CN102153057A - Method and device for purifying argon gas - Google Patents

Abstract

The invention provides a method and device for improving purity of recovered argon gas containing impurities through purification treatment, so as to prevent decrease of the functions of purification catalysts, reduce purification load and facilitate recouping of the management construction costs. Purification of argon gas containing impurities including at least oxygen, hydrogen, carbon monoxide and nitrogen includes the steps of setting the oxygen molar concentration in the argon gas to be lower than half of the total molar concentration of the carbon monoxide and hydrogen; subjecting the oxygen, the carbon monoxide and hydrogen in the argon gas to reaction by using a catalyst that allows the reaction between carbon monoxide and hydrogen carrying out before that between hydrogen and oxygen, thereby obtaining carbon dioxide and water through remaining hydrogen; and then reducing the impurity content in the argon gas through adsorbent.

Description

The purification process of argon gas and purification devices

Technical field

The present invention relates to carry out the method and apparatus of purifying for the argon gas that contains aerobic, hydrogen, carbon monoxide and nitrogen as impurity at least.

Background technology

For example silicon single crystal lifting furnace, ceramic post sintering stove, steel-making are with in the equipment such as vacuum deaerator plant, silicon for solar cell plasma body fusing device, polysilicon foundry furnace, and argon gas is used as furnace atmosphere gas etc.Descend because of sneaking into purity such as hydrogen, carbon monoxide, air from the argon gas that such equipment reclaims in order to utilize again.So the purity of the argon gas that reclaims in order to improve adopts to make the impurity absorption of sneaking in the method for sorbent material.In addition, in order to carry out such impurity absorption efficiently, proposed pre-treatment as adsorption treatment and made the oxygen in the impurity and the technical scheme (with reference to patent documentation 1,2) of combustiblecomponents reaction.

In the method that is disclosed in the patent documentation 1, the amount of the oxygen in the argon gas is adjusted to than making hydrogen, the required stoichiometric quantity of combustiblecomponents perfect combustions such as carbon monoxide is few slightly, to make the reaction of hydrogen and oxygen have precedence over the palladium of reaction of carbon monoxide and oxygen or gold again as catalyzer, make oxygen and carbon monoxide in the argon gas, reactions such as hydrogen, thereby under the state of residual carbon monoxide, generate carbonic acid gas and water, make carbonic acid gas contained in the argon gas and water be adsorbed in sorbent material at normal temperatures again, make carbon monoxide contained in the argon gas and nitrogen under-10 ℃～-50 ℃ temperature, be adsorbed in sorbent material then.

In the method that is disclosed in the patent documentation 2, make the amount of the oxygen in the argon gas reach the amount that is enough to make combustiblecomponents perfect combustions such as hydrogen, carbon monoxide, the catalyzer that re-uses the palladium class makes reactions such as oxygen in the argon gas and carbon monoxide, hydrogen, thereby under the state of residual oxygen, generate carbonic acid gas and water, make carbonic acid gas contained in the argon gas and water be adsorbed in sorbent material at normal temperatures again, make oxygen contained in the argon gas and nitrogen under the temperature about-170 ℃, be adsorbed in sorbent material then.

Patent documentation 1: No. 3496079 communique of Japanese Patent Laid

Patent documentation 2: No. 3737900 communique of Japanese Patent Laid

Summary of the invention

In the method for patent documentation 1 record, the amount of the oxygen in the argon gas is lacked than required stoichiometric quantitys of perfect combustion such as making hydrogen, carbon monoxide, made the reaction of hydrogen and oxygen have precedence over the catalyst for reaction of carbon monoxide and oxygen.Therefore, when realizing perfect combustion of hydrogen by this reaction, the carbon monoxide of remained unreacted on one's own initiative.But the hydrogen of trace is difficult to remove by adsorption treatment, but allows remaining hydrogen in the purposes of argon gas under many situations.On the other hand, carbon monoxide not only becomes paralyser, and more is difficult to absorption than carbonic acid gas when adopting general sorbent material such as zeolite.That is, in the stage before adsorption treatment, even realize the perfect combustion of the hydrogen that residual also problem is little, the simultaneously but residual on one's own initiative hypofunction and the difficult carbon monoxide of absorption that may make catalyzer, this processing is unreasonable.

In the method for patent documentation 2 record, make the amount of the oxygen in the argon gas reach the amount that is enough to make perfect combustions such as hydrogen, carbon monoxide, use the catalyzer of palladium class to make reactions such as oxygen in the argon gas and carbon monoxide, hydrogen.Therefore, when realizing perfect combustion of hydrogen, carbon monoxide etc. by this reaction, remaining on one's own initiative in most cases can be because of the residual oxygen that has problems in the purposes of argon gas.But, as mentioned above, allow remaining hydrogen in the purposes of argon gas under many situations.On the other hand, for adsorb oxygen, the temperature in the time of must making absorption drops to about-170 ℃.That is, in the stage before adsorption treatment, even realize the perfect combustion of the hydrogen that residual also problem is little, the cooling energy consumption of but on one's own initiative residual meeting simultaneously during because of adsorption treatment increases the oxygen that strengthens purification load, and this processing is unreasonable.

If adopt aforesaid irrational prior art, then there are the overhead charges of recovery system of argon gas and the problem that construction cost increases.The object of the present invention is to provide the purification process and the purification devices of the argon gas that can solve such prior art problems.

Method of the present invention is to containing aerobic, hydrogen, carbon monoxide and nitrogen carry out purifying as the argon gas of impurity method at least, it is characterized in that, with the oxygen volumetric molar concentration in the described argon gas be set at be lower than carbon monoxide volumetric molar concentration and hydrogen volumetric molar concentration and 1/2, re-use the catalyst for reaction that the reaction that makes carbon monoxide and oxygen has precedence over hydrogen and oxygen, make oxygen and carbon monoxide and H-H reaction in the described argon gas, thereby under the state of remaining hydrogen, generate carbonic acid gas and water, reduce foreign matter content in the described argon gas with sorbent material then.

According to the present invention, with the oxygen volumetric molar concentration in the argon gas be set at be lower than carbon monoxide volumetric molar concentration and hydrogen volumetric molar concentration and 1/2, the catalyst for reaction that makes the reaction of carbon monoxide and oxygen have precedence over hydrogen and oxygen makes oxygen and carbon monoxide and the H-H reaction in the argon gas.By this,, realize that absorption makes the perfect combustion of the oxygen that the cooling energy consumption increases when removing, and do not need the residual on one's own initiative carbon monoxide that may make the low and absorption of catalyst function than carbonic acid gas difficulty even can the little hydrogen of residual on one's own initiative also problem.By this, can become in the management that makes purifier apparatus and be easy to realize simultaneously the miniaturization of equipment, can cut down the consumption of energy.

In the method for the present invention, make the reaction of carbon monoxide and oxygen have precedence over the reaction of hydrogen and oxygen, so better be that described catalyzer platiniferous is as main component.In the method for the present invention, carry out the absorption of carbonic acid gas, water and nitrogen efficiently, therefore better be when using sorbent material to reduce foreign matter content in the described argon gas, at least after adsorbing carbonic acid gas and water in its impurity by the pressure swing adsorption process under the normal temperature, adsorb nitrogen in its impurity at least by the alternating temperature absorption method under-10 ℃～-50 ℃.

In the method for the present invention, better be that the oxygen volumetric molar concentration in the described argon gas is set at 1/2 the value that is higher than the carbon monoxide volumetric molar concentration.

By this, can realize to make the perfect combustion of carbon monoxide of the hypofunction of catalyzer.Under this situation, when better being the oxygen volumetric molar concentration in setting described argon gas, the oxygen volumetric molar concentration carbon monoxide volumetric molar concentration and hydrogen volumetric molar concentration and the situation more than 1/2 under add hydrogen, the oxygen volumetric molar concentration is added oxygen under the situation below 1/2 of carbon monoxide volumetric molar concentration.By this, do not add carbon monoxide when setting the oxygen volumetric molar concentration, the purity of argon gas is descended so can prevent the byproduct of reaction of carbon monoxide and water.

Device of the present invention is to containing aerobic, hydrogen, carbon monoxide and nitrogen carry out purifying as the argon gas of impurity device at least, it is characterized in that, the oxygen volumetric molar concentration in the described argon gas that comprise the reactor that imports described argon gas, will import described reactor be set at be lower than carbon monoxide volumetric molar concentration and hydrogen volumetric molar concentration with 1/2 concentration adjusting device, the adsorption unit that is connected with described reactor; Be filled with the catalyst for reaction that the reaction that makes carbon monoxide and oxygen has precedence over hydrogen and oxygen in the described reactor, make the oxygen in the described argon gas and carbon monoxide and H-H reaction in described reactor, thereby under the state of remaining hydrogen, generate carbonic acid gas and water; Described adsorption unit has the sorbent material of the foreign matter content that is used for reducing the described argon gas that flows out from described reactor.

If adopt device of the present invention, then can implement method of the present invention.

If employing the present invention, then can provide the purity that improves the argon gas that contains impurity that is reclaimed by rational purification process, thereby prevent that purifying from the hypofunction of catalyzer, reducing purification load, help the method and apparatus of minimizing of overhead charges, the construction cost of recovery system.

Description of drawings

Fig. 1 is the structure explanatory view of the argon purification device of embodiments of the present invention.

Fig. 2 is the structure explanatory view of the pressure-swing absorption apparatus in the argon purification device of embodiments of the present invention.

Fig. 3 is the structure explanatory view of the alternating temperature adsorption unit in the argon purification device of embodiments of the present invention.

The explanation of symbol

α ... purification devices, 3 ... reactor, 4 ... temperature control equipment, 6 ... adsorption unit, 10 ... the PSA unit, 20 ... the TSA unit.

Embodiment

Argon purification device α shown in Figure 1 makes its recycling device for reclaiming the argon gas after the use of supplying with from argon gas feed sources such as for example polysilicon foundry furnace 1 and carrying out purifying, comprises well heater 2, reactor 3, temperature control equipment 4, water cooler 5 and adsorption unit 6.

The argon gas of supplying with from supply source 1 is by not shown dedustings such as strainer, by the gas blower 7 importing well heaters 2 as gas transport unit.Be considered to aerobic, hydrogen, carbon monoxide and nitrogen at least as the contained impurity of the argon gas of purifying object, but can contain other impurity such as carbonic acid gas and hydrocarbon.The concentration of the impurity in the argon gas that is purified is not particularly limited, and for example is about 5 molar ppm～40000 molar ppm.Carbon monoxide is adsorbed in the activity of such catalysts site and hinders the viewpoint of the reaction of hydrogen and oxygen from prevent reactor 3, Heating temperature based on the argon gas of well heater 2 better is to be made as more than 200 ℃, viewpoint from preventing that life of catalyst from shortening better is provided in a side of below 300 ℃.

The argon gas of heater via 2 heating is imported into reactor 3.Concentration adjusting device 4 will through well heater 2 import oxygen volumetric molar concentration in the argon gas of reactors 3 be set at be lower than carbon monoxide volumetric molar concentration and hydrogen volumetric molar concentration and 1/2.The concentration adjusting device 4 of present embodiment has density measuring device 4a, hydrogen supply source 4b, hydrogen amount regulator 4c, oxygen supply source 4d, oxygen amount setter 4e and controller 4f.Density measuring device 4a measures oxygen volumetric molar concentration, carbon monoxide volumetric molar concentration, the hydrogen volumetric molar concentration in the argon gas that imports well heater 2, and its measured signal is sent to controller 4f.Controller 4f measured oxygen volumetric molar concentration carbon monoxide volumetric molar concentration and hydrogen volumetric molar concentration and the situation more than 1/2 under will with make it be lower than the corresponding control signal of 1/2 required hydrogen amount to be sent to hydrogen amount regulator 4c, under the situation 1/2 below of measured oxygen volumetric molar concentration in the carbon monoxide volumetric molar concentration will with make it be higher than the corresponding control signal of 1/2 required oxygen amount to be sent to oxygen amount setter 4e.Hydrogen amount regulator 4c carries out the aperture adjustment to the stream from hydrogen supply source 4b to reactor 3, thereby supplies with the hydrogen of the amount corresponding with control signal.Oxygen amount setter 4e carries out the aperture adjustment to the stream from oxygen supply source 4d to reactor 3, thereby supplies with the oxygen of the amount corresponding with control signal.By this, when setting as the oxygen volumetric molar concentration in the argon gas of purifying object, the oxygen volumetric molar concentration carbon monoxide volumetric molar concentration and hydrogen volumetric molar concentration and the situation more than 1/2 under add hydrogen, the oxygen volumetric molar concentration is added oxygen under the situation below 1/2 of carbon monoxide volumetric molar concentration.

Be filled with the catalyst for reaction that the reaction that makes carbon monoxide and oxygen has precedence over hydrogen and oxygen in the reactor 3.By this, oxygen in reactor 3 in the argon gas and carbon monoxide and hydrogen react under 200 ℃～300 ℃ temperature, thereby generate carbonic acid gas and water under the state of remaining hydrogen.The catalyzer platiniferous adopts the platinum catalyst with supported on alumina as main component in the present embodiment.Catalyzer is not limited to platinum, for example can use platinum alloy, also can contain other compositions such as a spot of palladium.

Water cooler 5 is connected with reactor 3, will be cooled to about 40 ℃ from reactor 3 effusive argon gas.Be imported into adsorption unit 6 through water cooler 5 refrigerative argon gas.

Adsorption unit 6 has the sorbent material that is used for reducing from the foreign matter content of reactor 3 effusive argon gas.The adsorption unit 6 of present embodiment has by the pressure swing adsorption process under the normal temperature and carries out thePSA unit 10 of absorption of the impurity in the argon gas and theTSA unit 20 that adsorbs by the alternating temperature absorption method under-10 ℃～-50 ℃, adopts the absorption of alternating temperature absorption method after the absorption of adopting pressure swing adsorption process.

PSA unit 10 can use knownunit.PSA unit 10 for example shown in Figure 2 is a four-tower, has carry out compressor for compressing 12 and totally 4 first～the4th adsorption tower 13 from reactor 3 effusive argon gas, is filled with sorbent material in each adsorption tower 13.As this sorbent material, adopt the sorbent material of the absorption that is suitable for carbonic acid gas and moisture, for example can adopt activated alumina, gac and CaA type zeolite.

Compressor 12 is situated between and is connected with theinlet 13a of eachadsorption tower 13 with transforming valve 13b.Theinlet 13a ofadsorption tower 13 is situated between respectively and is connected in the atmosphere with transformingvalve 13e andsourdine 13f.

Theoutlet 13k ofadsorption tower 13 is situated between respectively and is connected withoutflow pipeline 13m with transforming valve 13l, Jie is connected with the pipeline 13o that boosts with transformingvalve 13n, Jie cleans outside pipe road 13q and is connected with all pressing with transformingvalve 13p, is situated between to go intoside pipe road 13s with transformingvalve 13r with equal pressure cleanings and be connected.

Flow outpipeline 13m Jie and be connected withTSA unit 20, make the constant pressure of the argon gas that importsTSA unit 20 withpressure regulator valve 13t.

The pipeline 13o that boosts is situated between and is connected withoutflow pipeline 13m withflowrate control valve 13u,flow indication accommodometer 13v, and the flow among the pipeline 13o that boosts is adjusted to constant, thereby prevents to import the fluctuations in discharge of the argon gas ofTSA unit 20.

All press to clean outside pipe road 13q and all press cleaning to go intoside pipe road 13s Jie to interconnect with a pair of connectingtube 13w, each connectingtube 13w is provided with transformingvalve 13x.

Carry out absorption process, decompression I operation (purge gas goes out operation), decompression II operation (body of all calming the anger goes out operation), desorption step, matting (purge gas is gone into operation), the I operation of boosting (body of all calming the anger is gone into operation), the II operation of boosting in first ofPSA unit 10～the4th adsorption tower 13 respectively successively.

That is, infirst adsorption tower 13 only transformingvalve 13b and transforming valve 13l open, the argon gas of supplying with from reactor 3 importsfirst adsorption tower 13 fromcompressor 12 through transforming valve 13b.By this, in the argon gas that is imported infirst adsorption tower 13 at least carbonic acid gas and moisture be adsorbed on sorbent material, thereby carry out absorption process, the argon gas after foreign matter content reduces is delivered toTSA unit 20 fromfirst adsorption tower 13 through flowing out pipeline 13m.At this moment, a part that is sent to the argon gas that flows outpipeline 13m is delivered to other adsorption tower (beingsecond adsorption tower 13 in the present embodiment), the II operation of boosting through the pipeline 13o that boosts,flowrate control valve 13u insecond adsorption tower 13.

Then, close transformingvalve 13b, the 13l offirst adsorption tower 13, open transformingvalve 13p, open theflowrate control valve 13r of other adsorption tower (being the4th adsorption tower 13 in the present embodiment), open 1 among the transforming valve 13x.By this, the less argon gas of the foreign matter content on first adsorption tower, 13 tops is delivered to the4th adsorption tower 13 through all pressing cleaning to go intoside pipe road 13s, and the I operation reduces pressure in first adsorption tower 13.At this moment, transformingvalve 13e opens in the4th adsorption tower 13, carries out matting.

Then, under the state of theflowrate control valve 13r of transformingvalve 13p that opensfirst adsorption tower 13 and the4th adsorption tower 13, close the transformingvalve 13e of the4th adsorption tower 13, thereby reclaim gas to the four theadsorption towers 13 mutual homogeneous of internal pressure or decompression II operation of homogeneous roughly betweenfirst adsorption tower 13 and the 4th adsorption tower 13.At this moment, transformingvalve 13x can according to circumstances open 2.

Then, open the transformingvalve 13e offirst adsorption tower 13, close transformingvalve 13p, thereby carry out the desorption step of impurity from the sorbent material desorb, impurity is released in the atmosphere through sourdine 13f with gas.

Then, open theflowrate control valve 13r offirst adsorption tower 13, close transformingvalve 13b, the 13l ofsecond adsorption tower 13 of the state after absorption process finishes, open transforming valve 13p.By this, the less argon gas of the foreign matter content on second adsorption tower, 13 tops is delivered tofirst adsorption tower 13 through all pressing cleaning to go intoside pipe road 13s, carries out matting in first adsorption tower 13.The used gas of matting infirst adsorption tower 13 is released in the atmosphere through transformingvalve 13e, sourdine 13f.At this moment, the I operation that reduces pressure in second adsorption tower 13.Then, under the state of theflowrate control valve 13r of the transformingvalve 13p that openssecond adsorption tower 13 andfirst adsorption tower 13, close the transformingvalve 13e of first adsorption tower, thereby boost the I operation.At this moment, transformingvalve 13x can according to circumstances open 2.

Then, close theflowrate control valve 13r offirst adsorption tower 13, temporarily be in the holding state of no operation.The II operation of boosting that this holding state continues to the4th adsorption tower 13 finishes.The end of boosting of the4th adsorption tower 13, after absorption process switches to the4th adsorption tower 13 from the3rd adsorption tower 13, open the transformingvalve 13n of first adsorption tower, deliver to the part of the argon gas that flows outpipeline 13m from the other adsorption tower (being the4th adsorption tower 13 present embodiment) that is in absorption process and deliver tofirst adsorption tower 13 through the pipeline 13o that boosts,flowrate control valve 13u, the II operation of infirst adsorption tower 13, boosting.

By carry out each above-mentioned operation respectively successively repeatedly in first～the4th adsorption tower 13, the argon gas after foreign matter content reduces is delivered toTSA unit 20 continuously.

Also have,PSA unit 10 is not limited to unit shown in Figure 2, and for example the tower number can not be 4.

TSA unit 20 can use known unit.TheTSA unit 20 of present embodiment for example shown in Figure 3 is two tower, has the argon gas of sending here fromPSA unit 10 is carried out the heat exchange type pre-cooler 21 of precooling,heat exchanger 24 to further carrying out refrigerative heat exchangetype water cooler 22, first andsecond adsorption towers 23 and cover eachadsorption tower 23 through pre-cooler 21 refrigerative argon gas.Heat exchange department 24 cools off sorbent material by cooling agent when absorption process, add heat-adsorbent by thermophore when desorption step.Eachadsorption tower 23 has pipe in many that are filled with sorbent material.As this sorbent material, adopt the sorbent material of the absorption that is suitable for nitrogen, for example adopt CaX type zeolite.

Water cooler 22 is situated between and is connected with theinlet 23a of eachadsorption tower 23 with open andclose valve 23b.

Theinlet 23a ofadsorption tower 23 is situated between respectively and is communicated in the atmosphere with open andclose valve 23c.

Theoutlet 23e ofadsorption tower 23 is situated between respectively and is connected withoutflow pipeline 23g with open andclose valve 23f, and Jie is boosted with cooling with open andclose valve 23h and is connected with pipeline 23i, and being situated between is connected withcleaning tube road 23k with open andclose valve 23j.

Flow out the part ofpipeline 23g formation pre-cooler 21, the argon gas of sending here fromPSA unit 10 is cooled off from flowing out the effusive purified argon gas of pipeline 23g.Purified argon gas flows out through primary side pressure controlled valve 23l from flowing outpipeline 23g.

Cooling is boosted and is connected with undermeter 23m, flowrate control valve 23o, open andclose valve 23n andoutflow pipeline 23g with pipeline 23i,cleaning tube road 23k Jie.

Heat exchanger 24 adopts multitube, hasouter tube 24a, the coolingagent supply source 24b,cooling agent radiator 24c,thermophore supply source 24d, thethermophore radiator 24e that surround many interior pipes that constitute adsorption tower 23.In addition, be provided with a plurality of open andclose valve 24f, be used for the cooling agent supplied with from coolingagent supply source 24b is changed between withradiator 24e round-robin state byouter tube 24a, thermophore withradiator 24c round-robin state and from the thermophore ofthermophore supply source 24d supply byouter tube 24a, cooling agent.In addition, by constituting the part ofwater cooler 22 withradiator 24c ramose pipeline from cooling agent, the cooling agent cooling that argon gas is supplied with from coolingagent supply source 24b atwater cooler 22, this cooling agent is back to ajar 24g.

Carry out absorption process, desorption step, matting, refrigerating work procedure, the operation of boosting in first,second adsorption tower 23 ofTSA unit 20 respectively successively.

That is, in theTSA unit 20, after the argon gas of supplying with fromPSA unit 10 is cooled, importfirst adsorption tower 23 pre-cooler 21,water cooler 22 through open and close valve 23b.At this moment,first adsorption tower 23 is in and is cooled to-10 ℃～-50 ℃ state by circulating cooling agent inheat exchanger 24, and open andclose valve 23c, 23h, 23j close, and open andclose valve 23f opens, and contained nitrogen is adsorbed on sorbent material in the argon gas at least.By this, carry out absorption process infirst adsorption tower 23, the purifying argon gas after foreign matter content reduces flows out through primary side pressure controlled valve 23l fromadsorption tower 23.

Carry out during the absorption process infirst adsorption tower 23, carry out desorption step, matting, refrigerating work procedure, the operation of boosting insecond adsorption tower 23.

That is, insecond adsorption tower 23, absorption process in order to implement desorption step, is closed open andclose valve 23b, 23f after finishing, and opens open and close valve 23c.By this, insecond adsorption tower 23, impure helium is released in the atmosphere, and pressure drops to about normal atmosphere.In this desorption step, the open andclose valve 24f that theheat exchange department 24 of refrigerant cycle is arranged when the absorption process insecond adsorption tower 23 switched to closing condition and stop the circulation of cooling agent, will cooling agent be discharged and the open andclose valve 24f that gets back to coolingagent supply source 24b switches to open mode fromheat exchange department 24.

Then, in order insecond adsorption tower 23, to implement matting, the open andclose valve 23n of open andclose valve 23c, the 23j ofsecond adsorption tower 23 andcleaning tube road 23k is set as open mode, and the part of heated purifying argon gas importssecond adsorption tower 23 throughcleaning tube road 23k by the heat exchange in the heat exchange type pre-cooler 21.By this, insecond adsorption tower 23, implement the desorb and the cleaning of adopting the purifying argon gas of the impurity of self-absorbent, the used argon gas of this cleaning is released into the atmosphere with impurity from open and close valve 23c.In this matting, make the open andclose valve 24f of thermophore round-robinheat exchange department 24 switch to open mode with being used insecond adsorption tower 23.

Then, in order insecond adsorption tower 23, to implement refrigerating work procedure, the open andclose valve 23n of the open andclose valve 23j ofsecond adsorption tower 23 andcleaning tube road 23k is set as closing condition, the open andclose valve 23n that the open andclose valve 23h ofsecond adsorption tower 23 and cooling are boosted with pipeline 23i is set as open mode, and boosting through cooling from the part of first adsorption tower, 23 effusive purifying argon gas importssecond adsorption tower 23 with pipeline 23i.By this, refrigerative purifying argon gas having been carried out in second adsorption tower, 23 inside is released in the atmosphere through open and close valve 23c.In this refrigerating work procedure, will be used to make thermophore round-robin open andclose valve 24f switch to closing condition and the circulation that stops thermophore, and will thermophore be discharged and the open andclose valve 24f that gets back tothermophore supply source 24d switches to open mode from heat exchange department 24.After thermophore discharge to finish,, make it be the refrigerant cycle state with being used to make the open andclose valve 24f of theheat exchange department 24 of refrigerant cycle to switch to open mode in second adsorption tower 23.This refrigerant cycle state continuance to the operation of following of boosting, thereafter absorption process finishes.

Then,, close the open andclose valve 23c ofsecond adsorption tower 23, import a part, thereby boosted in the inside ofsecond adsorption tower 23 from first adsorption tower, 23 effusive purifying argon gas in order insecond adsorption tower 23, to implement to boost operation.The interior pressure that this operation of boosting continues to the interior pressure ofsecond adsorption tower 23 andfirst adsorption tower 23 about equally.After the operation of boosting finishes, the open andclose valve 23h and the cooling of closingsecond adsorption tower 23 are boosted with the open andclose valve 23n of pipeline 23i, form all open andclose valve 23b, 23c, 23f, 23h, the 23j closing state ofsecond adsorption tower 23 by this,second adsorption tower 23 keeps holding state to the absorption process of following.

The absorption process of the absorption process ofsecond adsorption tower 23 andfirst adsorption tower 23 is similarly implemented.Carry out during the absorption process insecond adsorption tower 23, similarly carry out desorption step, matting, refrigerating work procedure, the operation of boosting withsecond adsorption tower 23 infirst adsorption tower 23.

Also have,TSA unit 20 is not limited to unit shown in Figure 3, and for example the tower number can be for more than 2, and for example 3 or 4.

If adopt above-mentioned purification devices α, then can be when the argon gas that contains aerobic, hydrogen, carbon monoxide and nitrogen be at least carried out purifying, with the oxygen volumetric molar concentration in the described argon gas be set at be lower than carbon monoxide volumetric molar concentration and hydrogen volumetric molar concentration and 1/2, re-use the catalyst for reaction that the reaction that makes carbon monoxide and oxygen has precedence over hydrogen and oxygen, make oxygen and carbon monoxide and H-H reaction in the described argon gas, thereby under the state of remaining hydrogen, generate carbonic acid gas and water, reduce foreign matter content in the described argon gas with sorbent material then.By this, even can the little hydrogen of residual on one's own initiative also problem, realize that absorption makes the perfect combustion of the oxygen that the cooling energy consumption increases when removing.In addition, do not need the residual on one's own initiative carbon monoxide that may make the low and absorption of catalyst function than carbonic acid gas difficulty.By this, can become in the management that makes purifier apparatus and be easy to realize simultaneously the miniaturization of equipment, can cut down the consumption of energy.In addition, when using sorbent material to reduce foreign matter content in the argon gas, at least after adsorbing carbonic acid gas and water in its impurity by the pressure swing adsorption process under the normal temperature, at least adsorb nitrogen in its impurity by the alternating temperature absorption method under-10 ℃～-50 ℃, so can carry out the absorption of carbonic acid gas, water and nitrogen efficiently.In addition, by the oxygen volumetric molar concentration in the argon gas being set at 1/2 the value that is higher than the carbon monoxide volumetric molar concentration, can realize to make the perfect combustion of the low carbon monoxide of catalyst function.In addition, during oxygen volumetric molar concentration in setting argon gas, the oxygen volumetric molar concentration carbon monoxide volumetric molar concentration and hydrogen volumetric molar concentration and the situation more than 1/2 under add hydrogen, the oxygen volumetric molar concentration is added oxygen under the situation below 1/2 of carbon monoxide volumetric molar concentration, thereby do not add carbon monoxide, so can prevent the byproduct of reaction of carbon monoxide and water the purity of argon gas is descended.

Embodiment

Use above-mentioned purification devices α, the argon gas that reclaims from the polysilicon foundry furnace has been carried out purifying.Argon gas contains 3000 molar ppm nitrogen, 550 molar ppm oxygen, 200 molar ppm hydrogen, 1000 molar ppm carbon monoxide, the 10 molar ppm carbonic acid gas as impurity.By gas blower 7 argon gas is boosted to 0.05MPaG, with 200Nm³The flow of/h imports well heater 2, and temperature is controlled to be 250 ℃, imports reactor 3.Reactor 3 is the cylindric of diameter 400mm, long 1200mm, is filled with the platinum catalyst (the system DASH-220 of grace hundred million Keit Ltd. (NE ケ system キ ヤ Star ト society)) with supported on alumina.By the reaction in the reactor 3, it is that 3000 molar ppm, oxygen are that 1 molar ppm is following, hydrogen is that 100 molar ppm, carbon monoxide are that 1 molar ppm is following, carbonic acid gas is that 1010 molar ppm, moisture are 100 molar ppm that the impurity concentration of argon gas reaches nitrogen.

After this argon gas was cooled to 40 ℃ by the water cooler 5 that is made of the water-cooled water cooler,compressed machine 12 imported one ofadsorption tower 13 of PSA unit 10.Eachadsorption tower 13 is the cylindric of diameter 600mm, long 1800mm, is filled with the CaA type zeolite (the system 5AHP of associating Showa Corporation (the clear and society of ユ ニ オ Application)) as sorbent material.In eachadsorption tower 13, with 1 circulation of 800 seconds operations of boosting, absorption process, matting, desorption step.Argon gas boosts to 0.8MPaG by compressor 12.From the flow ofPSA unit 10 effusive argon gas is 120Nm³/ h, the impurity concentration in the argon gas reaches that nitrogen is that 150 molar ppm, oxygen are that 0.1 molar ppm is following, hydrogen is that 100 molar ppm, carbon monoxide are that 0.5 molar ppm is following, moisture and carbonic acid gas are below 0.5 molar ppm, and dew point reaches below-70 ℃.

After will inpre-cooler 21,water cooler 22, cooling off through the argon gas ofPSA unit 10 purifying, import anadsorption tower 23 of TSA unit 20.Eachadsorption tower 23 is the cylindric of diameter 900mm, long 1500mm, has its inside and is filled with CaX type zeolite ((East ソ one society of TOSOH Co., Ltd) system SA600A as sorbent material) 50 in pipe.The argon gas of interior pipe that will be by a side byheat exchanger 24 is cooled to-35 ℃, and the argon gas of interior pipe that will be by the opposing party is heated to 40 ℃.From the flow ofTSA unit 20 effusive argon gas is 110Nm³/ h, it is that 0.1 molar ppm is following, oxygen is that 0.1 molar ppm is following, hydrogen is that 110 molar ppm, carbon monoxide are that 0.5 molar ppm is following, carbonic acid gas is below 0.5 molar ppm that impurity concentration in the argon gas reaches nitrogen, dew point reaches below-70 ℃, and substantial impurity only is hydrogen.

The present invention is not limited to the above-described embodiment and examples.For example, need to reduce under the situation by the hydrogen concentration in the argon gas behind the purifying of the present invention, the hydrogen that can be provided with shown in the dotted line among Fig. 1 is removed device 30.Hydrogen is removed device 30 and for example can be made of following apparatus: by as the gas separation membrane separation of argon of tool hydrogen perviousnesies such as polyimide film and the device of hydrogen, perhaps remove the device of dehydrogenation etc. with this reactive metal oxide in the reactor of the catalyzer of the metal oxide that is filled with cupric, nickel etc.Also have, for example remove by filling moisture adsorbents such as alumina gel or zeolite in the downstream side of catalyzer by the moisture that the reaction of metal oxide and hydrogen generates.Hydrogen is removed the downstream that device 30 can be configured in TSA unit 20 as shown in Figure 1, also can be disposed between PSA unit 10 and the TSA unit 20.The hydrogen that cylindrical reactor with diameter 300mm is set in the downstream of TSA unit 20 is removed device 30, filling with the cupric oxide in this reactor is the catalyzer of main component, make after the argon gas behind the foregoing description purifying passes through wherein, the flow of argon gas is 110Nm³/ h, it is that 0.1 molar ppm is following, oxygen is that 0.1 molar ppm is following, hydrogen is that 0.5 molar ppm is following, carbon monoxide is that 0.5 molar ppm is following, carbonic acid gas is below 0.5 molar ppm that impurity concentration in the argon gas reaches nitrogen, dew point reaches below-70 ℃, can confirm that hydrogen is removed.Remove device 30 by such hydrogen is set, can also be adapted to require to reduce the purposes of the contained hydrogen of argon gas.

Claims (8)

1. the purification process of an argon gas, it is to carry out the method for purifying to containing aerobic, hydrogen, carbon monoxide and nitrogen at least as the argon gas of impurity, it is characterized in that,

With the oxygen volumetric molar concentration in the described argon gas be set at be lower than carbon monoxide volumetric molar concentration and hydrogen volumetric molar concentration and 1/2,

Re-use the catalyst for reaction that the reaction that makes carbon monoxide and oxygen has precedence over hydrogen and oxygen, make oxygen and carbon monoxide and H-H reaction in the described argon gas, thereby under the state of remaining hydrogen, generate carbonic acid gas and water,

Reduce foreign matter content in the described argon gas with sorbent material then.

2. the purification process of argon gas as claimed in claim 1 is characterized in that, described catalyzer platiniferous is as main component.

3. the purification process of argon gas as claimed in claim 1 or 2, it is characterized in that, when using sorbent material to reduce foreign matter content in the described argon gas, at least after adsorbing carbonic acid gas and water in its impurity by the pressure swing adsorption process under the normal temperature, adsorb nitrogen in its impurity at least by the alternating temperature absorption method under-10 ℃～-50 ℃.

4. the purification process of argon gas as claimed in claim 1 or 2 is characterized in that, the oxygen volumetric molar concentration in the described argon gas is set at 1/2 the value that is higher than the carbon monoxide volumetric molar concentration.

5. the purification process of argon gas as claimed in claim 3 is characterized in that, the oxygen volumetric molar concentration in the described argon gas is set at 1/2 the value that is higher than the carbon monoxide volumetric molar concentration.

6. the purification process of argon gas as claimed in claim 4, it is characterized in that, during oxygen volumetric molar concentration in setting described argon gas, the oxygen volumetric molar concentration carbon monoxide volumetric molar concentration and hydrogen volumetric molar concentration and the situation more than 1/2 under add hydrogen, the oxygen volumetric molar concentration is added oxygen under the situation below 1/2 of carbon monoxide volumetric molar concentration.

7. the purification process of argon gas as claimed in claim 5, it is characterized in that, during oxygen volumetric molar concentration in setting described argon gas, the oxygen volumetric molar concentration carbon monoxide volumetric molar concentration and hydrogen volumetric molar concentration and the situation more than 1/2 under add hydrogen, the oxygen volumetric molar concentration is added oxygen under the situation below 1/2 of carbon monoxide volumetric molar concentration.

8. the purification devices of an argon gas, it is to carry out the device of purifying to containing aerobic, hydrogen, carbon monoxide and nitrogen at least as the argon gas of impurity, it is characterized in that,

Comprise the reactor that imports described argon gas,

With import oxygen volumetric molar concentration in the described argon gas of described reactor be set at be lower than carbon monoxide volumetric molar concentration and hydrogen volumetric molar concentration and 1/2 concentration adjusting device,

The adsorption unit that is connected with described reactor;

Be filled with the catalyst for reaction that the reaction that makes carbon monoxide and oxygen has precedence over hydrogen and oxygen in the described reactor, make the oxygen in the described argon gas and carbon monoxide and H-H reaction in described reactor, thereby under the state of remaining hydrogen, generate carbonic acid gas and water;

Described adsorption unit has the sorbent material of the foreign matter content that is used for reducing the described argon gas that flows out from described reactor.

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