Air separation apparatus argon generation system

Abstract

The utility model provides a kind of argon system of air separation device, belong to hydrogen-free argon air separation oxygen process field, including crude argon I tower, crude argon II tower and fine argon tower, the crude argon I tower is connected with air separation rectifying tower upper tower, the crude argon I tower top is connected crude argon II tower bottom by pipeline, the crude argon II tower top is connected fine argon tower middle part by pipeline;Vacuum heat-insulated storage tank is further included, and the liquid outlet of vacuum heat-insulated storage tank is connected with fine argon tower condenser liquid air side discharge pipeline intercommunication.The utility model can provide stable cold source for fine argon tower condenser, ensure fine argon tower stable operation, improve the argon production efficiency.

Description

Technical Field

[0001] This utility model belongs to the field of hydrogen-free argon-to-oxygen air separation process, specifically relating to an argon production system for an air separation unit. Background Technology

[0002] Currently, large-scale air separation oxygen production systems are all equipped with hydrogen-free argon production units. Their main function is to reduce the oxygen content in the argon fraction to below 2 ppm through a full-distillation hydrogen-free argon production process, utilizing the difference in boiling points between oxygen and argon (only 3K) and multi-stage separation in the distillation column. Nitrogen impurities are then removed by a refining column, ultimately producing a refined argon product with a purity of 99.999%. This process avoids the complexity and safety hazards of traditional argon production processes and improves extraction efficiency.

[0003] In existing air separation units for argon production, a condenser is usually installed at the top of the distillation column. The evaporated argon gas in the distillation column is condensed into pure liquid argon by the condenser and discharged from the bottom of the distillation column. The condenser at the top of the distillation column usually uses liquid air from the lower column as a cold source and the pressure and cooling capacity are regulated by a throttling valve installed on the pipeline.

[0004] However, due to design and manufacturing reasons, some air separation units have throttling valves on the second level of the air separation tower. After throttling, the pressure decreases, and because the elevation of the liquid air inlet to the argon-refining tower is relatively high, the liquid air energy is insufficient to overcome the pipeline resistance and enter the argon-refining tower condenser. This results in insufficient cold source for the argon-refining tower, causing abnormal fluctuations in the operating conditions of the argon-refining tower and extremely unstable operation, which seriously affects the argon production efficiency. Utility Model Content In view of the defects or deficiencies in the existing technology, this utility model provides an argon production system for an air separation unit, which can provide a stable cold source for the condenser of the argon purification tower, ensure the stable operation of the argon purification tower, and improve the argon production efficiency.

[0005] To achieve the above objectives, the present invention adopts the following technical solution: An embodiment of this utility model provides an argon production system for an air separation unit, including a crude argon I column, a crude argon II column, and a refined argon column. The crude argon I column is connected to the upper column of an air separation distillation column, the top of the crude argon I column is connected to the bottom of the crude argon II column via a pipe, and the top of the crude argon II column is connected to the middle of the refined argon column via a pipe. It also includes a vacuum insulated storage tank, the outlet of which is connected to the liquid-air side discharge pipe of the argon tower condenser.

[0006] Furthermore, the lower part of the crude argon I column is provided with an argon fraction inlet, which is connected to the upper column of the air separation distillation column.

[0007] Furthermore, the bottom of the crude argon II tower is connected to the upper part of the crude argon I tower via a pipeline, and a circulating argon pump is installed on the pipeline between the bottom of the crude argon II tower and the upper part of the crude argon I tower.

[0008] Furthermore, the bottom of the crude argon I column is connected to the upper column of the air separation distillation column via a pipeline.

[0009] Furthermore, a crude argon tower condenser is provided at the top of the crude argon II tower, and the crude argon tower condenser at the top of the crude argon II tower is connected to the middle of the refined argon tower through a pipeline.

[0010] Furthermore, an argon-refining column evaporator is installed at the bottom of the argon-refining column, and the argon-refining column evaporator is connected to the lower column of the air separation distillation column via a pipeline.

[0011] Furthermore, the top of the argon column is equipped with an argon column condenser, which is connected to the lower column of the air separation distillation column.

[0012] Furthermore, the outlet of the vacuum insulated storage tank is connected to a pneumatic regulating valve via a pipe, and the other end of the pneumatic regulating valve is connected to a first valve via a pipe. The other end of the first valve is connected to the liquid-air side discharge pipe of the argon tower condenser.

[0013] Furthermore, a second valve is installed on the liquid air side discharge pipe of the argon tower condenser.

[0014] Furthermore, a drain pipe is connected to the pipe between the first valve and the second valve, and a third valve is installed on the drain pipe.

[0015] Compared with the prior art, the beneficial effects of this utility model are as follows: This invention features a vacuum-insulated storage tank connected to the liquid-air side discharge pipe of the argon tower condenser. The tank contains liquid nitrogen. When the argon tower condenser lacks sufficient cooling, liquid nitrogen is drawn from the vacuum liquid nitrogen storage tank and fed back into the argon tower condenser via the liquid-air side discharge pipe, thus providing a stable cooling source and ensuring stable operation of the argon tower, thereby improving argon production efficiency. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the argon production system of the air separation unit in this embodiment of the present invention; The components include: 1. Crude argon I tower; 2. Crude argon II tower; 3. Refined argon tower; 4. Circulating argon pump; 5. Crude argon tower condenser; 6. Refined argon tower condenser; 7. Refined argon tower evaporator; 8. Vacuum insulated storage tank; 9. Pneumatic regulating valve; 10. First valve; 11. Liquid air side discharge pipe of refined argon tower condenser; 12. Second valve; 13. Drain pipe; 14. Third valve. Detailed Implementation

[0017] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0018] This utility model is implemented in a typical manner, such as Figure 1 As shown, an argon production system for an air separation unit includes a crude argon I column 1, a crude argon II column 2, and a refined argon column 3. The lower part of the crude argon I column 1 is provided with an argon fraction inlet, which is connected to the upper column of the air separation distillation column. The upper column of the air separation distillation column delivers argon fraction into the crude argon I column 1.

[0019] The top of crude argon column 1 is connected to the bottom of crude argon column 2 via a pipeline, and the bottom of crude argon column 2 is connected to the top of crude argon column 1 via a pipeline. A circulating argon pump 4 is installed on the pipeline between the bottom of crude argon column 2 and the top of crude argon column 1. Argon fraction from the upper column of the air separation distillation column enters crude argon column 1 and is used as rising gas for distillation. The circulating argon pump 4 pumps the low-temperature liquid at the bottom of crude argon column 2 into crude argon column 1 as reflux liquid for distillation. A crude argon column condenser 5 is installed at the top of crude argon column 2. The gas at the top of crude argon column 1 enters crude argon column 2 as rising gas and is condensed after reaching the crude argon column condenser 5 at the top of crude argon column 2. Since oxygen, nitrogen and argon have different boiling points, oxygen becomes liquid and flows back down, thereby removing oxygen.

[0020] The bottom of crude argon column 1 is connected to the upper column of the air separation distillation column via a pipeline. The liquid at the bottom of crude argon column 1 returns to the upper column of the air separation distillation column by means of the height difference and its own weight.

[0021] The crude argon condenser 5 at the top of the crude argon II tower 2 is connected to the middle of the refined argon tower 3 via a pipeline. The crude argon gas containing nitrogen and argon at the top of the crude argon II tower 2 is liquefied and flows into the refined argon tower 3. The refined argon tower 3 distills the crude liquid argon to remove nitrogen and obtain high-purity liquid argon.

[0022] The top of the argon column 3 is equipped with an argon column condenser 6, and the bottom is equipped with an argon column evaporator 7. When the crude liquid argon flows back to the bottom of the argon column 3, the argon gas is heated and evaporated by the argon column evaporator 7 and enters the argon column condenser 6 at the top of the argon column 3. The argon gas is condensed into liquid argon in the argon column condenser 6 and then flows to the bottom of the argon column 3. A liquid discharge pipe is provided at the bottom of the argon column 3 for discharging pure liquid argon.

[0023] Furthermore, the argon-refining column evaporator 7 is connected to the lower column of the air separation distillation column via a pipeline. The lower column of the air separation distillation column supplies nitrogen gas to the argon-refining column evaporator 7 as a heat source. The argon-refining column condenser 6 is connected to the lower column of the air separation distillation column via a pipeline. The lean liquid air from the lower column of the air separation distillation column after subcooling enters the argon-refining column condenser 6 as a cold source.

[0024] Due to design and manufacturing reasons of some air separation units, the throttling valve has already throttled the flow in the second layer of the air separation tower. After throttling, the pressure is reduced. In addition, because the elevation of the liquid air inlet to the argon tower is relatively high, the liquid air energy is insufficient and cannot overcome the pipeline resistance to enter the condenser 6 of the argon tower. As a result, the argon tower has insufficient cold source, which affects the argon production efficiency.

[0025] Therefore, it also includes a vacuum insulated storage tank 8, which is a double-layer vacuum cryogenic liquid storage tank used to hold cryogenic liquid nitrogen. The outlet of the vacuum insulated storage tank 8 is connected to a pneumatic regulating valve 9 through a pipe. The other end of the pneumatic regulating valve 9 is connected to a first valve 10 through a pipe. The other end of the first valve 10 is connected to the liquid-air side discharge pipe 11 of the argon tower condenser. A second valve 12 is installed on the liquid-air side discharge pipe 11 of the argon tower condenser. An empty pipe 13 is connected to the pipe between the first valve 10 and the second valve 12. A third valve 14 is installed on the empty pipe 13.

[0026] Among them, the pneumatic regulating valve 9 is a cryogenic pneumatic regulating valve used to adjust the amount of liquid nitrogen being transported. The first valve 10, the second valve 12, and the third valve 14 are manual cryogenic valves used to close or open the pipeline for transporting liquid nitrogen. All valves are made of stainless steel, and their nominal pressure and diameter are determined according to the amount of liquid cooling required by the argon tower.

[0027] All valves and pipes must be insulated, and the main insulation material is double-layer polyurethane insulation.

[0028] When the air separation unit needs to increase liquid argon production, the outlet of the vacuum insulated storage tank 8 is opened, the first valve 10 is fully opened, and the third valve 14 and the pneumatic regulating valve 9 are slightly opened. The pipeline is pre-cooled through the third valve 14. After pre-cooling is completed, the third valve 14 is closed, and liquid nitrogen is drawn out from the vacuum insulated storage tank 8. The liquid air side discharge pipeline 11 of the argon tower condenser is reversed and fed into the argon tower condenser 6 as a cold source to increase the liquid argon production of the air separation unit.

[0029] During use, the cooling capacity of the argon tower is controlled by adjusting the pneumatic regulating valve, and the pressure of the system pipeline is adjusted by controlling the pressure in the vacuum insulated storage tank.

[0030] By setting up a vacuum insulated storage tank and connecting it to the liquid-air side discharge pipe of the argon tower condenser, liquid nitrogen is stored in the vacuum insulated storage tank. When the cold source of the argon tower condenser is insufficient, liquid nitrogen is drawn out from the vacuum liquid nitrogen storage tank and fed back into the argon tower condenser through the liquid-air side discharge pipe of the argon tower condenser as a cold source. This provides a stable cold source for the argon tower condenser, ensures the stable operation of the argon tower, and improves the argon production efficiency.

[0031] The above description is merely a preferred embodiment of this utility model and is not intended to limit the utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this utility model should be included within the protection scope of this utility model.

Claims

1. An argon production system for an air separation unit, characterized in that, It includes a crude argon I column, a crude argon II column, and a refined argon column. The crude argon I column is connected to the upper column of the air separation distillation column. The top of the crude argon I column is connected to the bottom of the crude argon II column via a pipeline. The top of the crude argon II column is connected to the middle of the refined argon column via a pipeline. It also includes a vacuum insulated storage tank, the outlet of which is connected to the liquid-air side discharge pipe of the argon tower condenser.

2. The argon production system for an air separation unit as described in claim 1, characterized in that, The lower part of the crude argon I column is provided with an argon fraction inlet, which is connected to the upper column of the air separation distillation column.

3. The argon production system for an air separation unit as described in claim 1, characterized in that, The bottom of the crude argon II tower is connected to the upper part of the crude argon I tower via a pipeline, and a circulating argon pump is installed on the pipeline between the bottom of the crude argon II tower and the upper part of the crude argon I tower.

4. An argon production system for an air separation unit as described in claim 1, characterized in that, The bottom of the crude argon I column is connected to the upper column of the air separation distillation column via a pipeline.

5. An argon production system for an air separation unit as described in claim 1, characterized in that, A crude argon tower condenser is installed at the top of the crude argon tower II, and the crude argon tower condenser at the top of the crude argon tower II is connected to the middle of the fine argon tower through a pipeline.

6. An argon production system for an air separation unit as described in claim 1, characterized in that, The bottom of the argon column is equipped with an argon column evaporator, which is connected to the lower column of the air separation distillation column via a pipeline.

7. An argon production system for an air separation unit as described in claim 1, characterized in that, The top of the argon column is equipped with an argon column condenser, which is connected to the lower column of the air separation distillation column.

8. An argon production system for an air separation unit as described in claim 1, characterized in that, The outlet of the vacuum insulated storage tank is connected to a pneumatic regulating valve via a pipe. The other end of the pneumatic regulating valve is connected to a first valve via a pipe. The other end of the first valve is connected to the liquid-air side discharge pipe of the argon tower condenser.

9. An argon production system for an air separation unit as described in claim 8, characterized in that, A second valve is installed on the liquid air side discharge pipe of the argon tower condenser.

10. An argon production system for an air separation unit as described in claim 9, characterized in that, A drain pipe is connected to the pipe between the first valve and the second valve, and a third valve is installed on the drain pipe.

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