An apparatus and method for NMP recycling of lithium batteries

Abstract

This invention discloses a lithium battery NMP recycling device, relating to the field of recycling equipment technology. It includes a recycling chamber, an air inlet, an exhaust outlet, a heat-conducting plate, and a cooling channel; a heat exchange unit used in conjunction with the heat-conducting plate; a filter body comprising a filter sponge and cotton felt adhered to the outer walls on both sides of the filter sponge in the thickness direction; and a compression unit disposed on the heat-conducting plate, which is used to compress the filter body when the temperature of the heat-conducting plate decreases. By setting up a movable perforated frame, a fixed perforated frame, a rotating arm, a drive unit, and a fixed column, as the temperature of the heat-conducting plate decreases, the drive unit gradually drives the fixed column to move the movable perforated frame, causing the movable perforated frame to begin compressing the filter body. This squeezes out the liquid in the filter body, preventing it from affecting the adsorption effect of the filter body on impurities. Furthermore, after the operation is completed, as the temperature of the heat-conducting plate rises, the movable perforated frame will move away from the fixed perforated frame, allowing the filter body to return to its expanded state.

Description

Technical Field

[0001] This invention relates to the field of recycling equipment technology, specifically to an apparatus and method for NMP recycling of lithium batteries. Background Technology

[0002] NMP (methylpyrrolidone) is a liquid formed by the condensation of γ-butyrolactone and methylamine. It is highly volatile and permeable, with an alkaline pH of 7-9. It is flammable and explosive and is widely used in lithium battery production. High-temperature NMP waste gas is generated during the manufacturing process of lithium battery electrodes.

[0003] Currently, the main method for recovering NMP waste gas generated during lithium battery manufacturing is through cooling. This involves cooling the waste gas using a heat exchange device, causing the NMP components in the waste gas to condense into liquid, collecting the condensed liquid, and then using filter materials to adsorb and filter particulate matter and other contaminants from the waste gas.

[0004] In existing technologies, when recovering NMP exhaust gas from lithium batteries, the filter material is generally filter cotton or cotton felt. The liquefied NMP exhaust gas will also be adsorbed by the filter cotton or filter cotton felt, which will lead to the filter cotton or filter cotton felt becoming saturated with water, thus affecting the continued treatment of NMP exhaust gas.

[0005] Therefore, we propose an apparatus and method for NMP recycling of lithium batteries. Summary of the Invention

[0006] The purpose of this invention is to provide an apparatus and method for NMP recycling of lithium batteries to solve the problems mentioned in the background art.

[0007] To achieve the above objectives, the present invention provides the following technical solution: a lithium battery NMP recycling device, comprising a hollow recycling chamber, wherein an air inlet and an exhaust outlet are respectively provided on the transversely opposite outer walls of the recycling chamber, and further comprising:

[0008] A heat-conducting plate is fixed at equal intervals inside the recycling bin. The heat-conducting plate divides the inside of the recycling bin into multiple cooling channels. The air inlet and the exhaust outlet are respectively connected to two of the cooling channels. The heat-conducting plate has a through-hole type mounting groove.

[0009] A heat exchange unit installed on the recycling bin and used in conjunction with the heat-conducting plate;

[0010] A filter body placed in the mounting groove, the filter body comprising a filter sponge and cotton felt adhered to the outer walls of the filter sponge on both sides in the thickness direction.

[0011] An extrusion unit is provided on the heat-conducting plate, which is used to extrude the filter body when the temperature of the heat-conducting plate decreases.

[0012] Preferably, the bottom of the recycling bin is provided with multiple collection bins, each of which is connected to a multiple cooling channel. The multiple collection bins are connected together by a collection pipe, and each collection bin is provided with a control valve.

[0013] Preferably, the heat exchange unit includes a semiconductor cooling chip vertically inserted into the recovery chamber, and the heat-conducting plate has an installation cavity for mounting the semiconductor cooling chip.

[0014] Preferably, the edge of the mounting groove is provided with an inwardly turned protrusion, and a fixed hollow frame and a movable hollow frame are arranged in the mounting groove. The fixed hollow frame and the movable hollow frame can slide freely horizontally in the mounting groove, and the protrusion is used to limit the horizontal movement of the fixed hollow frame and the movable hollow frame. The filter body is installed between the fixed hollow frame and the movable hollow frame.

[0015] Preferably, the filter sponge has two vertically formed slots, and thin sheets are inserted into the slots. The thickness direction of the thin sheets is consistent with the thickness direction of the filter body. The heat-conducting plate is provided with an elastic reset unit, which is used to move the two thin sheets away from each other.

[0016] Preferably, the elastic reset unit includes:

[0017] A sliding ring is fixed to the lower end of the thin sheet, and a clearance groove is provided on the bottom wall of the mounting groove to allow the sliding ring to pass freely.

[0018] A positioning post is horizontally fixed in the clearance groove, and a sliding ring is slidably fitted onto the positioning post;

[0019] Two tension springs are respectively wrapped around the two ends of the positioning post, and the two ends of the tension springs are respectively fixed to the sliding ring and the inner wall of the clearance groove.

[0020] Preferably, the extrusion unit comprises:

[0021] Rotary arm connected to the outer wall of the heat-conducting plate on one side in the thickness direction;

[0022] A fixed column is fixed to the movable hollow frame. The fixed column is away from the first sliding pin of the movable hollow frame. The rotating arm is provided with a first waist-shaped hole at the end away from the hinge point with the heat-conducting plate. The first sliding pin is inserted into the first waist-shaped hole and can slide freely.

[0023] A drive unit disposed on the heat-conducting plate and capable of driving the rotating arm to swing.

[0024] Preferably, the driving unit includes:

[0025] A sliding post is horizontally slidably inserted through the heat-conducting plate. One end of the sliding post that protrudes from the heat-conducting plate is provided with a second sliding pin. A second oblong hole is opened on the rotating arm. The second sliding pin is inserted into the second oblong hole and can slide freely.

[0026] A piston is fixed to one end of the sliding column and passes through the heat-conducting plate. The heat-conducting plate has an oil storage cavity for the piston to engage. The piston can slide freely horizontally in the oil storage cavity, and the oil storage cavity stores heat-conducting oil.

[0027] Preferably, a spring is horizontally installed inside the oil storage chamber, and the spring elastically abuts against the piston.

[0028] A method for operating a lithium battery NMP recycling device includes:

[0029] NMP exhaust gas is introduced into the recovery chamber through the air inlet, and the power supply of multiple semiconductor cooling chips is simultaneously turned on, causing the semiconductor cooling chips to work and generate low temperature at their cooling ends. The low temperature is transferred to the heat conduction plate to cool the heat conduction plate. Through heat conduction, the NMP exhaust gas in the cooling channel is cooled down, causing the NMP exhaust gas to cool down and condense. A portion of the NMP exhaust gas that does not condense in time is filtered out from the filter body and enters another cooling channel, where another semiconductor cooling chip continues to cool the NMP exhaust gas until the NMP exhaust gas liquefies to form condensate, which flows into the collection chamber. During the liquefaction process, the control valve on the collection chamber is in the closed state.

[0030] When the surface temperature of the heat-conducting plate reaches below zero degrees, the NMP exhaust gas condenses significantly, and the filter body becomes saturated with water. The heat-conducting oil in the oil storage chamber is affected by the low temperature and its volume decreases, thereby driving the piston to move away from the rotating arm. This causes the second sliding pin to slide in the second oblong hole, which in turn drives the rotating arm to swing along the hinge with the heat-conducting plate. This causes the first sliding pin to slide in the first oblong hole, driving the fixed column to move towards the inside of the mounting groove. This causes the movable hollow frame to move towards the fixed hollow frame, squeezing the filter sponge in the filter body and expelling the condensate from the filter sponge. During the squeezing process, the thin sheets in the filter sponge are squeezed by the movable hollow frame, causing the two thin sheets to move closer to each other and causing the sliding ring to stretch the tension spring, allowing the tension spring to accumulate elastic potential energy.

[0031] After a period of condensation, the supply of NMP exhaust gas to the air inlet is stopped, and the power supply to the semiconductor cooling chip is disconnected, causing the temperature of the heat transfer oil in the oil storage chamber to gradually rise. This allows the piston to move in the reverse direction. During the reverse movement, the piston slides in the reverse direction within the second oblong hole via the second sliding pin, which in turn drives the movable hollow frame to move in the reverse direction and reset. The compressive force on the sheet disappears, thereby releasing the elastic potential energy accumulated by the tension spring to expand the filter sponge.

[0032] Compared with the prior art, the beneficial effects of the present invention are:

[0033] This invention sets up a heat-conducting plate, a cooling channel, and a heat exchange unit. The heat exchange unit cools the heat-conducting plate, thereby cooling the NMP exhaust gas entering the cooling channel, allowing the exhaust gas to condense. Fine impurities such as particulate matter in the exhaust gas are adsorbed by the filter.

[0034] This invention comprises a movable hollow frame, a fixed hollow frame, a rotating arm, a drive unit, and a fixed column. As the temperature of the heat-conducting plate decreases, the drive unit gradually drives the fixed column to move the movable hollow frame, causing the movable hollow frame to begin squeezing the filter body. This squeezes out the liquid in the filter body, preventing it from affecting the filter body's adsorption effect on impurities. Furthermore, after the work is completed, as the temperature of the heat-conducting plate rises, the movable hollow frame will move away from the fixed hollow frame, allowing the filter body to return to its expanded state.

[0035] This invention, by setting two thin sheets and an elastic reset unit, allows the two thin sheets to be compressed when the movable perforated frame squeezes the filter body. As the filter sponge in the filter body is compressed, the two thin sheets move closer to each other, causing the elastic reset unit to accumulate elastic potential energy. When the movable perforated frame moves away from the fixed perforated frame, the elastic potential energy accumulated by the elastic reset unit is released, thereby driving the two thin sheets to move away from each other and expand the filter sponge. This prevents the filter sponge from being unable to smoothly recover its expansion state when it is under pressure for a long time, thus avoiding affecting the adsorption and filtration effect of the filter sponge. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall structure of a lithium battery NMP recycling device according to the present invention;

[0037] Figure 2 for Figure 1 A cross-sectional view of the middle section of the structure;

[0038] Figure 3 for Figure 2 A top-view diagram of the mid-structure;

[0039] Figure 4 This is a schematic diagram of the structure of the heat-conducting plate and the rotating arm after assembly in this invention;

[0040] Figure 5 for Figure 4 Cross-sectional view of the middle structure;

[0041] Figure 6 for Figure 4 Schematic diagram of the explosive decomposition of the medium structure;

[0042] Figure 7 for Figure 4 A side view diagram of the mid-structure;

[0043] Figure 8 for Figure 7 Cross-sectional view of the middle structure;

[0044] Figure 9 This is a schematic diagram of the heat-conducting plate in this invention;

[0045] Figure 10 for Figure 9 Cross-sectional view of the structure.

[0046] In the diagram: 1. Air inlet; 2. Semiconductor cooling chip; 3. Exhaust outlet; 4. Recovery chamber; 5. Collection chamber; 6. Control valve; 7. Collection pipe; 8. Cooling channel; 9. Fixed perforated frame; 10. Heat-conducting plate; 11. Rotating arm; 12. Movable perforated frame; 13. Fixed column; 14. Sliding column; 15. Second sliding pin; 16. Second oblong hole; 17. First oblong hole; 18. First sliding pin; 19. Filter sponge; 20. Thin sheet; 21. Tension spring; 22. Positioning column; 23. Spring; 24. Piston; 25. Mounting cavity; 26. Sliding ring; 27. Slot; 28. Cotton felt; 29. ​​Mounting groove; 30. Raised strip; 31. Oil storage cavity; 32. Replenishment port; 33. Void relief groove. Detailed Implementation

[0047] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0048] Please see Figures 1-10This invention provides a technical solution: a lithium battery NMP recycling device, comprising a hollow recycling chamber 4. The recycling chamber 4 has an air inlet 1 and an exhaust outlet 3 on its two laterally opposite outer walls. The air inlet 1 is connected to an NMP exhaust gas conveying pipeline via a pipe, and the exhaust outlet 3 is connected to external reprocessing equipment via an installation pipe. Three heat-conducting plates 10 are welded at equal intervals along the length of the recycling chamber 4. The heat-conducting plates 10 are vertically positioned within the recycling chamber 4, dividing the interior of the recycling chamber 4 into multiple cooling channels 8. The air inlet 1 and exhaust outlet 3 are respectively connected to two cooling channels 8. The heat-conducting plates 10 have through-hole mounting slots 29 for installation. The groove 29 has an inwardly flared protrusion 30 at its opening edge. A fixed perforated frame 9 and a movable perforated frame 12 are housed within the groove 29. The fixed perforated frame 9 and the movable perforated frame 12 can slide freely horizontally within the groove 29, and the protrusion 30 limits their horizontal movement. A filter body is housed within the groove 29. This filter body consists of a filter sponge 19 and cotton felt 28 adhered to the outer walls of the filter sponge 19 on both sides in the thickness direction. The filter body is installed between the fixed perforated frame 9 and the movable perforated frame 12. When the movable perforated frame 12 moves towards the fixed perforated frame 9, it will compress the filter body. Multiple thermoelectric coolers 2 are vertically inserted into the receiving chamber 4. The position and number of thermoelectric coolers 2 match the heat-conducting plate 10. The heat-conducting plate 10 has an installation cavity 25 for installing the thermoelectric coolers 2. The cooling end of the thermoelectric cooler 2 is located inside the heat-conducting plate 10, and its heating end is connected to an external heat-conducting component, enabling the thermoelectric cooler 2 to work normally. When the thermoelectric cooler 2 is working, its cooling end generates a low temperature, which cools the heat-conducting plate 10. After the heat-conducting plate 10 is cooled, the NMP exhaust gas in the cooling channel 8 comes into contact with the surface of the heat-conducting plate 10 and is cooled, allowing the NMP exhaust gas to condense into liquid. Multiple collection chambers 5 are provided, each of which is connected to multiple cooling channels 8. The multiple collection chambers 5 are connected to a collection pipe 7. Each collection chamber 5 is equipped with a control valve 6, which is controlled by an external PLC control module. That is, during the condensation and recovery process, the control valve 6 is closed by the PLC control module. After condensation, the control valve 6 is open, so that the NMP exhaust gas condensate in the cooling channel 8 can flow from the collection chamber 5 into the collection pipe 7, and then from the collection pipe 7 into the external recovery device. The NMP exhaust gas that is not condensed in time will be filtered out by the filter and enter another cooling channel 8 for further condensation.

[0049] like Figure 6 , 8As shown, a rotating arm 11 is rotatably connected to the outer wall of the heat-conducting plate 10 on one side of its thickness direction. A fixed post 13 is on the movable hollow frame 12. The fixed post 13 has a first sliding pin 18 away from the movable hollow frame 12. A first waist-shaped hole 17 is opened at the end of the rotating arm 11 away from its hinge point with the heat-conducting plate 10. The first sliding pin 18 is inserted into the first waist-shaped hole 17 and can slide freely. A sliding post 14 is horizontally slidably passed through the heat-conducting plate 10. A second sliding pin 15 is provided at the end of the sliding post 14 that protrudes from the heat-conducting plate 10. A second waist-shaped hole 16 is opened on the rotating arm 11. The second sliding pin 15 is inserted into the second waist-shaped hole 16. The piston 24 is coaxially fixed to one end of the heat-conducting plate 10 and can slide freely within the second waist-shaped hole 16. The heat-conducting plate 10 has an oil storage cavity 31 for the piston 24 to engage. The piston 24 can slide freely horizontally within the oil storage cavity 31, and the oil storage cavity 31 stores heat-conducting oil. In addition, the heat-conducting plate 10 has a replenishment port 32, and a cover (not shown in the figure) is installed at the opening of the replenishment port 32. By opening the cover, heat-conducting oil can be replenished into the oil storage cavity 31 through the replenishment port 32. A spring 23 is horizontally installed in the oil storage cavity 31, and the spring 23 elastically pushes against the piston 24.

[0050] As the surface temperature of the heat-conducting plate 10 decreases (below zero degrees Celsius), and the NMP exhaust gas condenses more and more, some of the condensed liquid will be absorbed by the filter sponge 19, causing the filter sponge 19 to become increasingly saturated, affecting the filtration and adsorption effect on particulate matter in the NMP exhaust gas. The heat-conducting oil in the oil storage chamber 31 shrinks in volume due to cooling. Since the molecular weight of the heat-conducting oil remains unchanged, after the heat-conducting oil shrinks in volume, under the action of hydraulic pressure, the piston 24 will move away from the rotating arm 11. When moving, it will drive the sliding column 14 to move, causing the second sliding pin 15 to slide in the second waist-shaped hole 16, thereby driving the rotating arm 11 to swing upward along the hinge with the heat-conducting plate 10, causing the first sliding pin 18 to slide in the first waist-shaped hole 17, thereby driving the fixed column 13 to move the movable hollow frame 12 towards the fixed hollow frame 9, so that the movable hollow frame 12 will squeeze the filter body, thereby gradually squeezing out the condensate in the filter sponge 19, preventing it from affecting the permeability and adsorption of impurities of the filter sponge 19.

[0051] like Figure 5 , 6As shown in Figure 8, two slots 27 are vertically formed on the filter sponge 19. Thin sheets 20 are inserted into the slots 27. The thickness direction of the thin sheets 20 is consistent with the thickness direction of the filter body. A sliding ring 26 is integrally formed at the lower end of the thin sheet 20. An clearance groove 33 is formed on the bottom wall of the mounting groove 29 to allow the sliding ring 26 to pass freely. A positioning post 22 is horizontally welded in the clearance groove 33. The sliding ring 26 is slidably fitted onto the positioning post 22. Two tension springs 21 are respectively wrapped around the two ends of the positioning post 22. The two ends of the tension springs 21 are respectively fixed to the sliding ring 26 and the inner wall of the clearance groove 33. During the process of the movable hollow frame 12 squeezing the filter sponge 19, the thin sheets 20 in the filter sponge 19 are squeezed by the movable hollow frame 12, causing the two thin sheets 20 to move closer to each other, and causing the sliding ring 26 to stretch the tension springs 21, so that the tension springs 21 accumulate elastic potential energy.

[0052] Working principle of the invention:

[0053] NMP exhaust gas is introduced into the recovery chamber 4 through the air inlet 1. At the same time, the power supply of multiple semiconductor cooling chips 2 is turned on, so that the semiconductor cooling chips 2 work and generate low temperature at their cooling ends. The low temperature is transferred to the heat conduction plate 10 to cool the heat conduction plate 10. Through heat conduction, the NMP exhaust gas in the cooling channel 8 is cooled down, so that the NMP exhaust gas is cooled down and condensed. Some of the NMP exhaust gas that is not condensed in time is filtered out from the filter body and enters another cooling channel 8. Then another semiconductor cooling chip 2 continues to cool the NMP exhaust gas until the NMP exhaust gas is liquefied and forms condensate, which flows into the collection chamber 5. During the liquefaction process, the control valve 6 on the collection chamber 5 is in the closed state.

[0054] When the surface temperature of the heat-conducting plate 10 reaches below zero degrees, the NMP exhaust gas condenses to a greater degree. At the same time, the filter body absorbs water to saturation. The heat-conducting oil in the oil storage chamber 31 is affected by the low temperature and its volume decreases. This drives the piston 24 to move away from the rotating arm 11, causing the second sliding pin 15 to slide in the second waist-shaped hole 16. This drives the rotating arm 11 to swing along the hinge with the heat-conducting plate 10, causing the first sliding pin 18 to slide in the first waist-shaped hole 17. This drives the fixed column 13 to move towards the inside of the mounting groove 29, causing the movable hollow frame 12 to move towards the fixed hollow frame 9. This causes the movable hollow frame 12 to squeeze the filter sponge 19 in the filter body, thereby squeezing out the condensed water in the filter sponge 19. During the squeezing process, the thin sheet 20 in the filter sponge 19 is squeezed by the movable hollow frame 12, causing the two thin sheets 20 to move closer to each other. This causes the sliding ring 26 to stretch the tension spring 21, allowing the tension spring 21 to accumulate elastic potential energy.

[0055] After a period of condensation, the supply of NMP exhaust gas to the air inlet 1 is stopped, and the power supply to the semiconductor cooling chip 2 is disconnected, causing the temperature of the heat transfer oil in the oil storage chamber 31 to gradually increase, thereby enabling the piston 24 to move in the reverse direction. During the reverse movement, the piston 24 slides in the reverse direction through the second sliding pin 15 in the second waist-shaped hole 16, and can drive the movable hollow frame 12 to move in the reverse direction and reset. The compressive force on the sheet 20 disappears, thereby releasing the elastic potential energy stored in the tension spring 21 to expand the filter sponge 19.

[0056] It should be noted that, in this document, relational terms such as "first" and "second" are used only to distinguish one entity or operation from another, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such process, method, article, or apparatus.

[0057] Although embodiments of the invention have been shown and described, it will be understood by those skilled in the art that various changes, modifications, substitutions and alterations can 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 lithium battery NMP recycling device, comprising an internally hollow recycling bin (4), the recycling bin (4) is provided with an air inlet (1) and an air outlet (3) on each of the transversely opposite two side walls, characterized in that, Also includes: A heat-conducting plate (10) is fixed in the recovery chamber (4) at equal intervals. The heat-conducting plate (10) divides the interior of the recovery chamber (4) into multiple cooling channels (8). The air inlet (1) and the exhaust outlet (3) are connected to two cooling channels (8) respectively. The heat-conducting plate (10) is provided with a through-hole mounting groove (29). A heat exchange unit installed on the recovery bin (4) and used in conjunction with the heat conduction plate (10); The filter body is placed in the mounting groove (29). The filter body includes a filter sponge (19) and cotton felt (28) bonded to the outer walls on both sides of the filter sponge (19) in the thickness direction. An extrusion unit is provided on the heat-conducting plate (10). The extrusion unit is used to extrude the filter body when the temperature of the heat-conducting plate (10) decreases. The extrusion unit includes: Rotary arm (11) is rotatably connected to the outer wall of the heat-conducting plate (10) on one side of the thickness direction; A fixed column (13) is fixed to the movable hollow frame (12). The fixed column (13) is away from the first sliding pin (18) of the movable hollow frame (12). The rotating arm (11) is provided with a first waist-shaped hole (17) at one end away from the hinge point with the heat-conducting plate (10). The first sliding pin (18) is inserted into the first waist-shaped hole (17) and can slide freely. A drive unit provided on the heat-conducting plate (10) and capable of driving the rotating arm (11) to swing; The drive unit includes: A sliding column (14) is horizontally slidably installed on the heat-conducting plate (10). A second sliding pin (15) is provided at one end of the sliding column (14) that protrudes from the heat-conducting plate (10). A second waist-shaped hole (16) is opened on the rotating arm (11). The second sliding pin (15) is inserted into the second waist-shaped hole (16) and can slide freely. A piston (24) is fixed to a sliding column (14) and inserted into one end of a heat-conducting plate (10). The heat-conducting plate (10) has an oil storage chamber (31) for the piston (24) to engage. The piston (24) can slide freely horizontally in the oil storage chamber (31), and the oil storage chamber (31) stores heat-conducting oil. A spring (23) is horizontally installed inside the oil storage chamber (31), and the spring (23) elastically pushes against the piston (24).

2. The lithium battery NMP recycling device according to claim 1, characterized in that, The bottom of the recovery chamber (4) is provided with multiple collection chambers (5), which are connected to multiple cooling channels (8) respectively. The multiple collection chambers (5) are connected to a collection pipe (7), and a control valve (6) is provided on the collection chamber (5).

3. The lithium battery NMP recycling device according to claim 2, characterized in that, The heat exchange unit includes a semiconductor cooling chip (2) that is vertically mounted on the recovery bin (4), and the heat conduction plate (10) has an installation cavity (25) for mounting the semiconductor cooling chip (2).

4. The lithium battery NMP recycling device according to claim 3, characterized in that, The mounting groove (29) has an inwardly turned protrusion (30) at the edge of the opening. A fixed hollow frame (9) and a movable hollow frame (12) are placed in the mounting groove (29). The fixed hollow frame (9) and the movable hollow frame (12) can slide freely horizontally in the mounting groove (29). The protrusion (30) is used to limit the horizontal movement of the fixed hollow frame (9) and the movable hollow frame (12). The filter body is installed between the fixed hollow frame (9) and the movable hollow frame (12).

5. The lithium battery NMP recycling device according to claim 4, characterized in that, Two slots (27) are vertically opened on the filter sponge (19). Thin sheets (20) are inserted into the slots (27). The thickness direction of the thin sheets (20) is consistent with the thickness direction of the filter body. An elastic reset unit is provided on the heat-conducting plate (10). The elastic reset unit is used to keep the two thin sheets (20) away from each other.

6. The lithium battery NMP recycling device according to claim 5, characterized in that, The elastic reset unit includes: The sliding ring (26) is fixed to the lower end of the thin sheet (20), and the bottom wall of the mounting groove (29) is provided with a clearance groove (33) for the sliding ring (26) to pass freely. The positioning post (22) is horizontally fixed in the clearance groove (33), and the sliding ring (26) is slidably fitted onto the positioning post (22); Two tension springs (21) are respectively wrapped around the two ends of the positioning post (22), and the two ends of the tension springs (21) are respectively fixed to the inner wall of the sliding ring (26) and the clearance groove (33).

7. A method for operating a lithium battery NMP recycling apparatus, comprising the lithium battery NMP recycling apparatus as described in any one of claims 1-6, characterized in that, include: NMP exhaust gas is introduced into the recovery chamber (4) through the air inlet (1), and the power supply of multiple semiconductor cooling chips (2) is simultaneously turned on, so that the semiconductor cooling chips (2) work and generate low temperature at their cooling end. The low temperature is transferred to the heat conduction plate (10) to cool the heat conduction plate (10). The NMP exhaust gas in the cooling channel (8) is cooled down through heat conduction, so that the NMP exhaust gas is cooled down and condensed. A portion of the NMP exhaust gas that is not condensed in time is filtered out from the filter body and enters another cooling channel (8). Then another semiconductor cooling chip (2) continues to cool the NMP exhaust gas until the NMP exhaust gas is liquefied and forms condensate, which flows into the collection chamber (5). During the liquefaction process, the control valve (6) on the collection chamber (5) is in the closed state. When the surface temperature of the heat-conducting plate (10) reaches below zero degrees, the NMP exhaust gas condenses significantly, and the filter becomes saturated with water. The heat-conducting oil in the oil storage chamber (31) is affected by the low temperature and its volume decreases. This drives the piston (24) to move away from the rotating arm (11), causing the second sliding pin (15) to slide in the second oblong hole (16). This drives the rotating arm (11) to swing along the hinge with the heat-conducting plate (10), causing the first sliding pin (18) to slide in the first oblong hole (17) to drive the piston. The fixed column (13) moves toward the inside of the mounting groove (29), thereby causing the movable hollow frame (12) to move toward the fixed hollow frame (9), so that the movable hollow frame (12) squeezes the filter sponge (19) in the filter body, thereby squeezing out the condensate in the filter sponge (19). During the squeezing process, the thin sheet (20) in the filter sponge (19) is squeezed by the movable hollow frame (12), causing the two thin sheets (20) to move closer to each other, and causing the sliding ring (26) to stretch the tension spring (21), so that the tension spring (21) accumulates elastic potential energy. After condensation for a period of time, NMP exhaust gas is stopped being supplied to the air inlet (1), and the power supply to the semiconductor cooling chip (2) is disconnected, causing the temperature of the heat transfer oil in the oil storage chamber (31) to gradually increase, thereby enabling the piston (24) to move in the opposite direction. During the reverse movement, the piston slides in the opposite direction in the second waist-shaped hole (16) through the second sliding pin (15), and can drive the movable hollow frame (12) to move in the opposite direction and reset. The pressure on the sheet (20) disappears, thereby releasing the elastic potential energy accumulated by the tension spring (21) to expand the filter sponge (19).

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