CN111544920A - NMP recovery system and lithium battery coating system - Google Patents

Abstract

The invention discloses an NMP recovery system and a lithium battery coating system, which comprise a coating machine drying oven, an NMP adsorption system and a plurality of circulation recovery systems, wherein the coating machine drying oven comprises a plurality of exhaust fans and a plurality of air return fans, each circulation recovery system comprises a heat exchanger and a condensation recovery device, an exhaust outlet is connected with a high-temperature medium inlet of the heat exchanger through an exhaust pipe, and a high-temperature medium outlet of the heat exchanger is connected with a first inlet of the condensation recovery device through a condensing pipe; an air inlet of the NMP adsorption system is respectively connected with a first outlet of each condensation recovery device through an NMP air pipe; and a second outlet of the condensation recovery device is connected with a low-temperature medium inlet of the heat exchanger through a first air return pipe, and a low-temperature medium outlet of the heat exchanger is connected with an air return inlet through a second air return pipe. The technical scheme of the invention not only can be controllably adjusted to meet the recovery requirements of various circulating air volumes (especially meet the ultra-large circulating air volume), but also can effectively reduce heat loss.

Description

NMP recycling system and lithium battery coating system

technical field

The invention relates to the technical field of lithium battery manufacturing, in particular to an NMP recovery system and a lithium battery coating system.

Background technique

In recent years, with the vigorous promotion of new energy policies, the lithium battery industry has shown a blowout growth, and as a key equipment in the lithium battery manufacturing industry, the demand for lithium battery coating machines is also closely followed. The lithium battery coating machine is mainly composed of a coating part and an oven part. The oven part consumes a lot of heat energy for heating the air; the function of the coating part is to apply the prepared paste insulating paste dissolved in NMP as a solvent according to the requirements. It is clothed on the electrode substrate (copper foil or aluminum foil), and then the ambient temperature air is heated to 120 ℃ by the heater in the oven part, so that the hot air dries the slurry solvent NMP coated on the electrode substrate, and the remaining The solid organic polymer forms a strong and highly insulating layer on the electrode substrate, which is used to make lithium battery electrodes, and the exhaust gas containing gaseous NMP is recycled and processed for organized discharge.

NMP is widely used as an irreplaceable organic solvent in the lithium battery manufacturing industry and other industries. NMP, chemical name: N-methyl pyrrolidone, also known as 1-methyl-2-pyrrolidone, N-methyl-2-pyrrolidone. NMP is a colorless transparent oily liquid with a slight amine odor. Low volatility, good thermal stability and chemical stability, can volatilize with water vapor, melting point -24 ℃, boiling point 202 ℃. Because NMP is expensive, it occupies a lot of cost in the production of lithium battery electrodes, and if the waste gas containing NMP is directly discharged, it will cause certain harm to the environment. Therefore, it is of great significance to recycle and limit the discharge of NMP. At present, the NMP recovery system is usually equipped with equipment such as a coating machine oven and an NMP adsorption system to recover NMP. In addition to the recycling of expensive NMP, the exhaust gas needs to be treated to meet the emission standard before it can be discharged outdoors. In addition, the gas in the NMP recovery system will also flow back from the return air channel and re-enter the coating machine oven for use, so as to reciprocate to form a circulating air volume. However, the existing NMP recovery system usually can only achieve a fixed circulating air volume (for example, the existing NMP recovery system is limited in volume due to factors such as transportation, so it can only achieve a maximum circulating air volume of 150,000 during operation), In addition, the volume of the air duct in the NMP recovery system also needs to be set very large, resulting in a large heat loss.

SUMMARY OF THE INVENTION

The present invention aims to solve at least one of the technical problems existing in the prior art. To this end, the present invention proposes an NMP recovery system and a lithium battery coating system, which can not only be controllably adjusted to meet the recovery requirements of various circulating air volumes, but also can effectively reduce heat loss.

A first aspect of the embodiment of the present invention provides an NMP recovery system, comprising:

The coating machine oven includes several exhaust fans and several return fans, the exhaust fans are provided with air outlets, and the return fans are provided with return air outlets;

The NMP adsorption system is provided with an air inlet and an air outlet for discharging the gas to the outside;

Several recycling systems, each of which includes a heat exchanger and a condensation recycling device, the air outlet is connected to the high-temperature medium inlet of the heat exchanger through an air discharge pipe, and the air outlet of the heat exchanger is The high-temperature medium outlet is connected to the first inlet of the condensation recovery device through a condensation pipe; the air inlet of the NMP adsorption system is connected to the first outlet of each condensation recovery device through an NMP air pipe; the condensation recovery device The second outlet of the device is connected to the low temperature medium inlet of the heat exchanger through a first return air pipe, and the low temperature medium outlet of the heat exchanger is connected to the air return port through a second return air pipe.

According to one or more technical solutions provided by the present invention, it has at least the following beneficial effects: On the one hand, by setting up multiple recycling systems in the embodiment of the present invention, the recycling and recovery systems can be intelligently adjusted according to the requirements of various air levels and circulating air volumes. The number and size of the system, or the circulating air volume between each recycling system can be controlled to be the same or different, so as to achieve the recovery requirement of a larger circulating air volume (for example, more than 200,000 circulating air volume can be achieved in the NMP recycling system. recycling), so as to achieve controllable adjustment. And because the circulating air volume between each recycling system is small, the air ducts such as the exhaust duct or the return air duct are also set smaller accordingly, thereby effectively reducing heat loss. On the other hand, compared with the prior art, the volume of the recycling system needs to be set to be very large in order to meet the recovery requirements of the fixed circulating air volume. This kind of recycling system is very inconvenient to transport and install; The system is equipped with a number of smaller recycling systems, which are convenient for transportation and installation, and reduce the floor space, which is practical.

According to some embodiments of the present invention, the NMP recovery system is provided with ten circulation recovery systems; the top of the coating machine oven is provided with ten of the exhaust fans, and the bottom is provided with ten of the return fans.

According to some embodiments of the present invention, the NMP adsorption system is provided with a freezer, a runner, a regeneration fan and a treatment fan, the regeneration fan is connected to the runner, and the regeneration fan is located between the freezer and the between the runners; the air inlet faces the freezer; the processing fan is connected to the air outlet through a first air duct, and the processing fan is also connected to the runner through a second air duct.

According to some embodiments of the present invention, the NMP adsorption system includes a heater and an electric heater, the runner is provided with an adsorption zone, a regeneration zone and a cooling zone, and the regeneration fan is connected to the regeneration zone; by preheating The pipe connects the cooling zone, the electric heater, the heater and the regeneration zone in sequence, the adsorption zone is connected to the processing fan, and the processing fan is connected to the cooling fan through the second air duct District connection.

According to some embodiments of the present invention, the condensation recovery device includes a first condensation device and a second condensation device connected in sequence, the first condensation device is provided with the first inlet, and the second condensation device is provided with the the first outlet and the second outlet; the high temperature medium outlet of the heat exchanger is connected to the first inlet of the first condensing device through the condensation pipe, and the air inlet of the NMP adsorption system passes through the The NMP air pipes are respectively connected to the first outlet of each of the second condensing devices; the second outlet of the second condensing device is connected to the low temperature medium inlet of the heat exchanger through the first return air pipe.

According to some embodiments of the present invention, the recycling system further includes a return air device, the air return device is located between the heat exchanger and the return fan, and the low temperature medium outlet of the heat exchanger passes through the The second air return duct is connected to the air inlet of the air return device, and the air outlet of the air return device is connected to the air return opening through the third air return duct.

According to some embodiments of the present invention, the coating machine oven includes a heating unit, the heating unit is disposed adjacent to the return fan, and the heating unit is used to heat the substances discharged from the return fan.

According to some embodiments of the present invention, the NMP adsorption system further includes an air exhaust valve, the air exhaust valve is connected to the air outlet, and the air exhaust valve is used to discharge the gas processed by the NMP adsorption system out of the room ; Both the first air return pipe and the second air return pipe are provided with air return valves.

According to some embodiments of the present invention, a high-efficiency filter is further provided on the second air return pipe, and the high-efficiency filter is located between the return fan and the heat exchanger.

A second aspect of the embodiments of the present invention provides a lithium battery coating system, including the NMP recovery system described in the first aspect above. Since the lithium battery coating system of the embodiment of the present invention is provided with the NMP recovery system of the first aspect, the lithium battery coating system has the beneficial effects and functional characteristics brought by any of the above NMP recovery systems.

Additional aspects and/or advantages of the present invention will be set forth in part in the description which follows, and in part will become apparent from the description below, or may be learned by practice of the invention.

Description of drawings

The above and/or additional aspects and advantages of the present invention will become apparent and readily understood from the following description of embodiments taken in conjunction with the accompanying drawings, wherein:

Fig. 1 is the structural representation of the NMP recovery system of the embodiment of the present invention;

Fig. 2 is the structural representation of the recycling system shown in Fig. 1;

Fig. 3 is the structural representation of the NMP adsorption system shown in Fig. 1;

4 is a schematic structural diagram of an NMP recovery system according to another embodiment of the present invention;

FIG. 5 is a schematic structural diagram of an NMP recovery system according to another embodiment of the present invention.

Reference number:

Coating machine oven 100, exhaust fan 110, return fan 120, heating unit 130,

Circulation recovery system 200, heat exchanger 210, high temperature medium inlet 211, high temperature medium outlet 212, low temperature medium inlet 213, low temperature medium outlet 214, condensation recovery device 220, first inlet 221, first outlet 222, second outlet 223, The first condensing device 230, the second condensing device 240, the air return device 250, the air inlet 251, the air outlet 252,

NMP adsorption system 300, air inlet 301, air outlet 302, freezer 310, runner 320, regeneration zone 321, cooling zone 322, adsorption zone 323, regeneration fan 330, treatment fan 340, heater 350, electric heater 360 .

Detailed ways

The following describes in detail the embodiments of the present invention, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals refer to the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary, only used to explain the present invention, and should not be construed as a limitation of the present invention.

In the description of the present invention, it should be understood that the orientation or positional relationship indicated in relation to orientation description, such as up, down, left, right, front, rear, outer, inner, longitudinal, lateral, vertical, horizontal, etc., is based on The orientation or positional relationship shown in the drawings is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the indicated device or element must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as Limitations of the present invention.

In the description of the present invention, the meaning of several is one or more, the meaning of multiple is two or more, greater than, less than, exceeding, etc. are understood as not including this number, above, below, within, etc. are understood as including this number. If it is described that the first and the second are only for the purpose of distinguishing technical features, it cannot be understood as indicating or implying relative importance, or indicating the number of the indicated technical features or the order of the indicated technical features. relation.

In the description of the present invention, it should be noted that, unless otherwise expressly specified and limited, the terms "installation", "connection" and "connection" should be understood in a broad sense, for example, it may be a fixed connection or a detachable connection , or integrally connected; it can be a mechanical connection or an electrical connection; it can be a direct connection, or an indirect connection through an intermediate medium, or the internal communication between the two components. For those of ordinary skill in the art, the specific meanings of the above terms in the present invention can be understood in specific situations.

The first aspect of the embodiment of the present invention provides an NMP recovery system, including: a coating machine oven 100, including a plurality of exhaust fans 110 and a plurality of return fans 120, the exhaust fan 110 is provided with an exhaust port, and the return fan 120 is provided with The air return port; the NMP adsorption system 300 is provided with an air inlet 301 and an air outlet 302 for discharging the gas outdoors; a number of recycling systems 200, each recycling system 200 includes a heat exchanger 210 and a condensation recovery device 220 , the air outlet is connected to the high temperature medium inlet 211 of the heat exchanger 210 through the air exhaust pipe, and the high temperature medium outlet 212 of the heat exchanger 210 is connected to the first inlet 221 of the condensation recovery device 220 through the condenser pipe; the inlet of the NMP adsorption system 300 The air port 301 is respectively connected to the first outlet 222 of each condensation recovery device 220 through the NMP air pipe; the second outlet 223 of the condensation recovery device 220 is connected to the low temperature medium inlet 213 of the heat exchanger 210 through the first return air pipe, and the heat The low temperature medium outlet 214 of the exchanger 210 is connected to the air return port through the second air return pipe.

The NMP recovery system of the embodiment of the present invention is provided with several recycling systems 200. Referring to FIG. 1, the embodiment of the present invention is provided with three recycling systems 200. The coating machine oven 100 is provided with three exhaust fans 110 and three return fans 120. . Each exhaust fan 110 is provided with an air outlet, and each return fan 120 is provided with a return air outlet. The treated reflux gas is returned to the oven 100 of the coating machine to realize multiple recycling, energy saving and environmental protection.

Specifically, since the NMP recovery system of the embodiment of the present invention is provided with three circulating recovery systems 200, three kinds of circulating recovery gases (through the exhaust air passage and the return air passage) are also formed, thereby forming a large circulating air volume. It is recycled in the entire NMP recovery system, saving energy and protecting the environment.

Exhaust passage: For example, as shown in FIG. 1 , the gas in the oven 100 of the coating machine is exhausted from the exhaust fan 110 and transported to the high temperature medium inlet 211 of the heat exchanger 210 through the exhaust pipe. The gas enters the heat exchanger 210 for heat exchange treatment, so that the temperature of the hot air of the exhaust gas containing NMP is lowered and then discharged from the high temperature medium outlet 212 . The gas enters the first inlet 221 of the condensation recovery device 220 through the condensation pipe, and is discharged from the first outlet 222 of the condensation recovery device 220 after being condensed. Since a plurality of circulation recovery systems 200 are provided, the first outlet 222 of each condensation recovery device 220 is connected to the air inlet 301 of the NMP adsorption system 300 through an NMP air pipe. In the gas discharged from the first outlet 222, 5% to 10% of the gas will finally enter the air inlet 301 of the NMP adsorption system 300, and the NMP-containing gas will be recovered and processed by the NMP adsorption system 300, so that the gas reaches the emission level. After standardization, the gas is discharged through the gas outlet 302 of the NMP adsorption system 300, thereby realizing gas discharge.

Return air passage: For example, as shown in FIG. 1 , most (90% to 95%) of the gas processed by the recycling system 200 will be refluxed to form a reflux gas, which will be discharged from the second outlet 223 of the condensation recovery device 220 . The return gas is transported to the low temperature medium inlet 213 of the heat exchanger 210 through the first return air duct, discharged from the low temperature medium outlet 214 of the heat exchanger 210, and finally reaches the return air port in the return fan 120 through the second return air duct. The return gas re-enters the oven 100 of the coating machine for recycling. The NMP recovery system in this embodiment is provided with multiple recycling systems 200, and the gas in the multiple exhaust air passages and the multiple return air passages together form a large circulating air volume to realize the recycling and reuse of NMP and save costs.

In other embodiments, the number of recycling systems 200 may be four, five, six, etc., but not limited thereto.

According to one or more technical solutions provided by the present invention, it has at least the following beneficial effects: On the one hand, by setting up multiple recycling systems 200 in the embodiment of the present invention, it is possible to intelligently adjust the circulating air volume according to the circulating air volume requirements of various wind levels. The number and size of the recovery systems 200 are to meet the recovery requirement of a larger circulating air volume. For example, one recycling system 200 can reach 20,000 circulating air volume, and the NMP recycling system can achieve the recovery requirement of 240,000 circulating air volume by setting up 12 20,000 recycling systems 200; setting 10 20,000 recycling systems 200 , can reach the recovery requirement of 200,000 circulating air volume. Or control the circulating air volume between each recycling system 200 to be different. For example, the first recycling system 200 can achieve a circulating air volume of 5,000 by adjusting the size, and the second recycling system 200 can be adjusted to a cycle of 50,000. The air volume can be set to meet the recovery needs of various circulating air volumes, so as to achieve controllable adjustment. By arranging several recycling systems 200, it is possible to meet the large circulating air volume (eg, 300,000, 400,000, etc.). And because the circulating air volume between each circulating recovery system 200 installed is small, the air ducts such as the exhaust air duct or the return air duct are correspondingly smaller, thereby effectively reducing heat loss. Compared with the NMP recovery system in the prior art, when the air duct is damaged, not only the production operation is affected, but the entire air duct needs to be repaired and replaced, which wastes resource costs; while each cycle recovery system 200 in the embodiment of the present invention is mutually exclusive. Independently, when the exhaust duct or the first return air duct or the second return air duct is damaged, the damaged air duct can be replaced in time without affecting the operation of other normal recycling systems 200, saving materials and facilitating replacement. On the other hand, compared with the volume of the recycling system in the prior art, the volume of the recycling system needs to be set to be very large in order to meet the recovery requirements of the fixed circulating air volume. This recycling system is very inconvenient during transportation and installation, and it occupies an The NMP recovery system in the embodiment of the present invention is provided with a plurality of recycling recovery systems 200 with a small volume, which is convenient for transportation and installation, and can reduce the floor space and is practical.

According to some embodiments of the present invention, the NMP recovery system is provided with ten recycling systems 200 ; the coating machine oven 100 is provided with ten exhaust fans 110 above, and ten return fans 120 are provided below.

5, the embodiment of the present invention is provided with ten recycling systems 200, each recycling system 200 is connected to the coating machine oven 100, the NMP adsorption system 300, to achieve NMP gas discharge and recycling. Specifically, the gas passes through the above-mentioned exhaust passages and is discharged to the outside after reaching the discharge standard; the return gas re-enters the coating machine oven 100 through the return air passages for recycling, and passes through ten exhaust passages and ten return air passages. The circulating recovered gas forms a large circulating air volume together. For example, in the embodiment of the present invention, each recycling system 200 can be set to achieve a circulating air volume of 20,000. The exhaust duct, the first return air duct or the second return air duct and other air ducts can also be set to accommodate 20,000 circulating air volumes. Compared with the existing technology, it can effectively reduce the heat loss. On the other hand, the NMP recovery system can reach 200,000 circulating air volume by setting ten circulating recovery systems 200, which can meet the recycling demand of super large circulating air volume. When the recycling demand for circulating air volume decreases, part of the recycling system 200 may also be disassembled to achieve a circulating air volume such as 160,000, 140,000, or 100,000, but not limited to this. The embodiment of the present invention can realize controllable adjustment to meet the requirement of cyclic recovery of various air levels and air volumes, and has practicability. In other embodiments, the number or size of the recycling system 200 may be controllably adjusted according to the recycling demand of the circulating air volume, which is not limited to this embodiment, and will not be repeated here.

According to some embodiments of the present invention, the NMP adsorption system 300 is provided with a freezer 310 , a runner 320 , a regeneration fan 330 and a treatment fan 340 , the regeneration fan 330 is connected to the runner 320 , and the regeneration fan 330 is located between the freezer 310 and the runner 320 The air inlet 301 faces the freezer 310; the processing fan 340 is connected to the air outlet 302 through the first air duct, and the processing fan 340 is also connected to the runner 320 through the second air duct.

Referring to FIG. 1 and FIG. 2 , 5% to 10% of the gas will enter from the air inlet 301 of the NMP adsorption system 300 through the exhaust passage. After the gas is cooled by the freezer 310, a large amount of NMP will be condensed and precipitated. After the NMP is condensed into a liquid, it can be discharged into a waste liquid tank or a waste liquid pool, thereby recovering the NMP and reducing the temperature of the hot air of the exhaust gas containing NMP. After that, the runner 320 adsorbs and processes the gas, and then the gas flows through the processing fan 340 . On the one hand, the gas reaches the emission standard after being processed, and reaches the air outlet 302 through the first air duct, so as to be discharged to the outside; After being processed by the runner 320 , the gas flows to the regeneration fan 330 and is discharged through the regeneration fan 330 . The NMP adsorption system 300 in the embodiment of the present invention is used to recover and process the exhaust gas containing NMP, so that the discharged gas meets the emission standard and protects the environment; the NMP in the exhaust gas can also be converted into a liquid by using the refrigerator 310, and the NMP is recovered. Reuse is practical.

According to some embodiments of the present invention, the NMP adsorption system 300 includes a heater 350 and an electric heater 360, the runner 320 is provided with an adsorption zone 323, a regeneration zone 321 and a cooling zone 322, and the regeneration fan 330 is connected to the regeneration zone 321; The heat pipe is sequentially connected to the cooling zone 322, the electric heater 360, the heater 350 and the regeneration zone 321, the adsorption zone 323 is connected to the processing fan 340, and the processing fan 340 is also connected to the cooling zone 322 through the second air pipe.

2, the runner 320 is respectively provided with a regeneration zone 321, a cooling zone 322 and an adsorption zone 323 from top to bottom. In other embodiments, the regeneration zone 321, the cooling zone 322 and the adsorption zone 323 can be heat-resistant and solvent-resistant. separated by a protective sealing material. Through the continuous operation of the runner, there are 3 kinds of gases with different air volumes (such as regeneration gas/cooling gas/processing gas) passing through. The exhaust gas containing NMP enters from the air inlet 301 of the NMP adsorption system 300, and after being cooled by the freezer 310, a large amount of NMP will be condensed and precipitated. The NMP is recovered and used, and the temperature of the exhaust gas hot air containing NMP can be lowered. At this time, as the processing gas with a large air volume, it will enter the adsorption zone 323 in the runner 320, and the organic solvent and other impurities in the processing gas will be adsorbed and filtered through the adsorption zone 323, and the processed gas after adsorption/purification can be clean, The extent to which emission standards are met. After that, the processing gas enters the processing fan 340 and reaches the gas outlet 302 through the first air duct, thereby being discharged to the outside.

In addition, after the processing gas enters the processing fan 340, the processing gas will also flow to the cooling zone 322 through the second air duct. The processing gas will be used as cooling gas after being absorbed and processed by the cooling zone 322 . Under the action of the regeneration fan 330 , the cooling gas flows to the electric heater 360 , the heater 350 sequentially through the preheating pipe, and finally flows to the regeneration zone 321 . Since the cooling gas will be heated to the desorption temperature after passing through the cooling zone 322, the electric heater 360 and the heater 350, the organic solvent in the regeneration zone 321 will be evaporated and separated and mixed into the gas to become the regeneration gas. The regeneration gas is finally discharged through the regeneration fan 330 . The NMP adsorption system 300 of the embodiment of the present invention can purify the gas to be treated and concentrate VOC (volatile organic compounds) in a continuous cycle, which is practical; The cooler 350 reaches the regeneration zone 321, so that the residual heat in the cooling zone 322 is reused, and the energy utilization efficiency is improved.

According to some embodiments of the present invention, the condensation recovery device 220 includes a first condensation device 230 and a second condensation device 240 connected in sequence, the first condensation device 230 is provided with a first inlet 221, and the second condensation device 240 is provided with a first outlet 222. The second outlet 223; the high-temperature medium outlet 212 of the heat exchanger 210 is connected to the first inlet 221 of the first condensing device 230 through a condenser pipe, and the air inlet 301 of the NMP adsorption system 300 is connected to each The first outlet 222 of the second condensing device 240 ; the second outlet 223 of the second condensing device 240 is connected to the low-temperature medium inlet 213 of the heat exchanger 210 through the first return air pipe.

3, the embodiment of the present invention is provided with a plurality of recycling systems 200, each condensation recovery device 220 is provided with a first condensation device 230 and a second condensation device 240 connected in sequence; The first outlets 222 are all connected to the air inlet 301 of the NMP adsorption system 300 through NMP air pipes. After the gas is discharged through the high temperature medium outlet 212 of the heat exchanger 210, it enters the first inlet 221 of the first condensing device 230 through the condenser pipe, and the gas passes through the first condensing device 230 and the second condensing device 240 to the second condensing device 240. One exit 222. After that, a small part of the gas (for example, 5% to 10%) will reach the air inlet 301 of the NMP adsorption system 300, and the NMP-containing gas will be recovered and processed by the NMP adsorption system 300, so that after the gas reaches the emission standard, it will finally pass through the NMP The gas outlet 302 of the adsorption system 300 is discharged, thereby realizing gas discharge.

In addition, after being condensed by the first condensing device 230 and the second condensing device 240 , most of the gas (eg, 90% to 95%) will be discharged from the second outlet 223 of the second condensing device 240 as reflux gas. The return gas is transported to the low temperature medium inlet 213 of the heat exchanger 210 through the first return air duct, discharged from the low temperature medium outlet 214 of the heat exchanger 210, and finally reaches the return air port in the return fan 120 from the second return air duct. The return gas re-enters the oven 100 of the coating machine for recycling. By arranging the first condensing device 230 and the second condensing device 240 to strengthen the condensation treatment of the gas or the reflux gas, it is convenient to further treat the NMP, which is highly efficient and energy-saving. In other embodiments, the first condensing device 230 and/or the second condensing device 240 may be a surface cooler, a cooling tower or other equipment.

According to some embodiments of the present invention, the recycling system 200 further includes a return air device 250, the return air device 250 is located between the heat exchanger 210 and the return fan 120, and the low temperature medium outlet 214 of the heat exchanger 210 passes through the second return air pipe Connected to the air inlet 251 of the air return device 250, and the air outlet 252 of the air return device 250 is connected to the air return through a third air return pipe. 4 , the recycling system 200 in the embodiment of the present invention further includes a return air device 250. The return air device 250 is arranged between the heat exchanger 210 and the return fan 120. By setting the return air device 250, the airflow of the return gas can be accelerated. speed, thereby speeding up the circulation rate of the entire circulating air volume and improving energy utilization efficiency.

According to some embodiments of the present invention, the coating machine oven 100 includes a heating unit 130 disposed adjacent to the return fan 120 , and the heating unit 130 is used to heat the substances discharged from the return fan 120 . Referring to FIG. 1 , the coating machine oven 100 in the embodiment of the present invention is further provided with a heating unit 130 , and the heating unit 130 is used to heat substances such as gas discharged by the return fan 120 , so that the heated gas can re-enter the coating machine oven 100 Recycle. By arranging the heating unit 130, the heating rate of the gas can be accelerated to prevent a large heat loss of the coating machine oven 100 when a large amount of low-temperature gas re-enters the coating machine oven 100, thereby ensuring the efficient operation of the equipment.

According to some embodiments of the present invention, the NMP adsorption system 300 further includes an air exhaust valve, the air exhaust valve is connected to the air outlet 302, and the air exhaust valve is used to discharge the gas processed by the NMP adsorption system 300 out of the room; the first air return pipe and The second air return ducts are all provided with air return valves. In the embodiment of the present invention, by setting an air exhaust valve at the air outlet 302, and setting return air valves on both the first air return pipe and the second air return pipe, the air flow speed of the gas can be accelerated, thereby accelerating the circulation in the entire NMP recovery system The recovery rate of air volume is practical.

According to some embodiments of the present invention, a high-efficiency filter is further provided on the second air return pipe, and the high-efficiency filter is located between the return fan 120 and the heat exchanger 210 . In the embodiment of the present invention, a high-efficiency filter is also provided on the second air return pipe, and impurities in the return gas are filtered through the high-efficiency filter to prevent impurities from entering the coating machine oven 100 and affecting the service life of the coating machine oven 100 .

In a second aspect of the embodiments of the present invention, a lithium battery coating system is provided, including the NMP recovery system according to the above-mentioned first aspect.

According to the lithium battery coating system of the embodiment of the present invention, by using the above-mentioned NMP recovery system, the floor space is reduced, and the structure of the NMP recovery system can be controllably adjusted to meet the recovery requirements of various circulating air volumes. By setting up several recycling systems 200, heat loss can also be effectively reduced. Specifically, in other embodiments, since the lithium battery coating system is provided with the NMP recovery system in any of the above embodiments, the lithium battery coating system has the benefits brought by the NMP recovery system in any of the above embodiments. Effects and functional characteristics.

Other structures and operations of the lithium battery coating system according to the embodiment of the present invention are known to those of ordinary skill in the art, and will not be described in detail here.

The NMP recovery system according to the embodiment of the present invention will be described in detail below with reference to FIG. 4 with a specific embodiment. It is to be understood that the following description is illustrative only and not specific limitation of the invention.

As shown in FIG. 4 , the NMP recovery system according to the embodiment of the present invention is provided with three recycling systems 200 , and the volume between each recycling system 200 can be different or the same. For example, the first recycling system 200 can be set. When the circulating air volume reaches 10,000, the second recycling system 200 can reach the circulating air volume of 50,000, and the third recycling system 200 can reach the circulating air volume of 100,000. According to the recovery demand of the circulating air volume, each circulating recovery system 200 can be controllably adjusted. Three exhaust fans 110 and three return fans 120 are correspondingly provided on the coating machine oven 100 , and each exhaust fan 110 and each return fan 120 respectively correspond to three recycling systems 200 . The three recycling systems 200 are respectively connected with the NMP adsorption system 300 and the coating machine oven 100, thereby forming three exhaust passages and three return air passages, and the three recycling gases will constitute a large circulating air volume. Recycled in the entire NMP recovery system.

Specifically, taking any recycling system 200 as an example, the exhaust fan 110 on the coating machine oven 100 is provided with an exhaust port, and the exhaust port passes through the exhaust pipe and the high temperature medium of the heat exchanger 210 in the recycling system 200 Inlet 211 is connected. The high temperature medium outlet 212 of the heat exchanger 210 is connected to the first inlet 221 of the first condensing device 230 through a condensation pipe. The first outlet 222 of the second condensing device 240 is connected to the air inlet 301 of the NMP adsorption system 300 through the NMP air pipe; The low temperature medium inlet 213 of the exchanger 210 is connected. The low temperature medium outlet 214 of the heat exchanger 210 is connected to the air return port of the return fan 120 through the second air return pipe. The NMP adsorption system 300 is provided with a freezer 310, a runner 320, a regeneration fan 330, a treatment fan 340, a heater 350 and an electric heater 360. The runner 320 is provided with an adsorption zone 323, a regeneration zone 321 and a cooling zone 322. The port 301 faces the freezer 310 , the regeneration fan 330 is located between the freezer 310 and the runner 320 , and the regeneration fan 330 is connected to the regeneration zone 321 . The cooling zone 322, the electric heater 360, the heater 350 and the regeneration zone 321 are connected in sequence through the preheating pipe, the adsorption zone 323 is connected with the processing fan 340, the processing fan 340 is connected to the air outlet 302 through the first air pipe, and the processing fan 340 also It is connected to the cooling zone 322 through the second air duct.

The specific working process of the NMP recovery system of the embodiment of the present invention:

Exhaust passage: the gas in the oven 100 of the coating machine is exhausted from the exhaust fan 110, and is transported to the high temperature medium inlet 211 of the heat exchanger 210 through the exhaust pipe. The gas enters the heat exchanger 210 for heat exchange treatment, so that the temperature of the hot air of the exhaust gas containing NMP is lowered and then discharged from the high temperature medium outlet 212 . The gas enters the first inlet 221 of the first condensing device 230 through the condensing pipe, and after being condensed by the first condensing device 230 and the second condensing device 240 , is discharged from the first outlet 222 of the second condensing device 240 . Since three circulation recovery systems 200 are provided, the first outlet 222 in each second condensing device 240 is connected to the air inlet 301 of the NMP adsorption system 300 through an NMP air pipe. Part of the gas (eg, 5% to 10%) reaches the air inlet 301 of the NMP adsorption system 300 through the NMP air duct. The freezer 310 cools the gas. At this time, a large amount of NMP will be condensed and precipitated. After the NMP is condensed into a liquid, it can be discharged into a waste liquid tank or a waste liquid pool to recycle the NMP. After that, the treatment gas enters the adsorption zone 323 in the runner 320, and the organic solvent and other impurities in the treatment gas are adsorbed and filtered through the adsorption zone 323 to meet the emission standard. On the one hand, part of the processing gas enters the processing fan 340 and reaches the air outlet 302 through the first air duct, so as to be discharged outdoors; on the other hand, after another part of the processing gas enters the processing fan 340, under the action of the regeneration fan 330, it will pass through the The second air duct flows to the cooling zone 322 . The cooling zone 322 absorbs the processing gas and turns it into cooling gas. The cooling gas passes through the electric heater 360 and the heater 350 in sequence through the preheating pipe, and finally flows to the regeneration zone 321 . The organic solvent in the regeneration zone 321 is evaporated and desorbed by the heated cooling gas, and mixed to become a regeneration gas. The regeneration gas is finally discharged through the regeneration fan 330 .

Return air passage: most (eg, 90% to 95%) of the gas processed by the condensation recovery device 220 will be refluxed to form a reflux gas. That is, after the reflux gas is condensed by the first condensing device 230 and the second condensing device 240, it is discharged from the second outlet 223 of the second condensing device 240, and the reflux gas is transported to the low-temperature medium of the heat exchanger 210 through the first return air pipe The inlet 213 is discharged from the low temperature medium outlet 214 of the heat exchanger 210 . The return air then reaches the air inlet 251 of the air return device 250 through the second air return pipe, and is discharged from the air outlet 252 of the air return device 250 . Under the action of the return fan 120, the return gas flows to the coating machine oven 100 through the third return air duct. The heating unit 130 heats the gas delivered by the return fan 120, so that the heated return gas re-enters the coating machine oven 100, thereby realizing recycling.

According to the NMP recovery system according to the embodiment of the present invention, by setting it in this way, at least some of the following effects can be achieved: by setting a plurality of circulating recovery systems 200, not only the recovery requirements of various circulating air volumes can be met (especially the super-large circulating air volume) , so as to achieve controllable adjustment and effectively reduce heat loss; and compared with the prior art, the embodiment of the present invention is very convenient for transportation and installation, and reduces floor space.

In the description of this specification, reference to the terms "one embodiment," "some embodiments," "exemplary embodiment," "example," "specific example," or "some examples", etc., is meant to incorporate the embodiments A particular feature, structure, material, or characteristic described by an example or example is included in at least one embodiment or example of the present invention. In this specification, schematic representations of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the particular features, structures, materials or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

Although embodiments of the present invention have been shown and described, it will be understood by those of ordinary skill in the art that various changes, modifications, substitutions and alterations can be made in these embodiments without departing from the principles and spirit of the invention, The scope of the invention is defined by the claims and their equivalents.

Claims (10)

1. an NMP recovery system, is characterized in that, comprises: The coating machine oven includes several exhaust fans and several return fans, the exhaust fans are provided with air outlets, and the return fans are provided with return air outlets; The NMP adsorption system is provided with an air inlet and an air outlet for discharging the gas to the outside; Several recycling systems, each of which includes a heat exchanger and a condensation recycling device, the air outlet is connected to the high-temperature medium inlet of the heat exchanger through an air discharge pipe, and the air outlet of the heat exchanger is The high-temperature medium outlet is connected to the first inlet of the condensation recovery device through a condensation pipe; the air inlet of the NMP adsorption system is connected to the first outlet of each condensation recovery device through an NMP air pipe; the condensation recovery device The second outlet of the device is connected to the low temperature medium inlet of the heat exchanger through a first return air pipe, and the low temperature medium outlet of the heat exchanger is connected to the air return port through a second return air pipe. 2. The NMP recovery system according to claim 1 is characterized in that: the NMP recovery system is provided with ten recycling systems; the top of the coating machine oven is provided with ten described exhaust fans, and the bottom is provided with ten described exhaust fans. one of the return fans. 3. The NMP recovery system according to claim 1, wherein the NMP adsorption system is provided with a freezer, a runner, a regeneration fan and a processing fan, the regeneration fan is connected with the runner, and the regeneration The fan is located between the freezer and the runner; the air inlet faces the freezer; the processing fan is connected to the air outlet through a first air duct, and the processing fan also passes through a second air A tube is connected to the runner. 4. The NMP recovery system according to claim 3 is characterized in that: the NMP adsorption system comprises a heater and an electric heater, the runner is provided with an adsorption zone, a regeneration zone and a cooling zone, and the regeneration fan is provided with an adsorption zone, a regeneration zone and a cooling zone. The regeneration zone is connected; the cooling zone, the electric heater, the heater and the regeneration zone are sequentially connected through a preheating pipe, and the adsorption zone is connected with the processing fan, and the processing fan passes through the The second air duct is connected to the cooling zone. 5. The NMP recovery system according to claim 1, wherein the condensation recovery device comprises a first condensation device and a second condensation device connected in sequence, and the first condensation device is provided with the first inlet, The second condensing device is provided with the first outlet and the second outlet; the high-temperature medium outlet of the heat exchanger is connected to the first inlet of the first condensing device through the condensing pipe, and the NMP The air inlet of the adsorption system is respectively connected to the first outlet of each second condensing device through the NMP air pipe; the second outlet of the second condensing device is connected with the heat through the first return air pipe. The low temperature medium inlet of the exchanger is connected. 6 . The NMP recovery system according to claim 1 , wherein the recycling system further comprises a return air device, and the return air device is located between the heat exchanger and the return fan, and the heat The low temperature medium outlet of the exchanger is connected to the air inlet of the air return device through the second air return pipe, and the air outlet of the air return device is connected to the air return port through the third air return pipe. 7 . The NMP recovery system according to claim 1 , wherein the coating machine oven comprises a heating unit, the heating unit is arranged adjacent to the return fan, and the heating unit is used to heat the return fan 7 . material discharged from the fan. 8 . The NMP recovery system according to claim 1 , wherein the NMP adsorption system further comprises an air exhaust valve, the air exhaust valve is connected to the air outlet, and the The gas treated by the NMP adsorption system is discharged to the outside; the first air return pipe and the second air return pipe are both provided with air return valves. 9 . The NMP recovery system according to claim 1 , wherein a high-efficiency filter is further provided on the second air return pipe, and the high-efficiency filter is located between the return air fan and the heat exchanger. 10 . . 10. A lithium battery coating system, characterized in that it comprises the NMP recovery system according to any one of claims 1 to 9.

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