Recovery device and recovery process for battery coating mixed solvent

Abstract

The invention discloses a battery coating mixed solvent recovery device which comprises a gas-gas heat exchanger, a circulating absorption tower and a condenser which are connected in sequence, and the gas inlet end of the condenser is connected with the gas outlet end of the circulating absorption tower; the device further comprises a tail gas absorption tower; the tail gas absorption tower comprises a tower body, a spraying pipe, a gas outlet and a gas inlet pipe, a first water receiving tank and a second water receiving tank are arranged on the lower portion in the tower body, and a butt joint pipe used for being inserted into the second water receiving tank is arranged at the bottom of the first water receiving tank and sealed in the top tank wall of the second water receiving tank in the initial state. The first water receiving tank is arranged in the tower body in an up-and-down sliding mode, the first water receiving tank moves downwards to unseal the butt joint pipe, and water in the second water receiving tank can reach the spraying pipe through the pump body and the filter to be sprayed circularly; and a regular cleaning mechanism for regularly cleaning the filter screen is arranged in the air inlet of the tower body. The absorbent can be circularly absorbed in the system, and the filter screen in the tail gas absorption tower can be regularly and automatically cleaned, so that the times of manual inspection and replacement are reduced.

Description

Technical Field

[0001] The invention relates to the technical field of NMP recovery and extraction, in particular to a mixed solvent recovery device and a recovery process for battery coating. Background Art

[0002] NMP (N-methylpyrrolidone) is a highly efficient and selective solvent with the advantages of non-toxicity, high boiling point, low corrosiveness, high solubility, low viscosity, low volatility, good stability and easy recovery.

[0003] The commonly used methods in the industry at present are: tower water washing absorption, condensation + rotary absorption, condensation + deep cooling + activated carbon adsorption and other recovery methods.

[0004] Among them, the tower water washing recovery system mainly utilizes the advantage of NMP's good water solubility and is used for the recovery of N-methylpyrrolidone (NMP for short) in the exhaust gas of the coater, but it is not applicable to the recovery of organic solvents with poor water solubility such as cyclohexanone and xylene; the condensation + rotor method requires a large amount of chilled water for condensation; the zeolite molecular sieve rotor needs to keep rotating during operation, and a large amount of steam is required to desorb the molecular sieve, which consumes too much energy, and the rotor device is easily contaminated by gas, blocking the molecular sieve channel, reducing the adsorption capacity, and the subsequent maintenance cost is high; condensation + deep cooling + activated carbon adsorption treatment requires cooling the exhaust gas of the coater at about 110°C to -15°C so that the solvent is condensed into liquid to achieve the purpose of recovery and treatment, but this treatment method is greatly affected by the partial pressure of the air. For example, when the exhaust volume of the coater is large, the gaseous solvent cannot reach the saturated concentration due to the small partial pressure, and the recovery effect is poor. Summary of the invention

[0005] The object of the present invention is to provide a mixed solvent recovery device for battery coating to solve the above technical problems.

[0006] To achieve the above-mentioned purpose, the present invention provides the following technical solutions: a mixed solvent recovery device for battery coating, comprising an air-to-air heat exchanger, a circulating absorption tower, and a condenser connected in sequence, wherein the air inlet of the condenser is connected to the air outlet of the circulating absorption tower, and the air outlet of the condenser returns the gas to the air-to-air heat exchanger and heats it up to be used as return air to supplement the coating machine; It also includes a tail gas absorption tower connected to the gas outlet of the condenser. Part of the tail gas enters the tail gas absorption tower after condensation to maintain a slight negative pressure state of the system, and part of the tail gas is discharged after being sprayed by the tail gas absorption tower; The tail gas absorption tower comprises a tower body and a spray pipe arranged in the tower body, an air outlet is arranged at the top of the tower body, an air inlet pipe is arranged at the side, a first water receiving box and a second water receiving box are arranged at the lower part of the inner part of the tower body, a docking pipe for inserting into the second water receiving box is arranged at the bottom of the first water receiving box, the docking pipe is initially closed in the top box wall of the second water receiving box, the first water receiving box is slidably arranged in the tower body up and down, the first water receiving box moves downward to release the closure of the docking pipe and drain the water inside the box body into the second water receiving box, a return water pipe is connected between the second water receiving box and the spray pipe, a pump body and a filter are arranged on the return water pipe, and the water in the second water receiving box can reach the spray pipe through the pump body and the filter for circulation and spraying; An air inlet is provided at the joint between the tower body and the air inlet pipe, a filter is provided in the air inlet, and a regular cleaning mechanism for regularly cleaning the filter is provided in the air inlet. The first water receiving box moves down a stroke to drive the regular cleaning mechanism to start and clean the filter once.

[0007] Preferably, a pipe insertion hole for inserting a butt-joint pipe is provided on the top of the second water receiving box, the bottom of the butt-joint pipe is closed, and water outlets are provided on both side walls of the bottom.

[0008] Preferably, a reaming hole is provided at the bottom of the tube insertion hole, a sealing ring is provided on the top inner wall of the reaming hole, and a reaming plate is provided at the bottom of the butt-joint tube, and the reaming plate is slidably arranged in the reaming hole.

[0009] Preferably, the regular cleaning mechanism includes a rotating shaft and a wind plate fixed on the rotating shaft, and also includes a first wire wheel and a second wire wheel, the first wire wheel being coaxially fixed on the rotating shaft, the second wire wheel being rotatably arranged in the tower wall of the tower body, the second wire wheel being located on one side of the first water receiving box, an air cavity is provided in the tower wall of the tower body below the second wire wheel, a piston plate is provided in the wind cavity which slides up and down, an air duct is fixedly connected between the rotating shaft and the wind cavity, one end of the air duct is inserted into the rotating shaft and is rotatably connected with the rotating shaft, an air duct is provided in the rotating shaft, an air groove is provided in the air plate, one end of the air duct is connected to the air duct, and the other end is connected to the air groove, a first connecting rope is connected between the first box body and the top of the piston plate, a second connecting rope is connected between the first wire wheel and the second wire wheel, and an air outlet is provided at the bottom of the air cavity.

[0010] Preferably, a first magnetic attraction is provided at the bottom of the air cavity, and a second magnetic attraction is provided at the bottom of the piston plate.

[0011] Preferably, one end of the rotating shaft passes through the filter, and a particle collecting plate is provided at the end of the rotating shaft passing through the filter. The particle collecting plate is arranged opposite to the wind plate and a particle collecting port is provided on the end face opposite to the wind plate.

[0012] Preferably, a cavity is provided in the particle collecting plate, extension plates are provided at both ends of the particle collecting plate in the length direction, a peripheral groove is provided on the inner wall of the air inlet for the extension plate to rotate, the peripheral wall of the peripheral groove gradually expands outward from one end to the other end, a pull-out groove is provided at the bottom of the tower body located at the peripheral groove, a pull-out box is provided in the pull-out groove, and the groove wall at the bottom of the peripheral groove is connected to the pull-out groove.

[0013] Preferably, a fan is provided on the side of the particle collection plate away from the filter screen, an isolation plate is rotatably provided in the air intake pipe, a third pulley is provided at one end of the isolation plate, a third connecting rope is connected between the fan and the third pulley, and a counterweight block is provided on one side of the isolation plate located on the third pulley.

[0014] Preferably, an inner ring is provided in the middle of the fan, a first one-way bearing is provided between the rotating shaft and the ring, an outer ring is provided on the outer periphery of the fan, an annular ring is provided on the outside of the outer ring, a second one-way bearing is provided between the annular ring and the outer ring, a plurality of groups of winding shafts are provided along the circumferential side on the outer wall of one axial end of the annular ring, and a plurality of groups of guide wheels for guiding the third connecting rope to the winding shaft are provided on the inner wall of the air inlet pipe.

[0015] A battery coating mixed solvent recovery process comprises the following steps: Step 1: The high-temperature gas containing various solvent components from the coating machine is cooled to 27°C by the gas-to-gas heat exchanger and then enters the circulating absorption tower for countercurrent absorption with the organic absorbent; Step 2: The gas in the circulating absorption tower rises and enters the condenser to exchange heat with 7°C cooling water, so that the gas is cooled to 14°C-16°C, and most of the organic components are distilled out in the form of condensate, further achieving the purpose of solvent recovery; Step 3: The tail gas finally reaches 100°C through the heat exchanger and is used as return air to supplement the coating machine; Step 4: After the exhaust gas is condensed, the exhaust gas with a temperature of about 4°C-6°C enters the exhaust gas absorption tower to maintain a slight negative pressure in the system. It is further absorbed by water in the exhaust tower and finally discharged into the atmosphere as required.

[0016] Compared with the prior art, the present invention has the following beneficial effects: The absorbent circulates and absorbs in the system of the present invention, and has a better absorption effect when the concentration decreases, and has a greater economic value; A first water receiving box and a second water receiving box are arranged in the tower body, the first water receiving box is slidably arranged up and down in the tower body, a first wire wheel, a second wire wheel and a piston are arranged in the tower body, and a first connecting rope and a second connecting rope for connecting the first wire wheel, the second wire wheel and the piston are arranged, the first water receiving box moves up and down, the piston can be driven to move and the first wire wheel can be rotated, the first wire wheel will drive the wind plate on the rotating shaft to rotate, the piston moves with the first water receiving box to generate gas, so that the filter screen is sprayed with air during the rotation of the wind plate, so as to effectively clean the filter screen; A first magnetic attraction is arranged at the bottom of the air cavity, and a second magnetic attraction is arranged at the bottom of the piston plate, so that the piston can be separated from the first magnetic attraction and move at high speed instantaneously only after the first water receiving box collects a certain amount of water, and the rotating shaft can be driven to rotate at high speed and then turn to slow speed, thereby improving the blowing effect on the filter screen; A particle collecting plate is arranged on the side of the filter screen opposite to the wind plate, a peripheral groove is arranged on the inner wall of the air inlet, the peripheral wall gradually expands outward from one end to the other end, a particle collecting port is arranged on one side of the wind plate, and the particle collecting plate can rotate synchronously with the wind plate and collect the particles blown off the filter screen and guide them into the collection box through the peripheral groove; A fan is arranged on the particle collecting plate, and an isolation plate is arranged to rotate in the air intake pipe. When the wind plate blows away the particles on the filter, the fan rotates accordingly and blows the exhaust gas in the air intake pipe that has not yet entered the tower body to the rear of the air intake pipe, and pulls the isolation plate through the third connecting rope to separate the exhaust gas, thereby preventing the exhaust gas from continuing to pass into the tower body when the wind plate is blowing away the particles on the filter. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the accompanying drawings required for describing the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other accompanying drawings can be obtained based on these accompanying drawings without paying creative work.

[0018] Figure 1 It is a schematic diagram of the connection process of the recovery device of the present invention; Figure 2 It is a cross-sectional schematic diagram of a tail gas absorption tower of the present invention; Figure 3 yes Figure 2 A magnified schematic diagram of part A; Figure 4 yes Figure 2 A magnified schematic diagram of part B; Figure 5 yes Figure 4 A magnified schematic diagram of part C; Figure 6 The present invention is a schematic diagram highlighting the connection structure of the first wire wheel, the second wire wheel and the piston; Figure 7 yes Figure 6 An enlarged schematic diagram of part D in the middle; Figure 8 It is a schematic diagram of another perspective of the present invention highlighting the connection structure of the first wire wheel, the second wire wheel and the piston; Fig. 9 yes Figure 8 The enlarged schematic diagram of part E in the middle; Fig.10 It is an enlarged schematic diagram highlighting the peripheral groove of the present invention.

[0019] In the accompanying drawings, the components represented by the reference numerals are listed as follows: 1. Gas-to-gas heat exchanger; 2. Circulating absorption tower; 3. Condenser; 4. Tail gas absorption tower; 5. Spray pipe; 6. Gas outlet; 7. Inlet pipe; 8. Tower body; 9. First water receiving box; 10. Second water receiving box; 11. Butt pipe; 12. Pipe jack; 13. Water outlet; 14. Expanding hole; 15. Sealing ring; 16. Expanding plate; 17. Return pipe; 18. Pump body; 19. Filter; 20. Gas inlet; 21. Filter screen; 22. Regular cleaning mechanism; 221. Rotating shaft; 222. Wind plate; 223. First wire wheel; 224. Second wire wheel; 225. Wind cavity; 226. Piston plate; 23. Wind Tube; 24, wind trough; 25, first connecting rope; 26, second connecting rope; 27, air port; 29, first magnetic attraction; 30, second magnetic attraction; 31, particle collecting plate; 32, particle collecting port; 33, substrate; 34, outer ring; 35, cavity; 36, extension plate; 37, through groove; 38, peripheral groove; 39, pull-out box; 40, fan; 41, isolation plate; 42, third reel; 43, third connecting rope; 44, counterweight; 45, inner ring; 46, first one-way bearing; 47, outer ring; 48, annular ring; 49, winding shaft; 50, guide wheel; 51, limit block; 52, air duct. DETAILED DESCRIPTION

[0020] 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.

[0021] See also Figure 1-10 , the present invention provides a technical solution: See also Figure 1-3, a mixed solvent recovery device for battery coating, comprising an air-to-air heat exchanger 1, a circulating absorption tower 2, and a condenser 3 connected in sequence, wherein the air inlet of the condenser 3 is connected to the air outlet of the circulating absorption tower 2, and the air outlet of the condenser 3 returns the gas to the air-to-air heat exchanger 1 and heats it up to be used as return air to supplement the coating machine; It also includes a tail gas absorption tower 4 connected to the gas outlet of the condenser 3. Part of the tail gas enters the tail gas absorption tower 4 after condensation to maintain a slight negative pressure state of the system, and part of the tail gas is discharged after being sprayed by the tail gas absorption tower 4; The tail gas absorption tower 4 includes a tower body 8 and a spray pipe 5 arranged in the tower body 8. The top of the tower body 8 is provided with an air outlet 6 and the side is provided with an air inlet pipe 7. Part of the tail gas that cannot be reused in the coating machine is sent into the tower body 8 through the air inlet pipe 7 and discharged to the outside after being sprayed by the spray pipe 5. The lower part of the tower body 8 is provided with a first water receiving box 9 and a second water receiving box (10). The bottom of the first water receiving box 9 is provided with a docking pipe 11 for inserting into the second water receiving box 10. The top of the second water receiving box 10 is only provided with a pipe insertion hole 12 for inserting the docking pipe 11. The bottom of the docking pipe 11 is closed and water outlets 13 are arranged on both side walls of the bottom. In the initial state, the docking pipe 11 is located in the pipe insertion hole 12 at the top of the second water receiving box 10. The water outlet 13 is closed by the inner wall of the pipe insertion hole 12, so that the first water receiving box 9 can normally collect the water sprayed by the spray pipe 5. In order to ensure that the water in the first water receiving box 9 does not flow into the second water receiving box 10 in the initial state, A reamer 14 is further provided at the bottom of the pipe insertion hole 12, a sealing ring 15 is provided on the top inner wall of the reamer 14, an expansion plate 16 is provided at the bottom of the butt joint pipe 11, and the expansion plate 16 is slidably arranged in the reamer 14 up and down. The top of the expansion plate 16 in the initial state is pressed against the bottom of the sealing ring 15 to improve the sealing effect. The first water receiving box 9 is slidably arranged in the tower body 8 up and down. After a certain amount of water is connected to the first water receiving box 9, it will move down and insert the butt joint pipe 11 into the second water receiving box 10. The butt joint pipe 11 is unsealed and the water inside the box is drained into the second water receiving box 10. A return pipe 17 is connected between the second water receiving box 10 and the spray pipe 5. A pump body 18 and a filter 19 are provided on the return pipe 17. After the second water receiving box 10 is connected to the water of the first water receiving box 9, the water in the second water receiving box 10 is pumped into the filter 19 through the pump body 18 for filtration and then sent to the spray pipe 5 for spraying, thereby realizing the recycling of water resources.

[0022] An air inlet 20 is provided at the joint between the tower body 8 and the air inlet pipe 7, and a filter screen 21 is provided in the air inlet 20. A regular cleaning mechanism 22 for regularly cleaning the filter screen 21 is provided in the air inlet 20. The first water receiving box 9 moves down a stroke to drive the regular cleaning mechanism 22 to start and clean the filter screen 21 once.

[0023] See also Figure 4-6Specifically, the regular cleaning mechanism 22 includes a rotating shaft 221 and a wind plate 222 fixed on the rotating shaft 221, and also includes a first wire wheel 223 and a second wire wheel 224. The first wire wheel 223 is coaxially fixed on the rotating shaft 221, and the second wire wheel 224 is rotatably arranged in the tower wall of the tower body 8. The second wire wheel 224 is located on one side of the first water receiving box 9. An air cavity 225 is arranged below the second wire wheel 224 in the tower wall of the tower body 8. A piston plate 226 is arranged in the wind cavity 225 for sliding up and down. An air duct 23 is fixedly connected between the rotating shaft 221 and the wind cavity 225. One end of the air duct 23 is inserted into the rotating shaft 221 and is rotatably connected to the rotating shaft 221. An air duct 52 is arranged in the rotating shaft 221, and an air slot 24 is arranged in the wind plate 222. One end of the air duct 52 is connected to the air duct 23, and the other end is connected to the wind The groove 24 is connected, a first connecting rope 25 is connected between the first box body and the top of the piston plate 226, a second connecting rope 26 is connected between the first wire wheel 223 and the second wire wheel 224, wherein the second wire wheel 224 includes a first side wheel 2241 and a second side wheel 2242, the second connecting rope 26 is connected to the second side wheel 2242, the first connecting rope 25 is connected to the first side wheel 2241, and an air port 27 is provided at the bottom of the air cavity 225. When the first water receiving box 9 moves downward, the piston plate 226 will be pulled upward by the first connecting rope 25. The upward movement of the first piston plate 226 will compress the air in the air cavity 225 and transport it to the rotating shaft 221 through the branch pipe. The air in the rotating shaft 221 will be sent to the wind plate 222 through the air duct 52, and the air will then pass through the wind groove 24 of the wind plate 222 (see Fig. 9 ) one end of the opening blows toward the filter 21. At the same time, the rotation of the second wire wheel 224 will drive the first wire wheel 223 to rotate, thereby driving the rotating shaft 221 to rotate. The rotation of the rotating shaft 221 will drive the wind plate 222 to rotate, thereby performing a comprehensive blowing and cleaning on the filter 21. In addition, the rotating shaft 221 is rotatably sleeved on one end of the air duct 23 and is connected to a torsion spring (not shown in the figure) between the air duct 23, which is beneficial to the subsequent return of the rotating shaft 221.

[0024] See also Figure 4 In order to wait until a certain amount of water is filled in the first water receiving tank 9 before it starts to move downward, a first magnetic attraction 29 is provided at the bottom of the wind cavity 225, and a second magnetic attraction 30 is provided at the bottom of the piston plate 226. In the initial state, the first magnetic attraction 29 and the second magnetic attraction 30 attract each other, and the first water receiving tank 9 cannot move downward. After a certain amount of water is filled in the first water receiving tank 9, the gravity of the first water receiving tank 9 and the water is greater than the suction force of the first magnetic attraction 29 and the second magnetic attraction 30, so that the first magnetic attraction 29 is separated from the second magnetic attraction 30, and the first water receiving tank 9 will drop rapidly, and the piston plate 226 will move upward rapidly, thereby providing high-pressure gas to the wind plate 222, so that the wind plate 222 ejects high-speed gas during the process of following the rotation of the rotating shaft 221, and effectively blows out the foreign particles on the filter screen 21. The first water receiving tank 9 is filled with water once, which just forms a cleaning cycle of the filter screen 21.

[0025] See also Figure 6 , 7 In order to collect the impurity particles blown off the filter 21, one end of the rotating shaft 221 passes through the filter 21, and a particle collecting plate 31 is provided at the end of the rotating shaft 221 passing through the filter 21. The particle collecting plate 31 is arranged opposite to the wind plate 222 and a particle collecting port 32 is provided on the end face opposite to the wind plate 222. The particle collecting port 32 is in a constricted shape to prevent the particle impurities from being blown out when entering the particle collecting plate 31. A substrate 33 for the rotating shaft 221 to pass through and form a rotation connection is provided in the middle of the filter 21, an outer ring 34 is provided on the periphery of the filter 21, and the filter 21 is covered with the outer ring 34 and the substrate 33. The wind plate 222 and the particle collecting plate 31 rotate synchronously with the rotating shaft 221, so that the impurity particles blown off the filter 21 are collected into the particle collecting plate 31 through the particle collecting port 32.

[0026] See also Figure 6 , 7 10. In order to better process the particles blown off the filter screen 21, a cavity 35 is provided in the particle collecting plate 31. Extension plates 36 are provided at both ends of the length direction of the particle collecting plate 31. A through groove 37 is provided on one side of the extension plate 36. An outer peripheral groove 38 for the extension plate 36 to rotate is provided on the inner wall of the air inlet 20. The outer peripheral wall of the outer peripheral groove 38 gradually expands outward from one end to the other end. A pull-out groove is provided at the bottom of the outer peripheral groove 38 of the tower body 8. A pull-out box 39 is provided in the pull-out groove (see Figure 4 ), the bottom groove wall of the peripheral groove 38 is connected to the pull-out groove, the rotation of the particle collecting plate 31 will drive the extension plate 36 to rotate in the peripheral groove 38, and the gas blown in by the wind plate 222 will blow the impurity particles inside the particle collecting plate 31 into the peripheral groove 38, and the particulate impurities are guided into the pull-out box 39 through the outward expansion structure of the outer shaft groove. After the pull-out box 39 collects the particulate impurities, it can be pulled out for processing.

[0027] See also Figure 4-7A fan 40 is provided on the side of the particle collecting plate 31 away from the filter screen 21, an isolation plate 41 is rotatably provided in the air inlet pipe 7, a third wire wheel 42 is provided at one end of the isolation plate 41, a third connecting rope 43 is connected between the fan 40 and the third wire wheel 42, and a counterweight block 44 is provided on one side of the isolation plate 41 located at the third wire wheel 42. In the initial state, the counterweight block 44 opens the isolation plate 41, and the exhaust gas enters the tower body 8 through the air inlet pipe 7. When the first water receiving box 9 moves downward and the wind plate 222 cleans the filter screen 21, the rotation of the rotating shaft 221 will drive the fan 40 to rotate, and the rotation of the fan 40 will blow the exhaust gas in the air inlet pipe 7 to the partition away from the tower The fan 40 is used to pull the isolation plate 41 to one side of the tower body 8, and at the same time, the isolation plate 41 is pulled by the third connecting rope 43 to make the isolation plate 41 rotate and close the air inlet pipe 7, so that the exhaust gas from the filter screen 21 cannot continue to enter the tower body 8 during the cleaning process. Because the rotating shaft 221 will continue to rotate for a period of time after the isolation plate 41 is closed, in order to avoid the third connecting rope 43 being unable to continue to move when the isolation plate 41 is closed, a certain length of connecting rope is reserved in the third pulley 42, and a torsion spring (not marked in the figure) is arranged between the third pulley 42 and the isolation plate 41. After the third connecting rope 43 pulls the isolation plate 41 to close the isolation plate 41, the third connecting rope 43 can continue to be wound by the fan 40.

[0028] See also Figure 4 , 8 9. In order to better wind up the third connection rope 43 when the fan 40 rotates, an inner sleeve ring 45 is provided in the middle of the fan 40, a first one-way bearing 46 is provided between the rotating shaft 221 and the inner sleeve ring 45, an outer sleeve ring 47 is provided on the outer periphery of the fan 40, an annular ring 48 is provided on the outer periphery of the outer sleeve ring 47, a second one-way bearing (not shown in the figure) is provided between the annular ring 48 and the outer sleeve ring 47, a plurality of winding shafts 49 are provided on the outer wall of one axial end of the annular ring 48, and a plurality of guide wheels for guiding the third connection rope 43 to the winding shaft 49 are provided on the inner wall of the air inlet pipe 7 50. When the fan 40 needs to blow the exhaust gas to the end of the intake pipe 7 away from the tower body 8, the rotating shaft 221 drives the fan 40 to rotate forward through the first bearing, and the fan 40 rotates forward and drives the annular ring 48 to rotate forward through the second one-way bearing, so that the winding shaft 49 winds up the third connecting rope 43 and the isolation plate 41 closes the intake pipe 7; in the process of the exhaust gas entering the tower body 8 normally, through the setting of the first one-way bearing 46 and the second one-way bearing, the fan 40 reverses and is not restricted by the annular ring 48 and the rotating shaft 221. The reversal of the fan 40 will be beneficial to the exhaust gas to enter the tower body 8 stably.

[0029] See also Figure 2-10When the device is in use, the external water pump draws the external water source to the spray pipe 5 to spray the exhaust gas, and the water spraying the exhaust gas will fall into the first water receiving box 9. After the first water receiving box 9 is filled with a certain amount of water, the first magnetic attraction 29 is separated from the second magnetic attraction 30, and the first water receiving box 9 will drop rapidly, and the piston plate 226 will move upward rapidly, thereby providing high-pressure gas to the wind plate 222, so that the wind plate 222 sprays high-speed gas during the rotation of the rotating shaft 221, and effectively blows out the impurity particles on the filter screen 21. At the same time, the downward movement of the first water receiving box 9 will drive the second wire wheel 224 to rotate, and the second wire wheel 224 drives the first wire wheel 223 to rotate through the second connecting rope 26, and the first wire wheel 223 drives the rotating shaft 221 to rotate, and the rotation of the rotating shaft 221 drives the fan 40 to rotate, and the rotation of the fan 40 blows the exhaust gas to the isolation plate 41 On the side away from the tower body 8, the annular ring 48 will be driven to rotate at the same time, and the third connecting rope 43 will be wound through the winding shaft 49. The third connecting rope 43 will pull the isolation plate 41 to make the isolation plate 41 close the air inlet pipe 7 (the limit block 51 on the inner wall of the air inlet pipe 7 can make the isolation plate 41 in a closed state). The rotation of the rotating shaft 221 will also drive the wind plate 222 to rotate, so as to blow air comprehensively to clear the impurity particles from the filter screen 21. The impurity particles blown off the filter screen 21 will enter the particle collecting plate 31. The particle collecting plate 31 will also rotate with the rotating shaft 221 while removing the impurity particles. Since the wind plate 222 continues to blow particles into the particle collecting plate 31, the particulate impurities in the particle collecting plate 31 will be blown into the pull-out box 39 from the vertical peripheral groove 38 of the through groove 37 and through the outward expansion structure of the peripheral groove 38.

[0030] After the first water receiving box 9 moves down, the docking pipe 11 at the bottom will enter the second water receiving box 10, causing the water outlet 13 of the docking pipe 11 to leak out. At this time, the water collected in the first water receiving box 9 will flow into the second water receiving box 10. After the water in the first water receiving box 9 flows out, the first water receiving box 9 will be pulled up by the gravity of the piston plate 226 (the gravity of the piston plate 226 is greater than the gravity of the first water receiving box 9 when there is no water). At the same time, under the action of the torsion spring (not shown in the figure) between the rotating shaft 221 and the air duct 23, the rotating shaft 221 will reverse. The reversal of the rotating shaft 221 will drive the fan 40 to reverse, thereby unwinding the third connecting rope 43. The isolation plate 41 will be reopened under the action of the counterweight block 44, allowing the exhaust gas to re-enter the tower body 8, and at the same time, the pump body 18 is started. The pump body 18 can directly pump the water in the second water receiving box 10 into the filter 19 for filtration, and pump the filtered water into the spray pipe 5 to spray the exhaust gas again.

[0031] See also Figure 1 , a battery coating mixed solvent recovery process, comprising the following steps: Step 1: The high-temperature gas containing multiple solvent components from the coating machine is cooled to 27°C by the gas-to-gas heat exchanger 1 and then enters the circulating absorption tower 2 for countercurrent absorption with the organic absorbent. In the circulating absorption tower 2, an organic solvent with stable physical properties and good absorption effect is used as the absorbent, which is sprayed from the top of the tower to countercurrently absorb cyclohexanone, ethyl acetoacetate, etc.; Step 2: The gas in the circulating absorption tower 2 rises and enters the condenser 3 to exchange heat with 7°C cooling water. The tail gas at the top of the tower is condensed by heat exchange with 7°C chilled water, and most of the absorbent and other trace organic solvents are condensed and distilled out. The solvent components in the return air tail gas greatly meet the return air requirements (normal battery coating return air requirements are 300ppm), and the gas is cooled to 14°C-16°C, generally cooled to 15°C. Most of the organic components are distilled out in the form of condensate, further achieving the purpose of solvent recovery; Step 3: The tail gas finally reaches 100°C through the heat exchanger and is used as return air to supplement the coating machine; Step 4: Most of the tail gas (90-95%) and the exhaust air of the coating machine are recycled for heat energy and then replenished to the production line; in order to maintain a slight negative pressure in the coating system, 5-10% of the tail gas enters the tail gas absorption tower 4 for water spray absorption, and is discharged to the atmosphere after meeting the tail gas emission requirements (less than 50 mg / m³).

[0032] In the description of the present invention, it is necessary to understand that the terms "coaxial", "bottom", "one end", "top", "middle", "the other end", "upper", "one side", "top", "inside", "front", "center", "both ends" and the like indicate orientations or positional relationships based on the drawings, which are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as a limitation on the present invention.

[0033] In the present invention, unless otherwise clearly stipulated and limited, the terms such as "installation", "setting", "connection", "fixation" and "screw-on" should be understood in a broad sense. For example, it can be a fixed connection, a detachable connection, or an integral one; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; it can be the internal connection of two elements or the interaction relationship between two elements. Unless otherwise clearly defined, ordinary technicians in this field can understand the specific meanings of the above terms in the present invention according to the specific circumstances.

[0034] While embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that changes may be made to these embodiments without departing from the principles and spirit of the invention, the scope of which is defined by the appended claims and their equivalents.

Claims

1. A mixed solvent recovery device for battery coating, characterized in that: It comprises an air-to-air heat exchanger (1), a circulating absorption tower (2), and a condenser (3) which are connected in sequence, wherein the air inlet of the condenser (3) is connected to the air outlet of the circulating absorption tower (2), and the air outlet of the condenser (3) returns the gas to the air-to-air heat exchanger (1) and then heats the gas to be used as return air to supplement the coating machine; It also includes a tail gas absorption tower (4) connected to the gas outlet end of the condenser (3), part of the tail gas enters the tail gas absorption tower (4) after being condensed to maintain a slightly negative pressure state of the system, and part of the tail gas is discharged after being sprayed by the tail gas absorption tower (4); The tail gas absorption tower (4) comprises a tower body (8) and a spray pipe (5) arranged in the tower body (8); the tower body (8) is provided with an air outlet (6) at the top and an air inlet pipe (7) at the side; a first water receiving box (9) and a second water receiving box (10) are provided at the lower part of the tower body (8); a butt pipe (11) for inserting into the second water receiving box (10) is provided at the bottom of the first water receiving box (9); the butt pipe (11) is initially sealed in the top box wall of the second water receiving box (10); The first water receiving box (9) is slidably disposed in the tower body (8). The first water receiving box (9) moves downward to release the sealing of the connecting pipe (11) and drain the water inside the box body into the second water receiving box (10). A return pipe (17) is connected between the second water receiving box (10) and the spray pipe (5). A pump body (18) and a filter (19) are provided on the return pipe (17). The water in the second water receiving box (10) can reach the spray pipe (5) through the pump body (18) and the filter (19) for circulation and spraying. An air inlet (20) is provided at the joint between the tower body (8) and the air inlet pipe (7), a filter screen (21) is provided in the air inlet (20), and a regular cleaning mechanism (22) for regularly cleaning the filter screen (21) is provided in the air inlet (20), and the first water receiving box (9) moves downward by one stroke to drive the regular cleaning mechanism (22) to start and clean the filter screen (21) once.

2. The mixed solvent recovery device for battery coating according to claim 1, characterized in that: The top of the second water receiving box (10) is provided with a pipe insertion hole (12) for inserting the butt-joint pipe (11); the bottom of the butt-joint pipe (11) is closed, and water outlets (13) are provided on two side walls of the bottom.

3. The mixed solvent recovery device for battery coating according to claim 2, characterized in that: The bottom of the tube insertion hole (12) is provided with an expansion hole (14), the top inner wall of the expansion hole (14) is provided with a sealing ring (15), and the bottom of the butt-joint tube (11) is provided with an expansion plate (16), and the expansion plate (16) is slidably arranged in the expansion hole (14) up and down.

4. The mixed solvent recovery device for battery coating according to claim 1, characterized in that: The regular cleaning mechanism (22) comprises a rotating shaft (221) and a wind plate (222) fixed on the rotating shaft (221), and further comprises a first wire wheel (223) and a second wire wheel (224), wherein the first wire wheel (223) is coaxially fixed on the rotating shaft (221), and the second wire wheel (224) is rotatably arranged in the tower wall of the tower body (8), and the second wire wheel (224) is located on one side of the first water receiving box (9), and an air cavity (225) is arranged in the tower wall of the tower body (8) below the second wire wheel (224), and a piston plate (226) is arranged in the wind cavity (225) to slide up and down, and the rotating shaft (221) and the wind cavity (225) are connected to each other. An air duct (23) is fixedly connected therebetween, one end of the air duct (23) is inserted into the rotating shaft (221) and is rotatably connected to the rotating shaft (221), an air duct (52) is provided in the rotating shaft (221), an air slot (24) is provided in the air plate (222), one end of the air duct (52) is connected to the air duct (23), and the other end is connected to the air slot (24), a first connecting rope (25) is connected between the first water receiving box (9) and the top of the piston plate (226), a second connecting rope (26) is connected between the first wire wheel (223) and the second wire wheel (224), and an air port (27) is provided at the bottom of the air cavity (225).

5. The mixed solvent recovery device for battery coating according to claim 4, characterized in that: A first magnetic attraction (29) is provided at the bottom of the air cavity (225), and a second magnetic attraction (30) is provided at the bottom of the piston plate (226).

6. The mixed solvent recovery device for battery coating according to claim 4, characterized in that: One end of the rotating shaft (221) passes through the filter screen (21), and a particle collecting plate (31) is provided at the end of the rotating shaft (221) passing through the filter screen (21). The particle collecting plate (31) is arranged opposite to the wind plate (222) and a particle collecting port (32) is provided on an end surface opposite to the wind plate (222).

7. The mixed solvent recovery device for battery coating according to claim 6, characterized in that: The particle collecting plate (31) is provided with a cavity (35) therein, and extension plates (36) are provided at both ends of the particle collecting plate (31) in the length direction. The inner wall of the air inlet (20) is provided with a peripheral groove (38) for the extension plate (36) to rotate, and the peripheral wall of the peripheral groove (38) gradually expands outward from one end to the other end. The tower body (8) is provided with a pull-out groove at the bottom of the peripheral groove (38), and a pull-out box (39) is provided in the pull-out groove. The bottom groove wall of the peripheral groove (38) is connected to the pull-out groove.

8. The device for recovering mixed solvent for battery coating according to claim 6, characterized in that: A fan (40) is provided on a side of the particle collecting plate (31) away from the filter screen (21); an isolation plate (41) is rotatably provided in the air intake pipe (7); a third wire wheel (42) is provided at one end of the isolation plate (41); a third connecting rope (43) is connected between the fan (40) and the third wire wheel (42); and a counterweight (44) is provided on one side of the isolation plate (41) located on the third wire wheel (42).

9. The mixed solvent recovery device for battery coating according to claim 8, characterized in that: An inner sleeve ring (45) is provided in the middle of the fan (40), a first one-way bearing (46) is provided between the rotating shaft (221) and the inner sleeve ring (45), an outer sleeve ring (47) is provided on the outer periphery of the fan (40), an annular ring (48) is provided on the outer periphery of the outer sleeve ring (47), a second one-way bearing is provided between the annular ring (48) and the outer sleeve ring (47), a plurality of groups of winding shafts (49) are provided on the outer wall of one axial end of the annular ring (48) along the circumferential side, and a plurality of groups of guide wheels (50) for guiding the third connecting rope (43) to the winding shaft (49) are provided on the inner wall of the air inlet pipe (7).

10. A mixed solvent recovery process using the mixed solvent recovery device for battery coating according to any one of claims 1 to 9, characterized in that: The following steps are involved: Step 1: The high-temperature gas containing various solvent components from the coating machine is cooled to 27° C. by the gas-to-gas heat exchanger (1) and then enters the circulating absorption tower (2) for countercurrent absorption with the organic absorbent; Step 2: The gas in the circulating absorption tower (2) rises and enters the condenser (3) to exchange heat with 7°C cooling water, so that the gas is cooled to 14°C-16°C, and most of the organic components are distilled out in the form of condensate, thereby further achieving the purpose of solvent recovery; Step 3: The tail gas finally reaches 100°C through the heat exchanger and is used as return air to supplement the coating machine; Step 4: After the tail gas is condensed, 4%-6% of the tail gas enters the tail gas absorption tower (4) to maintain a slight negative pressure in the system. It is further absorbed by water in the tail gas tower and finally discharged into the atmosphere according to the discharge requirements.

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