A cryogenic rectification column
By designing an isolation chamber and a pressure control unit in the cryogenic distillation column, combined with an insulating membrane and a vacuum jacket, the icing problem caused by liquid nitrogen was solved, achieving stable operation and efficient separation in the cryogenic distillation process.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI ZHENGFAN TECH
- Filing Date
- 2025-08-04
- Publication Date
- 2026-07-07
AI Technical Summary
When using liquid nitrogen, cryogenic distillation columns are prone to freezing, which can hinder normal operation and affect separation efficiency.
A cryogenic distillation column was designed, comprising multiple isolated chambers. Nitrogen gas, obtained by vaporizing liquid nitrogen, undergoes heat exchange within the isolated chambers. The temperature is regulated by a pressure control unit to avoid direct contact with the material. An insulating membrane and a vacuum jacket are installed on the outside of the column to maintain temperature stability.
It effectively prevents materials from freezing due to low temperatures, improves the stability and separation efficiency of the low-temperature distillation process, and enhances the utilization rate of liquid nitrogen cooling capacity.
Smart Images
Figure CN224462553U_ABST
Abstract
Description
Technical Field
[0001] This application relates to the field of distillation columns, and more specifically, to a cryogenic distillation column. Background Technology
[0002] The process of producing boron isotopes by cryogenic distillation utilizes the difference in saturated vapor pressure of different substances at low temperatures for separation. The distillation process is completed within a distillation column, where the liquid and vapor phases flow counter-currently. A condenser at the top of the column condenses the rising vapor into liquid, which then flows back down the column under its own gravity. At the bottom, the liquid is heated and vaporized by a reboiler, forming rising vapor. Simultaneously, molecular exchange occurs between the two phases; more precisely, the more volatile components preferentially move in the vapor phase and tend to accumulate at the top of the column, while the less volatile components concentrate in the liquid phase and accumulate at the bottom.
[0003] In cryogenic distillation for separating boron isotopes, reflux condensation under atmospheric pressure must occur between the melting point of BF3 (-127°C) and its normal boiling point (-101°C). Since liquid nitrogen is readily available in large quantities, it is commonly used as the cryogenic refrigerant. However, liquid nitrogen, typically at -198°C, can cause the BF3 material to freeze easily within the distillation column, hindering its normal operation. Utility Model Content
[0004] The purpose of this application is to provide a cryogenic distillation column that can improve the problem of the cryogenic distillation column being difficult to operate normally due to the freezing of materials by liquid nitrogen.
[0005] The embodiments of this application are implemented as follows:
[0006] In a first aspect, embodiments of this application provide a low-temperature distillation column, including a column body and a condenser located at the top of the column body; the column body has a longitudinal first channel for material to pass through, and the lower part of the condenser has a first chamber communicating with the first channel; the condenser also has a second chamber and a third chamber; the second chamber separates the third chamber from the first chamber, the second chamber is not communicating with the first chamber, and is capable of heat exchange.
[0007] The third chamber is used to store liquid nitrogen. The second chamber is provided with an air inlet and an exhaust port for discharging nitrogen from the condenser. The air inlet is connected to the third chamber so that the nitrogen vaporized in the third chamber can enter the second chamber. The exhaust port is provided with a pressure control unit.
[0008] In the above technical solution, the first chamber is connected to the first channel of the tower body, so the material entering from the tower body can enter the first chamber. The third chamber is used to contain liquid nitrogen, thus providing a low temperature for condensing gaseous materials into liquid. The second chamber separates the third chamber from the first chamber and is not connected to the first chamber, but it can exchange heat. Therefore, the second chamber can prevent gaseous materials from directly exchanging heat with the third chamber containing liquid nitrogen, which can improve the situation of icing of gaseous materials. The second chamber is connected to the third chamber through an air inlet, allowing nitrogen gas volatilized in the third chamber to enter the second chamber. Therefore, the second chamber can contain low-temperature nitrogen gas. The material in the first chamber exchanges heat with the nitrogen in the second chamber, but the amount of cooling obtained is less. Therefore, the phenomenon of material icing in the first chamber can be improved. By installing a pressure control unit at the exhaust port, the nitrogen pressure in the second chamber can be controlled, thereby controlling the temperature in the second chamber and improving the phenomenon of material freezing in the first chamber due to excessively low nitrogen temperature in the second chamber.
[0009] In some alternative implementations, the first chamber and the second chamber are separated by a first partition; a heat exchanger is provided in the second chamber, with one end of the heat exchanger in contact with the first partition and the other end in contact with the second partition.
[0010] In the above technical solution, by setting a heat exchanger in the second chamber, with one end of the heat exchanger in contact with the first partition and the other end in contact with the second partition, the cooling capacity of the liquid nitrogen in the third chamber can be transferred to the first partition through the second partition and the heat exchanger. The liquid nitrogen in the third chamber and the nitrogen in the second chamber together provide cooling capacity for the material, thereby improving the utilization rate of the cooling capacity of the liquid nitrogen in the third chamber.
[0011] In some alternative embodiments, the air inlet is located above the exhaust outlet, and the heat exchanger includes a transverse plate disposed within the second chamber to divide the second chamber into a communicating upper chamber and a lower chamber, the transverse plate being located between the air inlet and the exhaust outlet.
[0012] In the above technical solution, by setting a horizontal plate in the second chamber and placing the horizontal plate between the air inlet and the exhaust port, the movement path of nitrogen in the second chamber can be increased, making the temperature in the second chamber more uniform, and also enabling the nitrogen in the second chamber to exchange heat more fully with the material in the first chamber through the first partition.
[0013] In some alternative embodiments, the air inlet and the air outlet are both located on the first side of the second chamber, and the end of the cross plate away from the first side has a gap with the inner wall of the second chamber, so that the upper chamber and the lower chamber are in communication.
[0014] In the above technical solution, the movement path of nitrogen in the second chamber can be increased, making the temperature in the second chamber more uniform, and also enabling the nitrogen in the second chamber to exchange heat more fully with the material in the first chamber through the first partition.
[0015] In some optional embodiments, the heat exchanger further includes a plurality of first longitudinal plates arranged side by side in the horizontal direction in the upper chamber, with the space formed between two adjacent first longitudinal plates being interconnected, the upper end of the first longitudinal plate being connected to the second partition plate and the lower end being connected to the horizontal plate; and also includes a plurality of second longitudinal plates arranged side by side in the horizontal direction in the lower chamber, with the space formed between two adjacent second longitudinal plates being interconnected, the upper end of the second longitudinal plate being connected to the horizontal plate and the lower end being connected to the first partition plate.
[0016] In the above technical solution, the upper end of the first vertical plate is connected to the second partition plate, and the lower end is connected to the horizontal plate. This allows the cooling energy of the liquid nitrogen in the third chamber to be transferred sequentially through the second partition plate and the first vertical plate to the horizontal plate, facilitating heat exchange between the third and second chambers. The upper end of the second vertical plate is connected to the horizontal plate, and the lower end is connected to the first partition plate. This allows the cooling energy in the horizontal plate to be transferred through the second vertical plate to the first partition plate, enabling the material in the first chamber to liquefy through heat exchange with the first partition plate, thus facilitating heat exchange between the second and first chambers. Because of the spatial connectivity between adjacent first vertical plates and adjacent second vertical plates, nitrogen gas in the second chamber can flow between adjacent first vertical plates and adjacent second vertical plates, allowing nitrogen gas to move from the inlet to the outlet of the second chamber.
[0017] In some alternative implementations, adjacent first longitudinal plates are staggered to divide the upper chamber into an S-shaped channel; adjacent second longitudinal plates are staggered to divide the lower chamber into an S-shaped channel.
[0018] In the above technical solution, because the two adjacent first vertical plates are staggered, the upper chamber is divided into an S-shaped channel, so the nitrogen gas has a longer movement path in the upper chamber; because the two adjacent second vertical plates are staggered, the lower chamber is divided into an S-shaped channel, so the nitrogen gas has a longer movement path in the lower chamber, which can make the temperature distribution in the second chamber more uniform.
[0019] In some alternative implementations, the first partition, the second partition, the transverse plate, the first longitudinal plate, and the second longitudinal plate are structural components made of Hastelloy, Monel, or nickel; and the heat exchanger has porous fins, serrated fins, or corrugated fins.
[0020] In the above technical solution, the first partition, the second partition, the horizontal plate, the first vertical plate, and the second vertical plate are structural components made of Hastelloy, Monel alloy, or nickel, and the heat exchanger is finned, which allows the cooling capacity of the liquid nitrogen in the third chamber to be better transferred to the second chamber and the first partition, thereby improving the transfer efficiency and the utilization rate of the cooling capacity in the liquid nitrogen.
[0021] In some alternative embodiments, the first partition has a plurality of fins on the side facing the first chamber.
[0022] In the above technical solution, by arranging multiple fins on the side of the first partition facing the first chamber, and by having a gap between the fins and the bottom wall of the first chamber, heat exchange with the material in the first chamber can be better achieved.
[0023] In some alternative embodiments, a third longitudinal plate is provided in the third chamber, the lower end of the third longitudinal plate is connected to the second partition, and the upper end of the third longitudinal plate has a gap with the top wall of the third chamber.
[0024] In the above technical solution, by setting a third longitudinal plate in the third chamber and connecting the lower end of the third longitudinal plate to the second partition, the third longitudinal plate can transfer the cooling capacity of the liquid nitrogen in the upper layer of the third chamber to the second partition, and then transfer the cooling capacity to the first partition through the second partition and the heat exchanger, and then exchange heat with the material in the first chamber through the first partition to liquefy the material.
[0025] In some alternative implementations, the outer wall of the tower is covered with an insulating film for heat preservation, and vacuum jackets are provided on both the outside of the tower and the outside of the condenser.
[0026] In the above technical solution, by covering the outer wall of the column with an insulating film for heat preservation and setting a vacuum jacket on the outside of the column and the condenser, external heat can be isolated and the interference of ambient temperature on the distillation process can be reduced. Attached Figure Description
[0027] To more clearly illustrate the technical solutions of the embodiments of this application, the accompanying drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this application and should not be regarded as a limitation of the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0028] Figure 1 This is a schematic diagram of the structure of a cryogenic distillation column provided in an embodiment of this application.
[0029] Icons: 100 - Tower body; 110 - First channel; 200 - Condenser; 210 - First chamber; 220 - Second chamber; 221 - Air inlet; 222 - Exhaust outlet; 230 - Third chamber; 231 - Vertical pipe; 232 - Third longitudinal plate; 310 - First partition; 311 - Fin; 320 - Second partition; 410 - Horizontal plate; 420 - First longitudinal plate; 430 - Second longitudinal plate; 500 - Vacuum jacket. Detailed Implementation
[0030] To make the objectives, technical solutions, and advantages of the embodiments of this application clearer, the technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this application, and not all embodiments. The components of the embodiments of this application described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0031] Therefore, the following detailed description of the embodiments of this application provided in the accompanying drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application. All other embodiments obtained by those skilled in the art based on the embodiments of this application without inventive effort are within the scope of protection of this application.
[0032] It should be noted that similar labels and letters in the following figures indicate similar items. Therefore, once an item is defined in one figure, it does not need to be further defined and explained in subsequent figures.
[0033] In the description of this application, it should be noted that the terms "center," "upper," "lower," "vertical," "horizontal," "inner," and "outer," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use. They are used only for the convenience of describing this application and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this application. In addition, the terms "first," "second," and "third," etc., are used only to distinguish descriptions and should not be construed as indicating or implying relative importance.
[0034] Furthermore, terms such as "horizontal," "vertical," and "sag" do not imply that components must be absolutely horizontal or suspended, but rather that they can be slightly tilted. For example, "horizontal" simply means that its direction is more horizontal relative to "vertical," and does not mean that the structure must be completely horizontal, but can be slightly tilted.
[0035] In the description of this application, it should also be noted that, unless otherwise expressly specified and limited, the terms "set up," "install," "connect," and "link" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection of two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.
[0036] Distillation typically takes place in a distillation column, where the gas and liquid phases come into countercurrent contact, resulting in interphase heat and mass transfer. The more volatile components in the liquid phase enter the gas phase, while the less volatile components in the gas phase transfer to the liquid phase. Thus, almost pure more volatile components are obtained at the top of the column, and almost pure less volatile components at the bottom. The feed liquid is added from the middle of the column. The section above the feed inlet further concentrates the more volatile components in the rising vapor; this is called the rectification section. The section below the feed inlet extracts the more volatile components from the descending liquid; this is called the stripping section. The vapor drawn from the top of the column is condensed, with a portion of the condensate returning to the distillation column as reflux, and the remaining distillate becoming the top product. The liquid drawn from the bottom of the column is partially vaporized in a reboiler, with the vapor rising up the column, and the remaining liquid becoming the bottom product. The ratio of the amount of liquid refluxed from the top of the column to the amount of top product is called the reflux ratio, and its magnitude affects the separation efficiency and energy consumption of the distillation operation.
[0037] This application provides a cryogenic distillation column that can separate isotopes in boron trifluoride by using liquid nitrogen to provide a low temperature.
[0038] like Figure 1 As shown, the cryogenic distillation column provided in this application includes a column body 100 and a condenser 200 located at the top of the column body 100. The column body 100 has a longitudinal first channel 110 for material passage. The cryogenic distillation column provided in this application can be used for boron trifluoride isotope distillation, nitric oxide cryogenic distillation, and other applications.
[0039] The lower part of the condenser 200 has a first chamber 210 communicating with the first channel 110; the condenser 200 also has a second chamber 220 and a third chamber 230. The third chamber 230 is used to contain liquid nitrogen, and the second chamber 220 separates the third chamber 230 from the first chamber 210. The second chamber 220 and the first chamber 210 are not in communication, but heat exchange is possible. The second chamber 220 is provided with an inlet 221 and an outlet 222 for discharging nitrogen from the condenser 200. The inlet 221 communicates with the third chamber 230, allowing nitrogen vapors evaporating in the third chamber 230 to enter the second chamber 220. Therefore, after liquid nitrogen is introduced into the third chamber 230, the low-temperature nitrogen gas produced by the vaporization of the liquid nitrogen enters the second chamber 220 through the air inlet 221. Since the second chamber 220 is not connected to the first chamber 210, the nitrogen gas in the second chamber 220 will not enter the first chamber 210, thus preventing contamination of the raw materials. Since the second chamber 220 can exchange heat with the first chamber 210, the cold energy in the low-temperature nitrogen gas can be transferred to the material in the first chamber 210 through heat exchange, causing the material to liquefy into droplets. The droplets then fall into the first channel 110 and continue to move downwards. During the downward movement of the droplets, they exchange heat with the rising gaseous material, causing some components of the gaseous material to liquefy and some components of the liquid material to vaporize, thereby achieving the separation of different materials.
[0040] In some implementations, such as Figure 1 As shown, a vertical pipe 231 is installed in the third chamber 230, and the vertical pipe 231 is connected to the air inlet 221 of the second chamber 220. By installing the vertical pipe 231 in the third chamber 230, the liquid nitrogen in the third chamber 230 can be prevented from flowing directly into the second chamber 220.
[0041] Furthermore, in some embodiments, a pressure control unit is provided at the exhaust port 222 of the second chamber 220. The liquid nitrogen in the third chamber 230 continuously evaporates, and the evaporated nitrogen gas enters the second chamber 220, causing the pressure inside the second chamber 220 to continuously increase. By providing a pressure control unit at the exhaust port 222 of the second chamber 220, the pressure inside the second chamber 220 can be prevented from exceeding a safe range. Furthermore, since there is a correlation between the temperature and pressure of nitrogen, the temperature of the nitrogen in the second chamber 220 can be controlled by setting a pressure control unit. Therefore, in this embodiment, the temperature of the nitrogen in the second chamber 220 can be controlled by changing the pressure of the nitrogen in the second chamber 220, making the temperature of the nitrogen in the second chamber 220 compatible with the temperature in the material distillation process. This ensures that the material will not condense into a solid state in the first chamber 210 due to excessively low temperature, nor will it fail to condense into a liquid state due to excessively high temperature.
[0042] Specifically, the pressure control unit can be a pressure relief valve or similar structure. When the gas pressure in the second chamber 220 is higher than the opening pressure of the pressure relief valve, the valve opens, allowing nitrogen gas in the second chamber 220 to escape until the pressure in the second chamber 220 returns to the opening pressure. By setting the opening pressure of the pressure relief valve, the temperature of the nitrogen gas in the second chamber can be changed. Using this method, the temperature in the first chamber can be controlled between -80℃ and -170℃.
[0043] In other embodiments, a pressure control unit may be composed of a pressure gauge, a valve, and a control component. The pressure gauge detects the nitrogen pressure within the second chamber 220, and the valve opens or closes the outlet of the second chamber 220. Both the pressure gauge and the valve are signal-connected to the control component, which stores preset pressure values. When the pressure gauge detects that the nitrogen pressure within the second chamber 220 exceeds the preset value stored in the control component, the control component sends a signal to the valve to open it. This continues until the pressure gauge detects a first preset pressure within the second chamber 220, at which point the control component sends a signal to the valve to close it.
[0044] In some embodiments, a first partition 310 is provided between the second chamber 220 and the first chamber 210. By providing the first partition 310, the first chamber 210 and the second chamber 220 can be separated, and the material in the first chamber 210 and the nitrogen in the second chamber 220 can also exchange heat through the first partition 310. Furthermore, a second partition 320 is provided between the second chamber 220 and the third chamber, allowing the liquid nitrogen in the third chamber 230 to exchange heat with the nitrogen in the second chamber 220. Furthermore, a heat exchanger is also provided in the second chamber 220, with one end of the heat exchanger contacting the first partition 310 and the other end contacting the second partition 320. In other words, in this embodiment, besides the direct transfer of the cold energy from the nitrogen gas to the first partition 310 and then to the material in the first chamber 210, heat exchangers can also be used to transfer heat between the first partition 310 and the second partition 320, thereby transferring the cold energy of the liquid nitrogen to the material in the first chamber 210. This provides more sources of cold energy and improves the utilization rate of the liquid nitrogen's cold energy. Of course, in other embodiments, a heat exchanger may not be required; instead, heat exchange can be performed between the nitrogen gas in the second chamber 220 and the first partition 310, after which the cold energy is transferred to the material in the first chamber 210.
[0045] Furthermore, such as Figure 1As shown, the air inlet 221 is located above the exhaust outlet 222. The heat exchanger includes a horizontal plate 410 disposed within the second chamber 220 to divide the second chamber 220 into a connected upper chamber and a lower chamber. The horizontal plate 410 is located between the air inlet 221 and the exhaust outlet 222. Therefore, after the nitrogen gas volatilized in the third chamber 230 enters the second chamber 220 through the air inlet 221, it needs to pass through one side of the horizontal plate 410 before reaching the exhaust outlet on the other side of the second chamber 220. This increases the movement path of the nitrogen gas within the second chamber 220, making the temperature within the second chamber 220 more uniform and allowing the nitrogen gas in the second chamber 220 to exchange heat more fully with the material in the first chamber 210 through the first partition 310.
[0046] Furthermore, such as Figure 1 As shown, both the air inlet 221 and the exhaust outlet 222 are located on the first side of the second chamber 220. The end of the transverse plate 410 furthest from the first side has a gap with the inner wall of the second chamber 220, allowing communication between the upper and lower chambers. After entering the second chamber 220 through the air inlet 221, nitrogen gas needs to move from the first side of the second chamber 220 along the upper chamber separated by the transverse plate 410 to the second side of the second chamber 220. Then, it enters the lower chamber from the second side of the second chamber 220, and finally moves to the exhaust outlet position of the second chamber 220. In this embodiment, the movement path of nitrogen gas within the second chamber 220 can be increased, resulting in a more uniform temperature within the second chamber 220. It also allows the nitrogen gas in the second chamber 220 to more fully exchange heat with the material in the first chamber 210 through the first partition plate 310.
[0047] In some embodiments, the heat exchanger further includes a plurality of first vertical plates 420 arranged side by side in the horizontal direction in the upper chamber, and the space formed between adjacent first vertical plates 420 is interconnected, so nitrogen gas can pass through the space formed between adjacent first vertical plates 420. The upper end of the first vertical plate 420 is connected to the second partition plate 320 and the lower end is connected to the horizontal plate 410, so the cooling capacity of liquid nitrogen in the third chamber 230 can be transferred to the first vertical plate 420 through the second partition plate 320, and then transferred to the horizontal plate 410 through the first vertical plate 420. It also includes a plurality of second vertical plates 430 arranged side by side in the horizontal direction in the lower chamber, and the space formed between adjacent second vertical plates 430 is interconnected, so nitrogen gas can pass through the space formed between adjacent first vertical plates 420. The upper end of the second vertical plate 430 is connected to the horizontal plate 410 and the lower end is connected to the first partition plate 310. Therefore, the cold energy in the horizontal plate 410 can be transferred to the first partition plate 310 through the second vertical plate 430, and then the cold energy can be transferred to the material through the heat exchange between the first partition plate 310 and the material in the first chamber 210.
[0048] In some embodiments, adjacent first vertical plates 420 are staggered to divide the upper chamber into an S-shaped channel, thus providing a longer path for nitrogen gas within the upper chamber. Similarly, adjacent second vertical plates 430 are staggered to divide the lower chamber into an S-shaped channel, also providing a longer path for nitrogen gas within the lower chamber. This technical solution allows for a more uniform temperature distribution within the second chamber 220.
[0049] In some embodiments, the first partition 310, the second partition 320, the first longitudinal plate 420, and the second longitudinal plate 430 are all metal structural components. Specifically, they can be iron structural components, copper structural components, etc. The fact that the first partition 310, the second partition 320, the first longitudinal plate 420, and the second longitudinal plate 430 are metal structural components allows for better transfer of the cooling energy of the liquid nitrogen in the third chamber 230 to the second chamber 220 and the first partition 310, improving transfer efficiency and the utilization rate of the cooling energy in the liquid nitrogen.
[0050] In some embodiments, the first partition 310 has a plurality of fins 311 on the side facing the first chamber 210, and the fins 311 have gaps with the bottom wall of the first chamber 210. Furthermore, the fins 311 can also be metal structural components. By providing fins 311, the heat exchange area of the material in the first chamber 210 can be increased, thereby improving the heat exchange efficiency. In other embodiments, fins 311 may not be provided on the first partition 310.
[0051] In some embodiments, a third longitudinal plate 232 is provided within the third chamber 230. The lower end of the third longitudinal plate 232 is connected to the second partition 320, and the upper end of the third longitudinal plate 232 has a gap with the top wall of the third chamber 230. Furthermore, the third longitudinal plate 232 is also a metal structural component. By providing the third longitudinal plate 232 within the third chamber 230, and with its lower end connected to the second partition 320, the third longitudinal plate 232 can transfer the cooling energy of the liquid nitrogen in the upper layer of the third chamber 230 to the second partition 320. This cooling energy is then transferred to the first partition 310 via the second partition 320 and a heat exchanger, where it exchanges heat with the material in the first chamber, causing the material to liquefy. In other embodiments, the third longitudinal plate 232 may not be provided within the third chamber 230.
[0052] Furthermore, in some embodiments, the outer wall of the column body 100 is covered with an insulating film for heat preservation, and vacuum jackets 500 are provided on both the outer side of the column body 100 and the condenser 200. The insulating film can be made of insulating materials such as polytetrafluoroethylene (PTFE). The insulating effect of the film reduces heat loss within the column body 100 or heat transfer from the outside, thereby maintaining a stable temperature inside the column and improving distillation efficiency. In other embodiments, insulating materials such as fiberglass, asbestos, rock wool, and silicates can be used on the outside of the column body 100 to reduce heat loss within the column body 100 or heat transfer from the outside. The vacuum jacket 500 provides a vacuum environment, which reduces heat exchange between the condenser 200 and the column body 100, thereby reducing the impact of ambient temperature on the distillation process. Furthermore, a vacuum pump can be used to evacuate the vacuum jacket 500 to maintain a vacuum environment within it.
[0053] The above description is merely a preferred embodiment of this application and is not intended to limit this application. Various modifications and variations can be made to this application by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this application should be included within the protection scope of this application.
Claims
1. A low-temperature distillation column, characterized in that, The device includes a tower body and a condenser located at the top of the tower body; the tower body has a longitudinal first channel for material to pass through, and the lower part of the condenser has a first chamber communicating with the first channel; the condenser also has a second chamber and a third chamber; the second chamber separates the third chamber from the first chamber, the second chamber is not communicating with the first chamber, and is capable of heat exchange; The third chamber is used to store liquid nitrogen. The second chamber is provided with an air inlet and an exhaust port for discharging nitrogen from the condenser. The air inlet is connected to the third chamber so that the nitrogen vaporized in the third chamber can enter the second chamber. The exhaust port is provided with a pressure control unit.
2. The low-temperature distillation column according to claim 1, characterized in that, The first chamber is separated from the second chamber by a first partition, and the second chamber is separated from the third chamber by a second partition; a heat exchanger is provided in the second chamber, with one end of the heat exchanger in contact with the first partition and the other end in contact with the second partition.
3. The low-temperature distillation column according to claim 2, characterized in that, The air inlet is located above the exhaust outlet, and the heat exchanger includes a horizontal plate disposed in the second chamber to divide the second chamber into a communicating upper chamber and a lower chamber, the horizontal plate being located between the air inlet and the exhaust outlet.
4. The low-temperature distillation column according to claim 3, characterized in that, Both the air inlet and the exhaust outlet are located on the first side of the second chamber. The end of the horizontal plate away from the first side has a gap with the inner wall of the second chamber, so that the upper chamber and the lower chamber are connected.
5. The low-temperature distillation column according to claim 3, characterized in that, The heat exchanger also includes a plurality of first longitudinal plates arranged side by side in the horizontal direction in the upper chamber, and the space formed between two adjacent first longitudinal plates is connected. The upper end of the first longitudinal plate is connected to the second partition plate and the lower end is connected to the horizontal plate. The heat exchanger also includes a plurality of second longitudinal plates arranged side by side in the horizontal direction in the lower chamber, and the space formed between two adjacent second longitudinal plates is connected. The upper end of the second longitudinal plate is connected to the horizontal plate and the lower end is connected to the first partition plate.
6. The low-temperature distillation column according to claim 5, characterized in that, The two adjacent first vertical plates are staggered to divide the upper chamber into an S-shaped channel; the two adjacent second vertical plates are staggered to divide the lower chamber into an S-shaped channel.
7. The low-temperature distillation column according to claim 5, characterized in that, The first partition, the second partition, the horizontal plate, the first vertical plate, and the second vertical plate are structural components made of Hastelloy, Monel alloy, or nickel; the heat exchanger has porous fins, serrated fins, or corrugated fins.
8. The low-temperature distillation column according to claim 2, characterized in that, The first partition has multiple fins on the side facing the first chamber, and the fins have gaps with the bottom wall of the first chamber.
9. The low-temperature distillation column according to claim 2, characterized in that, The third chamber is provided with a third longitudinal plate, the lower end of which is connected to the second partition, and the upper end of which has a gap with the top wall of the third chamber.
10. The low-temperature distillation column according to claim 1, characterized in that, The outer wall of the tower is covered with an insulating film for heat preservation, and vacuum jackets are provided on both the outside of the tower and the outside of the condenser.