An argon recovery device with ultra-high argon recovery rate and a method of using the same

Abstract

The application discloses an argon recovery device with super-high argon recovery rate and a use method thereof, which comprises a raw material gas dust removal and pressurization system, a raw material gas buffer compression system, a raw material gas decarburization system, a raw material gas deoxidization and drying system, a water electrolysis hydrogen production system, a cold box system, a nitrogen-hydrogen-argon mixed gas circulation compression system, a raw material air filtration and compression system, an air precooling and purification system and a liquid storage and vaporization system, which are connected with each other through pipelines, wherein the cold box system is composed of an argon purification tower, a waste gas distillation tower, a nitrogen production rectification tower, a main heat exchanger, an expander, an argon tower auxiliary condenser, a nitrogen production condensation evaporator and a cold supplement system, which are connected and controlled with each other through pipelines and valves. The application has high reliability, good practical value and economic benefits.

Description

Technical Field

[0001] This invention relates to gas separation technology, specifically, to the recovery of sealed argon gas from a single crystal furnace, followed by filtration, dust removal, and pressurization. After decarbonization, deoxygenation, and drying pretreatment, a cryogenic distillation method is used to design an argon recovery device with an ultra-high argon recovery rate and its application method, which belongs to the field of cryogenic technology. Background Technology

[0002] Argon recovery units, by recovering the sealed argon gas from single crystal furnaces and performing decarbonization and deoxygenation pretreatment and cryogenic distillation separation, allow for the recycling of argon gas, significantly reducing the production cost of single crystal rods and enabling the industrial production of single crystal rods. Hydrogen-free argon recovery units, however, do not recover oxygen-containing argon gas collected by auxiliary pumps, resulting in high argon consumption and frequent liquid argon replenishment, leading to poor economic efficiency. Therefore, later-built argon recovery units for single crystal furnaces all adopt hydrogen-based processes. Hydrogen-based argon recovery units involve front-end processes such as dust removal and pressurization of the raw gas, compressor compression, decarbonization and drying, hydrogenation for deoxygenation and moisture adsorption, followed by cryogenic separation in a cold box.

[0003] In recent years, with the development of the social economy and the advancement of industrial technology, the market demand for high-purity argon has been increasing, and the requirements have become more stringent. The development of the photovoltaic and semiconductor industries has also led to a simultaneous increase in the number and scale of argon recovery units in operation. How to improve the argon recovery rate of argon recovery units, reduce liquid argon replenishment, and decrease the cost of purchasing liquid argon is a key challenge. Taking a currently operating argon recovery unit as an example, the cold box argon recovery rate is 97%~98%, with argon loss in the cold box system alone at 2%~3%. Based on a 10,000 argon recovery unit, the argon loss is 200~300 Nm³. 3 The annual loss is calculated based on the average value per hour: 250 * 24 * 365 = 2,190,000 Nm. 3 If the argon recovery rate of the cold box in the 10,000 argon recovery unit increases by 1%, the annual argon loss will be reduced by 876,000 Nm³. 3 Achieving a higher argon recovery rate in argon recovery devices is an urgent issue that needs to be addressed. Therefore, this paper designs an argon recovery device with an ultra-high argon recovery rate and its application method. Summary of the Invention

[0004] The purpose of this invention is to overcome the shortcomings of the existing technology and provide an argon recovery device and its method of use that has high reliability, good practical value and economic benefits and ultra-high argon recovery rate.

[0005] This invention is achieved through the following technical solution: an argon recovery device with ultra-high argon recovery rate, comprising a raw gas dust removal and pressurization system, a raw gas buffer compression system, a raw gas decarbonization system, a raw gas deoxygenation and drying system, a water electrolysis hydrogen production system, a cold box system, a nitrogen-hydrogen-argon mixed gas circulation compression system, a raw air filtration and compression system, an air precooling and purification system, and a liquid storage and vaporization system; all interconnected by pipelines. The cold box system consists of an argon purification tower, a waste gas distillation tower, a nitrogen production distillation tower, a main heat exchanger, an expander, an argon tower auxiliary condenser, a nitrogen production condenser-evaporator, and a cooling capacity replenishment system, etc., which are interconnected and controlled by pipelines and valves.

[0006] Preferably, the argon purification tower consists of an upper purification tower condenser, a lower purification tower evaporator, and an intermediate tower section; the waste gas distillation tower consists of an upper waste gas distillation tower condenser, a lower waste gas distillation tower evaporator, and an intermediate tower section; and the nitrogen production distillation tower and the nitrogen production condenser / evaporator are arranged as one unit or separately.

[0007] Preferably, the main heat exchanger is configured as two units based on the hydrogen-oxygen contact hazard, namely a first main heat exchanger and a second main heat exchanger. The first main heat exchanger is provided with a first raw material argon gas inlet pipe, a nitrogen-hydrogen-argon circulating gas inlet pipe, and a non-condensable waste gas outlet pipe. The second main heat exchanger is provided with a second raw material argon gas inlet pipe, an oxygen-enriched gas outlet pipe, a purified air inlet pipe, a nitrogen outlet pipe, a low-pressure nitrogen outlet pipe, and a product argon gas outlet pipe.

[0008] Preferably, the cold box system is also connected to a liquid argon return pipeline, which is connected to an argon purification tower, and the nitrogen production distillation tower is also provided with a product nitrogen pipeline connected to the outside of the cold box.

[0009] Preferably, the expander is provided in two units, namely a first expander and a second expander. The first expander and the second expander are gas bearing expanders, which use backflow waste gas expansion and refrigeration to provide cooling capacity for the cold box. One expander is in use and the other is on standby during operation.

[0010] A method for using an argon recovery device with ultra-high argon recovery rate, the method comprising the following steps:

[0011] 1) Argon pretreatment of raw materials;

[0012] 2) Argon recovery is achieved through cryogenic distillation;

[0013] 3) Argon gas from the product is delivered to the user.

[0014] Preferably, the argon pretreatment step in step 1) is as follows:

[0015] Step 1: The raw material is argon gas for dust removal, filtration, pressurization, and conveying; the dust removal filter adopts automatic multi-point back-blowing of argon gas;

[0016] Step 2: The raw material gas is buffered in a double-membrane gas holder and compressed by a compressor. The high-temperature compressed argon gas is then fed into the decarbonization system.

[0017] Step 3: Decarbonization of raw gas: The raw gas is reheated and converted into carbon dioxide through a high-temperature catalytic reaction. After the reaction, it is cooled and then removed by an adsorber to remove carbon dioxide and other impurities.

[0018] Step 4: Hydrogenation and drying of raw gas: After removing carbon dioxide, the raw gas is reheated and mixed with circulating nitrogen-hydrogen-argon mixture, and then fed into a deoxygenation reactor to carry out a chemical reaction to remove oxygen components from the raw gas. After the reaction, the gas is cooled and the moisture in the argon is removed by an adsorber.

[0019] Step 5: The water electrolysis hydrogen production system provides hydrogen consumed in the deoxygenation reaction and hydrogen lost in the non-condensable gas of the cold box distillation for the argon recovery unit.

[0020] Step 6: Start the raw material air filtration and compression system to provide raw material air for air separation nitrogen production;

[0021] Step 7: Start the air precooling unit to cool the air, and then start the purification system to remove impurities from the air.

[0022] As a preferred embodiment, the method for argon recovery in step 2) is as follows:

[0023] After deoxygenation and drying in step 7, the hydrogen-containing argon and dry air enter the cold box for distillation separation: the crude argon is split into two streams and pre-cooled in the first and second main heat exchangers respectively. After cooling, they merge and enter the evaporator of the argon purification tower. Part of the non-condensable gas is reheated through the first main heat exchanger and exits the cold box, while the remainder is condensed into crude liquid argon. The non-condensable gas exiting the cold box is mixed with supplementary hydrogen through a circulating compressor and then enters the hydrodeoxygenation system. The crude liquid argon is throttled and enters the argon purification tower for distillation. In the argon purification tower, high-purity liquid argon is obtained at the bottom, and hydrogen-containing argon sludge is obtained at the top. The hydrogen-containing argon sludge is condensed in the condenser of the purification tower, and the condensed liquid is used as reflux for the argon purification tower. The non-condensable gas is sent to the waste gas stripping tower for further distillation and separation. The waste gas stripping tower has an evaporator at the bottom and a condenser at the top. The non-condensable gas is sent to the lower part of the tower and separated by distillation. The bottom-rich liquid argon is heated and evaporated by nitrogen from the nitrogen-generating distillation tower, becoming the rising gas. The top gas is condensed into liquid by liquid nitrogen and becomes the reflux liquid for the waste gas stripping tower. The non-condensable portion is reheated in the first main heat exchanger and either vented from the cold box or reused. The liquid nitrogen condensed in the evaporator of the waste gas stripping tower is throttled into the condenser and evaporated as a cold source. A portion of the crude liquid argon is drawn from the bottom of the waste gas stripping tower and used as the reflux liquid at the top of the argon purification tower. Simultaneously, the crude liquid argon is evaporated from the nitrogen-generating condenser. Liquid nitrogen is drawn from the generator and throttled into the condenser of the waste gas stripping tower to supplement cooling capacity and increase the reflux ratio of the waste gas stripping tower. The evaporated low-pressure nitrogen gas is reheated through the first or second main heat exchanger and exits the cold box as regeneration gas for the deoxygenation purifier. The high-purity liquid argon obtained from the argon purification tower is throttled and enters the purification tower condenser, where the liquid argon is evaporated and then reheated through the second main heat exchanger before exiting the cold box. Air is pre-cooled in the second main heat exchanger and then enters the nitrogen generation distillation tower. Through distillation separation, oxygen-enriched liquid air is obtained at the bottom and high-purity nitrogen gas is obtained at the top. A portion of nitrogen gas is drawn from the top of the nitrogen generation distillation tower, reheated through the second main heat exchanger, and exits the cold box for user use and as regeneration gas for the deoxygenation purifier. The oxygen-enriched liquid air is throttled... The nitrogen enters the nitrogen-generating condenser-evaporator, where it evaporates into oxygen-enriched air. It is then reheated to a certain temperature by the second main heat exchanger and enters the first or second expander for expansion and refrigeration, providing cooling capacity for the cold box. After expansion, the oxygen-enriched air merges with the oxygen-enriched air evaporated by the argon tower auxiliary condenser, and then exits the cold box after being reheated by the second main heat exchanger. It serves as regeneration gas for the air purifier and decarbonization purifier. In the nitrogen-generating condenser-evaporator, nitrogen is condensed into liquid nitrogen. Most of it is used as reflux liquid in the nitrogen-generating distillation tower, part is used as a cold source for the condenser of the waste gas stripping tower, and part is sent to the liquid nitrogen storage tank as product liquid nitrogen. In order to maintain the balance of argon usage and the cooling capacity of the cold box, a portion of liquid argon is reinjected into the argon purification tower.

[0024] Preferably, the argon purification tower, the waste gas distillation tower, and the nitrogen production distillation tower are all structured packed towers.

[0025] Preferably, the condenser, the first main heat exchanger, and the second main heat exchanger are all plate-fin heat exchangers.

[0026] The beneficial effects of this invention are as follows:

[0027] This invention utilizes the principle of low-temperature distillation separation and performs secondary distillation on the non-condensable waste gas discharged from the primary distillation of the argon tower, achieving an argon recovery rate of over 99.95% in the cold box of the argon recovery unit (when the feed gas contains 1.2% oxygen). With the application of this invention, as the argon recovery rate in the cold box of the argon recovery unit reaches over 99.95%, the overall argon recovery rate of the argon recovery unit will also increase, reaching 99%. Based on a 10,000 argon recovery unit, the cold box argon recovery rate increases by 2%; users will reduce their annual liquid argon purchases by: 2% * 10,000 * 24 * 365 = 1,752,000 Nm³. 3 The increased argon recovery rate reduces both the cost of purchasing liquid argon and dependence on the liquid argon market. For regions with a shortage of liquid argon, its economic benefits are even more pronounced and substantial. Therefore, this invention has significant practical value and economic benefits. With the reduction of oxygen and nitrogen content in the feed gas, the argon recovery rate in the cold box will reach 100%. Attached Figure Description

[0028] Figure 1 This is a schematic diagram of the process flow of the present invention.

[0029] Wherein, N1 is the second raw material argon inlet pipe; N2 is the first raw material argon inlet pipe; N3 is the nitrogen-hydrogen-argon circulating gas inlet pipe; N4 is the product argon outlet pipe; N5 is the non-condensable waste gas outlet pipe; N6 is the return injection liquid argon pipeline; N7 is the purified air inlet pipe; N8 is the nitrogen outlet pipe; N9 is the oxygen-enriched outlet pipe; N10 is the product nitrogen pipeline; and N11 is the low-pressure nitrogen outlet pipe. Detailed Implementation

[0030] To enable those skilled in the art to more clearly understand the purpose, technical solution, and advantages of the present invention, the present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0031] In the description of this invention, it should be understood that the orientation or positional relationship indicated by terms such as "upper", "lower", "left", "right", "inner", "outer", "lateral", and "vertical" is based on the orientation or positional relationship shown in the accompanying drawings and is only for the convenience of describing this invention, and is not intended to indicate or imply that the device or component referred to must have a specific orientation, and therefore should not be construed as a limitation of this invention.

[0032] The invention will now be described in detail with reference to the accompanying drawings: Figure 1As shown, an argon recovery device with ultra-high argon recovery rate includes a raw gas dust removal and pressurization system, a raw gas buffer compression system, a raw gas decarbonization system, a raw gas deoxygenation and drying system, a water electrolysis hydrogen production system, a cold box system C501, a nitrogen-hydrogen-argon mixed gas circulation compression system, a raw gas air filtration and compression system, an air precooling and purification system, and a liquid storage and vaporization system. These components are interconnected via pipelines. The cold box system C501 consists of an argon purification tower C21, a waste gas distillation tower C23, a nitrogen production distillation tower C22, a main heat exchanger, an expander, an argon tower auxiliary condenser E23, a nitrogen production condenser-evaporator K23, and a cooling capacity replenishment system. These components are connected and controlled via pipelines and valves.

[0033] The argon tower auxiliary condenser in this invention is used to balance the cold box and can transfer excess cooling capacity from the nitrogen generation system to the argon separation system.

[0034] The argon purification tower C21 consists of an upper purification tower condenser K22, a lower purification tower evaporator K21, and an intermediate tower section. The waste gas distillation tower C23 consists of an upper waste gas distillation tower condenser K25, a lower waste gas distillation tower evaporator K24, and an intermediate tower section. The nitrogen production distillation tower C22 and the nitrogen production condenser / evaporator K23 are arranged as one unit or separately.

[0035] The main heat exchanger is configured as two units based on the hydrogen-oxygen contact hazard: a first main heat exchanger E21 and a second main heat exchanger E22. The first main heat exchanger E21 is equipped with a first raw material argon gas inlet pipe N2, a nitrogen-hydrogen-argon circulating gas inlet pipe N3, and a non-condensable waste gas outlet pipe N5. The second main heat exchanger E22 is equipped with a second raw material argon gas inlet pipe N1, an oxygen-enriched gas outlet pipe N9, a purified air inlet pipe N7, a nitrogen outlet pipe N8, a low-pressure nitrogen outlet pipe N11, and a product argon gas outlet pipe N4.

[0036] The cold box system is also connected to a liquid argon return pipeline N6, which is connected to the argon purification tower C21. The nitrogen production distillation tower is also equipped with a product nitrogen pipeline N10 that connects to the outside of the cold box.

[0037] The expander is provided in two units, namely the first expander ET501 and the second expander ET502. The first expander ET501 and the second expander ET502 are gas bearing expanders, which use the expansion and refrigeration of backflow waste gas to provide cooling capacity for the cold box. One unit is in use and the other is on standby during operation.

[0038] A method for using an argon recovery device with ultra-high argon recovery rate, the method comprising the following steps:

[0039] 1) Argon pretreatment of raw materials;

[0040] 2) Argon recovery is achieved through cryogenic distillation;

[0041] 3) Argon gas from the product is delivered to the user.

[0042] Preferably, the argon pretreatment step in step 1) is as follows:

[0043] Step 1: The raw material is argon gas for dust removal, filtration, pressurization, and conveying; the dust removal filter adopts automatic multi-point back-blowing of argon gas;

[0044] Step 2: The raw material gas is buffered in a double-membrane gas holder and compressed by a compressor. The high-temperature compressed argon gas is then fed into the decarbonization system.

[0045] Step 3: Decarbonization of raw gas: The raw gas is reheated and converted into carbon dioxide through a high-temperature catalytic reaction. After the reaction, it is cooled and then removed by an adsorber to remove carbon dioxide and other impurities.

[0046] Step 4: Hydrogenation and drying of raw gas: After carbon dioxide removal, the raw gas is reheated and mixed with circulating nitrogen-hydrogen-argon mixture, and then fed into a deoxygenation reactor for chemical reaction to remove oxygen components from the raw gas; after the reaction, it is cooled and the moisture in the argon gas is removed by an adsorber.

[0047] Step 5: The water electrolysis hydrogen production system provides hydrogen consumed in the deoxygenation reaction and hydrogen lost in the non-condensable gas of the cold box distillation for the argon recovery unit.

[0048] Step 6: Start the raw material air filtration and compression system to provide raw material air for air separation nitrogen production;

[0049] Step 7: Start the air precooling unit to cool the air, and then start the purification system to remove impurities from the air.

[0050] The method for argon recovery in step 2) is as follows:

[0051] After deoxygenation and drying in step 7, the hydrogen-containing argon and dry air enter the cold box for distillation separation: the crude argon is split into two streams and pre-cooled in the first main heat exchanger E21 and the second main heat exchanger E22 respectively. After cooling, they merge and enter the evaporator K21 of the argon purification tower. Part of the non-condensable gas is reheated through the first main heat exchanger E21 and exits the cold box, while the rest is condensed into crude liquid argon. The non-condensable gas exiting the cold box is mixed with supplementary hydrogen through a circulating compressor and then enters the hydrogenation and deoxygenation system. After throttling, the crude liquid argon enters the argon purification tower C21 to participate in distillation. In the argon purification tower C21, high-purity liquid argon is obtained at the bottom, and hydrogen-containing argon sludge is obtained at the top. The hydrogen-containing argon sludge is condensed in the condenser K22 of the purification tower, and the condensed liquid is used as the reflux liquid of the argon purification tower C21. Part of the non-condensable gas is sent to... The waste gas enters the waste gas stripping tower C23 for further rectification and separation. The waste gas stripping tower C23 has an evaporator K24 at the bottom and a condenser K25 at the top. Non-condensable gases are fed into the lower part of the waste gas stripping tower C23 and separated through rectification. The bottom-rich liquid argon is heated and evaporated by nitrogen from the nitrogen-generating distillation tower C22, becoming the rising gas in the distillation tower C23. The top gas is condensed into liquid by liquid nitrogen and becomes the reflux liquid in the waste gas stripping tower C23. The non-condensable portion is reheated in the first main heat exchanger E21 and discharged from the cold box or reused. The liquid nitrogen condensed in the evaporator K24 of the waste gas stripping tower is throttled into the condenser K25 of the waste gas stripping tower and evaporated as a cold source. A portion of crude liquid argon is drawn from the bottom of the waste gas stripping tower C23 as the reflux liquid at the top of the argon purification tower C21. Simultaneously, the nitrogen from the nitrogen-generating evaporator K24 is condensed and evaporated. 23. Liquid nitrogen is drawn and throttled into the condenser K25 of the waste gas stripping tower to supplement cooling capacity and increase the reflux ratio of the waste gas stripping tower C23. The evaporated low-pressure nitrogen gas is reheated through the first main heat exchanger E21 or the second main heat exchanger E22 and exits the cold box as regeneration gas for the deoxygenation purifier. The high-purity liquid argon obtained from the argon purification tower C21 is throttled and enters the purification tower condenser K22. The liquid argon is evaporated and then reheated through the second main heat exchanger E22 before exiting the cold box. Air is pre-cooled in the second main heat exchanger E22 and then enters the nitrogen production distillation tower C22. Through distillation separation, oxygen-enriched liquid air is obtained at the bottom and high-purity nitrogen gas is obtained at the top. Part of the nitrogen gas is drawn from the top of the nitrogen production distillation tower C22, reheated through the second main heat exchanger E22, and exits the cold box for user use and as regeneration gas for the deoxygenation purifier. The oxygen-enriched liquid air is throttled... The nitrogen enters the nitrogen-generating condenser-evaporator K23, where it evaporates into oxygen-enriched air. It is then reheated to a certain temperature by the second main heat exchanger E22 and enters the first expander ET501 or the second expander ET502 for expansion and refrigeration, providing cooling for the cold box. After expansion, the oxygen-enriched air merges with the oxygen-enriched air evaporated by the argon tower auxiliary condenser E23, and then reheats again by the second main heat exchanger E22 before exiting the cold box. This serves as regeneration gas for the air purifier and decarbonization purifier. In the nitrogen-generating condenser-evaporator K23, nitrogen condenses into liquid nitrogen. Most of this liquid nitrogen is used as reflux liquid in the nitrogen-generating distillation tower C22, part is used as a cold source for the condenser of the waste gas stripping tower C23, and part is used as product liquid nitrogen, which is sent to the liquid nitrogen storage tank. To maintain the balance of argon usage and the cooling capacity of the cold box, a portion of the liquid argon is reinjected into the argon purification tower C21.

[0052] The argon purification tower, waste gas distillation tower, and nitrogen production distillation tower are all structured packed towers. The condenser, the first main heat exchanger E21, and the second main heat exchanger E22 are all plate-fin heat exchangers.

[0053] Compared to current argon recovery devices, this invention aims to improve the argon recovery rate of the cold box while reducing losses in the pretreatment stage.

[0054] This invention studies methods to improve the argon recovery rate of an argon recovery device by increasing the argon recovery rate of the cold box: 1. A non-condensable waste gas distillation column is added to the existing argon recovery device's cold box. A reboiler is installed at the bottom of this distillation column, using nitrogen from the nitrogen tower as a heat source; a condenser is installed at the bottom of the distillation column, using liquid nitrogen as a cold source. 2. Due to the increased argon recovery rate, the liquid argon backflow needs to be reduced. To maintain the device's cooling balance, a reflux gas expander needs to be added to the cold box.

[0055] The design features of this invention are as follows:

[0056] 1) The focus is on the further separation of waste gas to reduce the argon content in the waste gas;

[0057] 2) By adjusting the condenser and evaporator of the waste gas distillation tower, the reflux ratio can be increased, effectively improving the argon recovery rate.

[0058] 3) The choice of cold fluid for the condenser of the waste gas distillation tower is important. Using liquid nitrogen can ensure that a certain temperature difference is maintained between the liquid nitrogen and the waste gas at the top of the tower.

[0059] The specific embodiments described herein are merely illustrative of the principles and effects of the invention and are not intended to limit the invention. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of the invention. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this invention should still be covered by the claims of this invention.

Claims

1. An argon recovery device with ultra-high argon recovery rate, comprising a raw gas dust removal and pressurization system, a raw gas buffer compression system, a raw gas decarbonization system, a raw gas deoxygenation and drying system, a water electrolysis hydrogen production system, a cold box system, a nitrogen-hydrogen-argon mixed gas circulation compression system, a raw gas air filtration and compression system, an air precooling and purification system, and a liquid storage and vaporization system; all interconnected by pipelines, characterized in that: The cold box system consists of an argon purification tower, a waste gas distillation tower, a nitrogen production distillation tower, a main heat exchanger, an expander, an argon tower auxiliary condenser, a nitrogen production evaporator, and a cooling capacity replenishment system, all connected and controlled by pipes and valves. The argon purification tower consists of an upper purification tower condenser, a lower purification tower evaporator, and an intermediate tower section. The waste gas distillation tower consists of an upper waste gas distillation tower condenser, a lower waste gas distillation tower evaporator, and an intermediate tower section. The nitrogen production distillation tower and the nitrogen production evaporator can be integrated or arranged separately. The main heat exchanger is configured with two units based on the hydrogen-oxygen contact hazard: a first main heat exchanger and a second main heat exchanger. The first main heat exchanger has a first raw material argon inlet pipe, a nitrogen-hydrogen-argon circulating gas inlet pipe, and a non-condensable waste gas outlet pipe. The second main heat exchanger has a second raw material argon inlet pipe, an oxygen-enriched gas outlet pipe, a purified air inlet pipe, a nitrogen outlet pipe, a low-pressure nitrogen outlet pipe, and a product argon outlet pipe.

2. The argon recovery device with ultra-high argon recovery rate according to claim 1, characterized in that: The cold box system is also connected to a liquid argon return pipeline, which is connected to an argon purification tower. The nitrogen production distillation tower is also equipped with a product nitrogen pipeline that connects to the outside of the cold box.

3. The argon recovery device with ultra-high argon recovery rate according to claim 1, characterized in that: The expander is provided in two units, namely the first expander and the second expander. The first expander and the second expander are gas bearing expanders, which use the expansion and refrigeration of backflow waste gas to provide cooling capacity for the cold box. One expander is in use and the other is on standby during operation.

4. The method of using the argon recovery device with ultra-high argon recovery rate according to any one of claims 1-3, characterized in that: The method includes the following steps: 1) Argon pretreatment of raw materials; 2) Argon recovery is achieved through cryogenic distillation. The steps and methods for argon recovery are as follows: After deoxygenation and drying in step 7, hydrogen-containing argon and dry air enter the cold box for distillation separation: crude argon is divided into two streams and enters the first and second main heat exchangers for pre-cooling. After cooling, they are combined and enter the evaporator of the argon purification tower. Part of the non-condensable gas is reheated through the first main heat exchanger and exits the cold box, while the rest is condensed into crude liquid argon. The non-condensable gas exiting the cold box is mixed with supplementary hydrogen through the circulating compressor and then enters the hydrogenation and deoxygenation system. After throttling, the crude liquid argon enters the argon purification tower to participate in distillation. High-purity liquid argon is obtained at the bottom of the argon purification tower. The top of the column yields hydrogen-containing argon-nitrogen waste, which is condensed in the condenser of the purification tower. The condensed liquid serves as the reflux liquid for the argon purification tower. A portion of the non-condensable gas is sent to the waste gas stripping tower for further distillation and separation. The waste gas stripping tower has an evaporator at the bottom and a condenser at the top. The non-condensable gas is sent to the lower part of the waste gas stripping tower and separated by distillation. The bottom-rich liquid argon is heated and evaporated by nitrogen from the nitrogen production distillation tower, becoming the rising gas in the distillation tower. The top gas is condensed into liquid by liquid nitrogen, serving as the reflux liquid for the waste gas stripping tower. The non-condensable portion is used as waste gas in the first... The reheated nitrogen from the main heat exchanger exits the cold box for venting or reuse. Liquid nitrogen condensed from the evaporator in the waste gas stripping tower is throttled into the condenser, where it is evaporated as a cold source. A portion of crude liquid argon is drawn from the bottom of the waste gas stripping tower as reflux liquid at the top of the argon purification tower. Simultaneously, liquid nitrogen is drawn from the nitrogen generator evaporator and throttled into the condenser to supplement cooling capacity and increase the reflux ratio. The evaporated low-pressure nitrogen is reheated in the first or second main heat exchanger and exits the cold box as regeneration gas for the deoxygenation purifier. The high-purity nitrogen obtained from the argon purification tower... After being throttled, liquid argon enters the purification tower condenser, where it evaporates. It then reheats in the second main heat exchanger before exiting the cold box. Air, after pre-cooling in the second main heat exchanger, enters the nitrogen-generating distillation tower. Distillation separates oxygen-enriched liquid air at the bottom and high-purity nitrogen at the top. A portion of the nitrogen is drawn from the top of the distillation tower, reheated in the second main heat exchanger, and exits the cold box for user use and as regeneration gas for the deoxygenation purifier. The oxygen-enriched liquid air, after being throttled, enters the nitrogen-generating condenser-evaporator, where it evaporates into oxygen-enriched air. It then reheats to a certain temperature in the second main heat exchanger before entering the first expander or the second... The second expander expands and cools the air to provide cooling capacity for the cold box. After expansion, the oxygen-enriched air merges with the oxygen-enriched air evaporated by the argon tower auxiliary condenser, and then is reheated by the second main heat exchanger before exiting the cold box as regeneration gas for the air purifier and decarbonization purifier. In the nitrogen-generating condenser evaporator, nitrogen is condensed into liquid nitrogen. Most of it is used as reflux liquid in the nitrogen-generating distillation tower, part is used as a cold source for the condenser of the waste gas stripping tower, and part is used as product liquid nitrogen and sent to the liquid nitrogen storage tank. In order to maintain the balance of argon usage and the cooling capacity of the cold box, part of the liquid argon is reinjected into the argon purification tower. 3) Argon gas from the product is delivered to the user.

5. The method of using the argon recovery device with ultra-high argon recovery rate according to claim 4, characterized in that: The step of pretreatment of raw material argon gas in step 1) is as follows: Step 1: The raw material is argon gas for dust removal, filtration, pressurization, and conveying; the dust removal filter adopts automatic multi-point back-blowing of argon gas; Step 2: The raw material gas is buffered in a double-membrane gas holder and compressed by a compressor. The high-temperature compressed argon gas is then fed into the decarbonization system. Step 3: Decarbonization of raw gas: The raw gas is reheated and converted into carbon dioxide through a high-temperature catalytic reaction. After the reaction, it is cooled and then removed by an adsorber to remove carbon dioxide and other impurities. Step 4: Hydrogenation and drying of raw gas: After removing carbon dioxide, the raw gas is reheated and mixed with circulating nitrogen-hydrogen-argon mixture, and then fed into a deoxygenation reactor to carry out a chemical reaction to remove oxygen components from the raw gas. After the reaction, the gas is cooled and the moisture in the argon is removed by an adsorber. Step 5: The water electrolysis hydrogen production system provides hydrogen consumed in the deoxygenation reaction and hydrogen lost in the non-condensable gas of the cold box distillation for the argon recovery unit. Step 6: Start the raw material air filtration and compression system to provide raw material air for air separation nitrogen production; Step 7: Start the air precooling unit to cool the air, and then start the purification system to remove impurities from the air.

6. The method of using the argon recovery device with ultra-high argon recovery rate according to claim 4, characterized in that: The argon purification tower, waste gas distillation tower, and nitrogen production distillation tower are all structured packed towers.

7. The method of using the argon recovery device with ultra-high argon recovery rate according to claim 4, characterized in that: The condenser, the first main heat exchanger, and the second main heat exchanger are all plate-fin heat exchangers.

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