CN219663311U

CN219663311U - NMP circulation recovery system

Info

Publication number: CN219663311U
Application number: CN202320472059.5U
Authority: CN
Inventors: 许玉山; 彭建林
Original assignee: Shenzhen Manst Technology Co Ltd
Current assignee: Shenzhen Manst Technology Co Ltd
Priority date: 2023-03-03
Filing date: 2023-03-03
Publication date: 2023-09-12
Anticipated expiration: 2033-03-03

Abstract

The utility model discloses an NMP circulating recovery system, which comprises a cooling spray device, wherein the cooling spray device is provided with a closed shell, one side of the shell is provided with an exhaust gas inlet which is suitable for connecting exhaust gas discharged by an oven into the shell through a pipeline, the other side of the shell is provided with an air outlet which is higher than the exhaust gas inlet, a first filtering structure and a second filtering structure which are higher than the exhaust gas inlet are sequentially arranged in the shell from bottom to top, a spray structure is arranged above the second filtering structure, a spray head of the spray structure is arranged in the shell and is positioned above the second filtering structure, a first air flow guide plate which is vertically extended and is positioned between the first filtering structure and the second filtering structure, and a second air flow guide plate which is vertically extended and is positioned above the second filtering structure are arranged in the shell, and the first air flow guide plate (b) and the second air flow guide plate are transversely staggered. The waste gas containing NMP flows under the guidance of the first air flow guide plate and the second air flow guide plate, the flow path is prolonged, and the NMP absorption effect of the solvent can be enhanced.

Description

NMP circulation recovery system

Technical Field

The utility model relates to the technical field of recycling, in particular to an NMP recycling system.

Background

NMP (N-methyl pyrrolidone) is strong polar aprotic water with excellent performance, has a series of advantages of stable chemical performance, high temperature resistance, strong dissolution capacity, low volatility, high safety, low toxicity and the like, and is widely applied to the production of lithium ion batteries. For example, in the lithium electric coating industry, the coating and drying of the positive electrode sheet involves the problem of NMP waste gas treatment and emission. In the traditional design, after NMP waste gas discharged by the whole oven reaches the discharge standard through centralized treatment, the waste NMP and heat are discharged into the atmosphere, and the pollution to the atmosphere is caused.

Aiming at the defects in the traditional design, an NMP recovery system comprises a heat exchange device and an NMP spray absorption device which are sequentially connected. In the heat exchange device, the waste gas from the oven and the air to be introduced into the oven realize heat exchange, so that the heat of the waste gas can be utilized, and the waste gas containing NMP after heat exchange enters the NMP spray absorption device. NMP sprays absorbing device and includes from first filtration, first structure, the second filtration that sprays, the second that upwards set gradually from down spray the structure. NMP is dissolved and absorbed by water in the NMP spray absorber, and the waste water absorbed with NMP flows into the recovery tank through a pipeline.

However, the above NMP recovery system has a disadvantage in that the NMP-containing exhaust gas travels in a short path in the NMP spray absorber, which affects the NMP absorption effect of water.

In view of the above drawbacks, it is necessary to design an NMP recycling system.

Disclosure of Invention

Therefore, the technical problem to be solved by the utility model is that the running path of the waste gas containing NMP in the NMP spray absorption device is short, and the NMP absorption effect of water is affected, so that the NMP recycling system is provided.

In order to solve the technical problems, the technical scheme of the utility model is as follows:

the utility model provides a NMP circulation recovery system, includes cooling spray set, cooling spray set has confined casing, exhaust gas inlet has been seted up to one side of casing is suitable for through the pipeline with oven exhaust gas access in the casing, the gas outlet that exceeds exhaust gas inlet has been seted up to the opposite side of casing, from down upwards having set gradually in the casing first filtration and the second filtration that exceeds exhaust gas inlet, the top of second filtration is equipped with spray structure, spray structure's shower nozzle is arranged in the casing and is located the top of second filtration, be equipped with vertical extension in the casing be located first filtration with first air current deflector between the second filtration and vertical extension be located second air current deflector above the second filtration, first air current deflector with second air current deflector transversely misplaces.

Further, the number of the first airflow guide plates and the second airflow guide plates is not less than two, and the first airflow guide plates and the second airflow guide plates are alternately arranged transversely.

Further, the first air flow guide plate divides the first space between the first filtering structure and the second filtering structure into a corresponding number of first subspaces, the widths of the first subspaces gradually increase in the transverse direction away from the exhaust gas inlet, one end of the first air flow guide plate extends upwards to the bottom of the second filtering structure, and the other end of the first air flow guide plate extends downwards to be suitable for being immersed in the solvent in the shell.

Further, the spraying structure comprises a main pipeline and a circulating pump arranged on the main pipeline, one end of the main pipeline is communicated with the bottom of the shell, the other end of the main pipeline is connected with a branch pipeline, a spray head is connected to the branch pipeline, and the circulating pump is suitable for extracting solvent in the shell and entering the spray head through the main pipeline and the branch pipeline.

Further, a cooling structure is also connected to the main pipe, the cooling structure being adapted to cool the solvent extracted from the cooling spray device.

Further, the lower part of the shell is provided with a liquid supplementing port, new solvent is supplemented into the shell through the liquid supplementing port, the bottom of the shell is provided with a liquid draining port, and the liquid draining port is connected to the recovery tank through a pipeline.

Further, still include adsorption equipment, adsorption equipment's air inlet pass through the pipeline with cooling spray set's gas outlet links to each other, adsorption equipment is suitable for absorbing from moisture in the gas that cooling spray set flows, the last air conditioning that is connected with of adsorption equipment blows off the structure towards adsorption layer setting of adsorption equipment, the air conditioning goes out to take off the structure and is suitable for blowing cold wind downwards to the adsorption layer.

Further, the device also comprises a heat exchange device, wherein two ends of an air inlet pipeline of the heat exchange device are suitable for being respectively connected with an air outlet of the adsorption device and an air inlet of the oven, and two ends of an exhaust pipeline of the heat exchange device are suitable for being respectively connected with an exhaust outlet of the oven and an exhaust inlet of the cooling spraying device.

Further, the bottom in the casing is equipped with NMP liquid concentration detection structure and is suitable for detecting NMP concentration in the solvent in the casing, certainly cooling spray set's gas outlet extremely connect gradually the one end and the first NMP gas concentration detection structure of first return air pump on the pipeline of adsorption equipment's the air inlet, certainly adsorption equipment's gas outlet extremely connect gradually the one end and the second NMP gas concentration detection structure of second return air pump on heat transfer device's the pipeline, the other end of first return air pump with the other end of second return air pump is respectively through the pipe connection exhaust gas inlet.

Further, the bottoms of the heat exchange device and the adsorption device are provided with a liquid level detection structure and a discharge port of NMP collecting liquid.

The technical scheme of the utility model has the following advantages:

1. according to the NMP circulating recovery system provided by the utility model, the first filtering structure and the second filtering structure which are higher than the waste gas inlet are sequentially arranged in the closed shell of the cooling spraying device from bottom to top, the spraying structure is arranged above the second filtering structure, the first air flow guide plate which is vertically extended and is positioned between the first filtering structure and the second filtering structure, and the second air flow guide plate which is vertically extended and is positioned above the second filtering structure are arranged in the shell, so that waste gas flows upwards through the first filtering structure after entering the cooling spraying device from the waste gas inlet, then flows under the guidance of the first air flow guide plate and the second air flow guide plate in the process of upwards floating after entering the second filtering structure, and part of waste gas entering the second filtering structure is also folded back to the lower part of the second filtering structure, and then the flow path of the waste gas is prolonged, so that the contact dissolving time of the NMP in the waste gas and the atomized solvent sprayed out of a spray nozzle is prolonged, and the NMP absorption effect is further enhanced.

2. According to the NMP circulating recovery system provided by the utility model, the first space between the first filtering structure and the second filtering structure is divided into the corresponding number of first subspaces by the first air flow guide plate, the width of the first subspaces gradually increases in the transverse direction far away from the waste gas inlet, one end of the first air flow guide plate extends upwards to the bottom of the second filtering structure, the other end of the first air flow guide plate extends downwards and is suitable for being immersed in the solvent in the shell, and thus, the vaporific solvent sprayed by each spray nozzle absorbs NMP in the waste gas more uniformly.

3. According to the NMP circulating recovery system provided by the utility model, the circulating pump is arranged on the main pipeline of the spraying structure, so that the solvent can be recycled, and in addition, the cooling structure is also arranged on the main pipeline of the spraying structure, so that the solvent extracted from the cooling spraying device can be cooled, the temperature of the vaporific solvent sprayed by the spray head is further reduced, and the condensation and precipitation effects of NMP in waste gas are further improved.

4. According to the NMP circulating recovery system provided by the utility model, the adsorption device is also connected with the cold air stripping structure arranged towards the adsorption layer of the adsorption device, and the cold air stripping structure is suitable for blowing cold air downwards towards the adsorption layer, so that the cold air can blow away the saturated adsorption liquid in the gap of the adsorption layer from the adsorption layer, and the service life of the adsorption layer is prolonged.

5. According to the NMP recycling system provided by the utility model, the NMP liquid concentration detection structure is arranged at the bottom in the shell and is suitable for detecting the NMP concentration in the solvent in the shell, so that the solvent can be replaced in time when the concentration in the solvent reaches a preset value, and the dissolution and absorption effects of NMP in the solvent are ensured; in addition, connect gradually the one end and the first NMP gas concentration detection structure of first return air pump on cooling spray set's the pipeline of gas outlet to adsorption equipment's the air inlet, connect gradually the one end and the second NMP gas concentration detection structure of second return air pump on adsorption equipment's the pipeline of gas outlet to heat transfer device, the other end of first return air pump and the other end of second return air pump are respectively through the exhaust gas entry of pipe connection, so, with the help of the detection of first NMP gas concentration detection structure and/or second NMP gas concentration detection structure, can return the gaseous cooling spray set that does not accord with NMP content requirement through first return air pump and/or second return air pump and carry out reprocessing, guarantee the removal effect of NMP, make from adsorption equipment exhaust gas can get into the oven and be recycled.

Drawings

In order to more clearly illustrate the embodiments of the present utility model or the technical solutions in the prior art, the drawings that are needed in the description of the embodiments or the prior art will be briefly described, and it is obvious that the drawings in the description below are some embodiments of the present utility model, and other drawings can be obtained according to the drawings without inventive effort for a person skilled in the art.

FIG. 1 is a schematic diagram of the structure of the NMP recycling system of the present utility model.

Reference numerals illustrate:

1. a heat exchange device; 2. cooling spraying device; 20. a circulation pump; 21. a first filtering structure; 22. a second filter structure; 23. a spray structure; 231. a main pipe; 24. a first return air pump; 25. a first NMP gas concentration detection structure; 26. a fluid supplementing port; 27. a liquid outlet; 29. NMP liquid concentration detection structure; 3. an adsorption device; 31. a second return air pump; 32. a second NMP gas concentration detection structure; a. a discharge port; b. a first airflow deflector; c. and a second air flow guide plate.

Detailed Description

The following description of the embodiments of the present utility model will be made apparent and fully in view of the accompanying drawings, in which some, but not all embodiments of the utility model are shown. All other embodiments, which can be made by those skilled in the art based on the embodiments of the utility model without making any inventive effort, are intended to be within the scope of the utility model.

In the description of the present utility model, it should be noted that the directions or positional relationships indicated by the terms "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer", etc. are based on the directions or positional relationships shown in the drawings, are merely for convenience of describing the present utility model and simplifying the description, and do not indicate or imply that the devices or elements referred to must have a specific orientation, be configured and operated in a specific orientation, and thus should not be construed as limiting the present utility model. Furthermore, the terms "first," "second," and "third" are used for descriptive purposes only and are not to be construed as indicating or implying relative importance.

In the description of the present utility model, it should be noted that, unless explicitly specified and limited otherwise, the terms "mounted," "connected," and "connected" are to be construed broadly, and may be either fixedly connected, detachably connected, or integrally connected, for example; can be mechanically or electrically connected; can be directly connected or indirectly connected through an intermediate medium, and can be communication between two elements. The specific meaning of the above terms in the present utility model will be understood in specific cases by those of ordinary skill in the art.

In addition, the technical features of the different embodiments of the present utility model described below may be combined with each other as long as they do not collide with each other.

Examples

As shown in fig. 1, the embodiment provides an NMP recycling system, which comprises a heat exchange device 1, a cooling spraying device 2 and an adsorption device 3. N-methyl pyrrolidone, chinese alias NMP.

The heat exchange device 1 comprises an air inlet pipeline and an exhaust pipeline, wherein the two ends of the air inlet pipeline are respectively connected with an air outlet of the adsorption device 3 and an air inlet of the oven, the two ends of the exhaust pipeline are respectively connected with an exhaust outlet of the oven and an exhaust inlet of the cooling spray device 2, the exhaust and the air inlet are suitable for realizing heat exchange in the heat exchange device 1, after heat exchange, less NMP steam is condensed and separated out, the NMP is settled to the bottom of the heat exchange device 1 through gravity, the bottom of the heat exchange device 1 is provided with a liquid level detection structure of NMP collecting liquid, the liquid level reaches a preset value, and the NMP collecting liquid is discharged through a discharge port a on the heat exchange device 1.

The cooling spraying device 2 is provided with a closed shell, the lower part of one side of the shell is provided with an exhaust gas inlet which is suitable for being communicated with an exhaust gas pipeline of the heat exchange device 1 so as to be connected with exhaust gas discharged from the oven and subjected to heat exchange by the heat exchange device 1, the other side of the shell is provided with an air outlet, and the air outlet is higher than the exhaust gas inlet in the shell. The lower part of the shell is also provided with a liquid supplementing port 26, the bottom of the shell is provided with a liquid draining port 27, and the liquid draining port 27 is communicated into the recovery tank through a pipeline. The bottom in the housing is also provided with an NMP liquid concentration detecting structure 29 adapted to detect the concentration of NMP in the solvent in the housing, and when the concentration reaches a preset value, the drain port 27 is opened to drain the solvent in the housing into the recovery tank for recovering NMP, and then a new solvent is injected into the housing through the liquid replenishing port 26. In this embodiment, the solvent is water, preferably water at about 15 ℃, but of course, ethanol, diethyl ether, acetone, ethyl acetate, chloroform and benzene may be used.

The housing is also provided with a first filter structure 21 and a second filter structure 22 which are higher than the exhaust gas inlet and are sequentially arranged from bottom to top. In this embodiment, the first filter structure 21 and the second filter structure 22 are both filter screens. The mesh density of the upper filter screen is preferably greater than that of the lower filter screen, the upper filter screen has two functions, liquid drops on the upper filter screen are beneficial to NMP absorption, wind resistance can be increased to enable gas to flow more uniformly, the lower filter screen can increase the resistance of the upward floating of bubbles containing NMP, the contact time of the bubbles and a solvent is increased, and the effect of dissolving and absorbing NMP by the solvent is further enhanced.

Above the second filter structure 22, a spray structure 23 is provided, the spray structure 23 being adapted to spray a solvent towards the second filter structure 22 to dissolve and absorb NMP in the exhaust gases. The spray structure 23 comprises a main pipe 231 and a circulating pump 20 arranged on the main pipe 231, one end of the main pipe 231 is communicated with the bottom of the shell, the other end of the main pipe 231 is connected with a branch pipe, one, two or more spray heads are connected to the branch pipe, the circulating pump 20 is suitable for pumping water in the shell and flowing into the spray heads through the main pipe 231 and the branch pipe, the main pipe 231 is also connected with a cooling structure, and the cooling structure is used for cooling the solvent pumped by the cooling spray device 2.

In addition, a first air flow guide plate b extending vertically and positioned between the first filtering structure 21 and the second filtering structure 22, and a second air flow guide plate c extending vertically and positioned above the second filtering structure 22 are also arranged in the shell, and the first air flow guide plate b and the second air flow guide plate c are arranged in a staggered manner in the transverse direction. In this embodiment, the number of the first airflow guiding plates b and the second airflow guiding plates c is two, and the first airflow guiding plates b and the second airflow guiding plates c are alternately arranged in the lateral direction, however, the number of the first airflow guiding plates b and the second airflow guiding plates may be greater, and may be even one. In addition, one end of the first air flow guiding plate b extends upwards to the bottom of the second filtering structure 22, the other end extends downwards to be suitable for being immersed in the solvent in the shell, one end of the second air flow guiding plate c extends downwards to the top of the second filtering structure 22, the other end extends upwards to the top of the shell, the length of the first air flow guiding plate b extending upwards out of the second filtering structure 22 is smaller than the length of the second air flow guiding plate c extending upwards from the second filtering structure 22, and the length of the second air flow guiding plate c extending downwards out of the second filtering structure 22 is smaller than the length of the first air flow guiding plate b extending downwards from the second filtering structure 22. In this way, in the process that the exhaust gas floats up through the first filtering structure 21 and then continues to float up through the second filtering structure 22, after being guided by the first airflow guiding plate b and the second airflow guiding plate c to flow, the exhaust gas entering the upper part of the second filtering structure 22 is folded back to enter the lower part of the second filtering structure 22, and part of the exhaust gas also enters the upper part of the second filtering structure 22 again, so that the flow path of the exhaust gas is prolonged, the time for contacting and dissolving NMP in the exhaust gas with the mist solvent sprayed by the spraying structure 23 is prolonged, and the NMP absorption effect is further enhanced.

The first air flow guiding plate b divides the first space between the first filtering structure 21 and the second filtering structure 22 into a corresponding number of first subspaces, wherein the term "corresponding number" refers to that when the number of the first air flow guiding plates b is two, the number of the first subspaces is three, when the number of the first air flow guiding plates b is three, the number of the first subspaces is four, and so on. The second air flow guide plate c divides the second space above the second filter structure 22 into a corresponding number of second subspaces. In the view of fig. 1, the first air flow guide b divides the first space into three first subspaces having gradually increasing widths from left to right. Because the waste gas inlet is formed on the left side wall of the shell, the waste gas content of the left side in the solvent is higher, the waste gas overflowed from the solvent is more, the transverse dimension of the first subspace of the left side is smaller, and the first air flow guide plate b extends upwards to the bottom of the second filter structure 22, so that the cross section area of the second filter structure which corresponds to the first subspace of the left side and can allow the waste gas to pass through is smaller, and the waste gas with higher content in the first subspace of the left side is slowly released below the spray nozzles through the second filter structure 22 with smaller cross section area, so that the NMP absorbed by the vaporous solvent sprayed by each spray nozzle is relatively uniform.

The air inlet of the adsorption device 3 is connected with the air outlet of the cooling spray device 2 through a pipeline, the adsorption device 3 is suitable for adsorbing water in the gas discharged from the cooling spray device 2, and because NMP is dissolved in the solvent, the adsorption device 3 adsorbs and removes NMP in the solvent at the same time, so that the gas treated by the adsorption device 3 becomes dry gas without NMP. The adsorption device 3 is further connected with a cold air stripping structure arranged towards the adsorption layer of the adsorption device 3, the cold air stripping structure is suitable for downwards blowing cold air to the adsorption layer, and solvents which are saturated and adsorbed in gaps of the adsorption layer are blown out directionally by means of cold air, so that the service life of the adsorption layer is prolonged, the liquid level detection structure of NMP collecting liquid is arranged at the bottom of the adsorption device 3 for liquid level detection, and after reaching a preset liquid level, the NMP collecting liquid is discharged through a discharge port a on the adsorption device 3.

In addition, connect gradually the one end and the first NMP gas concentration detection structure 25 of first return air pump 24 on the pipeline from the gas outlet of cooling spray set 2 to the air inlet of adsorption equipment 3, connect gradually the one end and the second NMP gas concentration detection structure 32 of second return air pump 31 on the pipeline from the gas outlet of adsorption equipment 3 to heat transfer device 1, the other end of first return air pump and the other end of second return air pump pass through the exhaust gas inlet respectively through the pipeline connection, in this way, with the help of the detection of first NMP gas concentration detection structure and/or second NMP gas concentration detection structure, can return the gas that does not accord with NMP content requirement to cooling spray set through first return air pump and/or second return air pump and carry out reprocessing, guarantee NMP's removal effect, make the gas that is discharged from adsorption equipment can get into the oven and be recycled.

Taking solvent as water, the first filtering structure 21 and the second filtering structure 22 as filter screens as examples, and injecting water to a preset water level through the fluid infusion port 26 in the shell, so that the first filtering structure 21 is submerged in the water, and the working process of the NMP recycling system provided in this embodiment is introduced under the condition that the oven and the NMP recycling system are normally operated:

the waste gas containing NMP, which is discharged from a waste gas outlet of the oven and is at a high temperature of about 120 ℃, enters a waste gas pipeline of the heat exchange device 1, the waste gas can preheat the gas which is discharged from a gas outlet of the adsorption device 3 and enters a gas inlet pipeline of the heat exchange device 1, after heat exchange, the temperature of the waste gas containing NMP is reduced to about 100 ℃, due to heat exchange, less NMP steam is condensed and separated out, a liquid level detection structure of NMP collecting liquid is arranged at the bottom of the heat exchange device 1 after gravity sedimentation is carried out, and the NMP collecting liquid is discharged and recovered in time when the liquid level reaches a preset value;

the waste gas after heat exchange enters the cooling spray device 2 through the waste gas inlet of the cooling spray device 2, the waste gas is mixed with water in the shell, part of NMP in the waste gas is dissolved in the water, in the process of ascending the waste gas, the waste gas passes through the lower filter screen, the lower filter screen can increase the floating resistance of bubbles, the contact time of the bubbles and the water is increased, the dissolution efficiency of NMP in the water is further enhanced, the bubbles continue to ascend after coming out of the lower filter screen, pass through the upper filter screen and reach the lower part of the spray head, in the process of ascending the waste gas after overflowing from the water, the flowing path of the waste gas can be prolonged by virtue of the drainage effect of the first air flow guide plate b and the second air flow guide plate c, further, the time that NMP in the waste gas is dissolved and absorbed by water mist is increased, of course, in the ascending process, the spray head continuously sprays water mist cooled to 15 ℃ to the upper filter screen, so that the waste gas can be cooled, and part of NMP is condensed and separated out, so that most NMP in the waste gas is condensed and absorbed, the temperature of the waste gas is reduced to about 40 ℃ and is discharged from the air outlet of the cooling spray device 2, when the first NMP gas concentration detection structure 25 detects that the NMP content reaches a preset value, the waste gas is sent back to the cooling spray device 2 again by the first return air pump 24 for treatment until the NMP content detected by the first NMP gas concentration detection structure 25 is lower than the preset value;

the waste gas treated by the cooling spray device 2 enters the adsorption device 3 along the pipeline after coming out of the gas outlet, the adsorption device 3 carries out adsorption treatment on the residual gas with a small amount of NMP and moisture, and the treated gas is changed into dry gas without NMP. Considering the problem of adsorption saturation, the cold air blowing-off structure blows cold air to the liquid saturated and adsorbed in the gaps of the adsorption layer, blows the liquid away from the adsorption layer so as to prolong the service life of the adsorption layer, detects the liquid level through a liquid level detection structure of NMP collection liquid arranged at the bottom of the adsorption device 3, and timely discharges and recovers the NMP collection liquid when the liquid level reaches a preset value;

the temperature of the gas treated by the adsorption device 3 is reduced to about 30 ℃, the gas flows out from the gas outlet of the adsorption device 3, enters the gas inlet pipeline of the heat exchange device 1, exchanges heat with the waste gas discharged from the oven in the heat exchange device 1, and then enters the oven to realize the recycling of the gas.

By way of supplementary explanation, in order to realize recycling of gas and miniaturizing the apparatus, the conventional centralized treatment can be dispersed, and a single oven or several ovens share one NMP recycling system provided in this embodiment.

It is apparent that the above examples are given by way of illustration only and are not limiting of the embodiments. Other variations or modifications of the above teachings will be apparent to those of ordinary skill in the art. It is not necessary here nor is it exhaustive of all embodiments. While still being apparent from variations or modifications that may be made by those skilled in the art are within the scope of the utility model.

Claims

1. The utility model provides a NMP circulation recovery system, its characterized in that, including cooling spray set (2), cooling spray set (2) have confined casing, exhaust gas inlet has been seted up to one side of casing is suitable for through the pipeline with oven exhaust gas access in the casing, the opposite side of casing has been seted up and has been exceeded exhaust gas inlet's gas outlet, from down upwards having set gradually in the casing first filtration (21) and second filtration (22) that exceed exhaust gas inlet, the top of second filtration (22) is equipped with spray structure (23), spray the shower nozzle of structure (23) is arranged in the casing and is located the top of second filtration (22), be equipped with vertical extension in the casing be located first air current deflector (b) between first filtration (21) and second filtration (22) and vertical extension be located second air current deflector (c) of second filtration (22) top, first air current deflector (b) and second air current deflector (c) set up transversely.

2. The NMP recycling system according to claim 1, wherein the number of said first air flow guide plates (b) and said second air flow guide plates (c) is not less than two, and said first air flow guide plates (b) and said second air flow guide plates (c) are alternately arranged in a lateral direction.

3. NMP recycling system according to claim 1, characterized in that the first gas flow guiding plate (b) divides the first space between the first filter structure (21) and the second filter structure (22) into a corresponding number of first subspaces, the width of which gradually increases in the lateral direction away from the off-gas inlet, and that one end of the first gas flow guiding plate extends up to the bottom of the second filter structure (22) and the other end extends down to be adapted to be immersed in the solvent in the housing.

4. The NMP recycling system according to claim 1, characterized in that said spray structure (23) comprises a main pipe (231) and a circulation pump (20) provided on said main pipe (231), one end of said main pipe (231) being connected to the bottom of said housing, the other end being connected to a branch pipe, said branch pipe being connected to a spray head, said circulation pump (20) being adapted to pump out solvent in said housing and to enter said spray head via said main pipe (231) and said branch pipe.

5. The NMP recycling system according to claim 4, characterized in that a cooling structure is also connected to said main pipe (231), said cooling structure being adapted to cool the solvent extracted from said cooling spray device (2).

6. The NMP recycling system according to claim 1, characterized in that the lower part of the housing is provided with a liquid replenishment port (26) adapted to replenish new solvent into the housing via the liquid replenishment port (26), the bottom of the housing is provided with a liquid drain port (27), the liquid drain port (27) being connected to the recycling tank by a pipe.

7. The NMP recycling system according to claim 1, further comprising an adsorption device (3), wherein an air inlet of the adsorption device (3) is connected with an air outlet of the cooling spray device (2) through a pipeline, the adsorption device (3) is suitable for adsorbing moisture in the air flowing out from the cooling spray device (2), and a cool air blowing-off structure arranged towards an adsorption layer of the adsorption device (3) is further connected to the adsorption device (3), and the cool air blowing-off structure is suitable for blowing cool air downwards towards the adsorption layer.

8. The NMP recycling system according to claim 7, characterized by further comprising a heat exchanging device (1), wherein both ends of an air inlet pipe of said heat exchanging device (1) are adapted to be connected to an air outlet of said adsorption device (3) and an air inlet of an oven, respectively, and both ends of an exhaust pipe of said heat exchanging device (1) are adapted to be connected to an exhaust outlet of said oven and an exhaust inlet of said cooling shower device (2), respectively.

9. The NMP recycling system according to claim 8, characterized in that an NMP liquid concentration detection structure (29) is arranged at the bottom in the shell and is suitable for detecting the concentration of NMP in the solvent in the shell, one end of a first return air pump (24) and a first NMP gas concentration detection structure (25) are sequentially connected to a pipeline from the air outlet of the cooling spray device (2) to the air inlet of the adsorption device (3), one end of a second return air pump (31) and a second NMP gas concentration detection structure (32) are sequentially connected to a pipeline from the air outlet of the adsorption device (3) to the heat exchange device (1), and the other end of the first return air pump (24) and the other end of the second return air pump (31) are respectively connected to the exhaust gas inlet through pipelines.

10. The NMP recycling system according to claim 8, characterized in that the bottoms of the heat exchanging device (1) and the adsorption device (3) are provided with a liquid level detection structure and a discharge port (a) of the NMP collecting liquid.