Waste lithium battery waste gas collection system and collection method

Abstract

The invention belongs to the technical field of waste battery waste gas collection, and particularly relates to a waste lithium battery waste gas collection system and method. The system comprises a controller, and further comprises a dust adsorption unit, a gas absorption tank, a drying box and an organic solution collection tank in sequence. A first three-way electromagnetic valve is arranged on a pipeline for connecting the gas absorption tank and the drying box, one pipeline connected with the first three-way electromagnetic valve is communicated with the drying box, and the other pipeline is communicated with the gas absorption tank in a backflow manner; a second three-way electromagnetic valve is arranged on a pipeline of an outlet above the organic solvent collecting tank, one pipeline connected with the second three-way electromagnetic valve is communicated with the atmosphere, and the other pipeline flows back to the bottom of the organic solvent collecting tank. And the first three-way electromagnetic valve and the second three-way electromagnetic valve are controlled by a controller. The system is simple in structure, the collecting method is rapid and efficient, backflow reabsorption or collection can be achieved, environmental protection is better facilitated, the requirement for green development is met, and the automation and intelligent control degree is high.

Description

Technical Field

[0001] The invention belongs to the technical field of waste battery recycling, and specifically relates to a waste gas collection system and a collection method for waste lithium batteries. Background Art

[0002] my country's lithium battery research and development technology and application fields have made great progress. Among them, industries represented by new energy vehicles have scrapped a large number of lithium batteries, and the number is increasing year by year.

[0003] In order to achieve the recycling of lithium battery resources, a large number of lithium batteries are separated and recovered by high-temperature calcination and organic solvent extraction. Although the operation is simple and the recovery rate is high, the treatment process will produce a large amount of toxic gases, such as sulfur dioxide, nitrogen oxides and hydrogen fluoride, which not only endanger people's health but also cause serious pollution and damage to the environment. Therefore, the development of a lithium battery waste gas recovery system compatible with the lithium battery recycling process is in line with the urgent need of the national green development policy.

[0004] Although there are some patents and research on lithium battery waste gas recovery, they often use a single functional unit recovery structure, which is incomplete in absorption. The use of complex absorption devices in actual application scenarios often brings higher maintenance costs to the subsequent process of use, and may also increase maintenance time and reduce the operating efficiency of the project. Therefore, the development of a waste gas absorption device with a simple structure and multiple units in series absorption can effectively fill the research gaps such as incomplete absorption of waste gas generated in the lithium battery recycling process. Summary of the invention

[0005] The problem to be solved by the present invention is to provide a waste gas collection system and a collection method for waste lithium batteries, which can recycle harmful gases and organic solvents after the waste batteries are crushed, thereby reducing the problem of environmental pollution.

[0006] The technical solutions adopted are:

[0007] A waste gas collection system for waste lithium batteries, comprising a controller, and also sequentially comprising a dust adsorption unit, a gas absorption tank, a drying box, and an organic solution collection tank;

[0008] The dust adsorption unit comprises a first adsorber and a second adsorber, and the first adsorber and the second adsorber are connected in series through a pipeline;

[0009] The dust adsorption unit is connected to the gas absorption tank through a pipeline, and a first three-way solenoid valve is arranged on the pipeline connecting the gas absorption tank and the drying box. One pipeline connected to the first three-way solenoid valve leads to the drying box, and the other pipeline refluxes into the gas absorption tank;

[0010] The drying box is connected to an organic solvent collection tank, a condenser is arranged inside the organic solvent collection tank, a second three-way solenoid valve is arranged on the pipeline at the upper outlet, one pipeline connected to the second three-way solenoid valve leads to the atmosphere, and the other pipeline refluxes into the bottom of the organic solvent collection tank;

[0011] The first three-way solenoid valve and the second three-way solenoid valve are connected to a controller and controlled by the controller. The gas absorption tank and the organic solution collection tank can be fixed by a base.

[0012] Preferably, the first adsorber is installed through a base, the second adsorber is installed above the first adsorber and fixed by a bracket, the inlet of the first adsorber is arranged at its side bottom, and the top outlet is connected to the inlet at the center of the bottom of the second adsorber.

[0013] Preferably, a filter is installed in both the first adsorber and the second adsorber, and the filter may be provided in multiple layers; the filter is any one of an activated carbon filter, a glass fiber filter, a honeycomb ceramic filter, and a stainless steel filter.

[0014] Preferably, a suction fan is arranged at the top end of the second adsorber, and is arranged at the top end outlet.

[0015] Preferably, the dust adsorption unit is connected to the side bottom of the gas absorption tank through a pipeline, the pipeline leading to the gas absorption tank is horizontally passed from the left side of the gas absorption tank to the right side, and gas outlets are evenly arranged above the pipeline in the gas absorption tank; a precipitation discharge port is arranged at the right bottom of the gas absorption tank; alkali solution is contained in the gas absorption tank, and the gas absorption tank is connected to the alkali solution cylinder through a water pump and an infusion pipe to provide alkali solution, and the gas absorption tank is also provided with a pH meter to detect the pH value of the alkali solution, and the water pump and the pH meter are connected to the controller.

[0016] Preferably, a gas detection device is provided on the pipeline between the gas absorption tank and the first three-way solenoid valve; the gas detection device is connected to the controller to receive signals.

[0017] Preferably, the inlet of the drying box is arranged at the top, and the outlet is arranged at the bottom, and the bottom outlet is connected to the bottom inlet of the organic solvent collection tank.

[0018] Preferably, circulating cold water is introduced into the condenser.

[0019] Preferably, an organic solvent detector is provided on the pipeline between the top outlet of the organic solvent collection tank and the second three-way solenoid valve, and the organic solvent detector is connected to the controller to receive signals; an organic solvent discharge port is provided at the bottom side of the organic solvent collection tank.

[0020] A method for collecting waste gas from a waste lithium battery collection system, comprising the following steps:

[0021] (1) Setting the thresholds M, N, and K of the gas detection device, pH detector, and organic solvent detector, passing the waste gas generated by dismantling the waste battery into the first adsorber, and under the action of the exhaust fan and the filter, the waste gas enters from the bottom inlet, is quickly discharged from the top outlet, and enters the second adsorber, where it is fully adsorbed; dust and fine particles are fully absorbed in the first adsorber and the second adsorber;

[0022] (2) The waste gas discharged from the second adsorber enters the inner bottom of the gas absorption tank and diffuses into the alkali solution. After absorption, it is discharged from the top outlet and detected by the gas detection device. If the detected value is less than M, the controller controls the first three-way solenoid valve to connect the pipeline connected to the drying box. If the detected value is greater than M, the controller controls the first three-way solenoid valve to connect the pipeline connected to the gas absorption tank, and the reflux continues to absorb the alkali solution until the value detected by the gas detection device is less than M;

[0023] (3) After the exhaust gas is dried in a drying oven, it is passed into an organic solvent collection tank. During the process of the exhaust gas diffusing from the bottom to the top outlet, the organic solvent in the exhaust gas is pre-cooled and liquefied under the action of the condenser and drips to the bottom of the organic solvent collection tank;

[0024] (4) The waste gas is discharged from the top outlet of the organic solvent collection tank. When the value detected by the organic solvent detector is less than N, the controller controls the second three-way solenoid valve to open the pipeline to the atmosphere. If the detected value is greater than N, the controller controls the second three-way solenoid valve to connect the pipeline connected to the organic solvent collection tank, and the reflux continues to condense and liquefy until the value detected by the organic solvent detector is less than N;

[0025] (5) When the pH detector detects a value less than K, the precipitation discharge port of the gas absorption tank is opened to discharge the precipitation, and at the same time, the water pump is started to replenish the alkali solution from the alkali solution tank; the organic solvent collection tank regularly discharges the organic solvent from the organic solvent discharge port.

[0026] The values ​​of M, N, and K are set according to actual needs.

[0027] Compared with the prior art, the present invention has the following beneficial effects:

[0028] In the system of the present invention, the adsorption unit is provided with two adsorbers, which can adsorb dust and tiny solid particles layer by layer, and an exhaust fan is provided at the top outlet of the second adsorber, so that the gas can be quickly sucked into the exhaust gas collection system, realizing internal rapid circulation and improving work efficiency;

[0029] The system of the present invention is provided with a three-way electromagnetic valve, and when the detection fails, the waste gas can be refluxed and then absorbed or collected, so that the waste gas can be discharged in compliance with the standards, which is more environmentally friendly.

[0030] The system structure of the present invention is simple, the collection method is fast and efficient, and it can be refluxed and reabsorbed or collected, which is more conducive to environmental protection, meets the needs of green development, and has a high degree of automation and intelligent control. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a structural diagram of a waste gas collection system for waste lithium batteries of the present invention.

[0032] Figure 2 The present invention is a flow chart of a collection method of a waste gas collection system for waste lithium batteries.

[0033] In the figure, 1. the first adsorber; 2. the bracket; 3. the second adsorber; 4. the filter; 5. the exhaust fan; 6. the base; 7. the gas outlet; 8. the lime water; 9. the gas absorption tank; 10. the gas detection device; 11. the first three-way solenoid valve; 12. the material return pipe I; 13. the water pump; 14. the pH detector; 15. the alkali liquid cylinder; 16. the precipitation discharge port; 17. the alkali liquid feed port; 18. the drying box; 19. the cold water inlet; 20. the organic solvent collection tank; 21. the cold water outlet; 22. the organic solvent detector; 23. the second three-way solenoid valve; 24. the material return pipe II; 25. the organic solvent discharge port; 26. the internal bracket. DETAILED DESCRIPTION

[0034] The drawings are for illustrative purposes only. To better illustrate the present embodiment, some parts of the drawings are omitted, enlarged or reduced, and do not represent the size of the actual product. For those skilled in the art, some well-known structures in the drawings and their descriptions may be omitted. The terms "upper", "lower", "top", "bottom", "inside" and "outside" indicate orientations or positional relationships based on the orientations or positional relationships shown in the drawings, and 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, should not be understood as a limitation on the present invention.

[0035] It should be understood that “first”, “second”, etc. do not refer to certain features, but are for the convenience of understanding the present technical solution.

[0036] The present invention will be further described below in conjunction with the accompanying drawings and embodiments.

[0037] Example 1

[0038] A waste gas collection system for waste lithium batteries, comprising a controller, and also sequentially comprising a dust adsorption unit, a gas absorption tank 9, a drying box 18, and an organic solution collection tank 20;

[0039] The dust adsorption unit comprises a first adsorber 1 and a second adsorber 3, wherein the first adsorber 1 and the second adsorber 3 are connected in series via a pipeline;

[0040] The dust adsorption unit is connected to the gas absorption tank 9 through a pipeline. A first three-way solenoid valve 11 is arranged on the pipeline connecting the gas absorption tank 9 and the drying box 18. One pipeline connected to the first three-way solenoid valve 11 leads to the drying box 18, and the other pipeline refluxes into the gas absorption tank 9.

[0041] The drying box 18 is connected to the organic solvent collection tank 20, a condenser is arranged inside the organic solvent collection tank 20, a second three-way solenoid valve 23 is arranged on the pipeline at the upper outlet, one pipeline connected to the second three-way solenoid valve 23 leads to the atmosphere, and the other pipeline refluxes into the bottom of the organic solvent collection tank 20;

[0042] The first three-way solenoid valve 11 and the second three-way solenoid valve 23 are connected to a controller and controlled by the controller.

[0043] Example 2

[0044] A waste gas collection system for waste lithium batteries, comprising a controller, and also sequentially comprising a dust adsorption unit, a gas absorption tank 9, a drying box 18, and an organic solution collection tank 20;

[0045] The dust adsorption unit includes a first adsorber 1 and a second adsorber 3, and the first adsorber 1 and the second adsorber 3 are connected in series through a pipeline; the first adsorber 1 is installed through a base 6, and the second adsorber 3 is installed above the first adsorber 1 and fixed by a bracket 2, and the inlet of the first adsorber 1 is set at its side bottom, and the top outlet is connected to the inlet at the bottom center of the second adsorber 3.

[0046] The first adsorber 1 and the second adsorber 3 are both equipped with a filter screen 4, which is provided with 5 to 8 layers; the filter screen 4 is an activated carbon filter screen. A fan 5 is provided at the top of the second adsorber 3, which is provided at the top outlet to accelerate the exhaust gas filtering speed and quickly circulate.

[0047] The dust adsorption unit is connected to the gas absorption tank 9 through a pipeline. A first three-way solenoid valve 11 is arranged on the pipeline connecting the gas absorption tank 9 and the drying box 18. One pipeline connected to the first three-way solenoid valve 11 leads to the drying box 18, and the other pipeline, i.e., the material reflux pipe Ⅰ12 refluxes into the gas absorption tank 9.

[0048] The pipeline is connected to the side bottom of the gas absorption tank 9, and the pipeline leading to the gas absorption tank 9 is horizontally passed from the left side of the gas absorption tank 9 to the right side, and the gas outlet 7 is evenly arranged above the pipeline in the gas absorption tank 9; the sedimentation discharge port 16 is arranged at the right bottom of the gas absorption tank 9; the gas absorption tank 9 contains alkali solution, and lime water is used in this embodiment, and the gas absorption tank 9 is connected to the alkali solution cylinder 15 through a water pump 13 and an infusion tube to provide alkali solution. An alkali solution feed port 17 is arranged inside the infusion tube entering the gas absorption tank 9, and the alkali solution feed port 17 extends from one side to the other side of the gas absorption tank 9 as much as possible to facilitate circulation. The gas absorption tank 9 is also provided with a pH detector 14 to detect the pH value of the alkali solution, and the water pump 13 and the pH detector 14 are connected to the controller to control or send signals.

[0049] The drying box 18 is connected to the organic solvent collection tank 20, a condenser is arranged inside the organic solvent collection tank 20, and a second three-way solenoid valve 23 is arranged on the pipeline of the upper outlet, one pipeline connected to the second three-way solenoid valve 23 leads to the atmosphere, and the other pipeline, i.e., the material reflux pipe II 24 refluxes into the bottom of the organic solvent collection tank 20;

[0050] The first three-way solenoid valve 11 and the second three-way solenoid valve 23 are connected to a controller and controlled by the controller.

[0051] Example 3

[0052] A waste gas collection system for waste lithium batteries, comprising a controller, and also sequentially comprising a dust adsorption unit, a gas absorption tank 9, a drying box 18, and an organic solution collection tank 20;

[0053] The dust adsorption unit includes a first adsorber 1 and a second adsorber 3, and the first adsorber 1 and the second adsorber 3 are connected in series through a pipeline; the first adsorber 1 is installed through a base 6, and the second adsorber 3 is installed above the first adsorber 1 and fixed by a bracket 2, and the inlet of the first adsorber 1 is set at its side bottom, and the top outlet is connected to the inlet at the bottom center of the second adsorber 3.

[0054] The first adsorber 1 and the second adsorber 3 are both equipped with a filter screen 4, which is provided with 5 to 8 layers; the filter screen 4 is an activated carbon filter screen. A fan 5 is provided at the top of the second adsorber 3, which is provided at the top outlet to accelerate the exhaust gas filtering speed and quickly circulate.

[0055] The dust adsorption unit is connected to the gas absorption tank 9 through a pipeline. The first three-way solenoid valve 11 is arranged on the pipeline connecting the gas absorption tank 9 and the drying box 18. One pipeline connected to the first three-way solenoid valve 11 leads to the drying box 18, and the other pipeline, i.e., the material reflux pipe Ⅰ12 refluxes into the gas absorption tank 9. A gas detection device 10 is arranged on the pipeline between the gas absorption tank 9 and the first three-way solenoid valve 11. The gas detection device is an HF gas detection device (or other detection devices are arranged according to different waste batteries according to actual needs). The gas detection device 10 is connected to the controller to receive signals.

[0056] The pipeline is connected to the side bottom of the gas absorption tank 9, and the pipeline leading to the gas absorption tank 9 is horizontally passed from the left side of the gas absorption tank 9 to the right side, and the gas outlet 7 is evenly arranged above the pipeline in the gas absorption tank 9; the sedimentation discharge port 16 is arranged at the right bottom of the gas absorption tank 9; the gas absorption tank 9 contains alkali solution, and lime water is used in this embodiment, and the gas absorption tank 9 is connected to the alkali solution cylinder 15 through a water pump 13 and an infusion tube to provide alkali solution. An alkali solution feed port 17 is arranged inside the infusion tube entering the gas absorption tank 9, and the alkali solution feed port 17 extends from one side to the other side of the gas absorption tank 9 as much as possible to facilitate circulation. The gas absorption tank 9 is also provided with a pH detector 14 to detect the pH value of the alkali solution, and the water pump 13 and the pH detector 14 are connected to the controller to control or send signals.

[0057] The inlet of the drying box 18 is arranged at the top, and the outlet is arranged at the bottom, and the bottom outlet is connected to the bottom inlet of the organic solvent collecting tank 20. Calcium oxide is contained in the drying box 18.

[0058] Preferably, circulating cold water is introduced into the condenser. The drying box 18 is connected to the organic solvent collection tank 20, a condenser is arranged inside the organic solvent collection tank 20, a second three-way solenoid valve 23 is arranged on the pipeline at the upper outlet, one pipeline connected to the second three-way solenoid valve 23 leads to the atmosphere, and the other pipeline, i.e., the material reflux pipe II 24 refluxes into the bottom of the organic solvent collection tank 20;

[0059] A condenser is installed inside the organic solvent collection tank 20, and the condenser is fixed by an internal bracket 26. A cold water inlet 19 is provided at the bottom of the condenser, and a cold water outlet 21 is provided at the top, and the cold water circulates from top to bottom. An organic solvent detector 22 is provided on the pipeline between the top outlet of the organic solvent collection tank 20 and the second three-way solenoid valve 23, and the organic solvent detector 22 is connected to the controller to receive a signal; an organic solvent discharge port 25 is provided at the bottom of the side of the organic solvent collection tank 20.

[0060] The first three-way solenoid valve 11 and the second three-way solenoid valve 23 are connected to a controller and controlled by the controller.

[0061] like Figure 2As shown, a method for collecting waste gas from a waste lithium battery collection system comprises the following steps:

[0062] (1) The threshold values ​​M, N, and K of the gas detection device 10 (HF detector in this embodiment), the pH detector 14, and the organic solvent detector 22 are set, and the waste gas generated by dismantling the waste battery is introduced into the first adsorber 1. Under the action of the exhaust fan 5 and the filter 4, the waste gas is introduced from the bottom inlet and quickly discharged from the top outlet. The dust and fine particles are absorbed in the first adsorber 1 and then enter the second adsorber 3, and are fully adsorbed in the second adsorber 3;

[0063] (2) The waste gas discharged from the second adsorber 3 enters the inner bottom of the gas absorption tank 9 (HF absorption tank in this embodiment) and diffuses into the alkali solution. After absorption, it is discharged from the top outlet and detected by the gas detection device 10. If the detected value is less than M, the controller controls the first three-way solenoid valve 11 to connect the pipeline connected to the drying box 18. If the detected value is greater than M, the controller controls the first three-way solenoid valve 11 to connect the material reflux pipe I 12 connected to the gas absorption tank 9, and the reflux continues to absorb the alkali solution until the value detected by the gas detection device 10 is less than M;

[0064] (3) After the exhaust gas is dried in the drying box 18, it is passed into the organic solvent collection tank 20. During the process of the exhaust gas diffusing from the bottom to the top outlet, the organic solvent in the exhaust gas is pre-cooled and liquefied under the action of the condenser and drips to the bottom of the organic solvent collection tank 20;

[0065] (4) The waste gas is discharged from the top outlet of the organic solvent collection tank 20. When the value detected by the organic solvent detector 22 is less than N, the controller controls the second three-way solenoid valve 23 to open the pipeline to the atmosphere. If the detected value is greater than N, the controller controls the second three-way solenoid valve 23 to connect the material reflux pipe II 24 connected to the organic solvent collection tank 20, and the reflux continues to condense and liquefy until the value detected by the organic solvent detector 22 is less than N.

[0066] (5) When the pH detector 14 detects a value less than K, the precipitation outlet 16 of the gas absorption tank 9 is opened to discharge the precipitate. In this embodiment, CaF2 precipitation is formed, which mainly absorbs HF harmful gas. At the same time, the water pump 13 is started to replenish the alkali solution from the alkali solution tank; the organic solvent collection tank 20 regularly discharges the organic solvent from the organic solvent outlet 25.

[0067] The terms "install", "connect", "fix" and the like used in the present invention should be understood in a broad sense.

[0068] Of course, the above description is not a limitation of the present invention, and the present invention is not limited to the above examples. Changes, modifications, additions or substitutions made by technicians in this technical field within the essential scope of the present invention should also fall within the protection scope of the present invention.

Claims

1. A waste gas collection system for waste lithium batteries, comprising a controller, characterized in that: It also includes a dust adsorption unit, a gas absorption tank, a drying box, and an organic solution collection tank in sequence; The dust adsorption unit comprises a first adsorber and a second adsorber, and the first adsorber and the second adsorber are connected in series through a pipeline; The dust adsorption unit is connected to the gas absorption tank through a pipeline, and a first three-way solenoid valve is arranged on the pipeline connecting the gas absorption tank and the drying box. One pipeline connected to the first three-way solenoid valve leads to the drying box, and the other pipeline refluxes into the gas absorption tank; The drying box is connected to an organic solvent collection tank, a condenser is arranged inside the organic solvent collection tank, a second three-way solenoid valve is arranged on the pipeline at the upper outlet, one pipeline connected to the second three-way solenoid valve leads to the atmosphere, and the other pipeline refluxes into the bottom of the organic solvent collection tank; The first three-way solenoid valve and the second three-way solenoid valve are connected to a controller and controlled by the controller.

2. A waste gas collection system for waste lithium batteries according to claim 1, characterized in that: The first adsorber is installed through a base, and the second adsorber is installed above the first adsorber and fixed through a bracket. The inlet of the first adsorber is arranged at its side bottom, and the top outlet is connected to the inlet at the center of the bottom of the second adsorber.

3. A waste gas collection system for waste lithium batteries according to claim 2, characterized in that: Filters are installed in both the first adsorber and the second adsorber; the filter is any one of an activated carbon filter, a glass fiber filter, a honeycomb ceramic filter, and a stainless steel filter.

4. A waste gas collection system for waste lithium batteries according to claim 2, characterized in that: A suction fan is arranged at the top of the second adsorber.

5. A waste gas collection system for waste lithium batteries according to claim 1, characterized in that: The dust adsorption unit is connected to the side bottom of the gas absorption tank through a pipeline, and the pipeline leading to the gas absorption tank is passed from the left side of the gas absorption tank to the right side in a horizontal direction, and gas outlets are evenly arranged above the pipeline in the gas absorption tank; a sedimentation discharge port is arranged at the right bottom of the gas absorption tank; alkali solution is contained in the gas absorption tank, and the gas absorption tank is connected to the alkali solution cylinder through a water pump and an infusion pipe to provide alkali solution, and the gas absorption tank is also provided with a pH detector to detect the pH value of the alkali solution in the gas absorption tank; the water pump and the pH detector are connected to the controller.

6. A waste gas collection system for waste lithium batteries according to claim 1, characterized in that: A gas detection device is arranged on the pipeline between the gas absorption tank and the first three-way solenoid valve; the gas detection device is connected to the controller to receive signals.

7. A waste gas collection system for waste lithium batteries according to claim 1, characterized in that: The inlet of the drying box is arranged at the top end, and the outlet is arranged at the bottom end, and the bottom end outlet is connected to the bottom end inlet of the organic solvent collection tank.

8. The waste gas collection system for waste lithium batteries according to claim 1, characterized in that: Circulating cold water is introduced into the condenser.

9. A waste gas collection system for waste lithium batteries according to claim 1, characterized in that: An organic solvent detector is arranged on the pipeline between the top outlet of the organic solvent collection tank and the second three-way solenoid valve, and the organic solvent detector is connected to the controller to receive signals; an organic solvent discharge port is arranged at the bottom of the side of the organic solvent collection tank.

10. A method for collecting waste gas from a waste lithium battery according to any one of claims 1 to 9, characterized in that: The steps include: (1) Setting the thresholds M, N, and K of the gas detection device, pH detector, and organic solvent detector, passing the waste gas generated by dismantling the waste battery into the first adsorber, and under the action of the exhaust fan and the filter, the waste gas enters from the bottom inlet, is quickly discharged from the top outlet, enters the second adsorber, and is fully adsorbed in the second adsorber; (2) The waste gas discharged from the second adsorber enters the inner bottom of the gas absorption tank and diffuses into the alkali solution. After absorption, it is discharged from the top outlet and detected by the gas detection device. If the detected value is less than M, the controller controls the first three-way solenoid valve to connect the pipeline connected to the drying box. If the detected value is greater than M, the controller controls the first three-way solenoid valve to connect the pipeline connected to the gas absorption tank, and the reflux continues to absorb the alkali solution until the value detected by the gas detection device is less than M; (3) After the exhaust gas is dried in a drying oven, it is passed into an organic solvent collection tank. During the process of the exhaust gas diffusing from the bottom to the top outlet, the organic solvent in the exhaust gas is pre-cooled and liquefied under the action of the condenser and drips to the bottom of the organic solvent collection tank; (4) The waste gas is discharged from the top outlet of the organic solvent collection tank. When the value detected by the organic solvent detector is less than N, the controller controls the second three-way solenoid valve to open the pipeline to the atmosphere. If the detected value is greater than N, the controller controls the second three-way solenoid valve to connect the pipeline connected to the organic solvent collection tank, and the reflux continues to condense and liquefy until the value detected by the organic solvent detector is less than N; (5) When the pH value detected by the pH detector is less than K, open the precipitation discharge port of the gas absorption tank to discharge the precipitation, and start the water pump to replenish the alkali solution from the alkali solution tank.

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