 2). In the pressure swing adsorption method, the adsorption step, the pressure reduction step, the desorption step, the washing step and a step of pressurizing, the adsorption gas contained in the raw material helium introduced into the adsorption tower is adsorbed to the adsorbent under pressure and the concentrated helium gas not adsorbed by the adsorbent is discharged, and the depressurization step is performed. The internal pressure of the adsorption tower is reduced. The desorption step is to desorb the impurity gas from the adsorbent and discharge as an outgas. The cleaning step is to clean the inside of the adsorption tower to discharge the outgas. The step of boosting is to raise the inside of the adsorption tower. pressure.

[Previous Technical Literature] [Patent Literature]

[Patent Document 1] Japanese Patent No. 3639087

[Patent Document 2] Japanese Patent No. 5372607

In the case of purification by the cryogenic separation method, a cold heat source such as liquid nitrogen is required, and the apparatus is large-scale, and the cost becomes high in the case where the amount of processing is small. Moreover, even in the case where the amount of processing is small, the gas liquefaction equipment becomes a suitable object of the high-pressure gas manufacturing security law, and the procedures or management are complicated.

The pressure swing type adsorption device is not applied to the high pressure gas production security method. However, with the prior art described in Patent Document 2, it is difficult to efficiently purify the lean helium gas using a small-scale apparatus.

Further, in the pressure swing adsorption method, when the repetition interval of the adsorption step is shortened and the number of times of transformation in a certain purification treatment time is increased, the number of adsorption times is increased, and the purity of the concentrated helium gas is increased. However, in this case, since the number of desorption times is increased, the number of outgassing is increased, the flow rate of the concentrated helium gas is decreased, and helium gas is contained in the outgas, and the helium gas recovery rate is also lowered. Therefore, high purity helium cannot be obtained efficiently using the prior art.

Further, regarding the failure time of the adsorbent in the adsorption step, the higher the impurity gas concentration in the raw material helium, the shorter the failure time. In particular, when a thin helium gas discharged from a fiber manufacturing step or the like is used as a raw material helium gas, it is guided by the incorporation of an impurity gas such as air. The cerium concentration becomes 20 vol% or less, and the failure time of the adsorbent becomes short. Therefore, if a large amount of thin helium gas is to be purified by the prior art, the adsorbent volume of the adsorption tower becomes large and the adsorption system becomes large-scale.

That is, if a large amount of thin helium gas is to be industrially purified to a high purity by the prior art, there is a problem that the purification efficiency is lowered and the system is large-scale. It is an object of the present invention to provide a purification method and purification system for helium which can solve the problems of the prior art using the pressure swing adsorption method.

The method of the present invention is a method for purifying a raw material helium gas containing an impurity gas by using a first pressure swing adsorption device having a plurality of adsorption columns for concentration and a second pressure swing adsorption device having a plurality of adsorption columns for reconcentration. In the method of the present invention, each of the adsorption column for concentration and the adsorption column for each of the reconcentration stores an adsorbent which adsorbs the impurity gas in preference to the helium gas, and sequentially introduces the raw material helium gas into each of the adsorption columns for concentration. Each of the adsorption adsorption towers sequentially performs an adsorption step, a depressurization step, a desorption step, and a pressure increasing step, wherein the adsorption step is performed by adsorbing the impurity gas contained in the introduced raw material helium gas under pressure to the adsorbent. The concentrated helium gas which is not adsorbed by the adsorbent is discharged, and the depressurizing step is to reduce the internal pressure, and the desorbing step is to desorb the impurity gas from the adsorbent and discharge as an outgas, and the step of increasing the pressure is to increase the internal pressure; Introducing a flow path for discharging the concentrated helium gas from the first pressure swing adsorption device to introduce the concentrated helium gas flow to each of the plurality of adsorption bases for reconcentration of the second pressure swing adsorption device The step of introducing the concentrated helium gas into each of the adsorption towers for reconcentration, and sequentially performing the adsorption step, the pressure reduction step, the desorption step, and the liter in each of the adsorption columns for reconcentration In the step of adsorbing, the impurity gas contained in the introduced concentrated helium gas is adsorbed to the adsorbent under pressure and the reconcentrated helium gas which is not adsorbed by the adsorbent is discharged, and the depressurization step is reduced. The internal pressure, the desorption step is such that the impurity gas is desorbed from the adsorbent and discharged as an outgas, and the step of boosting increases the internal pressure.

According to the method of the present invention, the helium-enriched concentrated helium gas can be continuously discharged by purifying the raw material helium gas by using the first pressure swing adsorption device, and the concentrated helium gas can be further purified by using the second pressure swing adsorption device. The ground gas is further enriched and further concentrated in the helium gas. That is, the raw helium gas is purified in two stages by a pressure swing adsorption method, and concentrated helium gas as a high purity helium gas can be continuously obtained. In this way, compared with the case where the raw material helium gas is purified in one stage as before, the fluctuation of the raw material gas flow rate and the concentration can be flexibly handled without making the adsorption system large-scale, and the target purity helium gas can be efficiently obtained.

The helium purification system of the present invention comprises a first pressure swing adsorption device having a plurality of adsorption adsorption columns and a second pressure swing adsorption device having a plurality of adsorption columns for reconcentration, each of the adsorption adsorption columns and the above Each of the reconcentration adsorption towers contains an adsorbent that preferentially adsorbs the impurity gas in the helium gas. The first pressure swing adsorption device includes a raw material gas introduction flow path for introducing the raw material helium gas into each of the concentration adsorption columns, and a concentrated gas flow path for discharging concentrated helium gas from the respective adsorption adsorption columns. a first communication flow path for discharging the outgas from the adsorption column for concentration, and a first communication flow path for allowing one of the adsorption adsorption columns to communicate with another column, a raw material gas introduction switch valve that is separately opened and closed between the adsorption adsorption column and the raw material gas introduction flow path, and a concentrated gas path on-off valve that individually switches between the concentration adsorption column and the concentrated gas flow path a first escape valve opening and closing valve that individually switches between the concentration adsorption column and the first flow path, and individually switches between the concentration adsorption column and the first communication channel The first communication path switching valve. The second pressure swing type adsorption device has a concentrated gas introduction flow path for connecting the concentrated gas flow path to the respective reconcentration adsorption columns and introducing the concentrated helium gas, and is used in the adsorption column for each reconcentration a reconcentrated gas flow path for discharging the re-concentrated helium gas, a second escape gas flow path for discharging the outgas from the respective reconcentration adsorption towers, and a column for the reconcentration adsorption tower and another a second communication channel in which the columns are connected to each other, and a concentrated gas introduction path switch that individually switches between the adsorption column for reconcentration and the concentrated gas introduction channel a valve, a reconcentrated gas path switching valve that individually switches between the respective reconcentrating adsorption columns and the reconcentrated gas flow path, and the respective reconcentration adsorption towers and the second escape flow path are individually A second air passage switching valve that performs switching, and a second communication path switching valve that individually switches between the respective reconcentrating adsorption towers and the second communication passage. Each of the above-described switching valves is respectively formed as an automatic valve having a switching actuator and is connected to a control device to individually perform a switching operation. The respective switching valves are controlled by the control device to sequentially perform an adsorption step, a pressure reduction step, a desorption step, and a pressure increasing step in each of the concentration adsorption columns, and sequentially perform adsorption in each of the reconcentration adsorption columns. a step of depressurizing, a desorption step, and a step of pressurizing, wherein the adsorption step in each of the adsorption columns for concentration is such that the impurity gas contained in the introduced raw material helium gas is adsorbed to the adsorbent under pressure and is not The concentrated helium gas adsorbed by the adsorbent is discharged, and the depressurizing step is to reduce the internal pressure. The desorbing step is to desorb the impurity gas from the adsorbent and discharge as an outgas, and the step of increasing the pressure is to increase the internal pressure; The adsorption step in the column is such that the impurity gas contained in the introduced concentrated helium gas is adsorbed to the adsorbent under pressure and the re-concentrated helium gas which is not adsorbed by the adsorbent is discharged, and the depressurization step reduces the internal portion. The pressure and desorption steps are such that the impurity gas is desorbed from the adsorbent and discharged as an outgas, and the step of boosting increases the internal pressure.

The method of the invention can be carried out in accordance with the system of the invention.

In the method of the present invention, it is preferable that the raw material helium gas is mixed with the outgas discharged from at least one of the first pressure swing adsorption device and the second pressure swing adsorption device. In this case, the system of the present invention preferably includes a circulation flow path for connecting at least one of the first gas flow path and the second gas flow path to the material gas introduction flow path.

Thereby, the helium gas contained in the outgas can be reused, so that the recovery rate can be improved.

In the method of the present invention, even if introduced into the above-mentioned respective adsorption towers for concentration The helium gas concentration of the helium gas is 20 vol% or less, and helium gas of a target purity can also be obtained efficiently. Thereby, the method of the invention can be effectively applied to the purification of lean helium. In addition, when the raw material argon gas is mixed with the recycled gas, it is introduced into the first pressure swing adsorption device after mixing, so that it is 20 vol% or less after mixing. The target purity helium can be efficiently obtained by the method of the present invention.

In the method of the present invention, it is preferable to set the repetition interval of the adsorption step in the first pressure swing adsorption device so that the concentration of the concentrated helium gas is 40 vol% to 80 vol%. Thereby, the amount of the impurity gas separated from the helium gas in the second pressure swing type adsorption device can be made an appropriate amount.

In the method of the present invention, it is preferable that the concentration of the reconcentrated helium gas discharged from the adsorption column in the adsorption step is the target purity, for example, 99.999 vol% or more. 2 The repetition interval of the above adsorption step in the pressure swing adsorption device. Thereby, high purity helium gas can be obtained. Furthermore, the repetition interval of the adsorption step in the second pressure swing adsorption device may be set so that the concentration of the concentrated helium gas discharged from the adsorption column in the adsorption step is 99.9999 vol% or more.

In the method of the present invention, the internal gas of the other concentration adsorption column in the depressurization step is introduced into the adsorption tower after the desorption step and the pressure increase step. Thereafter, the cleaning step of performing the cleaning of the inside of the concentration adsorption column after the desorption step and before the step of the pressure increasing step is performed, and is preferably introduced into the adsorption column for concentration. The amount of gas introduced into the above-mentioned certain adsorption adsorption tower from the other adsorption column in the above-described decompression step in the above-described washing step is changed in the above-described washing step. In this case, when the enthalpy concentration of the raw material helium gas introduced into the concentration adsorption column is equal to or lower than a predetermined set value, it is preferable not to carry out the above-described washing step.

By performing a washing step, the impurities remaining in the interior of the adsorption tower after the desorption step can be Since the gas is discharged as an outgas, the concentration of the concentrated helium gas can be efficiently increased. On the other hand, the concentration of the internal gas in the vicinity of the gas discharge port of the adsorption column for concentration in the depressurization step is close to the target concentration of the concentrated helium gas, so if the internal gas and the impurity gas are combined together in the cleaning step, When the gas is discharged, the helium recovery rate is lowered. Further, the lower the concentration of the helium gas of the raw material, the more impurities in the internal gas other than the vicinity of the gas discharge port of the adsorption column for concentration in the depressurization step, so the impurity concentration of the gas for cleaning and the desorption step are retained. The impurity concentration of the impurity gas inside the adsorption tower becomes the same level. That is, the lower the concentration of the helium gas of the raw material, the smaller the value of performing the washing step. Therefore, the gas introduced into the inside of one of the adsorption towers for concentration in the first pressure swing adsorption apparatus is reduced by the concentration of the helium gas introduced into the adsorption towers for concentration. The amount can prevent an unnecessary drop in the recovery rate of helium. When the ruthenium concentration of the raw material helium gas introduced into each concentration adsorption column is equal to or less than the set value, the washing step may not be performed.

Therefore, in the system of the present invention, it is preferable that the respective switching valves are controlled by the control device to introduce the decompression in the inside of the concentration adsorption column in the state after the desorption step and the pressure increasing step. In the step of the other internal gas of the adsorption adsorption column, the gas is discharged as a gas, and the cleaning step of cleaning the inside of the concentration adsorption column after the desorption step and before the pressure increasing step is performed. And a flow rate control valve for regulating a flow rate of the gas flowing through the first communication passage, wherein the flow rate control valve is formed as an automatic valve having a flow rate adjusting actuator and is connected to the control device to perform flow rate adjustment The operation includes a sensor that detects the radon concentration of the raw material helium gas and is connected to the control device, and stores a predetermined execution time of the cleaning step in the control device, and the cleaning step is a gas introduced into the above-mentioned adsorption tower by a certain adsorption tower of the above-mentioned concentration in the depressurization step The preset relationship between the flow rate in the first communication channel and the enthalpy concentration of the raw material helium introduced into the concentration adsorption column is stored in the control device, and the control device is used to The above implementation time of memory Controlling the on-off valve in response to the cleaning step, and changing the flow rate of the adjustment gas by the flow rate control valve based on the correspondence relationship, and changing the cleaning step to the above-described cleaning step according to a change in the concentration of germanium detected by the sensor The amount of gas introduced by the adsorption tower for concentration.

Or preferably, a sensor for detecting the radon concentration of the raw material helium introduced into the concentration adsorption column and connected to the control device, and performing the cleaning step and the radon concentration in the raw material helium gas The pre-set correspondence relationship is stored in the control device, and the control device changes the execution time of the cleaning step based on the correspondence relationship to change according to the change in the radon concentration detected by the sensor. The amount of gas introduced into the above-described adsorption column for concentration in the above-described washing step.

According to the present invention, it is possible to provide a method and system suitable for industrially purifying lean helium gas into high purity in a small scale apparatus.

1‧‧‧1st variable pressure adsorption device

2a, 2b, 2c‧‧‧ Concentration adsorption tower

2a', 2b', 2c'‧‧‧ gas passages formed at one end of each of the adsorption adsorption towers 2a, 2b, 2c

2a", 2b", 2c"‧‧‧ gas passages formed at the other end of each of the adsorption adsorption towers 2a, 2b, 2c

3‧‧‧Material gas introduction piping (raw material gas introduction flow path)

4‧‧‧Concentrated gas piping (concentrated gas flow path)

5‧‧‧1st escape pipe (1st air flow path)

6a, 6b, 6c‧‧‧1st to 3rd on-off valves (raw material gas introduction switch valve)

7a, 7b, 7c‧‧‧4th to 6th on-off valves (concentrated gas circuit switching valves)

8a, 8b, 8c‧‧‧7th to 9th on-off valves (1st escape valve)

9‧‧‧1st connecting pipe (first connecting flow path)

9a‧‧‧1st communication part of the first communication pipe 9

9b‧‧‧the second communication part of the first communication pipe 9

9c‧‧‧the third communication part of the first communication pipe 9

10a, 10b, 10c‧‧‧10th to 12th on-off valves (first communication path switching valve)

11a, 11b, 11c‧‧‧13th to 15th on-off valves (1st connected way switch valve)

12‧‧‧16th on-off valve (1st connected way switch valve)

13‧‧‧1st flow control valve

14‧‧‧17th on-off valve (1st connected way switch valve)

15‧‧‧2nd flow control valve

20‧‧‧Control device

21‧‧‧1st flow sensor

22‧‧‧Material gas buffer tank

22a‧‧‧Sensor for measuring the storage volume of the buffer tank 22

23‧‧‧Compressor

24‧‧‧1st concentration sensor

25‧‧‧3rd flow control valve

26a‧‧‧1st pressure regulating valve

26b‧‧‧2nd pressure regulating valve

27a, 27b, 27c‧‧‧ Pressure sensor for detecting the internal pressure of each of the adsorption adsorption towers 2a, 2b, 2c

28‧‧‧ Input device

29‧‧‧ Output device

41‧‧‧1st circulating pipe (circulating flow path)

42‧‧‧1st switching valve

43‧‧‧2nd cycle piping (circulating flow path)

44‧‧‧1st release piping

101‧‧‧2nd variable pressure adsorption device

102a, 102b, 102c‧‧‧reconcentration adsorption tower

102a', 102b', 102c'‧‧‧ gas passages formed at one end of each of the reconcentration adsorption towers 102a, 102b, 102c

102a", 102b", 102c"‧‧‧ gas passages formed at the other end of each of the reconcentration adsorption towers 102a, 102b, 102c

103‧‧‧Concentrated gas introduction piping (concentrated gas introduction flow path)

104‧‧‧Reconcentrated gas piping (reconcentrated gas flow path)

105‧‧‧2nd gas pipeline (2nd air flow path)

106a, 106b, 106c‧‧‧18th to 20th on-off valves (reconcentrated gas introduction switch valve)

107a, 107b, 107c‧‧‧21st to 23rd on-off valves (reconcentrated gas circuit switching valves)

108a, 108b, 108c‧‧‧24th to 26th on-off valves (2nd airway switch valve)

109‧‧‧2nd connecting pipe (2nd connecting flow path)

109a‧‧ The first re-concentration communication part of the second communication pipe 109

109b‧‧・2nd re-concentration communication part of the second communication pipe 109

109c‧‧・3rd re-concentration communication part of the second communication pipe 109

110a, 110b, 110c‧‧‧27th to 29th on-off valves (2nd communication switch valve)

111a, 111b, 111c‧‧‧30th to 32nd on-off valves (second communication path switch valve)

112‧‧‧33rd switch valve (2nd connecting way switch valve)

113‧‧‧3rd flow control valve

114‧‧‧34th on-off valve (2nd connected way switch valve)

115‧‧‧4th flow control valve

121‧‧‧2nd flow sensor

122‧‧‧Buffer tank for concentrated gas

124‧‧‧2nd concentration sensor

126a‧‧‧3rd pressure regulating valve

126b‧‧‧4th pressure regulating valve

127a, 127b, 127c‧‧‧ Pressure sensors for detecting the internal pressure of each of the adsorption columns 102a, 102b, and 102c for reconcentration

141‧‧‧3rd cycle piping (circulating flow path)

142‧‧‧2nd switching valve

143‧‧‧4th cycle piping (circulating flow path)

144‧‧‧Second release piping

G1‧‧‧ raw material helium

G2‧‧‧ Concentrated helium

G3, G3'‧‧‧ 逸气

G4‧‧‧ Internal gas of the adsorption tower for concentration in the depressurization step

G5‧‧‧ Internal gas in the adsorption tower for concentration in the depressurization pressure equalization step

G7‧‧‧ reconcentrated helium

G8, G8'‧‧‧ 逸气

G9‧‧‧ Internal gas for reconcentration adsorption tower in a depressurization step

G10‧‧‧ Internal gas for the reconcentration adsorption tower in the depressurization pressure equalization step

Α‧‧‧氦气的净化系统

Fig. 1 is a view showing the configuration of a purification system according to an embodiment of the present invention.

Fig. 2 is an explanatory view showing the configuration of a first pressure swing type adsorption apparatus according to an embodiment of the present invention.

Fig. 3 is an explanatory view showing the configuration of a second pressure swing type adsorption apparatus according to an embodiment of the present invention.

Fig. 4 is an explanatory view showing a control device of a purification system according to an embodiment of the present invention.

Fig. 5 is a view showing operational states (a) to (i) of the first pressure swing adsorption apparatus according to the embodiment of the present invention.

Fig. 6 is a view showing the correspondence relationship between the operating state of the first pressure swing adsorption apparatus according to the embodiment of the present invention, the purification processing steps in each adsorption tower, and the state of the on-off valve.

Fig. 7 is a view showing an operation state (a) '~(i)' of a second pressure swing type adsorption apparatus according to an embodiment of the present invention.

Fig. 8 is a view showing the correspondence relationship between the operating state of the second pressure swing adsorption apparatus according to the embodiment of the present invention, the purification processing steps in each adsorption tower, and the state of the on-off valve.

The helium purification system α according to the embodiment of the present invention shown in FIG. 1 includes a first pressure swing adsorption device 1 and a second pressure swing adsorption device 101 for purifying the raw material helium G1 containing an impurity gas.

As shown in Fig. 2, the first pressure swing adsorption apparatus 1 has a plurality of adsorption towers 2a, 2b, and 2c for concentration. In the present embodiment, the first to third concentration adsorption columns 2a, 2b, and 2c are provided, and gas passage ports 2a' and 2b' are formed at one end and the other end of each of the concentration adsorption columns 2a, 2b, and 2c. 2c', 2a", 2b", 2c".

As shown in FIG. 3, the second pressure swing adsorption apparatus 101 has a plurality of adsorption towers 102a, 102b, and 102c for reconcentration. In the present embodiment, the first to third reconcentration adsorption columns 102a, 102b, and 102c are provided, and gas passage ports 102a' and 102b are formed at one end and the other end of each of the reconcentration adsorption columns 10102a, 102b, and 102c. ', 102c', 102a", 102b", 102c".

Each of the adsorption towers 2a, 2b, 2c, 102a, 102b, and 102c houses an adsorbent that adsorbs impurity gas in preference to the helium gas. The adsorbent is not particularly limited as long as it can adsorb the impurity gas in preference to the helium gas. For example, activated carbon, synthetic zeolite, carbon molecular sieve, alumina gel or the like can be used.

As shown in FIG. 2, the raw material gas introduction pipe 3, the concentrated gas pipe 4, and the first escape pipe 5 are connected to each of the concentration adsorption towers 2a, 2b, and 2c.

One end of the material gas introduction pipe 3 is connected to a supply source of the raw material helium gas G1. For example, a fiber manufacturing device is used as a supply source. The other end of the raw material gas introduction pipe 3 is formed into three branch pipes toward the first to third concentration adsorption columns 2a, 2b, and 2c, and passes through the first to third on-off valves 6a, 6b, and 6c constituting the material gas introduction path switching valve. The gas passage ports 2a', 2b', and 2c' are connected to one end of each of the adsorption adsorption towers 2a, 2b, and 2c. In this way, the material gas introduction pipe 3 constitutes a material gas introduction flow path for introducing the raw material helium gas G1 to each of the concentration adsorption towers 2a, 2b, and 2c. Moreover, the suction for concentration is utilized by the first to third on-off valves 6a, 6b, and 6c. Each of the auxiliary towers 2a, 2b, and 2c is individually and electrically connected to the raw material gas introduction flow path, and the raw material argon gas G1 can be individually introduced into each of the concentration adsorption towers 2a, 2b, and 2c via the raw material gas introduction flow path.

The raw material helium G1 is a mixed gas of helium gas and impurity gas. The raw material helium gas G1 introduced into each of the concentration adsorption columns 2a, 2b, and 2c is preferably a cerium concentration of 1 vol% or more. In the present embodiment, the lean helium gas supplied from the supply source is selected as the concentration and flow rate change. The raw material helium gas G1 is, for example, a thin helium gas containing air as an impurity gas, the air concentration is 95 vol% when the cerium concentration is 5 vol%, the cerium concentration is varied between 1 and 20 vol%, and the helium gas flow rate is varied between 10 and 100 Nm ³ /h. .

One end of the concentrated gas pipe 4 is turned into three branch pipes toward the first to third concentration adsorption columns 2a, 2b, and 2c, and is concentrated by the fourth to sixth on-off valves 7a, 7b, and 7c constituting the concentrated gas path switching valve. The gas at the other end of each of the adsorption towers 2a, 2b, and 2c is connected through the ports 2a", 2b", and 2c". The other end of the concentrated gas pipe 4 becomes an outlet of the concentrated helium gas G2, and the second pressure swing type adsorption device 101 In this way, the concentrated gas pipe 4 constitutes a concentrated gas flow path for discharging the concentrated helium gas G2 from each of the adsorption adsorption towers 2a, 2b, and 2c. Further, by using the fourth to sixth on-off valves 7a and 7b 7c, the respective adsorption towers 2a, 2b, and 2c for concentration are individually and separately switched between the concentration gas channels, and the concentrated helium gas G2 can be separately discharged from each of the adsorption adsorption towers 2a, 2b, and 2c. The discharged concentrated helium gas G2 is sent to the second pressure swing type adsorption device 101.

The other end of the concentrated gas pipe 4 is provided with a first pressure regulating valve 26a for adjusting the back pressure, and the internal pressure in each of the concentration adsorption columns 2a, 2b, and 2c can be adjusted to a predetermined adsorption pressure for the adsorption step. .

One of the first outflow pipes 5 is formed into three branch pipes toward the first to third concentration adsorption towers 2a, 2b, and 2c, and passes through the seventh to ninth on-off valves 8a and 8b that constitute the first escape valve. 8c is connected to the gas passage ports 2a', 2b', 2c' at one end of each of the adsorption adsorption towers 2a, 2b, 2c. The other end of the first escape pipe 5 serves as an outlet for the outgassing G3 and G3'. Again, right The first circulation pipe 41 to which the first escape pipe 5 is connected is provided with a second pressure regulating valve 26b for adjusting the back pressure, and the internal pressure in each of the adsorption towers 2a, 2b, 2c can be adjusted to make the escape gas G3 in the desorption step. , G3' has a preset pressure. Thereby, the first escape pipe 5 constitutes a first escape flow path for discharging the outgass G3 and G3' from each of the adsorption adsorption towers 2a, 2b, and 2c. In addition, by separately switching between the concentration adsorption columns 2a, 2b, and 2c and the first flow path by the seventh to ninth on-off valves 8a, 8b, and 8c, the adsorption columns 2a and 2b can be self-concentrated. Each of 2c and 2c discharges the outgassing G3 and G3' individually.

The first communication pipe 9 is provided, and constitutes a first communication flow path for allowing one of the concentration adsorption towers 2a, 2b, and 2c to communicate with another tower. The first communication pipe 9 has a first communication portion 9a, a second communication portion 9b, and a third communication portion 9c. One end of the first communication portion 9a is formed as three branch pipes toward the first to third concentration adsorption towers 2a, 2b, and 2c, and is connected to the tenth to twelfth switch valves 10a, 10b, and 10c that constitute the first communication path switching valve. The gas passage ports 2a", 2b", and 2c" are connected to the other ends of the adsorption columns 2a, 2b, and 2c for concentration. One end of the second communication portion 9b faces the first to third concentration adsorption columns 2a, 2b, and 2c. The three branch pipes are connected to the gas passage ports 2a" and 2b of the other ends of the concentration adsorption towers 2a, 2b, and 2c via the thirteenth to fifteenth on-off valves 11a, 11b, and 11c constituting the first communication path switching valve. ", 2c" connection. The other end of the first communication portion 9a and the other end of the second communication portion 9b pass through the 16th on-off valve 12 constituting the first communication passage opening and closing valve and a flow rate control valve that regulates the flow rate of the gas flowing through the first communication passage. The first flow control valve 13 is connected to each other. One end of the third communication portion 9c is connected to the first flow control valve 15 that constitutes the first on-off valve of the first communication passage and the second flow control valve 15 that constitutes the flow control valve that regulates the flow rate of the gas flowing through the first communication passage. The 1 communication portion 9a and the second communication portion 9b are connected. The other end of the third communication portion 9c is connected to the concentrated gas pipe 4. By individually switching between the concentration adsorption columns 2a, 2b, and 2c and the first communication channel, one of the concentration adsorption columns 2a, 2b, and 2c can be connected to another column. The states of the states are switched between the states in which they are opened and connected to each other and the states in which they are locked and not connected.

As shown in FIG. 3, the concentrated gas introduction pipe 103, the reconcentrated gas pipe 104, and the second escape pipe 105 are connected to each of the reconcentration adsorption towers 102a, 102b, and 102c.

One end of the concentrated gas introduction pipe 103 is connected to the other end of the concentrated gas pipe 4 via the first pressure regulating valve 26a. The other end of the concentrated gas introduction pipe 103 is turned into three branch pipes toward the first to third reconcentration adsorption columns 102a, 102b, and 102c, and passes through the 18th to 20th on-off valves 106a and 106b constituting the concentrated gas introduction path switching valve. 106c is connected to the gas passage ports 102a', 102b', 102c' at one end of each of the reconcentration adsorption columns 102a, 102b, 102c. Thereby, the concentrated gas introduction pipe 103 constitutes a concentrated gas introduction flow path for introducing the concentrated helium gas G2 to each of the reconcentration adsorption towers 102a, 102b, and 102c. In other words, each of the adsorption towers 102a, 102b, and 102c for reconcentration for the second pressure swing adsorption device 101 is connected to the concentrated gas flow path for discharging the concentrated helium gas G2 from the first pressure swing adsorption device 1. The concentrated gas introduction channel of the concentrated helium G2 is introduced. Further, by the 18th to 20th on-off valves 106a, 106b, and 106c, the reconcentration adsorption towers 102a, 102b, and 102c are individually and individually switched between the adsorption gas introduction channels 102a, 102b, and 102c, and can be introduced into the flow path via the concentrated gas. The concentrated helium gas G2 is individually introduced into each of the adsorption adsorption towers 102a, 102b, and 102c.

One end of the re-concentrated gas pipe 104 is turned into three branch pipes toward the first to third re-concentration adsorption towers 102a, 102b, and 102c, and passes through the 21st to 23rd on-off valves 107a, 107b, 107c constituting the reconcentrated gas path switching valve. The other end of each of the adsorption columns 102a, 102b, and 102c for reconcentration is connected to the gas passage ports 102a", 102b", and 102c". The other end of the reconcentration gas pipe 104 becomes an outlet for reconcentrating the helium gas G7. The concentrated gas pipe 104 constitutes a reconcentrated gas flow path for discharging the reconcentrated helium G7 from each of the adsorption towers 102a, 102b, and 102c for reconcentration. Further, by using the 21st to 23th on-off valves 107a, 107b, 107c Each of the reconcentration adsorption columns 102a, 102b, and 102c is individually and selectively switched between the reconcentration gas channels, and the reconcentration helium gas G7 can be separately discharged from the reconcentration adsorption columns 102a, 102b, and 102c. The use of the recovered reconcentrated helium G7 is not limited.

The third pressure regulating valve 126a for back pressure adjustment is provided at the other end of the reconcentrated gas pipe 104, and the outlet of the reconcentrated gas pipe 104 communicates with the recovery region of the reconcentrated helium gas G7 via the third pressure regulating valve 126a. The pressure in the recovery zone of the reconcentrated helium G7 is set to be lower than the adsorption pressure, and the required pressure is set according to the use of the recovered reconcentrated helium G7. For example, the inside of the specific container in which the recovered reconcentrated helium G7 is stored or the recovered reconcentrated helium G7 directly supplied through the reconcentrated gas flow path is used as a recovery area. By the third pressure regulating valve 126a, the internal pressure in each of the reconcentrating adsorption towers 102a, 102b, and 102c can be adjusted to the adsorption pressure set in advance for the adsorption step.

One end of the second outflow pipe 105 is turned into three branch pipes toward the first to third reconcentration adsorption towers 102a, 102b, and 102c, and passes through the 24th to 26th on-off valves 108a and 108b that constitute the second escape pipe switching valve. And 108c is connected to the gas passage ports 102a', 102b', and 102c' at one end of each of the adsorption columns 102a, 102b, and 102c for reconcentration. The other end of the second escape pipe 105 serves as an outlet for the outgassing G8 and G8'. Further, the third circulation pipe 141 connected to the second escape pipe 105 is provided with a fourth pressure regulating valve 126b for adjusting the back pressure, and the internal pressure in each of the adsorption towers 102a, 102b, and 102c can be adjusted to desorb the step. Zhongyiqi G8, G8' have a preset pressure. Thereby, the second outgas pipe 105 constitutes a second escape flow path for discharging the outgass G8 and G8' from each of the adsorption towers 102a, 102b, and 102c for reconcentration. Further, by the 24th to 26th on-off valves 108a, 108b, and 108c, the re-concentration adsorption towers 102a, 102b, and 102c are individually and electrically switched between the second and the second flow paths, and the self-reconcentration adsorption tower 102a can be used. Each of 102b, 102c individually discharges outgassing G8, G8'.

The second communication pipe 109 is provided, and constitutes a second communication flow path for allowing one of the reconcentration adsorption towers 102a, 102b, and 102c to communicate with another tower. The second communication pipe 109 has a first reconcentration communication portion 109a, a second reconcentration communication portion 109b, and a third reconcentration communication portion 109c. One end of the first re-concentration communication portion 109a is directed to the first to third re-concentration adsorption towers 102a, 102b, and 102c to form three branch pipes and constitute the second The 27th to 29th on-off valves 110a, 110b, and 110c of the communication path switching valve are connected to the gas passage ports 102a", 102b", and 102c" at the other ends of the reconcentration adsorption towers 102a, 102b, and 102c. One of the communication portions 109b is turned into three branch pipes toward the first to third reconcentration adsorption towers 102a, 102b, and 102c, and is connected to the 30th to 32nd switch valves 111a, 111b, and 111c that constitute the second communication path switching valve. The gas at the other end of each of the adsorption-concentrating adsorption towers 102a, 102b, and 102c is connected to the gas passage ports 102a", 102b", and 102c". The other end of the first re-concentration communication portion 109a and the other end of the second re-concentration communication portion 9b pass through the 33rd on-off valve 112 constituting the second communication passage opening and closing valve and constitute a gas flowing through the second communication passage. The third flow rate control valve 113 of the flow rate control valve whose flow rate is adjusted is connected to each other. The fourth flow control valve of the flow control valve that regulates the flow rate of the gas flowing through the second communication passage is connected to one end of the third reconcentration communication portion 109c via the 34th on-off valve 114 that constitutes the second communication passage opening and closing valve 115 is connected to the first communication portion 109a and the second communication portion 109b. The other end of the third re-concentration communicating portion 109c is connected to the re-concentrated gas pipe 104. By individually switching between the reconcentration adsorption columns 102a, 102b, and 102c and the second communication channel, one of the reconcentration adsorption columns 102a, 102b, and 102c can be connected to another column. The state between the towers is switched between the states in which they are opened and connected to each other and the states in which they are locked and not connected.

First to 34th on-off valves 6a, 6b, 6c, 7a, 7b, 7c, 8a, 8b, 8c, 10a, 10b, 10c, 11a, 11b, 11c, 12, 14, 106a, 106b, 106c, 107a, 107b 107c, 108a, 108b, 108c, 110a, 110b, 110c, 111a, 111b, 111c, 112, 114 are respectively formed by a known automatic valve, thereby having a switch for a solenoid or a motor for actuating the valve. Actuator. As shown in FIG. 4, each of the on-off valves is controlled by the control device 20 by being connected to the control device 20 constituting the purification system α, so that the switching operation can be individually performed. The control device 20 can be constituted by a computer.

Each of the first to fourth flow control valves 13, 15, 113, and 115 is constituted by a known automatic valve, and has a flow rate adjusting actuator such as a motor for actuating the valve. As shown in Figure 4 It is shown that each flow control valve is controlled by the control device 20 by being connected to the control device 20, so that the flow rate adjustment operation can be performed individually. Each of the first to fourth pressure regulating valves 26a, 26b, 126a, and 126b is constituted by a known automatic valve, and has a pressure adjusting actuator such as a motor for actuating the valve. As shown in FIG. 4, each of the pressure regulating valves 26a, 26b, 126a, and 126b is controlled by the control device 20 by being connected to the control device 20, so that the pressure regulating operation can be performed individually.

The raw material gas introduction pipe 3 is provided with a first flow rate sensor 21 that detects the flow rate of the raw material helium gas G1 supplied from the supply source, and temporarily stores the raw material gas buffer tank 22 of the raw material helium gas G1, and the buffer tank 22 The storage amount measuring sensor 22a, the compressor 23, and the first concentration sensor 24 for detecting the enthalpy concentration of the raw material krypton G1 introduced into the concentration adsorption columns 2a, 2b, and 2c, and the raw material gas are introduced. The third flow rate control valve 25 for adjusting the flow rate of the raw material helium gas G1 introduced into the respective adsorption adsorption towers 2a, 2b, and 2c. The pressure in the buffer tank 22 is set to be lower than the internal pressure of each of the adsorption towers 2a, 2b, 2c, 102a, 102b, and 102c at the end of the desorption step and the end of the washing step, and is equal to or higher than atmospheric pressure. The compressor 23 draws the raw material helium gas G1 until the pressure rises to a predetermined pressure. The third flow rate control valve 25 is constituted by a known automatic valve, and has a flow rate adjusting actuator such as a motor for actuating the valve.

The concentrated gas introduction pipe 103 is provided with a concentrated gas buffer tank 122 for temporarily storing the concentrated helium gas G2 discharged from the first pressure swing type adsorption device 1, and a concentrated helium gas introduced into the second pressure swing type adsorption device 101. The second flow rate sensor 121 that measures the flow rate of G2 and the second concentration sensor 124 that detects the enthalpy concentration of the concentrated helium gas G2.

One end of the first circulation pipe 41 is connected to the first escape pipe 5, and the other end of the first circulation pipe 41 is connected to the first switching valve 42. The first switching valve 42 is connected to one end of the second circulation pipe 43 and one end of the first release pipe 44. The other end of the second circulation pipe 43 is connected to the material gas buffer tank 22, and the other end of the first release pipe 44 is opened to the atmospheric pressure space under atmospheric pressure. Thereby, the state of the first escape flow path is made to the buffer tank 22 by the first switching valve 42. The state is switched between the state in which the first release pipe 44 is led to the normal pressure space. In addition, the state of the first circulation pipe 41 is switched between the state in which the first circulation pipe 41 is in communication with the second circulation pipe 43 and the state in which the first release pipe 44 is in communication with each other. In addition, the first switching valve 42 and the first release pipe 44 may be omitted, and the first circulation pipe 41 and the second circulation pipe 43 may be always connected.

Further, one end of the third circulation pipe 141 is connected to the second escape pipe 105, and the other end of the third circulation pipe 141 is connected to the second switching valve 142. The second switching valve 142 is connected to one end of the fourth circulation pipe 143 and one end of the second release pipe 144. The other end of the fourth circulation pipe 143 is connected to the material gas buffer tank 22 via the second circulation pipe 43, and the other end of the second release pipe 144 is opened to the atmospheric pressure space under atmospheric pressure. By the second switching valve 142, the state of the second airflow path is switched between the state in which it flows to the buffer tank 22 and the state which passes through the second release pipe 144 to the normal pressure space. In addition, the state of the third circulation pipe 141 is switched between the state in which the third circulation pipe 141 is in communication with the fourth circulation pipe 143 and the state in which the second release pipe 144 is in communication. In addition, the second switching valve 142 and the second release pipe 144 may be omitted, and the third circulation pipe 141 and the fourth circulation pipe 143 may be always connected.

The first to fourth circulation pipes 41, 43, 141, and 143 constitute a circulation flow path that connects the first air flow path and the second air flow path to the material gas introduction flow path via the material gas buffer tank 22. Further, only one of the first escape flow path and the second escape flow path may be connected to the material gas introduction flow path through the circulation flow path, and the other may not be connected to the material gas introduction flow path. Pressure space connection. Thereby, the raw material helium G1 can be mixed into the outgas discharged from at least one of the first pressure swing adsorption device 1 and the second pressure swing adsorption device 101. In other words, the outgassing G3, G3', G8, and G8' can be released into the atmospheric pressure space, or can be circulated into the raw material gas introduction flow path via the raw material gas buffer tank 22.

As shown in FIG. 4, the first flow rate sensor 21, the storage amount measuring sensor 22a, the first concentration sensor 24, the third flow rate control valve 25, the second flow rate sensor 121, and the second concentration are shown. The sensor 124 is connected to the control device 20. Further, a control tower 20 is connected to the adsorption tower for concentration Pressure sensors 27a, 27b, and 27c for detecting the internal pressure of each of 2a, 2b, and 2c, and pressure sensors 127a, 127b, and 127c for detecting the internal pressure of each of the adsorption columns 102a, 102b, and 102c for reconcentration, An input device 28 such as a keyboard, and an output device 29 such as a display.

By temporarily storing the raw material helium G1 in the raw material gas buffer tank 22, the composition fluctuation of the raw material helium G1 can be alleviated. The buffer tank 22 is preferably constituted by a balloon that is deformed in accordance with the amount of stored gas. Further, by controlling the third flow rate control valve 25 based on the signal from the control device 20, the flow rate adjustment operation is performed to adjust the flow rate of the raw material helium gas G1 introduced into each of the concentration adsorption towers 2a, 2b, and 2c. Thereby, the flow rate of the raw material helium gas G1 introduced into each of the concentration adsorption towers 2a, 2b, and 2c is controlled so as to normally match the detected flow rate of the flow rate sensor 21. When the amount of stored gas in the buffer tank 22 detected by the sensor 22a exceeds the upper limit set value, the flow rate of the raw material helium gas G1 introduced into each of the concentration adsorption towers 2a, 2b, and 2c is larger than that of the flow rate sensor 21 The flow rate is detected to reduce the amount of stored gas. When the amount of stored gas in the buffer tank 22 detected by the pressure sensor 23 does not reach the lower limit set value, the flow rate of the raw material helium gas G1 introduced into each of the concentration adsorption towers 2a, 2b, and 2c is smaller than the flow rate sensing. The flow rate of the detector 21 is increased to increase the amount of stored gas.

By temporarily storing the concentrated helium G2 in the buffer tank 122 for concentrated gas, the composition fluctuation of the concentrated helium G2 can be alleviated.

In order to purify the raw material helium gas G1 by using the first pressure swing type adsorption device 1 and the second pressure swing type adsorption device 101, the raw material helium gas G1 is sequentially introduced into each of the concentration adsorption towers 2a, 2b, and 2c. In each of the adsorption adsorption towers 2a, 2b, and 2c for concentration, a plurality of purification treatment cycles for concentration-concentration purification steps are sequentially performed in sequence. In addition, the concentrated helium gas G2 discharged from the first pressure swing adsorption device 1 is sequentially introduced into each of the adsorption columns 102a, 102b, and 102c for reconcentration. Each of the adsorption columns 102a, 102b, and 102c for reconcentration is repeatedly subjected to a purification treatment cycle in which a plurality of reconcentration purification steps are sequentially performed by reconcentration.

In the first pressure swing adsorption device 1, the purification treatment cycle for concentration is sequentially performed. The plurality of purification purification treatment steps of one cycle, that is, the adsorption step, the depressurization step, the depressurization pressure equalization step, the desorption step, the washing step, the pressure increasing step, and the pressure increasing step. The execution time of each purification purification treatment step may be set in advance based on the purity or recovery rate of the desired concentrated helium gas G2. The execution timings of the purification treatment steps in each of the adsorption adsorption columns 2a, 2b, and 2c are different from each other. As a result, in the first pressure swing adsorption apparatus 1, as shown in FIG. 5, the operation steps of the purification processing steps for concentration in each of the adsorption adsorption towers 2a, 2b, and 2c are sequentially different (a). ~(i), the concentrated helium G2 is continuously discharged. The arrows in Fig. 5 indicate the flow direction of the gas.

The first to seventeenth on-off valves 6a, 6b, 6c, 7a, 7b, 7c, 8a, 8b, 8c are respectively controlled by the control device 20 in order to sequentially perform the purification processing steps for concentration in the first pressure swing adsorption device 1. The 10a, 10b, 10c, 11a, 11b, 11c, 12, and 14 and the first and second flow rate control valves 13, 15 are controlled. Fig. 6 shows the correspondence between the operation steps (a) to (i) and the purification processing steps and the states of the first to seventeenth on-off valves, respectively, in the concentration adsorption columns 2a, 2b, and 2c, and the ○ mark indicates the on-off valve. In the open state, the × mark indicates the closed state of the on-off valve.

In the second pressure swing adsorption apparatus 101, a plurality of purification processing steps for concentrating one cycle in the purification processing cycle for reconcentration, that is, an adsorption step, a pressure reduction step, a pressure equalization step for desorption, and a desorption step are sequentially performed. , a cleaning step, a pressure equalization step, and a pressure step. The execution time of each purification treatment step for reconcentration may be set in advance based on the purity or recovery rate of the reconcentrated helium G7 required. The execution timings of the purification treatment steps in each of the reconcentration adsorption columns 102a, 102b, and 102c are different from each other. As a result, in the second pressure swing adsorption apparatus 101, as shown in FIG. 7, the operation steps of the reconcentration purification processing steps in the reconcentration adsorption towers 102a, 102b, and 102c are different from each other ( a) '~(i)', continuously discharges and re-concentrates helium G7. The arrows in Fig. 7 indicate the flow direction of the gas.

In order to carry out the purification treatment step for reconcentration in the second pressure swing adsorption device 101 in order The control device 20 respectively controls the 18th to 34th on-off valves 106a, 106b, 106c, 107a, 107b, 107c, 108a, 108b, 108c, 110a, 110b, 110c, 111a, 111b, 111c, 112, 114 and 3. The fourth flow rate control valves 113, 115 are controlled. 8 shows the correspondence between the operation state (a) '~(i)' and the purification processing steps performed in each of the reconcentration adsorption columns 102a, 102b, and 102c and the states of the 18th to 34th on-off valves, ○ mark Indicates the open state of the on-off valve, and the × mark indicates the closed state of the on-off valve.

In the operating state (a) of the first pressure swing adsorption device 1, the first, fourth, eighth, eleventh, fifteenth, and sixteenth on-off valves 6a, 7a, 8b, 10b, 11c, and 12 are opened. Turn off the remaining on/off valves. The adsorption step is carried out in the first concentration adsorption column 2a by opening the first and fourth on-off valves 6a and 7a. By opening the eighth, eleventh, fifteenth, and sixteenth on-off valves 8b, 10b, 11c, and 12, the cleaning step is performed in the second concentration adsorption column 2b, and the third concentration adsorption column 2c is subjected to subtraction. Pressure step.

In the operating state (a) of the second pressure swing adsorption device 101, the 18th, 21st, 25th, 28th, 32nd, and 33rd on-off valves 106a, 107a, 108b, 110b, 111c, 112 are opened. , the remaining on-off valves are closed. The adsorption step is carried out in the first reconcentration adsorption column 102a by opening the 18th and 21st on-off valves 106a and 107a. By opening the 25th, 28th, 32nd, and 33rd on-off valves 108b, 110b, 111c, and 112, the second reconcentration adsorption tower 102b performs a washing step in the third reconcentration adsorption tower 102c. Perform a decompression step.

In the operating state (b) of the first pressure swing adsorption device 1, the first, fourth, eleventh, fifteenth, and sixteenth on-off valves 6a, 7a, 10b, 11c, and 12 are opened, and the remaining on-off valves are opened. shut down. By opening the first and fourth on-off valves 6a and 7a, the adsorption step is continued in the first concentration adsorption column 2a in the operating state (a). By opening the eleventh, fifteenth, and sixteenth on-off valves 10b, 11c, and 12, the pressure equalization step is performed in the second concentration adsorption column 2b, and the desorption is performed in the third concentration adsorption column 2c. Pressure equalization step.

In the operating state (b) of the second pressure swing adsorption device 101, the 18th, 21st, and the 28. The 32nd and 33rd on-off valves 106a, 107a, 110b, 111c, 112 are opened to close the remaining on-off valves. By opening the 18th and 21st on-off valves 106a and 107a, the adsorption step is continued in the first reconcentration adsorption tower 102a in the operating state (a)'. By the opening of the 28th, 32nd, and 33rd on-off valves 110b, 111c, and 112, the pressure equalization step is performed in the second re-concentration adsorption tower 102b, and is carried out in the third re-concentration adsorption tower 102c. The depressurization step is used for desorption.

In the operating state (c) of the first pressure swing adsorption device 1, the first, fourth, ninth, fourteenth, and seventeenth on-off valves 6a, 7a, 8c, 11b, and 14 are opened, and the remaining on-off valves are opened. shut down. By opening the first, fourth, fourteenth, and seventeenth on-off valves 6a, 7a, 11b, and 14 , the adsorption step is continued in the first concentration adsorption column 2a in the operating state (b), and the second adsorption step is performed. The pressure increasing step is carried out in the adsorption column 2b for concentration. The desorption step is carried out in the third concentration adsorption column 2c by opening the ninth on-off valve 8c.

In the operating state (c) of the second pressure swing adsorption device 101, the 18th, 21st, 26th, 31st, and 34th on-off valves 106a, 107a, 108c, 111b, and 114 are opened, and the remaining switches are turned on. The valve is closed. By opening the 18th, 21st, 31st, and 34th on-off valves 106a, 107a, 111b, and 114, the adsorption step is continued in the first reconcentration adsorption tower 102a in the operating state (b)'. The second reconcentration adsorption column 102b performs a pressure increasing step. The desorption step is carried out in the third reconcentration adsorption column 102c by opening the 26th on-off valve 108c.

In the operating state (d) of the first pressure swing adsorption device 1, the second, fifth, ninth, twelfth, thirteenth, and sixteenth on-off valves 6b, 7b, 8c, 10c, 11a, and 12 are opened. Turn off the remaining on/off valves. The adsorption step is carried out in the second concentration adsorption column 2b by opening the second and fifth on-off valves 6b and 7b. By opening the ninth, twelfth, thirteenth, and sixteenth on-off valves 8c, 10c, 11a, and 12, the first concentration adsorption column 2a is subjected to a pressure reduction step, and is carried out in the third concentration adsorption column 2c. Cleaning step.

In the operating state (d) of the second pressure swing adsorption device 101, the 19th, 22nd, and the 26. The 29th, 30th, and 33rd on-off valves 106b, 107b, 108c, 110c, 111a, 112 are opened to close the remaining on-off valves. The adsorption step is carried out in the second reconcentration adsorption column 102b by opening the 19th and 22nd on-off valves 106b and 107b. By opening the 26th, 29th, 30th, and 33th on-off valves 108c, 110c, 111a, and 112, the first reconcentration adsorption tower 102a performs a depressurization step, and the third reconcentration adsorption tower 102c The cleaning step is carried out.

In the operating state (e) of the first pressure swing adsorption device 1, the second, fifth, twelfth, thirteenth, and sixteenth on-off valves 6b, 7b, 10c, 11a, and 12 are opened, and the remaining on-off valves are opened. shut down. By opening the second and fifth on-off valves 6b and 7b, the adsorption step is continued in the second concentration adsorption column 2b in the operating state (d). By opening the 12th, 13th, and 16th on-off valves 10c, 11a, and 12, the desorption desorption step 2a is performed in the first concentration adsorption column 2a, and the third concentration adsorption column 2c is used for the pressure increase. Pressure equalization step.

In the operating state (e) of the second pressure swing adsorption device 101, the 19th, 22nd, 29th, 30th, and 33rd on-off valves 106b, 107b, 110c, 111a, and 112 are opened, and the remaining switches are turned on. The valve is closed. By opening the 19th and 22nd on-off valves 106b and 107b, the adsorption step is continued in the second reconcentration adsorption tower 102b in the operating state (d)'. By opening the 29th, 30th, and 33th on-off valves 110c, 111a, and 112, the first reconcentration adsorption tower 102a performs the desorption equalization step, and the third reconcentration adsorption tower 102c performs the liter. Press the pressure equalization step.

In the operating state (f) of the first pressure swing adsorption device 1, the second, fifth, seventh, fifteenth, and seventeenth on-off valves 6b, 7b, 8a, 11c, and 14 are opened, and the remaining on-off valves are opened. shut down. By opening the second, fifth, fifteenth, and seventeenth on-off valves 6b, 7b, 11c, and 14 and continuing the adsorption step in the second concentration adsorption column 2b in the operating state (e), the third step is performed. The pressure increasing step is carried out in the adsorption column 2c for concentration. The desorption step is carried out in the first concentration adsorption column 2a by opening the seventh on-off valve 8a.

In the operating state (f) of the second pressure swing adsorption device 101, the 19th, 22nd, and the 24. The 32nd and 34th on-off valves 106b, 107b, 108a, 111c, 114 are opened to close the remaining on-off valves. By opening the 19th, 22nd, 32nd, and 34th on-off valves 106b, 107b, 111c, and 114, the adsorption step is continued in the second reconcentration adsorption column 102b in the operating state (e)'. The pressure increasing step is carried out in the third reconcentration adsorption column 102c. The desorption step is carried out in the first reconcentration adsorption column 102a by opening the 24th on-off valve 108a.

In the operating state (g) of the first pressure swing adsorption device 1, the third, sixth, seventh, tenth, fourteenth, and sixteenth on-off valves 6c, 7c, 8a, 10a, 11b, and 12 are opened. Turn off the remaining on/off valves. The adsorption step is carried out in the third concentration adsorption column 2c by opening the third and sixth on-off valves 6c and 7c. By opening the seventh, tenth, fourteenth, and sixteenth on-off valves 8a, 10a, 11b, and 12, the first concentration adsorption column 2a performs a washing step, and the second concentration adsorption column 2b performs subtraction. Pressure step.

In the operating state (g) of the second pressure swing adsorption device 101, the 20th, 23rd, 24th, 27th, 31st, and 33rd on-off valves 106c, 107c, 108a, 110a, 111b, 112 are opened. , the remaining on-off valves are closed. The adsorption step is carried out in the third reconcentration adsorption column 102c by opening the 20th and 23rd on-off valves 106c and 107c. By opening the 24th, 27th, 31st, and 33rd on-off valves 108a, 110a, 111b, and 112, the first reconcentration adsorption tower 102a performs a washing step in the second reconcentration adsorption column 102b. Perform a decompression step.

In the operating state (h) of the first pressure swing adsorption device 1, the third, sixth, tenth, fourteenth, and sixteenth on-off valves 6c, 7c, 10a, 11b, and 12 are opened, and the remaining on-off valves are opened. shut down. By opening the third and sixth on-off valves 6c and 7c, the adsorption step is continued in the third concentration adsorption column 2c in the operating state (g). By opening the 10th, 14th, and 16th on-off valves 10a, 11b, and 12, the pressure equalization step is performed in the first concentration adsorption column 2a, and the second concentration adsorption column 2b is used for desorption. Pressure equalization step.

In the operating state (h) of the second pressure swing adsorption device 101, the 20th, 23rd, and the 27. The 31st and 33rd on-off valves 106c, 107c, 110a, 111b, 112 are opened to close the remaining on-off valves. By opening the 20th and 23rd on-off valves 106c and 107c, the adsorption step is continued in the third reconcentration adsorption tower 102c in the operating state (g)'. By opening the 27th, 31st, and 33rd on-off valves 110a, 111b, and 112, the pressure equalization step is performed in the first re-concentration adsorption tower 102a, and is carried out in the second re-concentration adsorption tower 102b. The depressurization step is used for desorption.

In the operating state (i) of the first pressure swing adsorption device 1, the third, sixth, eighth, thirteenth, and seventeenth on-off valves 6c, 7c, 8b, 11a, and 14 are opened, and the remaining on-off valves are opened. shut down. By opening the third, sixth, thirteenth, and seventeenth on-off valves 6c, 7c, 11a, and 14 , the first concentration adsorption column 2a is subjected to a pressure increasing step, and the third concentration adsorption column 2c is tightly closed. Then, in the operating state (h), the adsorption step is continued. The desorption step is carried out in the second concentration adsorption column 2b by opening the eighth on-off valve 8b.

In the operating state (i) of the second pressure swing adsorption device 101, the 20th, 23rd, 25th, 30th, and 34th on-off valves 106c, 107c, 108b, 111a, and 114 are opened, and the remaining switches are turned on. The valve is closed. By opening the 20th, 23rd, 30th, and 34th on-off valves 106c, 107c, 111a, and 114, a step of boosting is performed in the first reconcentration adsorption column 102a, and the third reconcentration adsorption column 102c is opened. Immediately following the operating state (h) 'continues the adsorption step. The desorption step is carried out in the second reconcentration adsorption column 102b by opening the 25th on-off valve 108b.

When the adsorption step is performed in one of the adsorption columns 2a, 2b, and 2c for concentration, the raw material argon gas G1 is introduced into the concentration adsorption column through the raw material gas introduction flow path. The inside of the adsorption adsorption column is pressurized to the adsorption pressure by the pressure of the raw material helium G1. The adsorption pressure can be adjusted by the first pressure regulating valve 26a. Thereby, the impurity gas contained in the introduced raw material helium G1 is adsorbed by the adsorbent under pressure. Further, the gas adsorbed by the adsorbent is discharged as a concentrated helium gas G2 from the inside of the adsorption tower for concentration via the concentrated gas flow path. It is preferable to set the first transformation pressure so that the concentration of the helium gas G2 is 40 vol% to 80 vol%. The repetition interval of the adsorption step in the adsorption device 1. More preferably, the repetition interval of the adsorption step in the first pressure swing adsorption device 1 is set such that the concentration of the helium gas G2 is 50 vol% to 70 vol%. For example, the concentration of the raw material helium gas G1 detected by the first concentration sensor 24, the flow rate adjusted by the third flow rate control valve 25, the target concentration of the concentrated helium gas G2, and the repetition interval of the adsorption step are experimentally obtained in advance. Based on the relationship, the relationship between the adsorption step corresponding to the detection concentration, the adjustment flow rate, and the target concentration may be set. The repetition interval of the adsorption step in the first pressure swing adsorption device 1 can be set by specifying the time of one cycle of the purification purification treatment cycle, and the setting is changed as long as the purification treatment cycle is concentrated. The execution time of the adsorption step in one cycle and the execution time of the desorption step may be changed.

When the adsorption step is performed in one of the adsorption towers 102a, 102b, and 102c for reconcentration, the concentrated helium gas G2 is introduced into the adsorption column for reconcentration via the concentrated gas introduction flow path. The inside of the adsorption column is further pressurized to the adsorption pressure by the pressure of the concentrated helium gas G2. The adsorption pressure can be adjusted by the second pressure regulating valve 126a. Thereby, the impurity gas contained in the introduced concentrated helium gas G2 is adsorbed by the adsorbent under pressure. Further, the gas which is not adsorbed by the adsorbent is discharged as a reconcentrated helium gas G7 from the inside of the adsorption tower for reconcentration via the reconcentrated gas flow path. It is preferable to set the repetition interval of the adsorption step in the second pressure swing adsorption apparatus 101 such that the concentration of the reconcentrated helium G7 becomes the target purity, for example, 99.999 vol% or more. For example, the concentration of the reconcentrated helium gas G7 detected by the first concentration sensor 124, the flow rate of the concentrated helium gas G2 detected by the second flow rate sensor 121, and the reconcentrated helium G7 are obtained experimentally in advance. Based on the relationship between the target concentration and the repetition interval of the adsorption step, the repetition interval of the adsorption step corresponding to the detection concentration, the detection flow rate, and the target concentration may be set. The repetition interval of the adsorption step in the second pressure swing adsorption apparatus 101 can be set by specifying the time of one cycle of the purification treatment cycle for reconcentration, and the setting is changed by the purification treatment for reconcentration. The execution time of the adsorption step in one cycle of the cycle and the execution time of the desorption step are changed. can.

When the pressure reduction step is performed in one of the adsorption towers 2a, 2b, and 2c for concentration, the inside of the adsorption adsorption tower and the first communication passage, and the adsorption towers 2a, 2b, and 2c for performing the washing step are used. In another tower, the first airflow path is connected, and the pressure is gradually reduced. At this time, the internal gas G4 of the adsorption column for concentration in the depressurization step is introduced into the adsorption column for concentration in the washing step. The reduction in the internal pressure of the concentration adsorption column in the depressurization step corresponds to the amount of gas introduced into the concentration adsorption column in the washing step.

When the pressure reduction step is performed in one of the adsorption towers 102a, 102b, and 102c for reconcentration, the inside of the adsorption column for reconcentration and the second communication channel and the adsorption column 102a, 102b for reconcentration in which the cleaning step is performed In another one of 102c, the inside of the other tower and the second escape flow path are connected, and the pressure is gradually reduced. At this time, the internal gas G9 of the reconcentration adsorption column which is in the depressurization step is introduced into the reconcentration adsorption column which is in the washing step. The reduction in the internal pressure of the adsorption column for reconcentration in the depressurization step corresponds to the amount of gas introduced into the adsorption column for reconcentration in the washing step.

When the desorption step for desorption is carried out in one of the adsorption columns 2a, 2b, and 2c for concentration, the inside of the adsorption column for concentration is passed through the first communication channel and the adsorption column 2a for concentration for performing the pressure equalization step. Another one of the columns 2b, 2c is internally connected, whereby the pressure is further reduced at the end of the depressurization step. At this time, the internal gas G5 of the concentration adsorption column which is in the depressurization pressure equalization step is introduced into the concentration adsorption column which is in the pressure equalization step. Since the inside of the adsorption adsorption column for the desorption desorption step and the inside of the adsorption adsorption column for the pressure equalization step are equalized, the internal pressure of the concentration adsorption column in the pressure equalization step is raised to and The internal pressure of the adsorption column for concentration in the depressurization pressure equalization step is equal.

When a desorption depressing step is performed in one of the reconcentration adsorption columns 102a, 102b, and 102c, the reconcentration adsorption column is internally connected to the booster via the second communication channel. The reconcentration of the pressure step is further communicated with the other of the adsorption towers 102a, 102b, 102c, whereby the pressure is further reduced at the end of the depressurization step. At this time, the internal gas G10 of the reconcentration adsorption column which is in the depressurization pressure equalization step is introduced into the reconcentration adsorption column which is subjected to the pressure equalization step. The inside of the adsorption column for reconcentration in the depressurization pressure equalization step and the inside of the adsorption column for reconcentration in the step of pressure equalization for pressure increase are equalized, so that the internal pressure of the adsorption column for reconcentration in the pressure equalization step is increased. To the extent that the internal pressure of the adsorption column for reconcentration in the depressurization pressure equalization step is equal.

When the desorption step is performed in one of the adsorption columns 2a, 2b, and 2c for concentration, the inside of the adsorption adsorption column is connected to the first flow path, and the pressure is gradually decreased at the end of the desorption depressing step, and the pressure is reduced. The impurity gas is desorbed from the adsorbent by the pressure regulated by the second pressure regulating valve 26b. The desorbed impurity gas is discharged as the outgas G3 from the inside of the adsorption adsorption tower via the first escape flow path. The pressure inside the adsorption tower at the end of the desorption step is set to a pressure higher than atmospheric pressure, so that in the desorption step, the outgas G3 flows from the first escape gas flow path to the circulation flow path by its own pressure to reach the raw material gas buffer tank. 22. Or, the first release pipe 44 is released into the normal pressure space.

When the desorption step is performed in one of the reconcentration adsorption towers 102a, 102b, and 102c, the inside of the reconcentration adsorption tower communicates with the second escape flow path, and the pressure gradually decreases at the end of the desorption depressing step. The pressure is reduced to the pressure adjusted by the fourth pressure regulating valve 126b, and the impurity gas is desorbed from the adsorbent. The desorbed impurity gas is discharged as the outgas G8 from the inside of the adsorption tower for reconcentration via the second escape flow path. The pressure inside the adsorption tower for reconcentration at the end of the desorption step is set to a pressure higher than atmospheric pressure, so that in the desorption step, the escape gas G8 flows from the second escape gas flow path to the circulation flow path by its own pressure to reach the buffer for the raw material gas. The groove 22 or the second release pipe 144 is released into the normal pressure space.

When the pressure increasing step is performed in one of the adsorption towers 2a, 2b, and 2c for concentration, the inside of the concentration adsorption column is passed through the first communication channel and the adsorption column 2a, 2b, and 2c for performing the adsorption step. In addition, a certain tower is internally connected. At this time, the concentration of the adsorption step is performed. A portion of the concentrated helium gas G2 discharged from the adsorption tower is introduced into the concentration adsorption column in the step of increasing pressure, whereby the inside of the adsorption adsorption column in the step of increasing pressure is pressurized, and the pressure rises to adsorption pressure or adsorption. Near the pressure.

When the pressure increasing step is performed in one of the adsorption towers 102a, 102b, and 102c for reconcentration, the inside of the adsorption column for reconcentration passes through the second communication channel and the adsorption columns 102a and 102b for reconcentration that perform the adsorption step, Another tower in 102c is internally connected. At this time, a portion of the reconcentrated helium gas G7 discharged from the adsorption column for reconcentration which is subjected to the adsorption step is introduced into the adsorption column for reconcentration in the step of increasing pressure, whereby the adsorption column for reconcentration in the step of increasing pressure is used. The inside is pressurized and the pressure rises to the vicinity of the adsorption pressure or the adsorption pressure.

When a washing step is performed in one of the adsorption columns 2a, 2b, and 2c for concentration, the certain adsorption column is in a state after the desorption step and before the pressure increasing step. One of the concentration adsorption towers 2a, 2b, and 2c in the state after the desorption step and before the pressure-up step passes through the first communication channel and the concentration adsorption column 2a, 2b, 2c in the depressurization step. The other of the towers communicates internally and is in communication with the first escape flow path. In this way, the other one of the concentration adsorption columns 2a, 2b, and 2c in the state after the desorption step and before the pressure increase step is introduced into the concentration adsorption column 2a, 2b, and 2c in the pressure reduction step. After the internal gas G4 of the towers is discharged as the outgas G3', the inside of one of the adsorption towers 2a, 2b, 2c for concentration after the desorption step and before the pressure increasing step can be carried out. Cleaning step of cleaning. The outgas G3' discharged from one of the concentration adsorption columns 2a, 2b, 2c in the washing step contains the inside of another one of the concentration adsorption columns 2a, 2b, 2c in the depressurization step Helium contained in gas G4. The escape gas G3' reaches the raw material gas buffer tank 22 through the circulation flow path from the first escape flow path, or is released into the normal pressure space via the first release pipe 44.

When a washing step is performed in one of the columns for reconcentration adsorption columns 102a, 102b, and 102c, the certain reconcentration adsorption column is in a state after the desorption step and before the pressure increasing step. The adsorption column 102a, 102b for reconcentration in a state after the desorption step and before the pressure increasing step, The inside of one of the columns 102c communicates with the inside of another one of the adsorption towers 102a, 102b, and 102c for reconcentration in the depressurization step via the second communication passage, and communicates with the second escape flow path. Thereby, the reconcentration adsorption towers 102a, 102b, and 102c in the reconcentration step are introduced into the reconcentration adsorption towers 102a, 102b, and 102c in the depressurization step in a state in which the reconcentration adsorption towers 102a, 102b, and 102c are in a state after the desorption step and before the pressure increase step. Further, the internal gas G9 of a certain column is discharged as the outgas G8', whereby one of the columns for reconcentration adsorption towers 102a, 102b, 102c which is in the state after the desorption step and before the pressure increasing step can be carried out. The cleaning step of cleaning inside. The outgas G8' discharged from one of the reconcentration adsorption columns 102a, 102b, 102c in the washing step includes another one of the reconcentration adsorption columns 102a, 102b, 102c in the depressurization step The helium contained in the internal gas G9. The escape gas G8 ′ reaches the raw material gas buffer tank 22 through the circulation flow path from the second escape flow path, or is released into the atmospheric pressure space via the second release pipe 144 .

In the first pressure swing adsorption apparatus 1, one of the concentration adsorption towers 2a, 2b, and 2c in the concentration step from the adsorption step 2a, 2b, and 2c in the pressure reduction step is one of the adsorption adsorption towers 2a, 2b, and 2c in the cleaning step. The amount of gas introduced into each of the columns is changed in accordance with the change in the concentration of the cesium gas G1 introduced into the adsorption columns 2a, 2b, and 2c for concentration. In other words, the amount of the gas increases as the concentration of the helium gas G1 becomes higher, and decreases as the concentration of the helium decreases. Therefore, as described below, the execution time of the washing step is made constant, and the flow rate of the gas flowing through the first communication passage is adjusted by the first flow rate control valve 13. Furthermore, in the present embodiment, when the enthalpy concentration of the raw material argon gas G1 introduced into the concentration adsorption towers 2a, 2b, and 2c is equal to or lower than a predetermined set value, the gas amount is set to zero, and the washing step is not performed. .

In order to introduce the internal gas of another one of the concentration adsorption towers 2a, 2b, 2c in the depressurization step into one of the concentration adsorption columns 2a, 2b, 2c in the washing step, the first communication is performed. One of the switching valves in the flow path is open. Therefore, the amount of gas introduced into one of the concentration adsorption towers 2a, 2b, 2c in the washing step corresponds to the cleaning step. The product of the line time and the flow of gas flowing through the connected flow path. The execution time of the cleaning step in the present embodiment is set to a predetermined time set in advance, and the constant execution time is stored in the control device 20.

In addition, the amount of gas introduced into one of the concentration adsorption towers 2a, 2b, and 2c in the cleaning step can be adjusted by adjusting the gas flow rate in the first communication passage by the first flow rate control valve 13. Make changes. Therefore, the flow rate of the gas G4 introduced into one of the concentration adsorption towers 2a, 2b, and 2c in the cleaning step in the first communication flow path and the raw material helium gas introduced into the adsorption adsorption towers 2a, 2b, and 2c are concentrated. The predetermined correspondence between the concentrations of G1 is stored in the control device 20.

The control device 20 controls the on-off valve in order to execute the cleaning step corresponding to the stored execution time, and changes the flow rate of the adjustment gas by the first flow rate control valve 13 based on the stored correspondence relationship, so that the first concentration sensor can be used. In the washing step, the other adsorption towers 2a, 2b, and 2c for concentration from the adsorption adsorption towers 2a, 2b, and 2c in the depressurization step in the washing step are changed in accordance with the change in the concentration of the helium gas G1 detected by the raw material 24; The amount of gas introduced by one of the towers. Further, the preset set value of the erbium concentration is stored in the control device 20, and when the enthalpy concentration detected by the first concentration sensor 24 is equal to or lower than the stored set value, the first flow rate control valve 13 is used. The gas flow is adjusted to zero and no cleaning steps are performed.

In this case, the amount of gas introduced into one of the concentration adsorption columns 2a, 2b, 2c in the washing step corresponds to another one of the concentration adsorption columns 2a, 2b, 2c in the depressurization step. The pressure difference δP at the internal pressure at the beginning of the washing step and the internal pressure at the end of the washing step. Therefore, by introducing the pressure difference δP according to the change in the enthalpy concentration detected by the first concentration sensor 24, the gas introduced into one of the concentration adsorption columns 2a, 2b, and 2c in the cleaning step is introduced. The quantity is the best. For example, when the enthalpy concentration is 5 vol% or less, the gas flow rate is adjusted to zero by the first flow rate control valve 13 without performing a washing step so that the pressure difference δP becomes zero. Further, when detecting that the cerium concentration exceeds 5 vol%, the gas flowing through the communication path regulated by the first flow rate control valve 13 is experimentally tested in advance. The relationship between the flow rate and the concentration of the raw material helium G1 is specified so as to increase the pressure difference δP as the concentration of the detected helium increases. For example, when the pressure difference δP is 50 kPa when the ruthenium concentration is 10 vol%, the pressure difference δP is 80 kPa when the ruthenium concentration is 15 vol%, and the first communication channel is circulated when the pressure difference δP is 100 kPa when the ruthenium concentration is 25 vol%. The relationship between the gas flow rate and the enthalpy concentration of the raw material helium G1. The gas flow rate adjustment by the first flow rate control valve 13 may be performed once for each cycle of the purification processing step for concentration. However, if the concentration fluctuation of the raw material gas G1 is small, it may be for each plural number. One cycle is performed once.

In the washing step, the other one of the concentration adsorption columns 2a, 2b, 2c in the depressurization step is added to the concentration adsorption column 2a, 2b, 2c in accordance with the change in the concentration of the ruthenium in the raw material krypton G1. In the case of the amount of gas introduced into a certain column, the pressure at the time point when the inside of the adsorption column for the pressure equalization step is equalized and the inside of the concentration column for concentration in the step of concentration for desorption is equalized. Therefore, it is preferred that when the pressure inside the concentration adsorption column in the step of increasing pressure is raised to the adsorption pressure, the concentration adsorption column from the adsorption column in the adsorption step is introduced into the concentration adsorption column in the concentration step. The amount of gas G2 changes. In this case, in the step of boosting, the time of the step of increasing the pressure is set to a predetermined constant value, and the flow rate of the gas flowing through the first communication passage is adjusted by the second flow rate control valve 15. Therefore, the relationship between the flow rate of the gas flowing through the first communication passage adjusted by the second flow rate control valve 15 and the concentration of the helium gas G1 of the raw material may be defined in advance.

The other adsorption towers 2a, 2b, 2c for concentration from the adsorption adsorption towers 2a, 2b, and 2c in the purification step in the purification step are changed in accordance with the change in the concentration of rhodium in the raw material helium G1. The variation of the amount of gas introduced by one of the towers can also adjust the execution time of the cleaning step. In this case, it is not necessary to control the flow rate by the first flow rate control valve 13.

That is, the gas introduced into one of the concentration adsorption towers 2a, 2b, 2c in the washing step The volume corresponds to the product of the execution time of the washing step and the gas flow rate flowing through the communication passage, and therefore the amount of gas can be changed by adjusting the execution time of the washing step.

Therefore, the preset correspondence relationship between the execution time of the washing step and the enthalpy concentration in the raw material krypton gas G1 is stored in the control device 20. The execution time of the cleaning step, that is, the control time of the on-off valve for performing the cleaning step, is changed based on the correspondence relationship stored by the control device 20 to be based on the concentration of the germanium G1 of the raw material G1 detected by the concentration sensor 24. The amount of gas introduced into one of the concentration adsorption towers 2a, 2b, and 2c from the adsorption towers 2a, 2b, and 2c in the depressurization step in the washing step is changed. Further, when it is desired to change the execution time of the adsorption step without changing the execution time of the cleaning step, the execution time of the pressure increasing step and the desorption step is changed. For example, when it is desired to change the execution time of the cleaning step in the operation state (a) without changing the execution time of the adsorption step in the first adsorption tower 2a in the operation states (a) to (c), It is sufficient to change the execution time of the step of boosting and the step of desorbing in the operating state (c). Alternatively, the control may be performed in the same manner as in the above embodiment.

In the second pressure swing adsorption device 101, one of the reconcentration adsorption columns 102a, 102b, and 102c in the depressurization step is in the reconcentration adsorption column 102a, 102b, 102c in the cleaning step. The amount of gas introduced by a certain tower is set to a predetermined amount. In order to achieve the constant gas amount, the execution time of the washing step is made constant, and the third flow rate control valve 113 adjusts the flow rate of the gas flowing through the communication passage. Further, in accordance with the amount of the gas, the time of the step of increasing the pressure is set to a predetermined value, and the flow rate of the gas flowing through the second communication passage is adjusted by the fourth flow rate control valve 115.

According to the above-described embodiment and the modification, the helium-enriched concentrated helium gas G2 can be continuously discharged by purifying the raw material helium G1 by using the first pressure swing adsorption device 1, and the second pressure swing adsorption device 101 is used again. The concentrated helium G2 is purified to continuously discharge the re-concentrated helium G7 from which helium is further enriched. That is, the reductive helium G7 which is a high-purity helium gas can be continuously obtained by purifying the raw material helium G1 in two stages by a pressure swing adsorption method. Take this Compared with the case where the raw material helium gas is purified in the first stage, the raw material gas flow rate and the concentration fluctuation can be flexibly handled without purifying the large-scale adsorption system, and the target purity helium can be efficiently obtained. . Moreover, since the helium contained in the outgassing G3, G3', G8, and G8' can be reused, the recovery rate can be improved, regardless of whether the concentration of the raw material helium G1 exceeds 20 vol% or the raw material is helium. When G1 is diluted by the cyclic outgassing and the cerium concentration is less than 20 vol%, the target purity helium can be efficiently obtained by the method of the present invention. Further, in the first pressure swing type adsorption device 1, the concentration of the raw material helium gas G1 introduced into each of the concentration adsorption towers 2a, 2b, and 2c is lowered, and the adsorption column 2a for concentration is reduced. The amount of gas introduced in the cleaning step in one of the columns 2b and 2c prevents an unnecessary drop in the helium recovery rate. Thereby, the lean helium gas can be industrially purified to high purity in a small-scale apparatus.

[Examples] [Example 1]

The raw material helium G1 was purified according to the above embodiment using the purification system α.

Regarding the raw material krypton G1, the cerium concentration was 15.3 vol%, and the concentration of the air as the impurity gas was 84.7 vol%.

The supply flow rate to the raw material helium gas G1 of the first pressure swing type adsorption device 1 was set to 150 NL/h.

Each of the adsorption adsorption towers 2a, 2b, and 2c is made of stainless steel, and has a cylindrical shape having an inner diameter of 37 mm and an internal height of 1000 mm, and has a capacity of about 1 L. The concentration adsorption columns 2a, 2b, and 2c were respectively filled with about 0.7 L of zeolite 5A and about 0.3 L of activated carbon as an adsorbent.

Each of the adsorption-concentrating adsorption towers 102a, 102b, and 102c is made of stainless steel, and has a cylindrical shape having an inner diameter of 23 mm and an inner height of 500 mm, and has a capacity of about 0.2 liter. The reconcentration adsorption columns 102a, 102b, and 102c were respectively filled with about 0.14 L of activated carbon and about 0.06 L of 5A zeolite as an adsorbent.

As a purification treatment step in the first pressure swing adsorption device 1, in the adsorption tower for concentration Each of 2a, 2b, and 2c sequentially performs an adsorption step of 365 seconds, a depressurization step of 40 seconds, a desorption depressing step of 20 seconds, a desorption step of 305 seconds, a washing step of 40 seconds, a step-up step of pressure increasing for 20 seconds, and a step-up. Step 305 seconds. The time from one start of the operation state (a) to the end of the operation state (i) is 1095 seconds.

The maximum internal pressure of the adsorption columns 2a, 2b, and 2c in the adsorption step was set to 0.85 MPa (gauge pressure). The pressure difference δP of the internal pressure at the start of the washing step and the internal pressure at the end of the washing step in the adsorption columns 2a, 2b, and 2c in the depressurization step was set to 80 kPa. The internal pressure of the adsorption adsorption towers 2a, 2b, and 2c at the end of the desorption step and at the end of the washing step was set to 5 kPa (gauge pressure).

The flow rate of the concentrated helium gas G2 was 33.9 NL/h, and the ruthenium concentration was 61 vol% (measured by GC-TCD manufactured by Shimadzu Corporation), and the concentrated helium gas G2 was introduced into the second pressure swing adsorption apparatus 101.

As a purification treatment step in the second pressure swing adsorption apparatus 101, the adsorption step 283 seconds, the pressure reduction step 60 seconds, and the desorption decompression step 20 seconds are sequentially performed in each of the reconcentration adsorption columns 102a, 102b, and 102c. The desorption step was 203 seconds, the washing step was 60 seconds, the boosting pressure equalization step was 20 seconds, and the pressure increasing step was 203 seconds. The time from one cycle of the operation state (a) to the end of the operation state (i) is 849 seconds.

The maximum internal pressure of the reconcentration adsorption columns 102a, 102b, and 102c in the adsorption step was set to 0.8 MPa (gauge pressure). The pressure difference δP of the internal pressure at the start of the washing step at the start of the washing step and the pressure at the end of the washing step at the end of the washing step in the depressurization step is set to 150 kPa. The internal pressure of the adsorption adsorption towers 2a, 2b, and 2c at the end of the desorption step and at the end of the washing step was set to 5 kPa (gauge pressure).

The outgassing G3, G3', G8, G8' are not reused and released into the atmospheric space.

The flow rate of the re-concentrated helium G7 was 15.1 NL/h, and the impurity concentration was 8.3 vol ppm (measured by GC-TCD manufactured by Shimadzu Corporation). The helium recovery rate for the entire step was 65.7%.

[Embodiment 2]

In the second pressure swing adsorption apparatus 101, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, and the flow rate of the concentrated helium gas G7 was 12.8 NL/h, and the impurity concentration was 0.7 vol ppm. Other than this, it is the same as that of the first embodiment. The helium recovery rate for the entire step in this case was 55.8%.

[Example 3]

The concentration fluctuation of the raw material helium G1 from the steady state of Example 1 was assumed, and the ruthenium concentration of the raw material helium G1 was changed to 5.4 vol%, and the air concentration was changed to 95.6 vol%. The cleaning step was not implemented. In the first pressure swing adsorption apparatus 1, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, the flow rate of the concentrated helium gas G2 was 11.3 NL/h, and the ruthenium concentration was 60 vol%. Further, in the second pressure swing adsorption apparatus 101, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, and the flow rate of the concentrated helium gas G7 was 4.4 NL/h, and the impurity concentration was 8.5 vol ppm. Other than this, it is the same as that of the first embodiment. The helium recovery rate for the entire step in this case was 54.6%.

[Example 4]

In the first pressure swing adsorption apparatus 1, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, the flow rate of the concentrated helium gas G2 was set to 46.2 NL/h, and the ruthenium concentration was set to 45 vol%. Further, in the second pressure swing adsorption apparatus 101, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, and the flow rate of the concentrated helium gas G7 was 14.3 NL/h, and the impurity concentration was 8.4 vol ppm. Other than this, it is the same as that of the first embodiment. The helium recovery rate for the entire step in this case was 62.4%.

[Example 5]

In the first pressure swing adsorption apparatus 1, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, the flow rate of the concentrated helium gas G2 was set to 26.6 NL/h, and the ruthenium concentration was set to 75 vol%. Further, in the second pressure swing type adsorption device 101, the repetition interval of the adsorption step is changed by adjusting the adsorption step time, and the flow rate of the concentrated helium gas G7 is set to 14.6 NL/h, and the impurity is The concentration was set to 8.3 vol ppm. Other than this, it is the same as that of the first embodiment. The helium recovery rate for the entire step in this case was 63.5%.

[Embodiment 6]

All of the outgassing G8 and G8' discharged from the second pressure swing adsorption device 101 are mixed into the raw material gas G1 via the circulation flow path. In the first pressure swing adsorption apparatus 1, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, the flow rate of the concentrated helium gas G2 was 45.1 NL/h, and the ruthenium concentration was 60 vol%. Further, in the second pressure swing adsorption apparatus 101, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, and the flow rate of the concentrated helium gas G7 was set to 20.2 NL/h, and the impurity concentration was set to 8.5 vol ppm. Other than this, it is the same as that of the first embodiment. The helium recovery rate for the entire step in this case was 88.1%.

[Embodiment 7]

The total amount of the outgass G3 and G3' discharged from the first pressure swing adsorption device 1 is 50% mixed into the raw material gas G1 via the circulation flow path. In the first pressure swing adsorption apparatus 1, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, the flow rate of the concentrated helium gas G2 was 47.9 NL/h, and the ruthenium concentration was 61 vol%. Further, in the second pressure swing adsorption apparatus 101, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, the flow rate of the concentrated helium gas G7 was 20.8 NL/h, and the impurity concentration was 8.1 vol ppm. Other than this, it is the same as that of the first embodiment. The helium recovery rate for the entire step in this case was 90.5%.

[Embodiment 8]

The concentration fluctuation of the raw material helium G1 from the steady state of Example 1 was assumed, and the enthalpy concentration of the raw material helium G1 was changed to 5.4 vol%, and the air concentration was changed to 95.6 vol%. The washing step was carried out in the same manner as in Example 1. In the first pressure swing adsorption apparatus 1, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, the flow rate of the concentrated helium gas G2 was 10.3 NL/h, and the ruthenium concentration was 61%. Further, in the second pressure swing adsorption apparatus 101, the adsorption step time was adjusted to change the repetition interval of the adsorption step, and the flow rate of the concentrated helium gas G7 was set to 3.8 NL/h, and the impurity concentration was set to 8.0 vol ppm. Other than this, it is the same as that of the first embodiment. The The helium recovery rate for the entire step was 47.1%.

[Embodiment 9]

In the first pressure swing adsorption apparatus 1, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, the flow rate of the concentrated helium gas G2 was set to 68.9 NL/h, and the ruthenium concentration was set to 30 vol%. Further, in the second pressure swing adsorption apparatus 101, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, and the flow rate of the concentrated helium gas G7 was 13.2 NL/h, and the impurity concentration was 8.1 vol ppm. Other than this, it is the same as that of the first embodiment. The helium recovery rate for the entire step in this case was 57.6%.

[Embodiment 10]

In the first pressure swing adsorption apparatus 1, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, the flow rate of the concentrated helium gas G2 was 19.6 NL/h, and the ruthenium concentration was 90 vol%. Further, in the second pressure swing adsorption apparatus 101, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, and the flow rate of the concentrated helium gas G7 was 13.3 NL/h, and the impurity concentration was 8.1 vol ppm. Other than this, it is the same as that of the first embodiment. The helium recovery rate for the entire step in this case was 57.8%.

[Comparative Example 1]

The raw material helium gas G1 is purified only by the first pressure swing type adsorption device 1 without using the second pressure swing type adsorption device 101. In the first pressure swing adsorption apparatus 1, the repetition interval of the adsorption step was changed by adjusting the adsorption step time, the flow rate of the concentrated helium gas G2 was 8.6 NL/h, and the impurity concentration was 8.9 vol ppm. Other conditions in the case of performing purification using the first pressure swing adsorption device 1 were the same as in the first embodiment. The helium recovery rate for the entire step in this case was 37.3%.

[Comparative Example 2]

The raw material helium gas G1 is purified only by the first pressure swing type adsorption device 1 without using the second pressure swing type adsorption device 101. In the first pressure swing adsorption device 1, the repetition interval of the adsorption step is changed by adjusting the adsorption step time, and the flow rate of the concentrated helium gas G2 is set to 2.9. NL/h, the impurity concentration was set to 2.2 vol ppm. Other conditions in the case of performing purification using the first pressure swing adsorption device 1 were the same as in the first embodiment. The helium recovery rate for the entire step in this case was 12.6%.

By comparing the above examples with the comparative examples, it was confirmed that the obtained high-purity helium gas flow rate and recovery rate were large, and the thin raw material helium gas was efficiently purified to high purity. By comparing Example 3 with Example 8, it was confirmed that the amount of gas introduced into the adsorption tower for concentration in the washing step was changed by the concentration of rhodium in the raw material, and the recovery rate was improved. From Examples 6 and 7, it was confirmed that the recovery rate was improved by recycling the outgas.

The present invention is not limited to the above embodiments, examples, and modifications. For example, as the purification treatment step in each adsorption device, the depressurization pressure equalization step and the pressure increase pressure equalization step are not essential, and the desorption step may be performed after the depressurization step, and the pressure increasing step may be performed after the washing step. Further, the number of adsorption columns in each adsorption device is not limited to three columns, and may be plural. Further, by further concentrating the reconcentrated helium gas by setting the number of adsorption devices to three or more, the raw material helium gas can be purified in three or more stages, whereby the concentration of the raw material helium gas is less than 1 vol%. High purity helium can be obtained efficiently.

1‧‧‧1st variable pressure adsorption device

2a, 2b, 2c‧‧‧ Concentration adsorption tower

21‧‧‧1st flow sensor

22‧‧‧Material gas buffer tank

22a‧‧‧Sensor for measuring the storage volume of the buffer tank 22

23‧‧‧Compressor

24‧‧‧1st concentration sensor

25‧‧‧3rd flow control valve

26a‧‧‧1st pressure regulating valve

26b‧‧‧2nd pressure regulating valve

41‧‧‧1st circulating pipe (circulating flow path)

42‧‧‧1st switching valve

43‧‧‧2nd cycle piping (circulating flow path)

44‧‧‧1st release piping

101‧‧‧2nd variable pressure adsorption device

102a, 102b, 102c‧‧‧reconcentration adsorption tower

121‧‧‧2nd flow sensor

122‧‧‧Buffer tank for concentrated gas

124‧‧‧2nd concentration sensor

126a‧‧‧3rd pressure regulating valve

126b‧‧‧4th pressure regulating valve

141‧‧‧3rd cycle piping (circulating flow path)

142‧‧‧2nd switching valve

143‧‧‧4th cycle piping (circulating flow path)

144‧‧‧Second release piping

G1‧‧‧ raw material helium

G2‧‧‧ Concentrated helium

G3, G3'‧‧‧ 逸气

G7‧‧‧ reconcentrated helium

G8, G8'‧‧‧ 逸气

Α‧‧‧氦气的净化系统

Claims (16)

A method for purifying helium, which uses a first pressure swing adsorption device comprising a plurality of adsorption adsorption columns and a second pressure swing adsorption device comprising a plurality of adsorption columns for reconcentration to produce helium gas containing an impurity gas. a method of purifying, wherein each of the adsorption column for concentration and the adsorption column for each of the reconcentration stores an adsorbent that preferentially adsorbs the impurity gas in the helium gas, and sequentially introduces the raw material helium gas into each of the adsorption columns for concentration. Each of the adsorption adsorption towers sequentially performs an adsorption step, a depressurization step, a desorption step, and a pressure increasing step, wherein the adsorption step is performed by adsorbing the impurity gas contained in the introduced raw material helium gas under pressure to the adsorbent. The concentrated helium gas which is not adsorbed by the adsorbent is discharged, and the depressurizing step is to reduce the internal pressure. The desorbing step causes the impurity gas to be desorbed from the adsorbent to be discharged as an outgas, and the step of increasing the pressure is to increase the internal pressure. a plurality of the above-mentioned reconcentration adsorptions for connecting the concentrated helium gas from the first pressure swing adsorption device to the second pressure swing adsorption device Each of the towers is introduced into the flow path of the concentrated helium gas, and the concentrated helium gas is sequentially introduced into the adsorption towers for reconcentration, and the adsorption step, the pressure reduction step, and the desorption step are sequentially performed in each of the adsorption towers for reconcentration. a step of pressurizing the impurity gas contained in the introduced concentrated helium gas adsorbed to the adsorbent under pressure and discharging the re-concentrated helium gas not adsorbed by the adsorbent, the depressurization step The internal pressure is reduced, and the desorbing step causes the impurity gas to be desorbed from the adsorbent to be discharged as an outgas, and the step of boosting is to raise the internal pressure. The method for purifying xenon according to claim 1, wherein the concentration of the helium gas of the raw material introduced into each of the adsorption towers for concentration is 20 vol% or less. The method for purifying xenon according to claim 1, wherein the repetition interval of the adsorption step in the first pressure swing adsorption device is set such that the concentration of the concentrated helium gas is 40 vol% to 80 vol%. The method for purifying xenon according to claim 1, wherein the concentration of the ruthenium of the raw material introduced into each of the adsorption towers for concentration is 20 vol% or less, and the enthalpy concentration of the concentrated helium gas is 40 vol% to 80 vol. In the % mode, the repetition interval of the adsorption step in the first pressure swing adsorption device is set. The purification method of the helium gas according to claim 1, wherein the second pressure-change type is set such that the concentration of the re-concentrated helium gas discharged from the adsorption step in the adsorption step is 99.999 vol% or more. The repetition interval of the above adsorption step in the adsorption device. The method for purifying xenon according to claim 1, wherein the concentration of the helium gas of the raw material introduced into each of the adsorption towers for concentration is 20 vol% or less, and the adsorption column for each reconcentration is used in the adsorption step. The repetition interval of the adsorption step in the second pressure swing adsorption device is set such that the concentration of the reconcentrated helium gas discharged is 99.999 vol% or more. The method for purifying xenon according to claim 1, wherein the concentration of the ruthenium of the raw material introduced into each of the adsorption towers for concentration is 20 vol% or less, and the enthalpy concentration of the concentrated helium gas is 40 vol% to 80 vol. In the method of %, the repetition interval of the adsorption step in the first pressure swing adsorption device is set, and the concentration of the reconcentrated helium gas discharged from the adsorption column for each reconcentration in the adsorption step is 99.999 vol%. In the above manner, the repetition interval of the adsorption step in the second pressure swing adsorption device is set. The method for purifying helium according to any one of claims 1 to 7, wherein the introduction into the above-mentioned decompression step is performed by the inside of the above-mentioned adsorption column which is in the state after the desorption step and before the step of the step of increasing One of the above-mentioned adsorption towers for concentration After the internal gas is discharged as a gas, a washing step of washing the inside of the concentration adsorption column after the desorption step and before the pressure increasing step is performed, and the step is introduced to the concentration adsorption column. The amount of gas introduced into the above-mentioned adsorption column by the other adsorption column in the above-described decompression step in the above-described washing step is changed by changing the concentration of helium in the raw material. The method for purifying xenon according to claim 8, wherein the washing step is not carried out when the concentration of the helium gas of the raw material introduced into the adsorption column for concentration is equal to or lower than a predetermined setting value. The method for purifying helium according to any one of claims 1 to 7, wherein the raw material helium gas is mixed into at least one of the first pressure swing adsorption device and the second pressure swing adsorption device. The above air. The method for purifying helium according to claim 8, wherein the raw material helium gas is mixed with the outgas discharged from at least one of the first pressure swing adsorption device and the second pressure swing adsorption device. The method for purifying helium according to claim 9, wherein the raw material helium gas is mixed with the outgas discharged from at least one of the first pressure swing adsorption device and the second pressure swing adsorption device. A purification system for helium gas, comprising: a first pressure swing adsorption device comprising a plurality of adsorption adsorption columns; and a second pressure swing adsorption device comprising a plurality of adsorption columns for reconcentration, and each of the adsorption adsorption towers And each of the reconcentration adsorption towers contains an adsorbent that preferentially adsorbs the impurity gas, and the first pressure swing adsorption apparatus includes a raw material gas introduction flow for introducing the raw material helium gas into each of the concentration adsorption towers. a concentrated gas flow path for discharging concentrated helium gas from each of the adsorption towers for concentration, for use in adsorption for each concentration a first communication flow path through which the tower discharges the outgas, a first communication flow path for allowing one of the adsorption adsorption towers to communicate with another column, and the introduction of the concentration adsorption column and the raw material gas a raw material gas introduction switch valve that is separately opened and closed between the flow paths, and a concentrated gas path on-off valve that individually switches between the respective adsorption adsorption towers and the concentrated gas flow path, and the adsorption towers for each concentration a first air passage opening and closing valve that is individually opened and closed between the first air flow paths, and a first communication path switching valve that individually switches between the respective adsorption adsorption towers and the first communication flow path, The second pressure swing type adsorption device includes a concentrated gas introduction flow path for connecting the concentrated gas flow path to the respective reconcentration adsorption columns and introducing the concentrated helium gas, and the adsorption column for each reconcentration a reconcentrated gas flow path for discharging the re-concentrated helium gas, a second escape gas flow path for discharging the outgas from each of the reconcentration adsorption towers, and one of the towers for the reconcentration adsorption tower and another tower a second communication channel that is interconnected, a concentrated gas introduction path switch valve that individually switches between the respective reconcentration adsorption columns and the concentrated gas introduction flow path, and the adsorption column and the re-concentration adsorption column a re-concentrated gas path switching valve that is separately opened and closed between the concentrated gas flow paths, a second escapeable gas switching valve that individually switches between the respective reconcentrating adsorption columns and the second escape flow path, and a pair a second communication path switching valve that is individually opened and closed between each of the reconcentration adsorption towers and the second communication flow path, wherein the switching valves are respectively formed as an automatic valve including a switching actuator and connected to the control device The switching operation can be individually performed, and the respective switching valves are controlled by the control device to sequentially perform an adsorption step, a pressure reduction step, a desorption step, and a pressure increasing step in each of the concentration adsorption columns, and use the respective reconcentration The adsorption step, the depressurization step, the desorption step and the pressure increasing step are sequentially performed in the adsorption tower, and the adsorption step in each of the adsorption towers for concentration is The impurity gas contained in the lead gas introduced into the raw material is adsorbed to the adsorbent under pressure and the concentrated helium gas not adsorbed by the adsorbent is discharged, and the depressurization step reduces the internal pressure, and the desorption step is to make the impurity gas The adsorbent is desorbed and discharged as an outgas, and the step of increasing pressure is to raise the internal pressure; and the adsorption step in each of the reconcentration adsorption towers is such that the impurity gas contained in the introduced concentrated helium gas is adsorbed under pressure The adsorbent discharges the reconcentrated helium gas which is not adsorbed by the adsorbent, and the depressurizing step reduces the internal pressure. The desorbing step causes the impurity gas to be desorbed from the adsorbent to be discharged as an outgas, and the step of boosting increases the internal pressure. . The purification system of the helium gas of claim 13, wherein the respective switching valves are controlled by the control device to be introduced into the inside of the certain concentration adsorption column after the desorption step and before the pressure increasing step After the internal gas of the other adsorption adsorption column of the above-mentioned decompression step is discharged as an outgas, the inside of the above-mentioned adsorption column which is in the state after the desorption step and before the pressure increase step is performed. a cleaning step including a flow rate control valve for regulating a flow rate of a gas flowing through the first communication passage, wherein the flow rate control valve is an automatic valve including a flow rate adjusting actuator and is connected to the control device And performing a flow adjustment operation, and including a sensor for detecting a radon concentration of the raw material helium gas and connected to the control device, and storing a predetermined execution time of the cleaning step in the control device, and cleaning the cleaning In the step, the other adsorption column for the concentration in the above-mentioned decompression step is adsorbed to the above certain concentration. A preset correspondence relationship between the flow rate of the gas introduced into the memory of the communication to the first flow path, the helium concentration in the raw material with the introduction of helium gas to the adsorption column was concentrated to the control means, The control device controls the on-off valve in order to execute the cleaning step corresponding to the stored execution time, and changes the flow rate of the adjustment gas by the flow control valve based on the correspondence relationship, based on the detection by the sensor. The amount of gas introduced into the above-described adsorption column in the above-described washing step is changed in the above-described washing step. The purification system of the helium gas of claim 13, comprising: a sensor for detecting a radon concentration of the raw material helium introduced into the concentration adsorption tower and connected to the control device, and performing the cleaning step Presetting the correspondence relationship with the radon concentration in the raw material helium gas is stored in the control device, and the control device changes the execution time of the cleaning step based on the correspondence relationship to be detected by the sensor The amount of gas introduced into the above-described adsorption column in the above-described washing step is changed in accordance with the change in the concentration of the mash. The helium purification system according to any one of claims 13 to 15, comprising a method for connecting at least one of the first gas flow path and the second gas flow path to the raw material gas introduction flow path Circulating flow path.