阅读说明：本技术 含氯尾气氦气提纯系统 (Chlorine-containing tail gas helium purification system ) 是由 杨森 刘亭婷 沈一春 王亚军 吴国其 于 2019-11-27 设计创作，主要内容包括：本发明提供的一种含氯尾气氦气提纯系统,依次包括除氯干燥模块、膜分离纯化模块、吸附纯化模块及回收供气单元,其中每一模块的出气端依次连接有检测装置和多通阀；当检测结果不符合预设指标时,含氯尾气自每一模块的出气端经多通阀导入至当前模块的进气端以再次进行同级净化；当检测结果符合预设指标,含氯尾气自每一模块的出气端经多通阀导入后一模块的进气端以进行下一级纯化,直至通入回收供气单元进入待使用阶段。本系统较高效率的处理回收利用氦气,可大大节约采购氦气的成本,也使氦气得到充分的利用。(The invention provides a chlorine-containing tail gas helium purification system which sequentially comprises a chlorine removal drying module, a membrane separation purification module, an adsorption purification module and a recovery gas supply unit, wherein the gas outlet end of each module is sequentially connected with a detection device and a multi-way valve; when the detection result does not accord with the preset index, leading the chlorine-containing tail gas from the gas outlet end of each module to the gas inlet end of the current module through the multi-way valve to perform the same-stage purification again; and when the detection result meets the preset index, leading the chlorine-containing tail gas from the gas outlet end of each module into the gas inlet end of the next module through the multi-way valve to carry out the next-stage purification until the chlorine-containing tail gas is introduced into the recycling gas supply unit to enter a stage to be used. The system has high efficiency in processing and recycling the helium, can greatly save the cost of purchasing the helium and also makes full use of the helium.)

1. The chlorine-containing tail gas helium purification system is characterized in that: the device sequentially comprises a dechlorination drying module, a membrane separation and purification module, an adsorption and purification module and a recovery gas supply unit, wherein the gas outlet end of each module is sequentially connected with a detection device and a multi-way valve; when the detection result does not accord with the preset index, leading the chlorine-containing tail gas from the gas outlet end of each module to the gas inlet end of the current module through the multi-way valve to perform the same-stage purification again; and when the detection result meets the preset index, leading the chlorine-containing tail gas from the gas outlet end of each module into the gas inlet end of the next module through the multi-way valve to carry out the next-stage purification until the chlorine-containing tail gas is introduced into the recycling gas supply unit to enter a stage to be used.

2. The helium purification system for chlorine-containing tail gas of claim 1, wherein: the chlorine removal drying module comprises a chlorine removal spray tower, a dryer and a dry type adsorption tower which are sequentially arranged, chlorine-containing tail gas is firstly subjected to chlorine removal and then dried, and residual chlorine is removed by the dry type adsorption tower.

3. The helium purification system for chlorine-containing tail gas of claim 2, wherein: the water removal filler in the dryer comprises one of a composition of silica and alumina, a combination of activated alumina and molecular sieve and a clay drying agent.

4. The helium purification system for chlorine-containing tail gas of claim 2, wherein: the detection device of the gas outlet end of the dechlorination drying module comprises a chlorine concentration analysis instrument, and the detection index is that the removal rate of chlorine in a gas source reaches more than 98%.

5. The helium purification system for chlorine-containing tail gas of claim 1, wherein: the membrane separation and purification module sequentially comprises a primary gas bag, a primary compressor, a buffer tank, a filter, a cold dryer and a membrane separation and purification device, wherein a gas source after chlorine removal is pressurized and stabilized, and then is filtered to remove oil, water and particles, and the gas temperature is reduced to the gas condition at the inlet of the membrane separation and purification device.

6. The helium purification system for chlorine-containing tail gas of claim 5, wherein: the membrane separation and purification device comprises a primary membrane group and a secondary membrane group, and each stage of membrane group is provided with a pure gas outlet and an impure gas outlet; the pure gas outlet of the first-stage membrane group is connected with the second-stage membrane group, and the impure gas outlet of the first-stage membrane group is connected with the first-stage gas bag; and a pure gas outlet of the secondary membrane group is connected with an adsorption and purification module, and the impure gas of the secondary membrane group is discharged into the atmosphere.

7. The helium purification system for chlorine-containing tail gas of claim 6, wherein: the membrane separation and purification device comprises a primary membrane group, a secondary membrane group and a tertiary membrane group, wherein each stage of membrane group is provided with a pure gas outlet and an impure gas outlet; the pure gas outlet of the first-stage membrane group is connected with the third-stage membrane group, and the impure gas outlet of the first-stage membrane group is connected with the second-stage membrane group; the pure gas outlet of the secondary membrane group is connected with a primary gas bag, and the impure gas of the secondary membrane group is discharged into the atmosphere; the pure gas outlet of the third-level membrane group is connected with the adsorption and purification module, and the pure gas outlet of the third-level membrane group is connected with the first-level gas bag.

8. The helium purification system for chlorine-containing tail gas of claim 6 or 7, wherein: a helium concentration analysis instrument is arranged at the outlet of each membrane group, and when the concentration of helium detected by pure gas of the last-stage membrane group is less than 99%, the pure gas is introduced into the inlet of the first-stage gas bag again; otherwise, an adsorption purification module is connected.

9. The helium purification system for chlorine-containing tail gas of claim 1, wherein: the adsorption purification module comprises a secondary air bag, a secondary compressor, a buffer tank, a filter, a cold dryer and an adsorption purification device which are sequentially arranged; the gas source after membrane purification is pressurized and stabilized, then oil, water and particles are filtered out, the gas temperature is reduced to minus 180 DEG and 196 ℃, and nitrogen, oxygen, water, carbon dioxide and argon are adsorbed by an adsorption purification device.

10. The helium purification system for chlorine-containing tail gas of claim 9, wherein: the adsorption and purification device is filled with liquid nitrogen or provided with an argon fixing tank; and a helium concentration analysis instrument is arranged at an outlet of the adsorption and purification module, when the concentration detection result of helium is less than 99.999%, the gas source is connected into the secondary gas bag to perform adsorption and purification again, and otherwise, the gas source is connected into the recovery gas supply unit for standby.

Technical Field

The invention relates to the technical field of gas purification, in particular to a chlorine-containing tail gas helium purification system.

Background

Helium, the inert gas characteristic of which is widely used, is particularly in industry. However, helium is a rare gas, so that the storage amount in China is small, the helium mainly depends on import, and the price is high. In fact, the concentration of the used helium is still high, and the direct discharge can cause great waste. The helium gas is required to be recovered, purified and reused. Not only saves resources, but also reduces cost from the economic perspective, and has important significance for the sustainable development of the earth. The helium recovery mode mainly comprises the following steps: cryogenic process, membrane separation process, pressure swing adsorption process, chemical adsorption.

In the optical fiber industry, 99.99% of high-purity helium is required, and the used tail gas still has a high helium content of 50-95%, but is mixed with other gases such as water vapor, nitrogen, chlorine and the like, so that the tail gas cannot be used normally in the process. The helium treatment and recovery at present have the following problems: (1) helium has small molecular weight and is difficult to collect; (2) the recovery purity is not high; (3) the tail gas contains other gases, and the removal is not thorough.

Disclosure of Invention

In view of the above, there is a need for an improved chlorine containing tail gas helium purification system.

The technical scheme provided by the invention is as follows: a helium purification system for chlorine-containing tail gas sequentially comprises a chlorine removal drying module, a membrane separation and purification module, an adsorption and purification module and a recovery gas supply unit, wherein a gas outlet end of each module is sequentially connected with a detection device and a multi-way valve; when the detection result does not accord with the preset index, leading the chlorine-containing tail gas from the gas outlet end of each module to the gas inlet end of the current module through the multi-way valve to perform the same-stage purification again; and when the detection result meets the preset index, leading the chlorine-containing tail gas from the gas outlet end of each module into the gas inlet end of the next module through the multi-way valve to carry out the next-stage purification until the chlorine-containing tail gas is introduced into the recycling gas supply unit to enter a stage to be used.

Further, the dechlorination drying module comprises a dechlorination spray tower, a dryer and a dry type adsorption tower which are sequentially arranged, the chlorine-containing tail gas is firstly dechlorinated and then dried, and residual chlorine is removed by the dry type adsorption tower.

Further, the water removal filler in the dryer comprises one of a composition of silica and alumina, a combination of activated alumina and molecular sieve, and a clay drying agent.

Further, the detection device at the gas outlet end of the dechlorination drying module comprises a chlorine concentration analysis instrument, and the detection index is that the removal rate of chlorine in the gas source reaches more than 98%.

Furthermore, the membrane separation and purification module sequentially comprises a primary air bag, a primary compressor, a buffer tank, a filter, a cold dryer and a membrane separation and purification device, wherein a chlorine-removed air source is pressurized and stabilized, then oil, water and particles are filtered out, and the air temperature is reduced to the air condition at the inlet of the membrane separation and purification device.

Furthermore, the membrane separation and purification device comprises a primary membrane group and a secondary membrane group, and each stage of membrane group is provided with a pure gas outlet and an impure gas outlet; the pure gas outlet of the first-stage membrane group is connected with the second-stage membrane group, and the impure gas outlet of the first-stage membrane group is connected with the first-stage gas bag; and a pure gas outlet of the secondary membrane group is connected with an adsorption and purification module, and the impure gas of the secondary membrane group is discharged into the atmosphere.

Furthermore, the membrane separation and purification device comprises a primary membrane group, a secondary membrane group and a tertiary membrane group, wherein each stage of membrane group is provided with a pure gas outlet and an impure gas outlet; the pure gas outlet of the first-stage membrane group is connected with the third-stage membrane group, and the impure gas outlet of the first-stage membrane group is connected with the second-stage membrane group; the pure gas outlet of the secondary membrane group is connected with a primary gas bag, and the impure gas of the secondary membrane group is discharged into the atmosphere; the pure gas outlet of the third-level membrane group is connected with the adsorption and purification module, and the pure gas outlet of the third-level membrane group is connected with the first-level gas bag.

Furthermore, a helium concentration analysis instrument is arranged at the outlet of each membrane group, and when the concentration of the pure gas of the last-stage membrane group is detected to be less than 99 percent, the pure gas is introduced into the inlet of the first-stage gas bag again; otherwise, an adsorption purification module is connected.

Furthermore, the adsorption purification module comprises a secondary air bag, a secondary compressor, a buffer tank, a filter, a cold dryer and an adsorption purification device which are sequentially arranged; the gas source after membrane purification is pressurized and stabilized, then oil, water and particles are filtered out, the gas temperature is reduced to minus 180 DEG and 196 ℃, and nitrogen, oxygen, water, carbon dioxide and argon are adsorbed by an adsorption purification device.

Further, the adsorption and purification device is filled with liquid nitrogen or provided with an argon fixing tank; and a helium concentration analysis instrument is arranged at an outlet of the adsorption and purification module, when the concentration detection result of helium is less than 99.999%, the gas source is connected into the secondary gas bag to perform adsorption and purification again, and otherwise, the gas source is connected into the recovery gas supply unit for standby.

Compared with the prior art, the helium purification system for the chlorine-containing tail gas provided by the invention is provided with the detection devices at the rear ends of the chlorine removal stage and the helium purification stage, detects that chlorine in the gas is not completely removed or the helium purity does not meet the requirement, and returns to the front end of the corresponding stage through valve switching to repeatedly purify or purify, so that other gases such as chlorine, water, nitrogen and the like in the tail gas are effectively removed, and the helium is efficiently purified.

Drawings

The present invention will be described in further detail with reference to the accompanying drawings and specific embodiments.

FIG. 1 is a schematic view of a recycling process of a helium purification system for chlorine-containing tail gas according to an embodiment of the present invention.

Fig. 2 is a schematic diagram of the system device structure shown in fig. 1.

Fig. 3 is a schematic view of a purification process flow of the three-stage membrane module shown in fig. 2.

Fig. 4 is a schematic diagram of membrane group separation in the membrane separation and purification apparatus shown in fig. 3.

Fig. 5 is an adsorption/desorption schematic diagram of the adsorption and purification apparatus shown in fig. 2.

Description of reference numerals:

dechlorination drying module 100

Dechlorination spray tower 101

Drying machine 103

Dry adsorption column 105

Chlorine gas concentration analyzer 107

Valve 109

Membrane separation purification module 200

First-level air bag 201

One-stage compressor 203

Buffer tank 205

Filter 207

Cold dryer 209

Membrane separation and purification device 220

First-stage membrane group 221

Second level Membrane Module 223

Three-level membrane group 225

Helium concentration analysis instrument 230

Valve 233

Adsorption purification module 300

Secondary air bag 301

Two-stage compressor 303

Buffer tank 305

Filter 307

Refrigeration dryer 309

Adsorption purification device 330

Helium concentration analysis instrument 350

Valve 355

Recovery air supply unit 400

The following detailed description further illustrates embodiments of the invention in conjunction with the above-described figures.

Detailed Description

So that the manner in which the above recited objects, features and advantages of embodiments of the present invention can be understood in detail, a more particular description of the invention, briefly summarized above, may be had by reference to the embodiments thereof which are illustrated in the appended drawings. In addition, the features of the embodiments of the present application may be combined with each other without conflict.

In the following description, numerous specific details are set forth to provide a thorough understanding of embodiments of the invention, and the described embodiments are merely a subset of embodiments of the invention, rather than a complete embodiment. All other embodiments obtained by a person of ordinary skill in the art based on the embodiments of the present invention without any creative effort belong to the protection scope of the embodiments of the present invention.

The term "dew point of atmospheric air" as used herein refers to the temperature at which the air reaches a saturated state by cooling with the amount of moisture contained in the air (moisture content) unchanged, and is referred to as the dew point temperature. It is a temperature that detects the dryness of the compressed air system, in other words, the temperature at which moisture in the air condenses into water droplets. The lower the dew point temperature, the less moisture is contained in the compressed air. The relative humidity of the air reaches 100% at the dew point temperature, and the dry bulb temperature, the wet bulb temperature, the saturation temperature and the dew point temperature are the same temperature value.

The working principle of the cool drying machine is as follows: the hot and humid compressed air from the air compressor and containing moisture is first pre-cooled in the air-to-air heat exchanger, then further cooled in the air-to-refrigerant heat exchanger by the refrigerant circulation loop of the freeze dryer, and then heat exchanged with the cold air cooled to the pressure dew point from the evaporator, so as to further lower the temperature of the compressed air.

Unless defined otherwise, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which embodiments of the present invention belong. The terminology used herein in the description of the invention is for the purpose of describing particular embodiments only and is not intended to be limiting of the embodiments of the invention.

Referring to fig. 1, the system for purifying helium in chlorine-containing tail gas provided by the invention sequentially comprises a chlorine removal drying module 100, a membrane separation and purification module 200, an adsorption and purification module 300 and a recovery gas supply unit 400 (also called as a recovery storage unit, see fig. 1), and is used for efficiently purifying helium in chlorine-containing tail gas generated by an equipment set, wherein the concentration of the purified helium is not lower than 99.999%, and the purified helium can be recovered for application in industrial production after recovery and storage, and the application relates to the fields of military industry, scientific research, petrochemical industry, refrigeration, medical treatment, semiconductors, pipeline leakage detection, superconducting experiments, metal manufacturing, deep sea diving, high-precision welding, production of optoelectronic products and the like.

The dechlorination drying module 100 comprises a dechlorination spray tower 101, a dryer 103 and a dry adsorption tower 105 which are sequentially arranged, wherein chlorine-containing tail gas is firstly dechlorinated and then dried, and residual chlorine is removed by the dry adsorption tower 105.

In one embodiment, the chlorine removal spray tower 101 is a main chlorine removal device, also called a primary chlorine removal device, and the chlorine content of the chlorine-containing tail gas is detected, and the amount of the actually required spray reactant is calculated, wherein the spray reactant comprises an alkaline solution and is sprayed from top to bottom, and the chlorine-containing tail gas and the alkaline solution react after meeting each other from bottom to top. For example, using a 30 wt% sodium hydroxide solution, the reaction with chlorine is as follows.

Cl₂+2NaOH＝NaCl+NaClO+H₂O

Of course, in the specific embodiment, the concentration of the alkali solution is not limited to 30 wt%, such as may be 32 wt%, etc.; the solute of the alkaline solution is also not limited to sodium hydroxide, such as aluminum hydroxide and the like. And a PH meter is arranged at the bottom of the dechlorination spray tower 101 and used for measuring the pH value of the solution after reaction and ensuring that the PH value of the solution is within the range of 10-11 to control the alkali adding amount.

In another embodiment, the chlorine removal alkali spray tower 101 can be replaced by a chlorine adsorption device, and limestone is arranged in the chlorine adsorption device to react with chlorine for neutralization, so that chlorine is removed.

The reaction formula is as follows: 2Cl₂+2Ca(OH)₂＝2Ca(ClO)₂+2H₂O。

In another embodiment, the spray tower for chlorine removal may also contain the limestone packing layer, and perform both spraying and adsorption reactions to ensure the removal of the majority of the chlorine. From the production efficiency and operability, limestone adsorption is preferably auxiliary, because the pure limestone is adopted to adsorb chlorine, the required reactant amount is large, the limestone is sticky, the reaction product is difficult to replace, and the limestone is not beneficial to high-efficiency production, and can be used in the dry-type adsorption tower 105 to remove a small amount of residual chlorine in the gas source, so that the chlorine removal rate is up to 98% above, and the chlorine removal rate can basically reach 98% -99% according to normal operation.

The water removal filler in the dryer 103 comprises one of a composition of silica and alumina, a combination of activated alumina and molecular sieve, and a clay drying agent.

The gas outlet end of the dechlorination drying module 100, namely the outlet of the dry adsorption tower 105, is connected with a detection device, the detection device shown in fig. 2 is a chlorine concentration analyzer 107, and the detection index is that the removal rate of chlorine in the gas source reaches more than 98%; the chlorine concentration analysis instrument 107 is communicated with a valve 109 and is connected with the inlet of the dechlorination spray tower 101 and the inlet of the membrane separation and purification module 200 through pipelines.

The operation of the dechlorination drying module 100 shown in fig. 2 is as follows:

(1) the chlorine removal spray tower 101 removes most of chlorine in the chlorine-containing tail gas;

(2) the dryer 103 dries the dechlorinated gas source in the step (1); in the process, the dryer can be regenerated for standby, wherein the regeneration means that the adsorbed moisture is removed to recover the adsorption capacity of the dryer on the moisture, or the dryer can be replaced by a new water removal filler to have the adsorption capacity on the moisture again, so that the air source can be continuously dried;

(3) the dry adsorption tower 105 adsorbs the residual chlorine in the air source dried in the step (2);

(4) a chlorine concentration analyzer 107 tests and analyzes the removal rate of chlorine in the gas source treated in the step (3);

if the product is qualified or reaches the standard, the valve 109 is controlled to conduct the gas source to the inlet of the membrane separation and purification module 200;

if the chlorine-free spraying tower is unqualified or does not reach the standard, the valve 109 is controlled to conduct the gas source to the inlet of the chlorine-removing spraying tower 101, and the circulation treatment is repeated until the chlorine-free spraying tower is qualified and enters the next module;

in this step, the control of the valve 109 may be manual or automatically controlled by the control unit, the latter being preferred in practice.

The membrane separation and purification module 200 sequentially comprises a primary gas bag 201, a primary compressor 203, a buffer tank 205, a filter 207, a freeze dryer 209 and a membrane separation and purification device 220, wherein a gas source subjected to chlorine removal is pressurized and stabilized, then oil, water and particles are filtered out, and the gas temperature is reduced to the gas condition at the inlet of the membrane separation and purification device 220.

And the primary air bag 201 is used for storing an air source to be subjected to membrane separation and purification.

And the primary compressor 203 is used for pressurizing the gas source to be subjected to membrane separation and purification.

And the buffer tank 205 is used for stabilizing the pressure of the incoming pressurized gas source to be subjected to membrane separation and purification.

And the filter 207 is used for removing oil, water and particles from the gas source to be subjected to membrane separation and purification.

And the cold dryer 209 is used for cooling the gas source to control the temperature of the gas source to be about minus 40 ℃, namely the dew point of atmospheric air, and the temperature meets the inlet gas condition of the membrane separation and purification device 220.

The membrane separation and purification apparatus 220 purifies helium gas by using the difference in the permselectivity of the molecular membrane to various gases. Specifically, the molecular membrane of the present invention can permeate helium gas of small molecules, and filter out substances of large molecules, as shown in fig. 4.

In the first embodiment, the membrane separation and purification device 220 comprises a primary membrane group 221 and a secondary membrane group 223, each of which is provided with a pure gas outlet and an impure gas outlet; the pure gas outlet of the primary membrane group 221 is connected to the secondary membrane group 223, and the impure gas outlet of the primary membrane group 221 is connected to the primary gas bag; the pure gas outlet of the secondary membrane group 223 is connected with the adsorption and purification module, and the impure gas of the secondary membrane group 223 is discharged into the atmosphere. In the device, the pure gas obtained by the secondary membrane separation of the gas source can enter the next module, and the impure gas after the secondary membrane separation directly abandons the recovery and reuse because of the low helium concentration.

In the second embodiment, as shown in fig. 3, the membrane separation and purification device 220 comprises a primary membrane group 221, a secondary membrane group 223 and a tertiary membrane group 225, wherein each stage of membrane group (221, 223, 225) is provided with a pure gas outlet and an impure gas outlet; the pure gas outlet of the primary membrane group 221 is connected with the tertiary membrane group, and the impure gas outlet of the primary membrane group 221 is connected with the secondary membrane group 223; the pure gas outlet of the secondary membrane group 223 is connected to the primary gas bag 201, and the impure gas of the secondary membrane group 223 is discharged into the atmosphere; the pure gas outlet of the third-stage membrane group 225 is connected to the adsorption and purification module 300, and the impure gas outlet of the third-stage membrane group 225 is connected to the first-stage gas bag 201. In this example, the pure gas and the impure gas after membrane separation are both subjected to membrane separation and purification again, the pure gas after the pure gas is re-purified can enter the next module, and the impure gas after the pure gas is re-purified and separated is returned to the first-stage gas bag for recycling treatment; returning the purified gas subjected to the repurification and separation of the impure gas to a first-stage gas bag for recycling treatment; thus, the purification effect of the module is ensured by layer-by-layer purification.

The pure gas outlet of the secondary membrane module 223 in the first embodiment and the pure gas outlet of the tertiary membrane module 225 in the second embodiment are both connected with the helium concentration analyzer 230 and the valve 233 in sequence, and only when the pure gas is detected to have a helium concentration of 99% or more, the pure gas can be introduced into the adsorption and purification module 300 through the valve; and when the detection result is unqualified, the pure gas needs to be introduced into the first-stage gas bag again for circular treatment.

In other embodiments, the membrane separation and purification device 220 may further include three or more membrane groups, which may be three or more purification treatments for first separating impure gas, wherein the final impure gas is still directly discharged to the atmosphere, and the pure gas returns to the first-stage gas bag for further separation; or three or more times of purification treatment for the first separation of pure gas, and the final pure gas after separation enters into adsorption purification treatment when the purity of the final pure gas reaches 99% or more through detection of a helium concentration analyzer 230; the final impure gas separated is directly returned to the first-stage gas bag 201 for separation, or the first-stage impure gas and the pure gas are separated for three times or more respectively, the impure gas separated from the impure gas by the last-stage membrane group is discharged to the atmosphere, the pure gas separated from the pure gas is introduced into a helium concentration analyzer, and the pure gas is guided into the next module or returned to the first-stage gas bag by a detection result starting valve 233. In a word, the device is provided with a multi-stage membrane group, so that the working efficiency is improved, and the recovery and reutilization rate of helium can be improved.

The adsorption purification module 300 comprises a secondary air bag 301, a secondary compressor 303, a buffer tank 305, a filter 307, a cold dryer 309 and an adsorption purification device 330 which are sequentially arranged; the gas source after membrane purification is pressurized and stabilized, then oil, water and particles are filtered out, the gas temperature is reduced to minus 180 DEG and 196 ℃, and nitrogen, oxygen, water, carbon dioxide and argon are adsorbed by the adsorption purification device 330.

And the secondary air bag 301 is used for storing an air source to be adsorbed and purified.

And the secondary compressor 303 is used for pressurizing the gas source to be adsorbed and purified.

And the buffer tank 305 is used for stabilizing the pressure of the gas source to be adsorbed and purified, which enters the buffer tank.

And the filter 307 is used for removing oil, water and particles from the gas source to be adsorbed and purified.

And the cold dryer 309 is used for cooling the gas source to make the gas source meet the inlet gas condition of the adsorption and purification device.

The adsorption purification device 330 adopts the physical principle (low-temperature high-pressure adsorption, high-temperature low-pressure desorption), the adsorbent has strong adsorption property at the low temperature of minus 180 ℃ to minus 196 ℃, nitrogen, oxygen, water, carbon dioxide and argon in the gas source are adsorbed by the adsorbent, and the gas is condensed when being cooled and becomes liquid. Under the standard atmospheric pressure, when the nitrogen is cooled to-195.8 ℃, the nitrogen becomes colorless liquid, and when the nitrogen is cooled to-209.8 ℃, the liquid nitrogen becomes snowy solid; the critical temperature of oxygen is-118.95 ℃, and the critical pressure is 5.08 MPa; critical pressure of water 22.1287MPa, critical temperature 647.3K (374.15 ℃); the critical temperature of the carbon dioxide is 31.3 ℃, and the critical pressure is 7.39 MPa; the critical temperature of argon is-122.4 ℃, and the critical pressure is 4.86 MPa; critical temperature of helium-267.8 deg.C, critical pressure of 2.26 atm; it is known that the lower the temperature, the faster the condensation speed, and when the temperature of the adsorbent is set to the range of-180 ℃ to-196 ℃, helium is not condensed and remains in a gaseous state, and other impurity components are condensed and adsorbed, thereby obtaining high-purity helium. In a specific embodiment, the adsorption purification device is filled with liquid nitrogen; the outlet of the adsorption and purification module 330 is provided with a helium concentration analysis instrument 350 and a valve 355, when the concentration detection result of helium is less than 99.999%, the gas source is connected to the secondary gas bag 301 for adsorption and purification again, and on the contrary, the gas source is connected to the recovery gas supply unit 400 for standby. In other embodiments, the adsorption purification device 330 may be replaced by an argon-fixing tank (-196 ℃) to adsorb nitrogen, oxygen, water, carbon dioxide, argon, etc. in the gas source, and as shown in fig. 5, the adsorbed substances at low temperature and high pressure can still be desorbed by heating at high temperature and low pressure, so that the adsorbent can be reused. In one embodiment, the cryoadsorptive purification unit 330 can be used for one standby and used for one regeneration standby to ensure continuous and stable production.

The air outlet end of each module is sequentially connected with a detection device and a multi-way valve; when the detection result in each module does not accord with the preset index, leading the chlorine-containing tail gas from the gas outlet end of each module to the gas inlet end of the current module through the multi-way valve so as to carry out the same-stage purification again; and when the detection result meets the preset index, leading the chlorine-containing tail gas from the gas outlet end of each module into the gas inlet end of the next module through the multi-way valve to carry out the next-stage purification until the chlorine-containing tail gas is introduced into the recycling gas supply unit to enter a stage to be used. Therefore, each module can be ensured to be circularly and repeatedly processed until reaching the standard, and finally, the module can be recycled and stored for industrial production. The purification device can efficiently treat and recycle helium gas and is used for an optical fiber manufacturing production line; greatly saves the cost of purchasing helium and fully utilizes the helium.

Although the embodiments of the present invention have been described in detail with reference to the preferred embodiments, it should be understood by those skilled in the art that various changes may be made and equivalents may be substituted without departing from the spirit and scope of the embodiments of the present invention.