Nitrogen production system with double distillation tower

Abstract

The invention discloses a nitrogen preparation system with a double distillation tower, and specifically relates to the field of distillation technology, including adsorbing impurities in the air, and then allowing the air to enter an upper distillation tower and a lower distillation tower to separate nitrogen and oxygen. The upper distillation tower includes a plurality of tower plates fixedly arranged in the upper distillation tower, a downcomer is fixed in the upper distillation tower, the downcomer is fixedly connected to the tower plate, an overflow weir is arranged on the tower plate, a gas riser is arranged on the tower plate, a bubble cap is arranged on the gas riser, and also includes a control component and a rotating component. The invention uses a gas riser hole that can be opened and closed, so that the rising gas can rise when the temperature reaches a certain level, and at the same time, the bubble cap is rotated, so that the reflux liquid contacts the rising gas frequently and the contact area is increased, thereby solving the problems of impure separation caused by the inconvenience of controlling the rise of the rising gas, and poor gas-liquid mass transfer and heat exchange effects.

Description

Technical Field

[0001] The present invention relates to the field of distillation technology, and more particularly to a nitrogen preparation system with a double distillation tower. Background Art

[0002] Air separation, referred to as air separation, is based on the different boiling points of various gases in the air. After pressurization, precooling, purification, and liquefaction using most of the cooling capacity provided by the turbine expander, the air separation equipment is distilled to obtain the required oxygen / nitrogen products. At present, the air separation equipment used to separate nitrogen and oxygen on the market is mainly composed of a double distillation tower system. In the lower tower of the distillation tower, the rising gas is fully in contact with the reflux liquid. After heat and mass transfer, pure nitrogen is obtained at the top and liquid oxygen is produced at the bottom of the lower tower. After the liquid oxygen evaporates, oxygen is produced at the bottom of the upper tower. In other words, the main products of the air separation device using this structure are nitrogen and oxygen.

[0003] In the process of using distillation towers to separate air and prepare nitrogen and oxygen, ultra-low temperature technology and double distillation tower technology are usually used to separate air, and the purity of the prepared nitrogen and oxygen can be controlled. However, when using this technology to prepare nitrogen, since the evaporation of nitrogen is controlled by temperature, only when the temperature is appropriate can the purity of nitrogen and oxygen be guaranteed. Moreover, when this technology is used to prepare nitrogen and oxygen, when steam and reflux liquid come into contact, gas will rise from the riser. The rising gas may be oxygen, or it may be mixed with a very small amount of nitrogen or contaminated nitrogen. Therefore, the purity of the gas often does not reach the ideal purity.

[0004] When the rising gas moves to the upper tower plate, due to insufficient power for gas movement, when the gas moves out from the bubble cover, the gas will rise directly to above the reflux liquid after a brief contact with the reflux liquid, resulting in a short contact time between the rising gas and the reflux liquid. Although the rising gas will move a short distance under the impact of the reflux liquid, the flow direction of the reflux liquid is fixed and it moves in the direction of the force applied by the rising gas. Therefore, the size of the bubble will not change. Only the gas outside the bubble has a high probability of contacting the reflux liquid, resulting in the gas inside the bubble not yet contacting the reflux liquid when the gas moves out of the reflux liquid, resulting in low mass transfer and heat exchange efficiency. Summary of the invention

[0005] In order to overcome the above defects of the prior art, the present invention provides a nitrogen preparation system with a double distillation tower to solve the problems raised in the above background technology.

[0006] To achieve the above-mentioned object, the present invention provides the following technical scheme: a nitrogen preparation system with double distillation towers, comprising an air compressor and an air precooling device, wherein the air exhausted from the air compressor flows into the air precooling device, and the air precooling device discharges the exhausted air into the adsorption tower, and the air exhausted from the adsorption tower enters the main heat exchanger and then enters the turbine expander and the lower part of the lower distillation tower respectively, and the air in the turbine expander is discharged into the middle part of the upper distillation tower, and the nitrogen exhausted from the top of the upper distillation tower and the oxygen exhausted from the lower part are respectively collected after passing through the main heat exchanger, and the nitrogen at the top of the lower distillation tower enters the bottom of the upper distillation tower through a condenser evaporator and is distilled again, and a part of the nitrogen at the bottom of the upper distillation tower flows into the top of the lower distillation tower as reflux liquid. The other part of the nitrogen is condensed by the supercooler and discharged into the upper part of the upper distillation tower as reflux liquid. The liquid oxygen in the lower distillation tower is discharged to the middle part of the upper distillation tower as reflux liquid. The dirty nitrogen in the upper distillation tower enters the dirty nitrogen pipe through the regeneration gas electric heater and merges with the air discharged from the adsorption tower. The upper distillation tower is provided with a control component for controlling the rise of the rising gas and a rotating component for evenly dispersing the bubbles. The rotating component includes a fixed rod fixedly arranged in each riser, each of which is rotatably provided with a rotating part, each of which is provided with a bubble cap, each of which is provided with a plurality of mounting holes, and each of which is fixed with a plurality of fixed blocks that can be inserted into the corresponding mounting holes.

[0007] Preferably, a plurality of tower plates are fixedly arranged in the upper distillation tower, a plurality of downcomers corresponding to the tower plates are fixedly arranged in the upper distillation tower, each of the downcomers is fixedly connected to the corresponding tower plate, an overflow weir is fixedly arranged on the tower plate, a plurality of riser pipes are arranged on each of the tower plates, and the control component includes a lifting member slidably arranged in each of the riser pipes, each of the lifting members is provided with a riser hole, and each of the lifting members is slidably provided with a covering member capable of covering the corresponding riser hole.

[0008] Preferably, the control component also includes a support member fixedly arranged in the riser, a cylinder is fixedly arranged on each of the support members, a piston is slidably arranged in the cylinder, one end of each piston close to the corresponding lifting member passes through the corresponding cylinder and is fixedly connected to the corresponding lifting member, and liquid nitrogen is arranged between the end of the piston away from the lifting member and the cylinder.

[0009] Preferably, two superconducting magnets with opposite magnetic properties are arranged in the riser along its axial direction, and the shielding member is made of magnetic material.

[0010] Preferably, the rotating assembly comprises a fixing box fixedly arranged on each fixing rod, each fixing box is rotatably connected to the corresponding rotating member, and each rotating member is fixedly provided with a plurality of blades located in the corresponding fixing box.

[0011] Preferably, a blocking plate is fixedly provided in each of the riser pipes, and one end of the blocking plate close to the corresponding lifting member is connected to the lower part of the corresponding riser pipe through a connecting pipe, and the other end of each connecting pipe is inserted into the corresponding fixing box and opens toward the blade plate.

[0012] Preferably, each of the fixing boxes is provided with an air outlet groove on a side away from the corresponding connecting pipe.

[0013] Preferably, each of the fixing rods is provided with a smooth gasket, and each of the fixing rods is threadedly connected with a nut capable of contacting the corresponding gasket.

[0014] Preferably, each of the air risers is provided with a plurality of notches, the end surface of each of the sealing plates close to the corresponding bubble is lower than the lowest point of the notches, and each of the bubble is provided with a plurality of exhaust grooves.

[0015] Preferably, a nitrogen outlet is provided at the top of the upper distillation tower, a nitrogen inlet, a contaminated nitrogen outlet, a liquid oxygen inlet, an air inlet, an oxygen outlet and a nitrogen outlet are provided on one side of the upper distillation tower in sequence from top to bottom, and a liquid nitrogen inlet is provided on the other side of the upper distillation tower.

[0016] Technical effects and advantages of the present invention:

[0017] 1. The temperature can be sensed by the provided lifting parts, gas lifting holes, cylinders, liquid nitrogen and pistons. The opening or closing of the gas lifting holes is determined by whether the temperature can vaporize the liquid nitrogen. This ensures that when the liquid nitrogen can be vaporized, the shielding part is driven to move by the superconducting magnet on the upper side, so that the gas lifting holes are no longer blocked, and the rising gas enters the upper tower plate through the gas lifting holes and the gas lifting pipe to contact the reflux liquid.

[0018] 2. When the temperature is not high enough to make the liquid nitrogen in a gaseous state, the shielding piece is attracted by the superconducting magnet on the lower side to move and cover the riser hole, ensuring the effectiveness of each step of gas separation and ensuring that the rising gas can rise through the riser pipe only when the temperature inside the distillation tower is adapted.

[0019] 3. The rotating part can rotate the bubble cap, so that when the bubbles are discharged from the exhaust groove, an initial centrifugal force is obtained, so that the bubbles move a longer distance in the reflux liquid, prolong the time the bubbles move in the reflux liquid, and increase the consumption of gas in the bubbles in the reflux liquid.

[0020] 4. The rotation of the bubble cap can make the reflux liquid rotate, thereby generating a small vortex, and the vortexes generated by two adjacent bubble caps in the same row are in opposite directions, so that the reflux liquid and the bubbles in the reflux liquid collide with each other, so that the bubbles collide and become multiple smaller bubbles, and the contact area between the bubbles and the reflux liquid is increased on the side, which is conducive to better consumption of the heavy components in the bubbles, and the impact between the reflux liquids can stir up some droplets, so that the droplets can contact with the rising gas, further increasing the contact probability between the reflux liquid and the rising gas, better consuming the heavy components in the bubbles and the light components in the reflux liquid, gasifying the light components in the reflux liquid and liquefying the heavy components in the rising gas, and achieving a better separation effect. BRIEF DESCRIPTION OF THE DRAWINGS

[0021] Figure 1 It is a system schematic diagram of the present invention.

[0022] Figure 2 It is a schematic diagram of the overall structure of the upper distillation tower in the present invention.

[0023] Figure 3 It is a schematic cross-sectional view of the upper distillation tower in the present invention.

[0024] Figure 4 Schematic diagram of the structural distribution of the tower tray and bubble cap in the present invention.

[0025] Figure 5 It is a schematic cutaway axonometric diagram of the tower tray in the present invention.

[0026] Figure 6 It is a schematic diagram of the structure of the bubble cap and the air riser in the present invention.

[0027] Figure 7 It is a schematic cutaway axonometric view of the bubble cap and the riser in the present invention.

[0028] Figure 8 For the present invention Figure 7 A magnified view of the structure at center.

[0029] Fig. 9 It is a top axonometric view of the fixed box and the rotating member in the present invention.

[0030] Fig.10 It is a schematic diagram of the distribution of the connecting pipes on the fixing box in the present invention.

[0031] Fig.11 It is a schematic diagram of the structure of the rotating part in the present invention.

[0032] Fig.12 Schematic diagram of the distribution of blades on the rotating part in the present invention.

[0033] Fig.13 It is a cutaway axonometric view of the fixing box in the present invention.

[0034] Fig.14 It is a schematic cutaway axonometric diagram of the cylinder and lifting member of the present invention.

[0035] The accompanying drawings are marked as follows: 1, air compressor; 2, air precooling equipment; 3, adsorption tower; 4, main heat exchanger; 5, lower distillation tower; 6, upper distillation tower; 7, subcooler; 8, regeneration gas electric heater; 9, tower plate; 10, riser; 1001, notch; 11, bubble cap; 1101, exhaust groove; 12, control component; 1201, lifting member; 1202, riser hole; 1203, shielding member; 1204, support member; 1205, cylinder; 1206, piston; 1207, superconducting magnet; 13, rotating assembly; 1301, fixing rod; 1302, rotating member; 1303, mounting hole; 1304, fixing block; 1305, fixing box; 1306, blade; 1307, sealing plate; 1308, connecting pipe; 1309, air outlet groove; 1310, gasket; 1311, nut; 14, condenser evaporator; 15, turbine expander; 16, downcomer; 17, overflow weir. DETAILED DESCRIPTION

[0036] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0037] Embodiment 1

[0038] At present, when a single distillation tower is used to prepare nitrogen, the nitrogen extraction rate is low. The single distillation tower only relies on a single tower body for distillation and cannot perform multiple and deep separations like a double distillation tower. The nitrogen extraction rate is relatively low. Due to the limitations of the number of distillation times and the separation effect, it is difficult for a single distillation tower to meet such high purity requirements and the energy consumption is high. The upper tower and the lower tower in the double distillation tower can cooperate with each other to reasonably utilize energy, realize effective energy recovery and reuse, and reduce the energy consumption of the entire system. In order to achieve the same nitrogen output and a certain purity, a single distillation tower often requires higher pressure and temperature conditions, resulting in increased energy consumption. Especially in large-scale production, the energy consumption cost is more significant. In addition, the single distillation tower is limited by its own structure and distillation principle, and the adjustment range of product specifications is relatively narrow. It is difficult to simultaneously meet the nitrogen needs of multiple different purity and pressure requirements.

[0039] In order to solve the problem of preparing nitrogen with a single distillation tower, refer to the attached drawings of the specification. Figures 1 to 14It can be seen that in order to effectively prepare nitrogen with higher purity, the present embodiment provides a nitrogen preparation system with a double distillation tower, including an air compressor 1, an air precooling device 2, an adsorption tower 3, a main heat exchanger 4, a turbine expander 15, a lower distillation tower 5, a subcooler 7 and a regeneration gas electric heater 8, and also includes an upper distillation tower 6, the upper distillation tower 6 is used for secondary distillation of nitrogen and oxygen, the air compressor 1 is used to compress air, the air precooling device 2 is used to precool the air, the air discharged from the air compressor 1 flows into the air precooling device 2, the adsorption tower 3 is used to adsorb impurities in the air, the air precooling device 2 is discharged into the adsorption tower 3 through the discharged air, the main heat exchanger 4 is used to exchange heat between air and nitrogen, oxygen and dirty nitrogen, the air discharged from the adsorption tower 3 enters the main heat exchanger 4 and is divided into two streams, the turbine expander 15 is used to cool the air and accelerate the movement speed of the air, one of the air discharged from the main heat exchanger 4 is discharged into the turbine expander 15, and the lower distillation tower 5 is used to In the preliminary distillation, one of the air discharged from the main heat exchanger 4 enters the lower part of the lower distillation tower 5 for distillation, and the air in the turbine expander 15 is discharged into the middle part of the upper distillation tower 6. The nitrogen discharged from the top and the oxygen discharged from the bottom of the upper distillation tower 6 are collected after passing through the main heat exchanger 4 respectively. The nitrogen at the top of the lower distillation tower 5 enters the bottom of the upper distillation tower 6 through the condenser evaporator 14 and is distilled again. The condenser evaporator 14 is used to condense the gas in the lower distillation tower 5 and evaporate the liquid in the upper distillation tower 6. A part of the nitrogen at the bottom of the tower 6 flows into the top of the lower distillation tower 5 as reflux liquid, and the liquid oxygen in the lower distillation tower 5 is discharged to the middle of the upper distillation tower 6 as reflux liquid. The subcooler 7 is used to condense the nitrogen and liquid oxygen. Another part of the nitrogen at the lower part of the upper distillation tower 6 is condensed by the subcooler 7 and discharged into the upper part of the upper distillation tower 6 as reflux liquid. The regeneration gas electric heater 8 is used to heat the dirty nitrogen. The dirty nitrogen in the upper distillation tower 6 enters the dirty nitrogen pipe through the regeneration gas electric heater 8 and merges with the air discharged from the adsorption tower 3.

[0040] The air compressor 1, air precooling equipment 2, adsorption tower 3, main heat exchanger 4, lower distillation tower 5, subcooler 7, regeneration gas electric heater 8, condenser evaporator 14 and turbine expander 15 and their connection methods in the present invention are all prior arts and will not be described in detail here.

[0041] Through the setting of the double distillation tower system, the double distillation tower can make fuller use of the boiling point differences of the air components through the coordinated distillation effect of the upper tower and the lower tower, realize multiple distillations, and effectively improve the nitrogen extraction rate. Through the precise control of the upper and lower towers and multiple distillations, impurities and other gas components can be better removed, thereby producing high-purity nitrogen. The upper tower and the lower tower in the double distillation tower can cooperate with each other, reasonably utilize energy, realize effective energy recovery and reuse, reduce the energy consumption of the entire system, solve the narrow application range of the single distillation tower, and better meet the needs of large-scale industrial production and industries with high requirements for nitrogen purity and pressure.

[0042] Embodiment 2

[0043] In the process of using a distillation tower to separate air and prepare nitrogen and oxygen, ultra-low temperature technology and double distillation tower technology are usually used to separate air, and the purity of the prepared nitrogen and oxygen can be controlled. However, when using this technology to prepare nitrogen, since the evaporation of nitrogen is controlled by temperature, only when the temperature is appropriate can the purity of nitrogen and oxygen be guaranteed. In addition, when this technology is used to prepare nitrogen and oxygen, when steam and reflux liquid come into contact, gas will rise from the riser 10. The rising gas may be oxygen, or it may be mixed with a very small part of nitrogen or contaminated nitrogen. Therefore, the purity of the gas often does not reach the ideal purity.

[0044] In order to solve the above technical problems, based on the above embodiment 1, Figures 1 to 14The technical solution adopted includes an upper distillation tower 6, wherein a plurality of tower plates 9 are fixedly arranged in the upper distillation tower 6, a plurality of downcomers 16 corresponding to the tower plates 9 are fixedly arranged in the upper distillation tower 6, each downcomer 16 is fixedly connected to the corresponding tower plate 9, an overflow weir 17 is fixedly arranged on the tower plate 9, a plurality of riser pipes 10 are arranged on each tower plate 9, a bubble cap 11 is arranged on each riser pipe 10, and a control component 12 for controlling the rise of rising gas is also included, the control component 12 includes a lifting member 1201 slidably arranged in each riser pipe 10, each lifting member 1201 is provided with a riser hole 1202, each lifting member 1201 is slidably provided with a shielding member 1203 capable of covering the corresponding riser hole 1202, and the control component 12 also includes a lifting member 1201 fixedly arranged in the riser pipe 1 0, each support member 1204 is fixedly provided with a cylinder 1205, a piston 1206 is slidably provided in the cylinder 1205, one end of each piston 1206 close to the corresponding lifting member 1201 penetrates the corresponding cylinder 1205 and is fixedly connected to the corresponding lifting member 1201, liquid nitrogen is provided between the end of the piston 1206 away from the lifting member 1201 and the cylinder 1205, two superconducting magnets 1207 with opposite magnetic properties are provided in the riser 10 along its axial direction, the shielding member 1203 is made of magnetic material, a nitrogen outlet is provided at the top of the upper distillation tower 6, a nitrogen inlet, a dirty nitrogen outlet, a liquid oxygen inlet, an air inlet, an oxygen outlet and a nitrogen outlet are provided on one side of the upper distillation tower 6 from top to bottom, and a liquid nitrogen inlet is provided on the other side of the upper distillation tower 6.

[0045] During specific use, the condensate at the bottom of the upper distillation tower 6 evaporates under the action of the condenser evaporator 14, and then the rising gas begins to move upward through the riser pipe 10. When the rising gas enters the riser pipe 10, the gas exchanges heat with the liquid nitrogen in the cylinder 1205. The cylinder 1205 and the piston 1206 are both thermosensitive materials and can exchange heat well. When the liquid nitrogen receives enough heat and the temperature reaches a suitable temperature, the liquid nitrogen gradually evaporates into gas in the cylinder 1205. Due to the pressure change, the gas drives the piston 1206 to move upward, and the piston 1206 drives the lifting member 1201 to move upward, and the lifting member 1201 drives the shielding member 1203 to move upward. After the lifting member 1201 moves upward to a certain height, the shielding member 1203 is no longer affected by the magnetism of the superconducting magnet 1207 on the lower side, and the superconducting magnet 1207 on the lower side no longer attracts the shielding member 1203.

[0046] As the temperature rises, the higher the degree of evaporation of liquid nitrogen, the longer the distance the piston 1206 moves upward, and when the piston 1206 drives the lifting member 1201 and the shielding member 1203 to move upward close to the upper superconducting magnet 1207, when the shielding member 1203 and the superconducting magnet 1207 are close enough, the upper superconducting magnet 1207 begins to repel the shielding member 1203, causing the shielding member 1203 to move into the lifting member 1201, so that the shielding member 1203 no longer blocks the lifting hole 1202. The rising gas is covered and discharged to the upper part of the rising pipe 10 through the rising hole 1202, and then the gas is discharged to the tower plate 9 at that location through the exhaust groove 1101 on the bubble cap 11, and the rising gas contacts with the reflux liquid and mass transfer and heat exchange occur, so that the light components evaporate and rise, and the heavy components absorb heat and are converted into liquid and enter the reflux liquid, and the excess reflux liquid passes over the overflow weir 17 and enters the downcomer 16, and flows to the next tower plate 9 through the downcomer 16, and mass transfer and heat exchange occur with the rising gas at the next position.

[0047] When the temperature is low, due to the poor separation effect, the nitrogen in the cylinder 1205 cannot receive continuous heat to keep the nitrogen in a gaseous state, and the nitrogen gradually condenses into liquid nitrogen. Under the action of pressure, the piston 1206 moves downward, and the piston 1206 drives the lifting member 1201 to move downward, and the lifting member 1201 drives the shielding member 1203 to move downward, and the shielding member 1203 gradually moves away from the superconducting magnet 1207 on the upper side, so that the superconducting magnet 1207 on the upper side no longer repels the shielding member 1203. When the lifting member 1201 moves downward to the initial position, the superconducting magnet 1207 on the lower side attracts the shielding member 1203, so that the shielding member 1203 moves outward to block the rising hole 1202, so as to prevent the gas from rising when it is not separated purely, resulting in low purity of the separated nitrogen and oxygen.

[0048] The temperature can be sensed by the lifting member 1201, the gas riser 1202, the cylinder 1205, the liquid nitrogen and the piston 1206. The opening or closing of the gas riser 1202 is determined by whether the temperature can vaporize the liquid nitrogen. This ensures that when the liquid nitrogen can be vaporized, the shielding member 1203 is driven to move by the superconducting magnet 1207 on the upper side, so that the gas riser 1202 is no longer blocked, and the rising gas passes through the gas riser 1202 and the gas riser pipe 10 to enter the upper tower plate 9 and contact the reflux liquid. When the temperature is not high enough to make the liquid nitrogen in a gaseous state, the shielding member 1203 is driven by the superconducting magnet 1207 on the lower side to block the gas riser 1202, thereby ensuring the effectiveness of each step of gas separation.

[0049] Embodiment 3

[0050] Although the above embodiment can solve the problem of insufficient gas purity during separation due to insufficient temperature, when the rising gas moves to the upper tower plate, due to insufficient power for gas movement, when the gas moves out from the bubble cover, the gas will directly rise to the top of the reflux liquid after a brief contact with the reflux liquid, resulting in a short contact time between the rising gas and the reflux liquid. Although the rising gas will move a short distance under the impact of the reflux liquid, the flow direction of the reflux liquid is fixed and moves in the direction of the force applied by the rising gas. Therefore, the size of the bubble will not change. Only the gas outside the bubble has a high probability of contacting the reflux liquid, resulting in the gas inside the bubble not yet contacting the reflux liquid when the gas moves out of the reflux liquid, resulting in low mass transfer and heat exchange efficiency.

[0051] In order to solve the above technical problems, on the basis of the above embodiments, the following improvements are made. The adopted technical solution includes a rotating component 13 that makes the bubbles dispersed evenly. The rotating component 13 includes a fixed rod 1301 fixedly arranged in each riser 10, and a rotating member 1302 is rotatably arranged on each fixed rod 1301. A plurality of mounting holes 1303 are opened on each bubble cap 11, and a plurality of fixed blocks 1304 that can be inserted into the corresponding mounting holes 1303 are fixedly arranged on each rotating member 1302. The rotating component 13 includes a fixed box 1305 fixedly arranged on each fixed rod 1301, and each fixed box 1305 is rotatably connected to the corresponding rotating member 1302. A plurality of blades 1306 located in the corresponding fixed box 1305 are fixedly arranged on each rotating member 1302. A sealing plate 1307 is fixedly provided on each of them, and one end of the sealing plate 1307 close to the corresponding lifting member 1201 is connected to the lower part of the corresponding air riser 10 through a connecting pipe 1308, and the other end of each connecting pipe 1308 is inserted into the corresponding fixing box 1305 and the opening is facing the blade 1306, and an air outlet groove 1309 is provided on the side of each fixing box 1305 away from the corresponding connecting pipe 1308, and a smooth gasket 1310 is provided on each fixing rod 1301, and a nut 1311 capable of contacting the corresponding gasket 1310 is threadedly connected on each fixing rod 1301, and a plurality of notches 1001 are provided on each air riser 10, and the end face of each sealing plate 1307 close to the corresponding bubble 11 is lower than the lowest point of the notch 1001, and a plurality of exhaust grooves 1101 are provided on each bubble 11.

[0052] When the rising air moves upward in the riser 10, the rising air can only enter upward between the fixed box 1305 and the rotating member 1302 through the connecting pipe 1308 under the action of the blocking plate 1307, and the air outlet direction of the connecting pipe 1308 is oriented in a direction that is conducive to pushing the blade 1306 and the rotating member 1302 to rotate. The opening diameter of the connecting pipe 1308 at one end of the blocking plate 1307 is larger than the diameter in the fixed box 1305, which is convenient for a large amount of gas to enter. The small opening diameter can provide a greater impact force and speed, which is convenient for the rotation of the blade 1306. The gas pushes the blade 1306 and the rotating member 1302 to rotate through the connecting pipe 1308. Since the nut 1311 and the gasket 1310 are provided, and the surface of the gasket 1310 in contact with the bubble 11 is a smooth surface, the friction is small, the nut 1311 does not press the bubble 11 and the gasket 1310, and does not affect the rotation of the bubble 11. The rotating member 1302 drives the bubble 11 to rotate through the fixed block 1304 and the mounting hole 1303, and the excess gas is discharged into the bubble 11 through the air outlet groove 1309, and then discharged into the reflux liquid through the exhaust groove 1101 on the bubble 11.

[0053] Since the bubble cap 11 rotates under the action of the rotating member 1302, etc., the gas discharged through the exhaust groove 1101 has an initial centrifugal force, so that the discharged gas is uniform in size and can move a longer distance in the reflux liquid, so that the heavy components in the bubble can be consumed more effectively. When the bubble cap 11 rotates, it can drive the surrounding reflux liquid to generate a small vortex along the center of the bubble cap 11, so that the movement of the reflux liquid is no longer just along the overall flow direction of the reflux liquid.

[0054] The bubbles 11 are arranged in rows on the corresponding tower plates 9, and the two adjacent bubbles 11 in the same row rotate in opposite directions, and the vortices generated by the rotation are opposite, which can make the moving direction of the reflux liquid more chaotic, so that the vortices of the reflux liquid can impact each other, so that the bubbles and the reflux liquid impact each other, making the volume of the bubbles smaller, so that the contact area between the bubbles and the reflux liquid is larger, which is more conducive to consuming the heavy components in the bubbles and the light components in the reflux liquid, and is more conducive to mass transfer and heat exchange. The impact between the reflux liquids can arouse some droplets, so that the droplets can contact with the rising gas, further increasing the contact probability between the reflux liquid and the rising gas, and better consuming the heavy components in the bubbles and the light components in the reflux liquid. In this process, each component is discharged through the corresponding outlet respectively, such as nitrogen is discharged and collected from the nitrogen outlet, and other gases are discharged through the dirty nitrogen outlet and the oxygen outlet.

[0055] By setting the rotating part 1302, the bubble cap 11 can be rotated, so that when the bubble is discharged from the exhaust groove 1101, an initial centrifugal force is obtained, so that the bubble can move a longer distance in the reflux liquid, prolong the time for the bubble to move in the reflux liquid, and increase the consumption of the gas in the bubble in the reflux liquid. The rotation of the bubble cap 11 can cause the reflux liquid to rotate, thereby generating a vortex, and the vortexes generated by two adjacent bubble caps 11 in the same row are in opposite directions, so that the reflux liquid and the bubbles in the reflux liquid can collide with each other, so that after the bubbles collide, they become multiple smaller bubbles, and the contact area between the bubbles and the reflux liquid is increased on the side, which is conducive to better consumption of the heavy components in the bubbles, and the impact between the reflux liquids can make some droplets contact with the rising gas, further increasing the contact probability between the reflux liquid and the rising gas, better consuming the heavy components in the bubbles and the light components in the reflux liquid, gasifying the light components in the reflux liquid and liquefying the heavy components in the rising gas.

[0056] The above description is only a preferred specific implementation manner of the present invention, but the protection scope of the present invention is not limited thereto. Any technician familiar with the technical field can make equivalent replacements or changes according to the technical scheme and inventive concept of the present invention within the technical scope disclosed by the present invention, which should be covered by the protection scope of the present invention.

Claims

1. A nitrogen preparation system with a double distillation tower, comprising an air compressor and an air precooling device, characterized in that: The air discharged from the air compressor flows into the air precooling device, and the air precooling device is discharged into the adsorption tower through the discharged air. The air discharged from the adsorption tower enters the main heat exchanger and then enters the turbine expander and the lower part of the lower distillation tower respectively. The air in the turbine expander is discharged into the middle part of the upper distillation tower. The nitrogen discharged from the top of the upper distillation tower and the oxygen discharged from the lower part are collected after passing through the main heat exchanger respectively. The nitrogen at the top of the lower distillation tower enters the bottom of the upper distillation tower through the condenser evaporator and is distilled again. A part of the nitrogen at the bottom of the upper distillation tower flows into the top of the lower distillation tower as reflux liquid, and the other part of the nitrogen is condensed by the subcooler and discharged into the upper part of the upper distillation tower as reflux liquid. The liquid oxygen in the lower distillation tower is discharged to the middle part of the upper distillation tower as reflux liquid. The dirty nitrogen in the upper distillation tower enters the dirty nitrogen pipe through the regeneration gas electric heater and merges with the air discharged from the adsorption tower. The upper distillation tower is provided with a control component for controlling the rise of rising gas and a rotating component for evenly dispersing bubbles. A plurality of tower plates are fixedly provided in the upper distillation tower, and a plurality of riser pipes are provided on each of the tower plates. The rotating component includes a fixed rod fixedly provided in each riser pipe, and a rotating member is rotatably provided on each of the fixed rods. A bubble cap is provided on each of the riser pipes, and a plurality of mounting holes are provided on each of the bubble caps. A plurality of fixing blocks capable of being inserted into the corresponding mounting holes are fixedly provided on each of the rotating members. The control assembly comprises a lifting member slidably arranged in each of the air risers, each of the lifting members is provided with an air rise hole, and each of the lifting members is slidably provided with a shielding member capable of covering the corresponding air rise hole; The control assembly further comprises a support member fixedly arranged in the riser pipe, each of the support members is fixedly provided with a cylinder, a piston is slidably arranged in the cylinder, one end of each piston close to the corresponding lifting member penetrates the corresponding cylinder and is fixedly connected to the corresponding lifting member, and liquid nitrogen is arranged between the end of the piston away from the lifting member and the cylinder; Two superconducting magnets with opposite magnetic properties are arranged in the riser along its axial direction.

2. The nitrogen production system with double distillation towers according to claim 1, characterized in that: A plurality of downcomers corresponding to the tower plates are fixedly arranged in the upper distillation tower, each of the downcomers is fixedly connected to the corresponding tower plate, and an overflow weir is fixedly arranged on the tower plate.

3. The nitrogen production system with double distillation towers according to claim 2, characterized in that: The shielding member is made of magnetic material.

4. The nitrogen production system with double distillation towers according to claim 3, characterized in that: The rotating assembly includes a fixing box fixedly arranged on each fixing rod, each fixing box is rotatably connected to the corresponding rotating member, and each rotating member is fixedly provided with a plurality of blades located in the corresponding fixing box.

5. The nitrogen production system with double distillation towers according to claim 4, characterized in that: A blocking plate is fixedly provided in each riser, and one end of the blocking plate close to the corresponding lifting member is connected to the lower part of the corresponding riser through a connecting pipe, and the other end of each connecting pipe is inserted into the corresponding fixing box and opens toward the blade plate.

6. The nitrogen production system with double distillation towers according to claim 5, characterized in that: A gas outlet groove is formed on one side of each fixing box away from the corresponding connecting pipe.

7. The nitrogen production system with double distillation towers according to claim 6, characterized in that: A smooth gasket is arranged on each of the fixing rods, and a nut capable of contacting the corresponding gasket is threadedly connected on each of the fixing rods.

8. The nitrogen production system with double distillation towers according to claim 7, characterized in that: Each of the air risers is provided with a plurality of notches, the end surface of each of the sealing plates close to the corresponding bubble cap is lower than the lowest point of the notches, and each of the bubble caps is provided with a plurality of exhaust grooves.

9. The nitrogen production system with double distillation towers according to claim 8, characterized in that: A nitrogen outlet is arranged at the top of the upper distillation tower, a nitrogen inlet, a contaminated nitrogen outlet, a liquid oxygen inlet, an air inlet, an oxygen outlet and a nitrogen outlet are arranged in sequence on one side of the upper distillation tower from top to bottom, and a liquid nitrogen inlet is arranged on the other side of the upper distillation tower.

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