Small air separation liquid argon rectification device

Abstract

The utility model relates to a small air separation liquid argon rectification device which comprises a main rectification tower, the main rectification tower comprises an upper tower, a main condensation evaporator and a lower tower, a rectification raw material conveying pipe is arranged on the upper tower, a first rectification tower is arranged at the outlet end of the rectification raw material conveying pipe, and first return pipes are arranged on the first rectification tower and the upper tower. A first filler layer, a second return pipe and a middle gas conveying pipe are arranged in the first rectifying tower, a second rectifying tower is arranged on the second return pipe and the middle gas conveying pipe, a second filler layer, a liquid argon collecting barrel and a third filler layer are arranged in the second rectifying tower, and a liquid argon extraction pipe is arranged at the bottom end of the liquid argon collecting barrel; a first connecting pipe is arranged on the liquid argon extraction pipe, a second connecting pipe is arranged on the second rectifying tower above the liquid argon collection cylinder, and first liquid level sensors are arranged on the second connecting pipe and the first connecting pipe. And the liquid argon product can be extracted from the small-flow liquid argon reflux liquid. The utility model has the advantages of convenient use and wide market prospect.

Description

Technical Field

[0001] This utility model relates to the field of liquid argon distillation equipment for small air separation units, and specifically to a liquid argon distillation device for small air separation units. Background Technology

[0002] In the air separation unit's process flow, the feed air undergoes a series of operations including filtration, compression, precooling, purification, pressurization, expansion, and heat exchange before entering the lower column. After preliminary distillation in the lower column, oxygen-enriched liquid air is obtained at the bottom, and pure liquid nitrogen is obtained at the top. This liquid nitrogen is then subcooled by a subcooler and throttled before entering the upper column. After further distillation in the upper column, liquid oxygen is obtained at the bottom. This liquid oxygen is compressed by a liquid oxygen pump and enters the main heat exchanger. After reheating, it exits the cold box as gaseous oxygen. A portion of the liquid oxygen exits the cold box directly as liquid oxygen and enters the liquid oxygen storage tank. Liquid nitrogen is extracted from the top of the upper column and enters the liquid nitrogen storage tank.

[0003] Air separation equipment adheres to the principles of material balance and the law of conservation of energy. With a fixed expander efficiency and expansion air volume, the total amount of liquid the equipment can produce is also fixed, given a given refrigeration capacity. According to the principle of material balance, the amount of oxygen produced remains constant. The transfer of liquid oxygen and liquid nitrogen products is achieved by simultaneously increasing and decreasing the amount of liquid nitrogen refluxed from the upper column and the amount of oxygen rising. Based on the oxygen content of the argon fraction, the reflux ratio remains constant; only the amount of refluxed liquid nitrogen and rising gaseous oxygen changes. For users of small air separation units, some customers require liquid argon products. However, for small air separation units, the amount of compressed air entering the main distillation column is relatively small, resulting in a relatively low flow rate of reflux liquid from the upper column. The amount of reflux liquid suitable for producing liquid argon is even smaller, making the process of producing liquid argon using small air separation units difficult. The key issue is that the unit flow rate of the raw material suitable for liquid argon distillation is already low, and the flow rate of the standard-compliant liquid argon produced after distillation is even lower, making it difficult to implement using conventional continuous liquid argon extraction processes. Because the liquid argon produced by small-scale air separation units is insufficient to meet the process conditions required for continuous extraction, there is room for improvement in the existing technology. The aim is to modify the argon production equipment attached to the small-scale air separation unit to meet the liquid argon product requirements of users of this type of air separation unit. Summary of the Invention

[0004] To address the shortcomings of existing technologies, this invention provides a small-scale air separation liquid argon distillation device capable of extracting liquid argon products from low-flow-rate liquid argon reflux liquid, thereby overcoming the deficiencies in existing technologies.

[0005] The technical solution adopted in this utility model is as follows: a small-scale air separation liquid argon distillation device, including a main distillation column, which, from top to bottom, includes an upper column, a main condenser / evaporator, and a lower column. The upper column is provided with the inlet end of a distillation feed pipe, and a first distillation column is provided at the outlet end of the distillation feed pipe. A first reflux pipe is provided on the first distillation column and the upper column. A first packing layer is provided inside the first distillation column above the first reflux pipe and the distillation feed pipe. The first distillation column above the first packing layer is provided with the outlet end of a second reflux pipe and the inlet end of an intermediate gas conveying pipe. The inlet end of the second reflux pipe and the intermediate gas conveying pipe... A second distillation column is installed at the outlet end of the gas delivery pipe. Inside the second distillation column above the second reflux pipe and the intermediate gas delivery pipe, a second packing layer, a liquid argon collection cylinder, and a third packing layer are arranged sequentially from bottom to top. The liquid argon collection cylinder adopts a barrel-shaped structure with its open end facing the third packing layer. The diameter of the inner circle at the top of the liquid argon collection cylinder gradually decreases as the height of the liquid argon collection cylinder decreases. A liquid argon outlet pipe is installed at the bottom end of the liquid argon collection cylinder, and a first connecting pipe is installed on the liquid argon outlet pipe. A second connecting pipe is installed on the second distillation column above the liquid argon collection cylinder, and a first liquid level sensor is installed on the second connecting pipe and the first connecting pipe.

[0006] Preferably, the top of the second distillation column is provided with a top condenser. The inlet end of the heat source channel of the second distillation column above the third packing layer and the top condenser are connected. The outlet end of the heat source channel of the top condenser is provided with the inlet end of a mixture conveying pipe. A gas-liquid separator is provided at the outlet end of the mixture conveying pipe. The liquid phase outlet end of the gas-liquid separator is connected to the second distillation column above the third packing layer through a third reflux liquid conveying pipe. A non-condensable gas discharge pipe is provided at the gas phase outlet end of the gas-liquid separator. A first regulating valve is provided on the non-condensable gas discharge pipe, the third reflux liquid conveying pipe, the liquid argon extraction pipe, the distillation feed conveying pipe, and the first reflux pipe.

[0007] Preferably, a pressure sensor is installed on the non-condensable gas discharge pipe between the first regulating valve on the non-condensable gas discharge pipe and the gas-liquid separator, and a second liquid level sensor is installed on the gas-liquid separator.

[0008] Preferably, the upper and lower towers are provided with a liquid-air transport main pipe, the liquid-air transport main pipe is provided with a first heat source channel for a subcooler, the cold source channel of the subcooler and the upper tower are provided with a sludge nitrogen transport pipe, the inlet end of the liquid-air transport main pipe between the subcooler and the upper tower is provided with a first liquid-air transport branch pipe, the outlet end of the first liquid-air transport branch pipe is connected to the cold source channel of the condenser at the top of the tower, the top end of the cold source channel of the condenser at the top of the tower and the upper tower are provided with an oxygen-enriched air transport pipe, the bottom end of the cold source channel of the condenser at the top of the tower and the upper tower are provided with a second liquid-air transport branch pipe, and a second regulating valve is provided on the liquid-air transport main pipe between the first liquid-air transport branch pipe and the upper tower, the first liquid-air transport branch pipe and the second liquid-air transport branch pipe respectively.

[0009] Preferably, a main heat exchanger is installed on the waste nitrogen gas delivery pipe on the side of the subcooler away from the upper tower. A raw material air delivery pipe is installed on the main heat exchanger and the lower tower. A pressure nitrogen delivery pipe is installed at the inlet end of the heat source channel of the main condenser-evaporator and on the lower tower. A liquid nitrogen delivery main pipe is installed at the outlet end of the heat source channel of the main condenser-evaporator and the second heat source channel of the subcooler. A first liquid nitrogen reflux pipe, a second liquid nitrogen reflux pipe, and a third regulating valve are sequentially installed along the direction from the inlet end to the outlet end of the liquid nitrogen delivery main pipe. The second heat source channel of the subcooler is located between the first liquid nitrogen reflux pipe and the second liquid nitrogen reflux pipe. A fourth regulating valve is installed on both the first liquid nitrogen reflux pipe and the second liquid nitrogen reflux pipe.

[0010] Preferably, the second reflux pipe is provided with a filter and a reflux pump in sequence along the direction from the second distillation column to the first distillation column.

[0011] The beneficial effects of this utility model are as follows: First, this utility model fully utilizes the distillation conditions inside the second distillation column and uses the temperature inside the second distillation column as a heat preservation cold source, thereby avoiding the technical problem that the liquid argon product cannot be successfully and effectively extracted due to the insufficient amount of finished liquid argon extracted. Furthermore, this product sets a second connecting pipe and a first connecting pipe, and sets a first liquid level sensor on the second connecting pipe and the first connecting pipe. The parameters fed back by the first liquid level sensor can promptly reflect the liquid level parameters in the liquid argon collection cylinder, making it easier to determine the time of liquid argon extraction.

[0012] Secondly, a pressure sensor is installed on the non-condensable gas discharge pipe between the first regulating valve on the non-condensable gas discharge pipe and the gas-liquid separator as described in this utility model. The installation of the pressure sensor facilitates the feedback of pressure parameters. A second liquid level sensor is installed on the gas-liquid separator to facilitate the feedback of liquid level parameters.

[0013] This utility model is easy to operate, ingeniously designed, greatly improves work efficiency, has good social and economic benefits, and is a product that is easy to promote and use. Attached Figure Description

[0014] Figure 1 This is a schematic diagram of the structure of this utility model.

[0015] Figure 2 for Figure 1 A magnified view of detail A. Detailed Implementation

[0016] like Figure 1 and Figure 2As shown, a small-scale air separation liquid argon distillation unit includes a main distillation column and a main heat exchanger 33 for gas heat exchange. The main distillation column, from top to bottom, includes an upper column 1, a main condenser-evaporator 2, and a lower column 3. The cold source channel of the main condenser-evaporator 2 is connected to the upper column 1. The upper column 1 is provided with the inlet end of a distillation feed pipe 4. The outlet end of the distillation feed pipe 4 is provided with a first distillation column 5. The first distillation column 5 and the upper column 1 are provided with a first reflux pipe 6. The first distillation column 5 above the first reflux pipe 6 and the distillation feed pipe 4 is provided with a first packing layer 7. The first distillation column 5 above the first packing layer 7 is provided with the outlet end of a second reflux pipe 8 and the inlet end of an intermediate gas conveying pipe 9. The inlet end of the second reflux pipe 8 and the intermediate gas conveying pipe 9 are connected to the lower column 1. A second distillation column 10 is installed at the outlet end of the gas delivery pipe 9. Inside the second distillation column 10 above the second reflux pipe 8 and the intermediate gas delivery pipe 9, a second packing layer 11, a liquid argon collection cylinder 12, and a third packing layer 13 are arranged sequentially from bottom to top. The liquid argon collection cylinder 12 has a barrel-shaped structure with its open end facing the third packing layer 13. The diameter of the inner circle at the top of the liquid argon collection cylinder 12 gradually decreases as the height of the liquid argon collection cylinder 12 decreases. A liquid argon extraction pipe 14 is installed at the bottom end of the liquid argon collection cylinder 12. A first connecting pipe 15 is installed on the liquid argon extraction pipe 14. A second connecting pipe 16 is installed on the second distillation column 10 above the liquid argon collection cylinder 12. A first liquid level sensor 17 is installed on the second connecting pipe 16 and the first connecting pipe 15.

[0017] The second distillation column 10 is equipped with a top condenser 18. The inlet end of the heat source channel of the second distillation column 10 above the third packing layer 13 and the top condenser 18 are connected. The outlet end of the heat source channel of the top condenser 18 is equipped with the inlet end of the mixture conveying pipe 19. The outlet end of the mixture conveying pipe 19 is equipped with a gas-liquid separator 20. The liquid phase outlet end of the gas-liquid separator 20 and the second distillation column 10 above the third packing layer 13 are connected through a third reflux liquid conveying pipe 21. The gas phase outlet end of the gas-liquid separator 20 is equipped with a non-condensable gas discharge pipe 22. The non-condensable gas discharge pipe 22, the third reflux liquid conveying pipe 21, the liquid argon extraction pipe 14, the distillation feed conveying pipe 4 and the first reflux pipe 6 are each equipped with a first regulating valve 23. A pressure sensor 24 is installed on the non-condensable gas discharge pipe 22 between the first regulating valve 23 on the non-condensable gas discharge pipe 22 and the gas-liquid separator 20, and a second liquid level sensor 25 is installed on the gas-liquid separator 20.

[0018] The upper tower 1 and lower tower 3 are provided with a liquid-air transport main pipe 26. The liquid-air transport main pipe 26 is provided with a first heat source channel of a supercooler 27. The cold source channel of the supercooler 27 and the upper tower 1 are provided with a sludge nitrogen transport pipe 28. The inlet end of the first liquid-air transport branch pipe 29 is provided on the liquid-air transport main pipe 26 between the supercooler 27 and the upper tower 1. The outlet end of the first liquid-air transport branch pipe 29 is connected to the cold source channel of the tower top condenser 18. The top end of the cold source channel of the tower top condenser 18 and the upper tower 1 are provided with an oxygen-enriched air transport pipe 30. The bottom end of the cold source channel of the tower top condenser 18 and the upper tower 1 are provided with a second liquid-air transport branch pipe 31. The liquid-air transport main pipe 26 between the first liquid-air transport branch pipe 29 and the upper tower 1, the first liquid-air transport branch pipe 29 and the second liquid-air transport branch pipe 31 are each provided with a second regulating valve 32.

[0019] A main heat exchanger 33 is installed on the waste nitrogen gas delivery pipe 28 on the side of the subcooler 27 away from the upper tower 1. A raw material air delivery pipe 34 is provided on the main heat exchanger 33 and the lower tower 3. A pressure nitrogen delivery pipe 35 is provided at the inlet end of the heat source channel of the main condenser evaporator 2 and on the lower tower 3. A liquid nitrogen delivery main pipe 36 is provided at the outlet end of the heat source channel of the main condenser evaporator 2 and the second heat source channel of the subcooler 27. A first liquid nitrogen reflux pipe 37, a second liquid nitrogen reflux pipe 38 and a third regulating valve 39 are arranged sequentially along the direction from the inlet end to the outlet end of the liquid nitrogen delivery main pipe 36. The second heat source channel of the subcooler 27 is located between the first liquid nitrogen reflux pipe 37 and the second liquid nitrogen reflux pipe 38. A fourth regulating valve 40 is provided on both the first liquid nitrogen reflux pipe 37 and the second liquid nitrogen reflux pipe 38. A finished liquid oxygen delivery pipe 43 is installed at the bottom of the cold source channel of the main condenser evaporator 2, and a fifth regulating valve 44 is installed on the finished liquid oxygen delivery pipe 43. The second reflux pipe 8 is provided with a filter 41 and a reflux pump 42 in sequence along the direction from the second distillation column 10 to the first distillation column 5.

[0020] The outlet ends of the second liquid nitrogen reflux pipe 38, the outlet ends of the liquid air transport main pipe 26, the outlet ends of the oxygen-enriched air transport pipe 30, the outlet ends of the second liquid air transport branch pipe 31, the inlet ends of the distillation feedstock transport pipe 4, and the outlet ends of the first reflux pipe 6 are all connected to the upper column 1. The outlet end of the liquid air transport main pipe 26 is located below the outlet end of the second liquid nitrogen reflux pipe 38, the outlet end of the oxygen-enriched air transport pipe 30 is located below the outlet end of the liquid air transport main pipe 26, the outlet end of the second liquid air transport branch pipe 31 is located below the outlet end of the oxygen-enriched air transport pipe 30, the inlet end of the distillation feedstock transport pipe 4 is located below the outlet end of the second liquid air transport branch pipe 31, and the outlet end of the first reflux pipe 6 is located below the inlet end of the distillation feedstock transport pipe 4.

[0021] The usage instructions for this product are as follows: Figure 1 and Figure 2 As shown, it includes the following steps:

[0022] S1. Compressed air, after being processed by the precooling system and purification system, forms raw material compressed air and is delivered to the raw material air delivery pipe 34. It passes through the heat source channel of the main heat exchanger 33 as one of the heat sources of the main heat exchanger 33 and exchanges heat with the cold source delivered to the main heat exchanger 33. After heat exchange, it is delivered to the lower column 3 to participate in the rectification of the lower column 3 as the rectification raw material of the lower column 3. After the raw material compressed air enters the lower column 3, it continues to rise and continuously exchanges heat with the first reflux liquid continuously received at the top of the lower column 3. The nitrogen component in the first reflux liquid continuously volatilizes. During this period, the oxygen component in the raw material air is liquefied and continues to descend with the first reflux liquid to the bottom of the lower column 3. Finally, an oxygen-rich liquid air accumulation zone is formed at the top of the lower column 3, and a high-pressure nitrogen accumulation zone is formed at the top of the upper column 1.

[0023] S2, the high-pressure nitrogen enrichment zone of the lower tower 3 is transported to the heat source channel and cold source channel of the main condenser-evaporator 2 via the pressure nitrogen delivery pipe 35 for heat exchange. The outlet of the heat source channel of the main condenser-evaporator 2 continuously supplies liquid nitrogen to the liquid nitrogen delivery main pipe 36. After entering the liquid nitrogen delivery main pipe 36, the liquid nitrogen is divided into two parts: a first part and a second part. The first part of liquid nitrogen is transported to the top of the lower tower 3 via the first liquid nitrogen reflux pipe 37 as the first reflux condensate of the lower tower 3. Two portions of liquid nitrogen are supplied to the second heat source channel of the subcooler 27 and the cold source continuously supplied to the subcooler 27 to exchange heat and form subcooled liquid nitrogen. The subcooled liquid nitrogen continues to move toward the outlet end of the liquid nitrogen supply main pipe 36 and is divided into two parts, namely the first part of subcooled liquid nitrogen and the second part of subcooled liquid nitrogen. The first part of subcooled liquid nitrogen is supplied to the liquid nitrogen storage equipment through the outlet end of the liquid nitrogen supply main pipe 36 as the finished liquid nitrogen product. The second part of subcooled liquid nitrogen is supplied to the upper tower 1 through the second liquid nitrogen reflux pipe 38 as the second reflux liquid of the upper tower 1.

[0024] S3. The oxygen-enriched liquid air accumulation zone of the lower tower 3 is transported outward through the liquid air conveying main pipe 26. The oxygen-enriched liquid air is first sent to the first heat source channel of the subcooler 27 and the cold source continuously supplied to the subcooler 27 for heat exchange to form subcooled oxygen-enriched liquid air. Then it is divided into two parts, namely the first part of subcooled oxygen-enriched liquid air and the second part of subcooled oxygen-enriched liquid air. The first part of subcooled oxygen-enriched liquid air is transported to the upper tower 1 through the outlet end of the liquid air conveying main pipe 26 as the third reflux liquid of the upper tower 1. The second part of subcooled oxygen-enriched liquid air is transported to the cold source channel of the top condenser 18 through the first liquid air conveying branch pipe 29 as the cold source of the top condenser 18.

[0025] The third reflux liquid in the upper column 1 continuously flows downwards and is supplied to the cold source channel and heat source channel of the main condenser-evaporator 2 for heat exchange. The medium in the cold source channel of the main condenser-evaporator 2 is continuously vaporized to form a distillation feed gas. This feed gas is divided into two parts: a first part and a second part. The first part of the feed gas continues to flow upwards and sequentially exchanges heat counter-currently with the third reflux liquid and the second reflux liquid. The oxygen component in the first part of the feed gas is gradually liquefied and incorporated into the descending liquid flow of the upper column 1, which consists of the third reflux liquid and the second reflux liquid. Meanwhile, the nitrogen component in the descending liquid flow is continuously vaporized and incorporated into the first part of the feed gas. The upward airflow from the upper column 1 eventually forms a liquid oxygen enrichment zone in the cold source channel of the main condenser-evaporator 2, and a low-pressure nitrogen enrichment zone above the outlet of the second liquid nitrogen reflux pipe 38. Non-condensable gases and other impurities are enriched at the top of the low-pressure nitrogen enrichment zone. The nitrogen carrying the non-condensable gases is continuously discharged to the waste nitrogen conveying pipe 28 to form waste nitrogen. The waste nitrogen is first transported to the cold source channel of the subcooler 27 and exchanged with the heat source medium continuously transported to the subcooler 27. After heat exchange with the cold source channel of the main heat exchanger 33 and the heat source continuously transported to the main heat exchanger 33, it is discharged to the outlet of the waste nitrogen conveying pipe 28. The second part of the distillation feed gas is transported to the first distillation column 5 below the first packing layer 7 through the distillation feed gas conveying pipe 4 as the distillation feed of the first distillation column 5.

[0026] S4. During the continuous upward flow of the second part of the distillation feed gas into the first distillation column 5, it undergoes countercurrent heat exchange with the fourth reflux liquid transported through the second reflux pipe 8. The oxygen component in the second part of the distillation feed gas is liquefied and flows downward with the fourth reflux liquid to form the descending liquid flow of the first distillation column 5. Finally, a crude argon enrichment zone is formed at the top of the first distillation column 5, and an argon-free liquid enrichment zone is formed at the bottom of the first distillation column 5. The argon-free liquid enrichment zone is transported to the upper column 1 through the first reflux pipe 6. The argon-free liquid flow is merged into the descending liquid flow of the upper column 1 and transported together to the cold source channel of the main condenser evaporator 2. The argon-free liquid enrichment zone is then transported to the second distillation column 10 through the intermediate gas transport pipe 9 as the distillation feed of the second distillation column 10.

[0027] S5. During the continuous upward flow of the crude argon gas into the second distillation column 10, it undergoes continuous countercurrent heat exchange with the downward flow of the liquid in the first distillation column 5. The argon component in the crude argon gas is liquefied for the first time, forming a first liquid argon enrichment zone at the bottom of the second distillation column 10. The first liquid argon enrichment zone continuously supplies liquid argon through the first distillation column 5 as the fourth reflux liquid of the first distillation column 5. The crude argon gas continues to rise to the top of the second distillation column 10 and is supplied to the heat source channel of the top condenser 18 for heat exchange with the medium in the heat source channel of the top condenser 18. The argon component is completely liquefied and transported to the gas-liquid separator 2 through the mixture delivery pipe 19. Gas-liquid separation is performed in the gas-liquid separator 20. The gas phase in the gas-liquid separator 20 is non-condensable gas, which is periodically discharged through the non-condensable gas discharge pipe 22. During this period, the value fed back by the pressure sensor 24 needs to be kept within the preset range. The liquid argon in the gas-liquid separator 20 is sent back to the top of the second distillation column 10 through the third reflux liquid delivery pipe 21 as the descending liquid flow of the first distillation column 5. The descending liquid flow of the first distillation column 5 delivered from the top of the second distillation column 10 is collected by the liquid argon collection cylinder 12 as the finished liquid argon product during the descent. The uncollected part is used as the cold source required for the countercurrent heat exchange of the crude argon gas in the second distillation column 10.

[0028] The second portion of subcooled oxygen-enriched liquid air, which is transported through the first liquid air delivery branch pipe 29 and received by the cold source channel of the top condenser 18, undergoes heat exchange and is partially vaporized. The gas phase portion is sent back to the upper column 1 through the oxygen-enriched air delivery pipe 30 and merges into the rising gas flow of the upper column 1 to participate in the rectification of the upper column 1. The second portion of subcooled oxygen-enriched liquid air that has not been vaporized in the cold source channel of the top condenser 18 is sent back to the upper column 1 through the second liquid air delivery branch pipe 31 and merges into the descending liquid flow of the upper column 1, thereby forming a liquid oxygen enrichment zone in the cold source channel of the main condenser evaporator 2. The liquid oxygen enrichment zone continuously supplies finished liquid oxygen to the outside through the finished liquid oxygen delivery pipe 43.

[0029] S6. As distillation continues in the second distillation column 10, once the liquid level parameters in the gas-liquid separator 20, which are fed back through the first connecting pipe 15, the second connecting pipe 16, and the first liquid level sensor 17, reach the preset range, the first regulating valve 23 of the liquid argon extraction pipe 14 can be opened to deliver the finished liquid argon product.

[0030] In this embodiment, the product fully utilizes the distillation conditions within the second distillation column 10 and uses the temperature within the second distillation column 10 as a heat preservation and cold source, thereby avoiding the technical problem that the liquid argon product cannot be successfully and effectively extracted due to insufficient liquid argon extraction volume and vaporization during the extraction process. Furthermore, by setting a second connecting pipe 16 and a first connecting pipe 15, and installing a first liquid level sensor 17 on the second connecting pipe 16 and the first connecting pipe 15, the parameters fed back by the first liquid level sensor 17 can promptly provide feedback on the liquid level parameters within the liquid argon collection cylinder 12, making it easier to determine the time of liquid argon extraction.

[0031] The embodiments described above are merely preferred embodiments of this utility model and are not intended to limit the scope of implementation of this utility model. Therefore, all equivalent changes or modifications made to the structure, features and principles described in the patent claims of this utility model should be included within the scope of the patent application of this utility model.

Claims

1. A small-sized, air-spaced liquid argon rectification device comprising a main rectification column, said main rectification column comprising, from top to bottom, an upper column (1), a main condenser-evaporator (2) and a lower column (3), characterized in that: The upper tower (1) is provided with the inlet end of the rectification raw material conveying pipe (4), the outlet end of the rectification raw material conveying pipe (4) is provided with the first rectification tower (5), the first rectification tower (5) and the upper tower (1) are provided with the first reflux pipe (6), the first reflux pipe (6) and the first rectification tower (5) above the rectification raw material conveying pipe (4) are provided with the first filler layer (7), the first rectification tower (5) above the first filler layer (7) is provided with the outlet end of the second reflux pipe (8) and the inlet end of the intermediate gas conveying pipe (9), the inlet end of the second reflux pipe (8) and the outlet end of the intermediate gas conveying pipe (9) are provided with the second rectification tower (10), the second rectification tower (10) above the second reflux pipe (8) and the intermediate gas conveying pipe (9) are sequentially provided with the second filler layer (11), the liquid argon collecting cylinder (12) and the third filler layer (13) along the direction from bottom to top, the liquid argon collecting cylinder (12) adopts the barrel-shaped structure with the open end facing the third filler layer (13), the inscribed circle diameter of the top of the liquid argon collecting cylinder (12) gradually decreases with the decrease of the height of the liquid argon collecting cylinder (12), the bottom end of the liquid argon collecting cylinder (12) is provided with the liquid argon extraction pipe (14), the liquid argon extraction pipe (14) is provided with the first connecting pipe (15), the second rectification tower (10) above the liquid argon collecting cylinder (12) is provided with the second connecting pipe (16), and the first liquid level sensor (17) is arranged on the first connecting pipe (15) and the second connecting pipe (16).

2. The compact, small-scale, liquid argon distillation apparatus of claim 1, wherein: The top of the second rectification tower (10) is provided with the tower top condenser (18), the second rectification tower (10) above the third filler layer (13) and the inlet end of the heat source channel of the tower top condenser (18) are connected in communication, the outlet end of the heat source channel of the tower top condenser (18) is provided with the inlet end of the mixture conveying pipe (19), the outlet end of the mixture conveying pipe (19) is provided with the gas-liquid separation tank (20), the liquid phase outlet end of the gas-liquid separation tank (20) and the second rectification tower (10) above the third filler layer (13) are connected in communication through the third reflux liquid conveying pipe (21), the gas phase outlet end of the gas-liquid separation tank (20) is provided with the non-condensable gas discharge pipe (22), the non-condensable gas discharge pipe (22), the third reflux liquid conveying pipe (21), the liquid argon extraction pipe (14), the rectification raw material conveying pipe (4) and the first reflux pipe (6) are respectively provided with the first regulating valve (23).

3. The compact, small-scale, liquid argon distillation apparatus of claim 2, wherein: The pressure sensor (24) is arranged on the non-condensable gas discharge pipe (22) between the first regulating valve (23) on the non-condensable gas discharge pipe (22) and the gas-liquid separation tank (20), and the second liquid level sensor (25) is arranged on the gas-liquid separation tank (20).

4. The compact, small-scale, liquid argon distillation apparatus of claim 2, wherein: The upper tower (1) and the lower tower (3) are provided with a liquid air delivery main pipe (26), the liquid air delivery main pipe (26) is provided with a first heat source channel of the subcooler (27), the subcooler (27) is provided with a cold source channel, the upper tower (1) is provided with a waste nitrogen gas delivery pipe (28), the liquid air delivery main pipe (26) between the subcooler (27) and the upper tower (1) is provided with an inlet end of a first liquid air delivery branch pipe (29), the outlet end of the first liquid air delivery branch pipe (29) is connected with the cold source channel of the overhead condenser (18), the top end of the cold source channel of the overhead condenser (18) is provided with an oxygen-rich air delivery pipe (30) on the upper tower (1), the bottom end of the cold source channel of the overhead condenser (18) is provided with a second liquid air delivery branch pipe (31) on the upper tower (1), and the liquid air delivery main pipe (26) between the first liquid air delivery branch pipe (29) and the upper tower (1), the first liquid air delivery branch pipe (29) and the second liquid air delivery branch pipe (31) are all provided with a second adjusting valve (32) respectively.

5. The compact, small-scale, liquid argon distillation apparatus of claim 4, wherein: The waste nitrogen gas delivery pipe (28) away from the upper tower (1) side of the subcooler (27) is provided with a main heat exchanger (33), the main heat exchanger (33) and the lower tower (3) are provided with a raw material air delivery pipe (34), the inlet end of the heat source channel of the main condensation evaporator (2) is provided with a pressurized nitrogen gas delivery pipe (35) on the lower tower (3), the outlet end of the heat source channel of the main condensation evaporator (2) is provided with a liquid nitrogen delivery main pipe (36) on the second heat source channel of the subcooler (27), the liquid nitrogen delivery main pipe (36) is sequentially provided with a first liquid nitrogen backflow pipe (37), a second liquid nitrogen backflow pipe (38) and a third adjusting valve (39) from the inlet end of the liquid nitrogen delivery main pipe (36) to the outlet end of the liquid nitrogen delivery main pipe (36), the second heat source channel of the subcooler (27) is located between the first liquid nitrogen backflow pipe (37) and the second liquid nitrogen backflow pipe (38), and the first liquid nitrogen backflow pipe (37) and the second liquid nitrogen backflow pipe (38) are both provided with a fourth adjusting valve (40) respectively.

6. The compact, small-scale, liquid argon distillation apparatus of claim 1, wherein: The second backflow pipe (8) is sequentially provided with a filter (41) and a backflow pump (42) from the second rectifying tower (10) to the first rectifying tower (5).

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