An apparatus for preparing ultra-pure nitrogen

Abstract

The present invention discloses a device for preparing ultra-pure nitrogen, which relates to the technical field of dehydrogenation devices and includes a lower column, an upper column and a dehydrogenation column for removing hydrogen components from high-purity nitrogen. In the present invention, pure and dry air enters the main heat exchanger and exchanges heat with the refluxing low-temperature waste gas and the product nitrogen in the main heat exchanger. Then, a part of the air returns to the main heat exchanger after being cooled by an expander, and the remaining air is cooled and enters the lower column, where it is rectified and separated into high-purity nitrogen and oxygen-rich liquid air. Part of the liquid air throttles into the dehydrogenation column condenser, vaporizes and then returns to the upper column; the remaining liquid air throttles into the upper column condensing evaporator, condenses after exchanging heat with nitrogen, part of it refluxes to the lower column, and part of it enters the dehydrogenation column. Ultra-pure nitrogen is drawn out from the bottom of the dehydrogenation column and output after being reheated by the main heat exchanger. The low-pressure pure nitrogen at the top of the upper column condenses into liquid nitrogen, part of it refluxes to the upper column, and part of it is pressurized by a liquid nitrogen pump and enters the lower column to improve the nitrogen extraction rate.

Description

Technical Field

[0001] The present invention relates to the technical field of dehydrogenation equipment, and more specifically, the present invention relates to an apparatus for preparing ultra-pure nitrogen. Background Art

[0002] A distillation column is a tower-type gas-liquid contact device for distillation. By utilizing the property that each component in a mixture has different volatilities, that is, the vapor pressures of each component are different at the same temperature, the light components (low-boiling substances) in the liquid phase are transferred to the gas phase, while the heavy components (high-boiling substances) in the gas phase are transferred to the liquid phase, thus achieving the purpose of separation. Therefore, distillation columns are often used in many industrial productions to purify substances.

[0003] For example, the Chinese patent with the application number CN202411128477.8 specifically discloses a distillation column for sustainable aviation fuel production, including a tower body and tower plates. An overflow weir is provided on the tower plates. The tower plates, the tower body, and the overflow weir form a receiving groove for receiving the reflux liquid. A plurality of bubble cap mechanisms are provided on the tower plates. The bubble cap mechanism includes a fixed sleeve and a movable cover. The top of the fixed sleeve is open and fixed on the tower plate. The top of the movable cover is closed, the bottom is open, and it is hermetically slidably assembled in the fixed sleeve in the vertical direction. An elastic member for pulling the movable cover downward is provided between the movable cover and the fixed sleeve. An air inlet pipe extending into the movable cover is provided on the tower plate;

[0004] The above patent adopts the design of a movable bubble cap and an elastic member, enabling the gas to be stored in the bubble cap mechanism first and then contact the reflux liquid. Theoretically, this design prolongs the contact time between the gas phase and the liquid phase, creating more favorable conditions for gas-liquid mass transfer. However, in the actual operation process, there are some problems that cannot be ignored. During the gas storage stage, due to the continuous entry of gas, the bubble cap will move upward under the action of gas pressure. This movement significantly shortens the path length of the bubbles in the reflux liquid, that is, the effective travel of gas-liquid mass transfer is reduced.

[0005] In addition, when the bubbles are discharged, the gas pre-stored in the bubble cap is compressed to form high-pressure gas. When the high-pressure gas is discharged, the bubbles are ejected at high speed, greatly shortening the residence time of the bubbles in the reflux liquid. In the process of gas-liquid heat exchange, the residence time is one of the key factors affecting the exchange effect. If the residence time is too short, the gas and liquid cannot fully exchange heat. Considering the above factors, ultimately, the efficiency of separating nitrogen from the mixed gas is significantly reduced, making it difficult to meet the requirements of efficient separation. Summary of the Invention

[0006] Aiming at the deficiencies of the prior art, the present invention provides an apparatus for preparing ultra-pure nitrogen, which solves the problems raised in the above background art.

[0007] The technical solution of the present invention is as follows:

[0008] To achieve the above object, the present invention is realized through the following technical solutions: An apparatus for preparing ultra-pure nitrogen includes a lower column, an upper column, a dehydrogenation column body, and a plurality of trays axially arranged in the dehydrogenation column body. A plurality of riser pipes for allowing the rising gas to enter are provided on the surface of the trays close to the top of the dehydrogenation column body. A bubble cap capable of moving back and forth and rotating along its axis is provided at the top of the riser pipe. A power component for delivering power to the bubble cap is provided in the riser pipe;

[0009] The power component includes a driving fan rotatably arranged around the inside of the riser pipe. A driving rod is fixedly connected to the top of the driving fan. A blocking driving component is fixedly connected to the top of the bubble cap. A plurality of auxiliary driving plates capable of being clamped on the blocking driving component are provided at the top of the driving rod;

[0010] A first elastic member for urging the bubble cap to reset is provided at the top of the riser pipe.

[0011] Preferably, a plurality of air inlets adapted to the riser pipes are provided on the horizontal plane of the tray.

[0012] Preferably, one end of the first elastic member away from the riser pipe is fixedly connected to a first ring plate, and one end of the first ring plate away from the first elastic member is rotatably connected to the inner top surface of the bubble cap.

[0013] Preferably, one end of the driving rod close to the driving fan is rotatably connected to a fixing plate, and a plurality of fixing columns with one ends all arranged on the riser pipe are fixedly connected to the outer peripheral surface of the fixing plate. The middle part of the driving rod is rotatably connected to a screw sleeve, and a plurality of fixing rods with one ends all arranged on the riser pipe are fixedly connected to the bottom of the screw sleeve;

[0014] An auxiliary moving barrel is fixedly connected to the inner top surface of the bubble cap. The bottom of the auxiliary moving barrel is movably connected to the screw sleeve, and a convex block clamped on the spiral groove of the screw sleeve protrudes from the bottom of the auxiliary moving barrel.

[0015] Preferably, the blocking driving component includes a driving barrel fixedly connected to the top surface of the bubble cap. A plurality of driving baffles are evenly fixedly connected to the inner peripheral surface of the driving barrel. An auxiliary positioning cylinder is slidably connected to the top of the driving rod along its axis. A plurality of limiting rods are vertically arranged at the top of the driving rod. The auxiliary positioning cylinder is rotatably connected to the bottom of the driving barrel, and the top of the driving rod extends into the driving barrel.

[0016] Preferably, an auxiliary circular plate is fixedly connected to the top of the driving rod. A plurality of limiting grooves are evenly formed on the outer peripheral surface of the auxiliary circular plate. The plurality of auxiliary driving plates are respectively slidably connected in the corresponding limiting grooves. One end of the auxiliary driving plate away from the inner peripheral surface of the driving barrel is fixedly connected with a second elastic member, and the end of the second elastic member away from the auxiliary driving plate is fixedly connected in the limiting groove.

[0017] Preferably, an auxiliary connecting cylinder is rotatably connected to the bottom of the outer peripheral surface of the bubble cap. A sliding mounting cylinder capable of sliding along its axial direction is arranged on the outer peripheral surface of the auxiliary connecting cylinder. A plurality of driving plates are evenly and fixedly connected to the outer peripheral surface of the sliding mounting cylinder.

[0018] Preferably, a floating plate is fixedly connected to the surface of the sliding mounting cylinder away from the tray.

[0019] Preferably, one side outer surface of the driving plate is an inclined surface.

[0020] Preferably, a plurality of sliding grooves are evenly formed on the outer peripheral surface of the auxiliary connecting cylinder, and a plurality of convex plates protrude from the inner peripheral surface of the sliding mounting cylinder. The plurality of convex plates are respectively slidably connected in the corresponding sliding grooves.

[0021] Beneficial effects

[0022] The present invention provides a device for preparing ultra-pure nitrogen, having the following beneficial effects:

[0023] 1. For the device for preparing ultra-pure nitrogen, through the settings of the driving fan, driving rod, auxiliary driving plate and blocking driving component, when the rising speed of nitrogen increases, the increase in gas flow rate further increases the rotation speed of the driving fan. As the rotation speed of the driving fan increases, the auxiliary driving plate is thrown out due to the increase in centrifugal force. When the auxiliary driving plate is clamped on the driving baffle, it will drive the bubble cap to rotate together. Due to the special design of the screw sleeve, the bubble cap will move downward when rotating. In this way, the path of the mixed gas entering the riser from the air inlet and discharged from the bottom end of the bubble cap becomes longer, and the rising path of the bubbles also becomes longer correspondingly, which greatly enhances the effect of separating nitrogen by the reflux liquid.

[0024] 2. For the device for preparing ultra-pure nitrogen, through the setting of the dehydrogenation tower body, it is not only unnecessary to consider the service life of the adsorbent, but also the later maintenance cost is reduced.

[0025] 3. The equipment for preparing ultra-pure nitrogen, through the setting of the driving plate, can cause a series of physical phenomena when the driving plate rotates. On the one hand, it will extend the movement trajectory of the bubbles in the reflux liquid, that is, by increasing the travel path of the bubbles, to strengthen the interaction between gas and liquid; on the other hand, the rotation of the driving plate will generate a shearing and crushing effect on the rising bubbles, breaking the large bubbles into multiple small bubbles, greatly increasing the contact area between nitrogen and the reflux liquid. This series of action mechanisms can significantly improve the mass transfer efficiency between the liquid phase and the gas phase, and thus greatly improve the conversion efficiency between the flowing liquid and nitrogen.

[0026] 4. The equipment for preparing ultra-pure nitrogen, through the setting of the driving plate, can cause additional turbulence in the reflux liquid when the driving plate rotates. This turbulence will form complex vortices and circulations in the liquid, further enhancing the energy exchange between different layers of the liquid. Under the action of this strong turbulence, the originally stratified liquid is difficult to maintain a stable temperature stratification state, and the temperature stratification phenomenon will be significantly damaged. At the same time, the mechanical energy generated by the agitation of the driving plate will intensify the mixing between different parts of the reflux liquid. The reflux liquid close to the tray with a lower temperature and the reflux liquid close to nitrogen with a higher temperature will be forced to mix, and the temperature difference will gradually decrease during the mixing process, effectively destroying the stratification phenomenon formed by the liquid ammonia due to different temperatures, and thus being able to greatly increase the conversion efficiency between its reflux liquid and nitrogen. Description of the Drawings

[0027] Figure 1 is a schematic flow chart of preparing ultra-pure nitrogen according to the present invention;

[0028] Figure 2 is a schematic structural diagram of the dehydrogenation tower body according to the present invention;

[0029] Figure 3 is a partial sectional structural diagram of the front view of the dehydrogenation tower body according to the present invention;

[0030] Figure 4 is a schematic structural diagram of the front view of the tray according to the present invention;

[0031] Figure 5 According to the present invention Figure 4 is an enlarged structural diagram at A;

[0032] Figure 6 is a schematic structural diagram of the cooperation between the sliding mounting cylinder and the driving plate according to the present invention;

[0033] Figure 7 is a schematic structural diagram of the auxiliary connection cylinder according to the present invention;

[0034] Figure 8 is a schematic structural diagram of the cooperation between the driving rod and the auxiliary positioning cylinder according to the present invention;

[0035] Figure 9 This is a schematic cross-sectional view of the drive bucket of the present invention as seen from above.

[0036] In the figure: 1. Dehydrogenation tower body; 2. Tray; 3. Uptake pipe; 4. Bubble cap; 5. Drive bucket; 6. Drive plate; 7. Drive fan; 8. First elastic member; 9. Drive rod; 10. Drive baffle; 11. Auxiliary circular plate; 12. Auxiliary drive plate; 13. Second elastic member; 14. First ring plate; 15. Auxiliary moving bucket; 16. Sleeve; 17. Floating plate; 18. Fixed rod; 19. Auxiliary connecting cylinder; 20. Sliding mounting cylinder; 21. Air inlet; 22. Chute; 23. Auxiliary positioning cylinder; 24. Limiting rod; 25. Main heat exchanger; 26. Expander; 27. Subcooler; 28. Lower column; 29. Lower column condensing evaporator; 30. Dehydrogenation tower condenser; 31. Dehydrogenation tower evaporator; 32. Upper column; 33. Upper column condenser; 34. Liquid nitrogen pump. Detailed implementation manners

[0037] Next, the technical solutions in the embodiments of the present invention will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present invention. Obviously, the described embodiments are only a part of the embodiments of the present invention, rather than all the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without creative efforts shall fall within the protection scope of the present invention.

[0038] Embodiment 1

[0039] Ultra-pure nitrogen has wide applications in the fields of electronics and semiconductor manufacturing. It is usually used as a protective gas and a carrier gas to ensure the excellence of the process and avoid the influence of impurities. For example, in the chemical vapor deposition (CVD) process, ultra-pure nitrogen is used as a carrier gas, a carrier gas for liquid diffusion sources, and a protective gas for devices in a high-temperature diffusion furnace. However, in the field of semiconductor chips, there are very strict requirements for the purity of nitrogen (the oxygen content cannot exceed 1 ppm and the hydrogen content cannot exceed 1 ppb). Conventional high-purity nitrogen contains hydrogen components and cannot effectively remove hydrogen. Generally, high-purity nitrogen obtained by cryogenic rectification technology is introduced into a hydrogen removal and purification device, and an adsorbent is used to adsorb and remove hydrogen, thereby obtaining an ultra-pure nitrogen device;

[0040] Existing high-purity nitrogen purification equipment needs to add a hydrogen removal and purification device. Not only the service life of the adsorbent needs to be considered, but also the later maintenance cost is increased invisibly. To solve the above problems, this embodiment is specifically invented.

[0041] Please refer to Figure 1, the present invention provides a technical solution: an apparatus for preparing ultra-pure nitrogen, comprising a lower column 28, an upper column 32, a dehydrogenation column body 1, and a plurality of trays 2 axially arranged in the dehydrogenation column body 1. The apparatus for preparing ultra-pure nitrogen further comprises an expander 26, a main heat exchanger 25, a sub-cooler 27, a lower column condensing evaporator 29, a dehydrogenation column condenser 30, a dehydrogenation column evaporator 31, and an upper column condenser 33;

[0042] The pure and dry air from which water, carbon dioxide, and some hydrocarbons are removed is sent into the main heat exchanger 25, and heat exchange is carried out with the refluxing low-temperature waste gas and the product nitrogen in the main heat exchanger 25. A stream of air is drawn out from the middle of the main heat exchanger 25 as expansion air and enters the expander 26 for expansion refrigeration. After expansion, it directly returns to the bottom of the main heat exchanger 25, is reheated, and then sent out of the main heat exchanger 25 for venting;

[0043] The remaining air is cooled and then enters the bottom of the lower column 28, and is separated by rectification into high-purity nitrogen and oxygen-rich liquid air. A part of the liquid air at the bottom of the column passes through the sub-cooler 27 and then throttles into the dehydrogenation column condenser 30 to serve as a cold source. After vaporization, it returns to the upper column 32 to continue participating in rectification. The rest throttles into the lower column condensing evaporator 29 at the bottom of the upper column (where the lower column condensing evaporator 29 acts on both the lower column 28 and the upper column 32. It acts as a condenser on the lower column 28 and as an evaporator on the upper column 32. And the working principle of the lower column condensing evaporator 29 is prior art, so it will not be described in detail here) and exchanges heat with nitrogen by phase change. After the nitrogen is condensed, it serves as the rectification column reflux liquid. A part of it refluxes into the lower column 28, and a part is intercepted and then enters the dehydrogenation column body 1. Ultra-pure product nitrogen is drawn out from the bottom of the dehydrogenation column body 1, and after being reheated by the main heat exchanger 25, it is sent out;

[0044] The liquid air evaporates into oxygen-rich steam and continues to participate in rectification in the upper column 32. Finally, low-pressure pure nitrogen is obtained at the top of the upper column 32, and then it is condensed by the upper column condenser 33 and converted into liquid nitrogen. A part of it refluxes into the upper column 32 as the upper column reflux liquid, and the other part is pumped by the liquid nitrogen pump 34 into the top of the lower column, increasing the liquid nitrogen reflux ratio of the lower column 28, improving the nitrogen extraction rate of the lower column 28. At the same time, a part of the oxygen-rich liquid air in the lower column 28 is pumped into the upper column 32 to serve as the cold source of the upper column condenser 33, and at the same time, the oxygen-rich liquid air is vaporized into waste nitrogen.

[0045] The waste nitrogen is led out from the top of the upper column condenser 33, reheated to room temperature in the main heat exchanger 25, and then discharged. A part of it serves as the regeneration gas of the purification system, and the rest is discharged.

[0046] The pure and dry air from which water, carbon dioxide and some hydrocarbons have been removed is sent into the main heat exchanger 25, where it exchanges heat with the returning low-temperature waste gas and the product nitrogen. Part of the air condenses into a liquid state while the rest remains in a gaseous state, and it is introduced into the bottom of the lower column 28. The lower column 28 is a structured packing column to achieve sufficient gas-liquid contact and mass transfer. At the top of the lower column 28, a lower column condenser-evaporator 29 is provided. Light components such as (nitrogen, hydrogen) are not easily condensed and rise along the lower column 28 to the top of the column. Some enter the lower column 28. Since the liquid air at the bottom of the lower column 28 passes through the subcooler 27 and is subcooled to reduce the vaporization of the liquid air and then throttles into the lower column condenser-evaporator 29, the temperature drops. As a result, the gas rising in the lower column 28 can be condensed into a liquid state and refluxed to the top of the lower column 28. The reflux liquid condenses the heavy components such as oxygen in the gas rising in the lower column 28 into a liquid state and accumulates at the bottom of the column. Light components such as nitrogen and hydrogen are not easily condensed and rise along the column body and accumulate at the top of the column. Since the lower column condenser-evaporator 29 is provided at the top of the lower column 28 and the temperature of the rising gas is higher than the temperature of the lower column condenser-evaporator 29, the oxygen-rich liquid air is evaporated into a gaseous state and introduced into the bottom of the upper column. At the top of the upper column, an upper column condenser 33 is provided. The oxygen-rich liquid air provided by the lower column condenser-evaporator 29 first enters the bottom of the upper column 32 and then throttles into the upper column condenser 33. At this time, the oxygen-rich gas rising along the upper column 32 enters the upper column 32 and is condensed into a liquid state by the liquid air and refluxed to the top of the upper column 32. The reflux liquid condenses the heavy components such as oxygen in the rising gas into a liquid state and accumulates at the bottom of the column, while the light components that are not easily condensed such as nitrogen and hydrogen accumulate at the top of the column. At this time, a part of the liquid nitrogen is extracted from the reflux liquid of the upper column 32, pressurized by the liquid nitrogen pump 34, and introduced into the top of the lower column 28 to increase the reflux liquid of the lower column. Since the upper and lower columns cannot remove the hydrogen component, the working principles and connection relationships of the above-mentioned main heat exchanger 25, expander 26, subcooler 27, lower column 28, lower column condenser-evaporator 29, upper column 32 and upper column condenser 33 are all prior arts, so they will not be described in detail;

[0047] At this time, a dehydrogenation tower body 1 is added. A dehydrogenation tower condenser 30 is arranged at the upper part of the dehydrogenation tower body 1, and a dehydrogenation tower evaporator 31 is arranged at the bottom. First, a part of the liquid nitrogen at the top of the lower tower 28 is introduced into the top of the dehydrogenation tower body 1 as reflux liquid. At the same time, a part of the nitrogen gas entering the lower tower condensing evaporator 29 from the top of the lower tower 28 is extracted and introduced into the dehydrogenation tower evaporator 31 at the bottom of the dehydrogenation tower body 1. And the dehydrogenation tower condenser 30 at the top of the dehydrogenation tower body 1 is introduced with throttled oxygen-rich liquid air. At this time, the dehydrogenation tower condenser 30 reaches -174 °C. The dehydrogenation tower evaporator 31 at the bottom uses the nitrogen gas with a high temperature of -172 °C as a heat source, continuously evaporates the liquid nitrogen. The hydrogen component and part of the nitrogen component in the liquid nitrogen rise along the dehydrogenation tower body 1 and enter the upper tower condenser 33. Due to the lower temperature of the oxygen-rich liquid air, the nitrogen component is condensed into a liquid state and flows back to the top of the dehydrogenation tower body 1 as reflux liquid. The hydrogen component has a lower boiling point and is still in a gaseous state, and is directly discharged from the upper tower condenser 33 at the top of the dehydrogenation tower body 1. In the dehydrogenation tower body 1, nitrogen is the heavy component and hydrogen is the light component. The nitrogen component is condensed into a liquid state by the reflux liquid and accumulates at the bottom of the tower. The light component cannot be condensed by the reflux liquid due to its lower boiling point, so the hydrogen component accumulates at the top of the tower. Thus, ultra-pure nitrogen gas is obtained at the bottom of the dehydrogenation tower body 1 and is then reheated and extracted through the main heat exchanger 25.

[0048] Therefore, through the setting of the dehydrogenation tower body 1, it is not only unnecessary to consider the service life of the adsorbent, but also the later maintenance cost is reduced.

[0049] Embodiment 2

[0050] In the above embodiment, although the problem of later maintenance cost can be solved, when the hydrogen content in the rising gas (nitrogen gas) in the dehydrogenation tower body 1 is different, it will cause the rising speed of nitrogen gas to be different. Because the density of hydrogen is much lower than that of nitrogen, when the hydrogen content is high, the average density of the mixed gas decreases. Under the action of gravity, the mixed gas with a smaller density is easier to flow upward, which will also cause the rising speed of nitrogen gas to increase. Just like a hydrogen balloon will rise rapidly in the air, the mixed gas containing a large amount of hydrogen will also flow upward more rapidly in the dehydrogenation tower. At the same time, because gas separation mainly relies on the full contact and interaction between nitrogen gas and reflux liquid, when the gas rising speed increases, it means that the contact time between the gas and the reflux liquid is greatly shortened. In a limited time, it is difficult for nitrogen gas to be fully dissolved in the reflux liquid and achieve effective separation, resulting in part of the nitrogen gas escaping rapidly with the rapidly rising gas flow, and finally reducing the efficiency of separating nitrogen gas. To solve the above problems, this embodiment is specifically invented.

[0051] Please refer to Figures 2 - 9, on the basis of the above embodiments, the adopted technical solution includes a dehydrogenation tower body 1 and a plurality of trays 2 axially arranged in the dehydrogenation tower body 1. A plurality of riser pipes 3 for allowing the rising gas to enter are arranged on the surface of the tray 2 close to the top of the dehydrogenation tower body 1. A bubble cap 4 capable of moving back and forth and rotating along its axis is arranged at the top of the riser pipe 3. A power component for delivering power to the bubble cap 4 is arranged in the riser pipe 3;

[0052] The power component includes a driving fan 7 rotatably arranged on the inner peripheral surface of the riser pipe 3. A driving rod 9 is fixedly connected to the top of the driving fan 7. Therefore, when the driving fan 7 rotates, the driving rod 9 can be driven to rotate together with it. A blocking driving component is fixedly connected to the top of the bubble cap 4. A plurality of auxiliary driving plates 12 capable of being clamped on the blocking driving component are arranged at the top of the driving rod 9;

[0053] A first elastic member 8 for urging the bubble cap 4 to reset is arranged at the top of the riser pipe 3, and the first elastic member 8 is a spring.

[0054] A plurality of air inlets 21 adapted to the riser pipes 3 are opened on the horizontal plane of the tray 2. Therefore, the rising gas can enter the riser pipes 3 through the air inlets 21, and the upward flow of the gas can cause the driving fan 7 to rotate.

[0055] One end of the first elastic member 8 far from the riser pipe 3 is fixedly connected to a first ring plate 14. One end of the first ring plate 14 far from the first elastic member 8 is rotatably connected to the inner top surface of the bubble cap 4. Therefore, when the bubble cap 4 rotates, the first elastic member 8 will not hinder the bubble cap 4.

[0056] One end of the driving rod 9 close to the driving fan 7 is rotatably connected to a fixing plate, and a plurality of fixing columns with one ends all arranged on the riser pipe 3 are fixedly connected to the outer peripheral surface of the fixing plate. Through the arrangement of the fixing plate, the driving rod 9 can be vertically stabilized on the riser pipe 3. At the same time, when the driving fan 7 rotates, the driving rod 9 will also rotate on the fixing plate. The middle of the driving rod 9 is rotatably connected to a screw sleeve 16. A plurality of fixing rods 18 with one ends all arranged on the riser pipe 3 are fixedly connected to the bottom of the screw sleeve 16. Through the arrangement of the fixing rods 18, the screw sleeve 16 can be fixed on the riser pipe 3. Therefore, the rotation of the driving rod 9 will not cause the screw sleeve 16 to rotate together with it;

[0057] An auxiliary moving barrel 15 is fixedly connected to the inner top surface of the bubble cap 4. The bottom of the auxiliary moving barrel 15 is movably connected to the screw sleeve 16, and a convex block clamped on the spiral groove of the screw sleeve 16 protrudes from the bottom of the auxiliary moving barrel 15. Therefore, when the bubble cap 4 rotates, the auxiliary moving barrel 15 will also be driven to rotate. At the same time, when the auxiliary moving barrel 15 rotates, through the arrangement of the convex block, the bubble cap 4 can be urged to move downward.

[0058] The blocking drive component includes a drive barrel 5 fixedly connected to the top surface of the blister 4. A plurality of drive baffles 10 are fixedly connected to the inner peripheral surface of the drive barrel 5 at equal intervals. The top of the drive rod 9 is slidably connected with an auxiliary positioning cylinder 23 along its axial direction. A plurality of limiting rods 24 are vertically arranged at the top of the drive rod 9. The auxiliary positioning cylinder 23 is rotatably connected to the bottom of the drive barrel 5 through a bearing. The top of the drive rod 9 extends into the drive barrel 5. The number of the limiting rods 24 is four, and the limiting rods 24 are slidably connected with the auxiliary positioning cylinder 23. Therefore, when the drive rod 9 rotates, the auxiliary positioning cylinder 23 can be driven to rotate together through the arrangement of the limiting rods 24.

[0059] The top of the drive rod 9 is fixedly connected with an auxiliary circular plate 11. A plurality of limiting grooves are evenly formed on the outer peripheral surface of the auxiliary circular plate 11. A plurality of auxiliary drive plates 12 are respectively slidably connected in the corresponding limiting grooves. One end of the auxiliary drive plate 12 away from the inner peripheral surface of the drive barrel 5 is fixedly connected with a second elastic member 13. The second elastic member 13 is a tension spring. One end of the second elastic member 13 away from the auxiliary drive plate 12 is fixedly connected in the limiting groove.

[0060] Therefore, when the drive rod 9 rotates, the auxiliary circular plate 11 will also rotate together with it. When the auxiliary circular plate 11 rotates, the auxiliary drive plates 12 will move away from the auxiliary circular plate 11 due to centrifugal force. Therefore, when the auxiliary drive plates 12 are clamped onto the drive baffles 10, the drive barrel 5 will be driven to rotate together, so that the drive barrel 5 drives the blister 4 to rotate together. When the blister 4 rotates, it will also drive the auxiliary moving barrel 15 to rotate. At the same time, when the auxiliary moving barrel 15 rotates, through the arrangement of the convex block and the screw sleeve 16, the blister 4 can be driven to move downward.

[0061] When the hydrogen content in the rising gas remains constant, the rotation speed of the drive fan 7 will be maintained stable. Under this stable working condition, the auxiliary drive plate 12 drives the drive barrel 5 to rotate through the drive baffle 10. Since the drive baffle 10 adopts an inclined design, during the continuous downward displacement of the drive barrel 5, the contact state between the drive baffle 10 and the auxiliary drive plate 12 will change until they are separated from each other. At this time, the elastic potential energy of the first elastic member 8 begins to play a role. Under the action of the elastic restoring force of the first elastic member 8, the blister 4 pushes the drive barrel 5 together with the drive baffle 10 to move upward until the drive baffle 10 re-establishes contact with the next auxiliary drive plate 12. After that, the system will repeat the above series of actions to form a periodic dynamic cycle process to maintain the stable operation of the system and the realization of specific functions.

[0062] When the hydrogen content in the updraft decreases, the rotational speed of the driving fan 7 decreases accordingly. The decrease in the rotational speed of the driving fan 7 causes the centrifugal force acting on the auxiliary driving plate 12 to decrease. At this time, under the elastic restoring force of the second elastic member 13, the auxiliary driving plate 12 is pulled back. As the auxiliary driving plate 12 is pulled back, its blocking effect on the driving barrel 5 is eliminated. The first elastic member 8 releases its elastic potential energy, generating an upward driving force to prompt the driving barrel 5 together with the bubble cap 4 to move upward. Through such a mechanical linkage mechanism, the precise regulation of the vertical position of the bubble cap 4 according to the dynamic change of the hydrogen content in the updraft is achieved.

[0063] The rising gas is nitrogen, but the nitrogen contains hydrogen. When the hydrogen content in the nitrogen is different, it will cause the rising speed of nitrogen to be different. Because the density of hydrogen is much lower than that of nitrogen, when the hydrogen content is high, the average density of the mixed gas decreases. Under the action of gravity, the mixed gas with a smaller density is more likely to flow upward, which will also cause the rising speed of nitrogen to increase. Just like a hydrogen balloon will rise rapidly in the air, the mixed gas containing a large amount of hydrogen will also flow upward more rapidly in the dehydrogenation tower. At the same time, because gas separation mainly relies on the full contact and interaction between nitrogen and the reflux liquid, when the gas rising speed increases, it means that the contact time between the gas and the reflux liquid is greatly shortened. In a limited time, it is difficult for nitrogen to be fully dissolved in the reflux liquid and achieve effective separation, resulting in part of the nitrogen escaping rapidly with the rapidly rising gas flow, ultimately reducing the efficiency of separating nitrogen.

[0064] When the hydrogen content in the nitrogen is relatively high, the rising speed of nitrogen increases, and the increase in gas flow rate further causes the rotational speed of the driving fan 7 to increase. As the rotational speed of the driving fan 7 increases, the auxiliary driving plate 12 is thrown out due to the increased centrifugal force. When the auxiliary driving plate 12 is clamped on the driving baffle 10, it will drive the bubble cap 4 to rotate together. Due to the special design of the screw sleeve 16, the bubble cap 4 will move downward when it rotates. In this way, the path of the mixed gas entering the riser 3 from the air inlet 21 and discharging from the bottom end of the bubble cap 4 increases, and the bubble rising path also becomes longer accordingly, which greatly enhances the effect of separating nitrogen by the reflux liquid.

[0065] Embodiment III

[0066] In the above embodiments, the problem of the concentration fluctuation of hydrogen in nitrogen is successfully solved. As a key parameter, the hydrogen concentration has a significant impact on the upward flow rate of nitrogen, and thus affects the mass transfer and separation efficiency of nitrogen during the contact with the reflux liquid. By optimizing the structural design, the movement distance of nitrogen in the reflux liquid is effectively regulated, and the mass transfer and separation efficiency of nitrogen in the reflux liquid is greatly improved. However, in the dehydrogenation tower body 1, there is an equilibrium relationship between the gas and the liquid. Factors such as the temperature and composition of the gas phase will affect the temperature of the reflux liquid. The liquid ammonia far from the tray is closer to the gas phase and is more easily affected by the gas phase, exchanging heat and matter with the gas phase, thereby affecting its temperature. The reflux liquid near tray 2 mainly interacts with tray 2 and a small amount of liquid above it, and is less directly affected by the gas phase. The temperature change mechanism is different from that of the liquid ammonia far from the tray, and there will be a difference in their temperatures. Therefore, this phenomenon will greatly affect the conversion efficiency of the reflux liquid to nitrogen. To solve the above problems, this embodiment is specifically invented.

[0067] Please refer to Figures 2 - 9 , on the basis of the above embodiments, the technical solutions adopted include that the bottom of the outer peripheral surface of the bubble cap 4 is rotatably connected to the auxiliary connecting cylinder 19. The outer peripheral surface of the auxiliary connecting cylinder 19 is provided with a sliding mounting cylinder 20 that can slide along its axial direction. A plurality of driving plates 6 are evenly and fixedly connected to the outer peripheral surface of the sliding mounting cylinder 20. Therefore, when the driving plates 6 are subjected to external forces, they will drive the sliding mounting cylinder 20 to rotate on the auxiliary connecting cylinder 19.

[0068] A floating plate 17 is fixedly connected to the surface of the sliding mounting cylinder 20 away from tray 2.

[0069] One side outer surface of the driving plate 6 is an inclined surface. Therefore, when the flowing reflux liquid impacts the plurality of driving plates 6, the inclined surface can disperse the force. So, from Figure 6From a perspective, the driving plate 6 will drive the sliding mounting cylinder 20 to rotate in the clockwise direction. At the same time, due to the setting of the inclined surface, when the driving plate 6 rotates, it will also push the liquid at the bottom of the upper surface of the tray 2 upward, thereby being able to destroy the temperature stratification phenomenon of the reflux liquid on the tray 2 (because there will be a certain degree of flow and mixing of the reflux liquid on the tray, but this flow and mixing may not necessarily make the temperature of the liquid nitrogen layer completely uniform. In the part close to the tray, due to factors such as the friction between the liquid and the tray surface, the flow velocity is relatively slow and the mixing degree is relatively weak. The reflux liquid far from the tray is subject to less frictional resistance, has relatively strong convection and mixing, and the heat exchange with the gas phase is also relatively more sufficient, which results in its temperature being different from that of the liquid ammonia close to the tray. At the same time, in the dehydrogenation tower body 1, there is an equilibrium relationship between the gas and the liquid. Factors such as the temperature and composition of the gas phase will affect the temperature of the reflux liquid. The liquid ammonia far from the tray is closer to the gas phase, is more easily affected by the gas phase, and exchanges heat and substances with the gas phase, thus affecting its temperature. The reflux liquid close to the tray 2 mainly interacts with the tray 2 and a small amount of liquid above it, is less directly affected by the gas phase, and has a different temperature change mechanism from the liquid ammonia far from the tray, and there will be a difference in their temperatures. Therefore, this phenomenon will greatly affect the conversion efficiency of the reflux liquid to nitrogen). When the driving plate 6 rotates, it can cause the reflux liquid to generate additional turbulence. This turbulence will form complex eddies and circulations in the liquid, further enhancing the energy exchange between different layers of the liquid. Under the action of this strong turbulence, the originally stratified liquid is difficult to maintain a stable stratified state, and the temperature stratification phenomenon will be significantly destroyed. At the same time, the mechanical energy generated by the agitation of the driving plate 6 will intensify the mixing between different parts of the reflux liquid. The reflux liquid close to the tray 2 with a lower temperature and the reflux liquid close to the nitrogen with a higher temperature will be forced to mix, and the temperature difference will gradually decrease during the mixing process, thereby effectively destroying the stratification phenomenon formed by the liquid ammonia due to different temperatures, and thus being able to greatly increase the conversion efficiency between the reflux liquid and nitrogen.

[0070] A plurality of chutes 22 are evenly opened on the outer peripheral surface of the auxiliary connection cylinder 19, and a plurality of convex plates protrude from the inner peripheral surface of the sliding mounting cylinder 20. The plurality of convex plates are respectively slidably connected in the corresponding chutes 22. The height of the lower surface of the floating plate 17 is exactly level with the upper surface of the reflux liquid. Therefore, through the setting of the floating plate 17, it can be ensured that when the bubble cap 4 moves downward, the vertical position of the driving plate 6 will not change.

[0071] When the driving plate 6 rotates, a series of physical phenomena will be triggered. On the one hand, it will extend the movement trajectory of the bubbles in the reflux liquid, that is, by increasing the travel path of the bubbles, to strengthen the interaction between gas and liquid. On the other hand, the rotation of the driving plate 6 will produce a shearing and breaking effect on the rising bubbles, breaking the large bubbles into multiple small bubbles, greatly increasing the contact area between nitrogen and the reflux liquid. This series of action mechanisms can significantly improve the mass transfer efficiency between the liquid phase and the gas phase, and thus greatly improve the conversion efficiency between the flowing liquid and nitrogen.

[0072] To sum up, when the equipment for preparing ultra-pure nitrogen is in use, the rising gas enters the riser 3 from the air inlet 21. In the riser 3, the gas maintains a certain flow rate and pressure to maintain its upward driving force. Subsequently, the gas enters the reflux liquid inside the bubble cap 4 in the form of bubbles. Inside the bubble cap 4, the gas and liquid start to make initial contact and a mass transfer process occurs. Immediately afterwards, the bubbles formed by the gas overflow from the bottom end of the bubble cap 4 and pass through the liquid layer on the tray 2. During this process, the bubbles are in full contact with the reflux liquid and a heat exchange occurs, that is, a gas-liquid heat transfer process. Finally, the bubbles passing through the reflux liquid return to the gas phase space of the dehydrogenation tower body 1 again and continue to participate in the gas-liquid separation and conversion process inside the tower. At the same time, the reflux liquid will also come into contact with the hydrogen in the rising gas. Although the temperature of the reflux liquid does not reach the condition for liquefying hydrogen, the reflux liquid can still promote the adsorption of some hydrogen atoms. During this process, the reflux liquid accumulated at the bottom of the dehydrogenation tower body 1 continuously evaporates and continuously processes the rising gas through the reflux liquid to achieve continuous removal of hydrogen until the nitrogen purity reaches the preset standard.

[0073] It should be noted that in the description of the present invention, the terms indicating directions or position relationships such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or position relationships shown in the drawings. This is only for the convenience of description and does not indicate or imply that the device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation to the present invention. In addition, the terms "first", "second", "third" are only used for descriptive purposes and cannot be understood as indicating or implying relative importance.

[0074] In addition, it should also be noted that in the description of the present invention, unless otherwise clearly specified and limited, the terms "installation", "connection", "connection" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be directly connected or indirectly connected through an intermediate medium, and it can be the communication inside two elements. For those skilled in the art, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0075] The above are only the preferred specific embodiments of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art within the technical scope disclosed by the present invention should cover within the protection scope of the present invention any equivalent replacement or change made according to the technical solution of the present invention and its inventive concept.

Claims

1. An apparatus for preparing ultrapure nitrogen, comprising a lower tower (28), an upper tower (32), a dehydrogenation tower body (1), and a plurality of tower plates (2) axially arranged in the dehydrogenation tower body (1), characterized in that: A plurality of riser pipes (3) are arranged on the surface of the tower plate (2) close to the top of the dehydrogenation tower body (1) so as to allow rising gas to enter, a bubble cap (4) is arranged on the top of the riser pipe (3) and is capable of moving back and forth and rotating along its axial direction, and a power component capable of transmitting power to the bubble cap (4) is arranged inside the riser pipe (3); The power component comprises a driving fan (7) rotatably arranged on the inner circumference of the riser (3), the top of the driving fan (7) being fixedly connected to a driving rod (9), the top of the bubble cap (4) being fixedly connected to a blocking driving component, the top of the driving rod (9) being provided with a plurality of auxiliary driving plates (12) capable of being snapped onto the blocking driving component; A first elastic member (8) capable of causing the bubble cap (4) to return to its original position is provided at the top of the air riser (3); The middle part of the driving rod (9) is rotatably connected to a screw sleeve (16), and the bottom of the screw sleeve (16) is fixedly connected to a plurality of fixing rods (18) each having one end disposed on the riser (3); The inner top surface of the bubble cap (4) is fixedly connected to an auxiliary movable barrel (15), the bottom of the auxiliary movable barrel (15) is movably connected to a screw sleeve (16), and a protrusion protrudes from the bottom of the auxiliary movable barrel (15) and is clamped on a spiral groove of the screw sleeve (16).

2. The device for preparing ultrapure nitrogen according to claim 1, characterized in that: A plurality of air inlets (21) adapted to the air riser (3) are provided on the horizontal surface of the tower plate (2).

3. The device for preparing ultrapure nitrogen according to claim 2, characterized in that: One end of the first elastic member (8) away from the riser (3) is fixedly connected to a first ring plate (14), and one end of the first ring plate (14) away from the first elastic member (8) is rotatably connected to the inner top surface of the bubble cap (4).

4. The device for preparing ultrapure nitrogen according to claim 3, characterized in that: One end of the driving rod (9) close to the driving fan (7) is rotatably connected to a fixing plate, and the outer peripheral surface of the fixing plate is fixedly connected to a plurality of fixing columns, each of which has one end disposed on the riser (3).

5. The device for preparing ultrapure nitrogen according to claim 4, characterized in that: The blocking driving component comprises a driving barrel (5) fixedly connected to the top surface of the bubble cap (4); a plurality of driving baffles (10) are evenly fixedly connected to the inner circumference of the driving barrel (5); the top of the driving rod (9) is slidably connected to an auxiliary positioning barrel (23) along its axial direction; a plurality of limiting rods (24) are vertically arranged on the top of the driving rod (9); the auxiliary positioning barrel (23) is rotatably connected to the bottom of the driving barrel (5); and the top of the driving rod (9) extends into the driving barrel (5).

6. The device for preparing ultrapure nitrogen according to claim 5, characterized in that: An auxiliary circular plate (11) is fixedly connected to the top of the driving rod (9); a plurality of limit grooves are evenly formed on the outer circumference of the auxiliary circular plate (11); a plurality of auxiliary driving plates (12) are slidably connected in the corresponding limit grooves; an end of the auxiliary driving plate (12) away from the inner circumference of the driving barrel (5) is fixedly connected to a second elastic member (13); an end of the second elastic member (13) away from the auxiliary driving plate (12) is fixedly connected in the limit groove.

7. The device for preparing ultrapure nitrogen according to claim 6, characterized in that: The bottom of the outer peripheral surface of the bubble cap (4) is rotatably connected to an auxiliary connecting cylinder (19), the outer peripheral surface of the auxiliary connecting cylinder (19) is provided with a sliding mounting cylinder (20) that can slide along its axial direction, and the outer peripheral surface of the sliding mounting cylinder (20) is evenly fixedly connected to a plurality of driving plates (6).

8. The device for preparing ultrapure nitrogen according to claim 7, characterized in that: A floating plate (17) is fixedly connected to a surface of the sliding installation cylinder (20) away from the tower plate (2).

9. The device for preparing ultrapure nitrogen according to claim 8, characterized in that: One side of the driving plate (6) has an outer surface which is an inclined surface.

10. The device for preparing ultrapure nitrogen according to claim 9, characterized in that: The outer circumference of the auxiliary connection cylinder (19) is evenly provided with a plurality of slide grooves (22), and the inner circumference of the sliding installation cylinder (20) is provided with a plurality of convex plates, and the plurality of convex plates are respectively slidably connected in the corresponding slide grooves (22).

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