Intelligent wastewater treatment equipment for extracting N-methylpyrrolidone and treatment method thereof

Abstract

The application provides an intelligent wastewater treatment equipment for extracting N-methylpyrrolidone, which comprises a crystallizer box body, a crystallization plate assembly is arranged in the crystallizer box body, the crystallization plate assembly comprises a plurality of crystallization plates arranged in sequence and baffles arranged between adjacent two crystallization plates, and a medium channel is arranged in each crystallization plate; a plurality of groups of flow-through openings for wastewater extract liquid flow are horizontally arranged on the crystallization plate; the baffle is continuously bent in an S shape, a plurality of protruding parts are horizontally arranged on the two sides of the baffle, the protruding parts are longitudinally arranged, the protruding parts are respectively arranged in close contact with the surfaces of the two crystallization plates and block and close the gaps between the two crystallization plates, and the positions of each protruding part are respectively located on the two sides of the adjacent two groups of flow-through openings on the crystallization plate, so that the wastewater extract liquid sequentially passes through each group of flow-through openings and reciprocally flows on the two sides of the crystallization plate under the guidance of the baffles on the two sides of the crystallization plate, so that the solution can fully contact with the crystallization plate, and the solution flow driven by the circulating flow guide device realizes circulation, and the cooling crystallization efficiency is greatly improved.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of wastewater treatment, and particularly relates to an intelligent wastewater treatment equipment for extracting N-methyl pyrrolidone and a treatment method thereof. BACKGROUND

[0002] Methyl pyrrolidone (NMP) is a polar solvent with strong selectivity and good stability and an important chemical raw material, is a polar aprotic solvent, has low viscosity, good stability, high boiling point, strong solubility, recycling, safe use and suitable for various formula uses, and is widely used in lithium ion battery production and used as a solvent of PVDF binder. At present, the separation and purification of NMP from wastewater and the recycling of NMP are difficult problems frequently encountered in the use and refining process of NMP. In the prior art, the NMP wastewater recovery process first separates the NMP wastewater by a pretreatment process, carries out sand filtration and carbon filtration, and carries out reverse osmosis treatment and other processes to separate and treat impurities, then uses a solvent to extract the waste liquid to obtain an extraction liquid, and finally the extraction liquid is sequentially subjected to freezing crystallization separation in a primary and secondary step crystallizer, so that the NMP solvent is condensed and separated in the crystallizer, so as to realize the recovery and extraction of NMP.

[0003] Chinese patent document CN202410261288.1 discloses a solvent recovery system and recovery method for para-aramid production, which discloses a recovery process for NMP by using an extraction tower combined with a primary and secondary step crystallizer. The crystallizer in the application adopts a column tube structure. Due to the limited space for crystal growth in the column tube crystallizer, small crystals are easily produced, which affects the overall crystallization efficiency and leads to low NMP recovery efficiency. In addition, more energy is consumed in the crystal growth process in the column tube crystallizer, thereby increasing the wastewater treatment cost. SUMMARY

[0004] The present application discloses an intelligent wastewater treatment equipment for extracting N-methyl pyrrolidone and a treatment method thereof, which solves the problems of low recovery efficiency and high recovery cost of the NMP wastewater treatment equipment in the prior art.

[0005] The specific technical solutions are as follows:

[0006] The utility model provides an intelligent wastewater treatment equipment of extracting N-methyl pyrrolidone, including crystallizer box body, the front end of the crystallizer box body is contracted and is provided with the liquid inlet pipe and the liquid outlet pipe respectively in the front and rear ends of crystallizer box body, three way electromagnetic valve is equipped on the liquid inlet pipe and the liquid outlet pipe respectively, two three way electromagnetic valves are connected through circulation pipeline, and the circulation pipeline is equipped with the circulation pump for driving wastewater extractant to form the circulation flow in the crystallizer box body, the crystallizer box body is equipped with crystallization plate assembly, and the crystallization plate assembly includes a plurality of crystallization plates arranged in sequence and baffles arranged between the adjacent two crystallization plates, the medium channel in S shape is arranged in each crystallization plate, the top of both ends of medium channel is connected with the collecting pipe arranged outside the crystallizer box body through the connecting pipe, and the medium inlet pipe and the medium outlet pipe for connecting with the external heat exchange system are arranged on the collecting pipe, a plurality of groups of flow-through ports for wastewater extractant flow are arranged on each crystallization plate, and the number of each group of flow-through ports is a plurality of and is arranged in longitudinal direction, the baffle is arranged in S shape continuously, a plurality of convex parts are arranged on the both sides of baffle in horizontal direction, the convex part is arranged in longitudinal direction, the both sides of baffle are arranged with the surface of two sides of crystallization plate respectively in the form of sticking and blocking the gap between the crystallization plate, and the position of each convex part is located on the both sides of adjacent two groups of flow-through ports on the crystallization plate, so that wastewater extractant passes through each group of flow-through ports under the guidance of baffle on the both sides of crystallization plate and reciprocally flows on the both sides of crystallization plate.

[0007] Further, the crystallizer box body is provided with a steam discharge pipe at the top and a liquid discharge pipe at the bottom, and a guide plate is obliquely arranged at the middle of the lower end in the crystallizer box body, which guides the crystallized melt flowing down the crystallization plate to the liquid discharge pipe and supports the bottom of the crystallization plate through a support.

[0008] Further, the convex parts on the both sides of the baffle are in plane structure, and the convex part is in contact with the position of the medium channel on the crystallization plate, and the both sides of the convex part are inclined surfaces, and the maximum distance between the two inclined surfaces is greater than the distance between the adjacent two groups of flow-through ports, so that the wastewater extractant reciprocally flows on the both sides of the crystallization plate under the guidance of the baffle.

[0009] Further, the surface of the crystallization plate is also provided with a cleaning assembly for cleaning the flow-through port, the cleaning assembly comprising a plurality of grooves arranged on the outer side of each group of flow-through ports and a movable plate hingedly arranged on one side of each groove, the grooves being arranged in a longitudinal strip structure, and each groove being hingedly arranged with a movable plate on one side of the baffle protrusion, the movable plate being movable outwardly under the support of an elastic member and being pressed against one side of the baffle protrusion, the inner surface of the movable plate being longitudinally arranged with a plurality of protrusions, each protrusion corresponding to the position of one flow-through port, and the baffles being driven to move horizontally by a displacement driving device arranged in the crystallizer tank, so that the baffles push the movable plates to flip into the grooves when moving horizontally and the protrusions are embedded into the flow-through ports, thereby cleaning the blocked crystallization blocks in the flow-through ports by the protrusions.

[0010] Further, the displacement driving device comprises a positioning frame, a lead screw, a driving motor and a guide rail, the positioning frame being arranged longitudinally on the front and rear ends of the crystallization plate assembly, and each baffle being provided with a flat plate on the front and rear ends, the two flat plates extending towards the two positioning frames and being fixedly connected with the surfaces of the positioning frames, the two sides of the positioning frame being horizontally slidably connected with the inner walls of the crystallizer tank through the guide rails, and the left and right sides of the crystallizer tank being outwardly protruding to form accommodating cavities in the form of a "one" character, each positioning frame being provided with a fixed plate extending into the accommodating cavities on the left and right sides, and the fixed plates being threadedly connected with the lead screws horizontally arranged in the accommodating cavities, one end of the lead screw penetrating through one end of the accommodating cavity and being driven to rotate by the driving motor arranged on the outer wall of the crystallizer tank, so that the two positioning frames drive the plurality of baffles to move synchronously forward and backward under the thread action of the lead screw, thereby driving the movable plates to flip and realizing the dredging and cleaning of the flow-through ports by the protrusions.

[0011] Further, the positioning frame is in the form of a square box, and a plurality of insertion seats for inserting and fixing one end of the baffle are arranged transversely on the upper and lower ends of the positioning frame, and the insertion seats are fixed by penetrating the one end of the baffle through fasteners horizontally.

[0012] Further, a control system is also included, which comprises a PLC controller and a flow meter arranged on the circulating pipeline, and the PLC controller is connected with the flow meter, the driving motor, the circulating pump and two three-way electromagnetic valves.

[0013] A processing method of an intelligent wastewater treatment equipment for extracting N-methyl pyrrolidone, specifically comprising the following steps:

[0014] Step one, inject the wastewater extract into the crystallizer tank, and circulate in the crystallizer tank under the driving of the circulating pump;

[0015] Step two, through the heat exchange system control circulating medium in the crystallization plate flowing heating temperature is maintained at 100-120 DEG C, to evaporate the wastewater extract containing moisture;

[0016] Step three, through the heat exchange system control circulating medium in the crystallization plate flowing cooling temperature is maintained at -10 to -5 DEG C, to make the wastewater extract containing NMP solvent crystallization, and the remaining non-crystallized wastewater extract from the outlet pipe discharge;

[0017] Step four, finally through the heat exchange system control circulating medium in the crystallization plate flowing heating temperature is maintained at 5-15 DEG C, to make the crystallization of NMP solvent on the crystallization plate, and the NMP solvent is discharged through the liquid discharge pipe.

[0018] The beneficial effects of the present application are embodied in:

[0019] In the present application, the crystallization plate assembly in the crystallizer is provided with a plurality of groups of flow-through openings on the crystallization plate and is blocked and guided by the baffle, so that the solution flows through each group of flow-through openings in turn under the guidance of the baffle and reciprocally flows on both sides of the crystallization plate, thereby enabling the solution to fully contact the crystallization plate and the solution to flow under the driving of the circulating flow guide device to realize circulation, thereby greatly improving the cooling crystallization efficiency.

[0020] In the present application, a cleaning assembly is provided at each group of flow-through openings on the crystallization plate, which synchronously displaces the baffle to make the baffle press against the movable plate and clear the crystalline block in the flow-through opening through the protrusion, thereby avoiding the flow-through opening from being blocked and enabling the solution to smoothly flow in the flow-through opening, thereby ensuring the stable operation of the crystallizer. BRIEF DESCRIPTION OF DRAWINGS

[0021] Fig. 1 The figure is a structural schematic diagram of the present application.

[0022] Fig. 2 The figure is a structural schematic diagram of the present application.

[0023] Fig. 3 The figure is a structural schematic diagram of the present application.

[0024] Fig. 4 The figure is a structural schematic diagram of the present application.

[0025] Fig. 5 The figure is a structural schematic diagram of the present application.

[0026] Fig. 6 The figure is a structural schematic diagram of the present application.

[0027] Explanation of reference signs: crystallizer box 1, liquid inlet pipe 101, liquid outlet pipe 102, three-way electromagnetic valve 103, collecting pipe 11, medium inlet pipe 11-1, medium outlet pipe 11-2, steam discharge pipe 12, liquid discharge pipe 13, accommodating cavity 14, crystallization plate 2, medium channel 2-1, flow-through opening 2-2, groove 2-3, movable plate 2-4, protrusion 2-4-1, elastic member 2-5, baffle plate 3, protruding portion 3-1, flat plate portion 3-2, flow guide plate 4, displacement driving device 5, positioning frame 51, plug-in seat 51-1, fixed plate 51-2, lead screw 52, driving motor 53, guide rail 54, circulation pipe 6, flow meter 61, circulation pump 7. DETAILED DESCRIPTION

[0028] In order to make the technical scheme of the present application clearer and more explicit, the present application will be further described below in conjunction with the drawings. Any equivalent replacement and conventional inference of the technical features of the technical scheme of the present application all fall within the protection scope of the present application. The fixed connection and fixed arrangement mentioned in the present application are all general connection modes in the mechanical field, and can be welding, bolt and nut connection, and screw connection.

[0029] In the description of the present application, it should be understood that the terms "upper", "lower", "front", "back", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like indicate the orientation or positional relationship based on the orientation or positional relationship shown in the drawings, and are only for the convenience of describing the present application and simplifying the description, and do not indicate or imply that the device or element referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the present application.

[0030] Example 1

[0031] As Figs. 1-3As shown, the embodiment provides an intelligent wastewater treatment equipment for extracting N-methyl pyrrolidone, which comprises a crystallizer box body 1. The crystallizer box body is in a rectangular structure. The front end of the crystallizer box body 1 is arranged in a tapered manner. The rear end of the crystallizer box body 1 is arranged in a tapered manner on both sides. The front and rear ends of the crystallizer box body 1 are respectively provided with a liquid inlet pipe 101 and a liquid outlet pipe 102. The liquid inlet pipe 101 and the liquid outlet pipe 102 are respectively provided with a three-way electromagnetic valve. The two three-way electromagnetic valves 103 are connected through a circulating pipe 6. The circulating pipe 6 is provided with a circulating pump 7 for driving the wastewater extractant to form a circulating flow in the crystallizer box body 1. The crystallizer box body 1 is provided with a crystallization plate assembly. The crystallization plate assembly comprises a plurality of crystallization plates 2 arranged in sequence and baffles 3 arranged between adjacent two crystallization plates 2. Each crystallization plate 2 is internally provided with a medium channel 2-1 arranged in an S shape. The two ends of the medium channel 2-1 are respectively connected to a collecting pipe 11 arranged outside the crystallizer box body 1 through connecting pipes. The collecting pipe 11 is respectively provided with a medium inlet pipe 11-1 and a medium outlet pipe 11-2 for connecting with an external heat exchange system, so that the circulating medium forms a circulation in the crystallizer box body 1, and the heating and cooling of the crystallization plate 2 are realized. In the embodiment, the circulating medium is heat conducting oil. A plurality of groups of flow-through openings 2-2 for wastewater extractant flow are arranged on each crystallization plate 2 in a transverse manner. Each group of flow-through openings 2-2 is arranged in a longitudinal manner and has a plurality of flow-through openings.

[0032] In the embodiment, the crystallizer box body 1 is provided with a steam discharge pipe 12 at the top. The crystallizer box body 1 is provided with a liquid discharge pipe 13 at the bottom for discharging NMP crystallization melt. A guide plate 4 is arranged at the lower middle part of the crystallizer box body 1 in a slanting manner. The guide plate 4 is used for guiding the crystallization melt flowing down from the crystallization plate 2 to the liquid discharge pipe 13. A plurality of supports are arranged on the guide plate 4 in a transverse manner. Each support supports the bottom of each crystallization plate 2.

[0033] In the embodiment, the protruding parts 3-1 on both sides of the baffle plate 3 are in planar structure, and the protruding parts 3-1 are in line with the positions of the medium passage 2-1 on the crystallization plate 2, so as to improve the heat conduction efficiency, so that the baffle plate 3 can play a certain heat exchange role, thereby increasing the heat exchange area. The two sides of the protruding part 3-1 are provided with inclined surfaces, and the maximum distance between the two inclined surfaces is greater than the distance between the adjacent two groups of flow-through openings 2-2, so that the solution flows back and forth on both sides of the crystallization plate 2 under the guidance of the baffle plate 3.

[0034] The embodiment also provides a treatment method of the intelligent wastewater treatment equipment for extracting N-methyl pyrrolidone.

[0035] Step one, inject the wastewater extract into the crystallizer box 1, and circulate in the crystallizer box 1 under the driving of the circulating pump 7;

[0036] Step two, control the heating temperature of the circulating medium flowing in the crystallization plate 2 to be kept at 100-120℃ through the heat exchange system, so as to evaporate the water contained in the wastewater extract;

[0037] Step three, control the cooling temperature of the circulating medium flowing in the crystallization plate 2 to be kept at -10-5℃ through the heat exchange system, so as to crystallize and precipitate the NMP solvent contained in the wastewater extract, and discharge the remaining wastewater extract which has not been crystallized from the liquid outlet pipe 102;

[0038] Step four, finally control the heating temperature of the circulating medium flowing in the crystallization plate 2 to be kept at 5-15℃ through the heat exchange system, so as to melt the NMP solvent crystallized on the crystallization plate 2, and discharge the NMP solvent through the liquid discharge pipe 13, and finally complete the extraction of the NMP solvent from the NMP wastewater.

[0039] Embodiment two

[0040] As Figs. 4-6As shown, in order to avoid the crystallizer in the process of cooling crystallization, the solution at the flow port 2-2 forms a crystalline block, the crystalline block is bonded in the flow port 2-2, thereby causing the flow port 2-2 to be blocked, the embodiment is different from the embodiment 1, the surface of the crystallization plate 2 is further provided with a cleaning assembly for cleaning the flow port 2-2, the cleaning assembly comprises a plurality of grooves 2-3 arranged outside each group of flow ports and a movable plate 2-4 hingedly arranged on one side of each groove 2-3, the groove 2-3 is arranged in a longitudinal strip structure, the movable plate 2-4 is hingedly arranged on one side of each groove 2-3 close to the protruding part 3-1 of the baffle 3, the inner side of the movable plate 2-4 is provided with an elastic element 2-5, the elastic element 2-5 is a V-shaped elastic sheet, the movable plate 2-4 is outwardly movable under the support of the elastic element 2-5 and is pressed against one side of the protruding part 3-1 of the baffle 3, a plurality of protrusions 2-4-1 are longitudinally arranged on the inner side surface of the movable plate 2-4, the position of each protrusion 2-4-1 corresponds to the position of one flow port 2-2 respectively, the baffle 3 is driven to move horizontally by the displacement driving device 5 arranged in the crystallizer tank 1, so that the baffle 3 pushes the movable plate 2-4 to flip into the groove 2-3 when moving horizontally and makes the protrusion 2-4-1 embedded into the flow port 2-2, the protrusion 2-4-1 is embedded into the flow port 2-2, so that the crystalline block is separated from the inner wall of the flow port 2-2, to realize cleaning of the blocked crystalline block.

[0041] In the embodiment, the displacement driving device 5 comprises a positioning frame 51, a lead screw 52, a driving motor 53 and a guide rail 54, the positioning frame 51 is two in number and is longitudinally arranged at the front and rear ends of the crystallization plate assembly respectively, and the front and rear ends of each baffle 3 are respectively provided with a flat plate part 3-2, the two flat plate parts 3-2 extend towards the two positioning frames 51 respectively and are fixedly connected with the surface of the positioning frame 51, the two sides of the positioning frame 51 are horizontally slidably connected with the two sides of the inner wall of the crystallizer tank 1 through the guide rail 54, and the left and right sides of the crystallizer tank 1 are outwardly protrudingly provided with accommodating cavities 14, the accommodating cavities 14 are in a "one" shape structure, the two sides of each positioning frame 51 are provided with fixed plates 51-2 and extend into the two accommodating cavities 14 respectively, and the fixed plates 51-2 are respectively threadedly connected with the lead screws 52 which are horizontally rotatably arranged in the accommodating cavities 14, one end of the lead screw 52 penetrates one end of the accommodating cavity 14 and is driven to rotate by the driving motor 53 arranged on the outer wall of the crystallizer tank 1, so that the two positioning frames 51 drive the plurality of baffles 3 to move forward and backward synchronously under the thread action of the lead screw 52, thereby making the baffle 3 and the movable plate 2-4 abutting and driving the movable plate 2-4 to flip and realizing the dredging and cleaning of the flow port 2-2 through the protrusion 2-4-1.

[0042] In the embodiment, the positioning frame 51 is in a square box structure and the inside of the positioning frame 51 is used for wastewater extractant flow passage, a plurality of plug-in seats 51-1 for plug-in fixing with the upper and lower ends of one end of the baffle plate 3 are arranged on the upper and lower ends of the positioning frame 51 in transverse direction, the plug-in seat 51-1 is fixed by plug-in of the upper end of the baffle plate 3 through a fastener horizontally penetrating the baffle plate 3.

[0043] In the embodiment, the control system is further included, the control system includes a PLC controller and a flow meter 61 arranged on the circulation pipe 6, the PLC controller is connected with the flow meter 61, the driving motor 53, the circulation pump 7 and two three-way electromagnetic valves 103 respectively, the flow meter 61 is used for monitoring the flow of the solution in the circulation pipe 6, when the flow is reduced, it indicates that the flow passage 2-2 of the crystallization plate 2 is blocked, then the PLC controller controls the driving motor 53 to start, and the baffle plate 3 is driven by the displacement driving device 5 to move forward and backward in sequence, so that the movable plate 2-4 is turned over and the flow passage 2-2 is cleaned by the protruding block 2-4-1.

[0044] The above is only the preferred specific embodiment of the present application, but the protection scope of the present application is not limited to this, any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered in the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.

Claims

1. An intelligent wastewater treatment device for extracting N-methylpyrrolidone, characterized in that, The crystallizer includes a crystallizer housing (1), which is tapered at the front end and narrowed at both ends at the rear end. The crystallizer housing (1) has an inlet pipe (101) and an outlet pipe (102) at its front and rear ends, respectively. A three-way solenoid valve is installed on each of the inlet pipe (101) and outlet pipe (102). The two three-way solenoid valves (103) are connected by a circulation pipe (6), and a circulation pump (7) is installed on the circulation pipe (6) to drive the wastewater extract to circulate within the crystallizer housing (1). The crystallizer housing (1) contains a crystallization plate assembly, which includes several sequentially arranged crystallization plates (2) and baffles (3) positioned between adjacent crystallization plates (2). Each crystallization plate (2) has an S-shaped media channel (2-1) inside. The top ends of the media channel (2-1) are connected to a collecting pipe (11) located outside the crystallizer housing (1) via connecting pipes. The collecting pipe (11) is divided into... The system is equipped with a medium inlet pipe (11-1) and a medium outlet pipe (11-2) for connection to an external heat exchange system; each crystallizing plate (2) is provided with several sets of flow ports (2-2) arranged laterally for the flow of wastewater extract, and each set of flow ports (2-2) has several ports arranged longitudinally; the baffle plate (3) is continuously bent in an S-shape, and several protrusions (3-1) are arranged laterally on both sides of the baffle plate (3), and each protrusion (3-1) is... The longitudinal arrangement allows the protrusions (3-1) on both sides of the baffle (3) to fit against the surfaces of the crystallizing plates (2) on both sides and block and seal the gap between the crystallizing plates (2). Each protrusion (3-1) is located on both sides of two adjacent sets of flow ports (2-2) on the crystallizing plate (2), so that the wastewater extract passes through each set of flow ports (2-2) in sequence under the guidance of the baffles (3) on both sides of the crystallizing plate (2) and flows back and forth on both sides of the crystallizing plate (2).

2. The intelligent wastewater treatment equipment for extracting N-methylpyrrolidone as described in claim 1, characterized in that, The top of the crystallizer box (1) is provided with a steam exhaust pipe (12), the bottom of the crystallizer box (1) is provided with a liquid drain pipe (13), and the middle of the lower end of the crystallizer box (1) is provided with a guide plate (4). The guide plate (4) is used to guide the crystallized melt flowing down the crystallization plate (2) to the liquid drain pipe (13). The bottom of the crystallization plate (2) is supported by a support on the guide plate (4).

3. The intelligent wastewater treatment equipment for extracting N-methylpyrrolidone as described in claim 1, characterized in that, The protrusions (3-1) on both sides of the baffle (3) are planar structures, and the protrusions (3-1) are in contact with the position on the crystallizing plate (2) located in the medium channel (2-1); both sides of the protrusions (3-1) are inclined surfaces, and the maximum distance between the two inclined surfaces is greater than the distance between the two adjacent sets of flow ports (2-2), so that the wastewater extract flows back and forth on both sides of the crystallizing plate (2) under the guidance of the baffle (3).

4. The intelligent wastewater treatment equipment for extracting N-methylpyrrolidone as described in claim 3, characterized in that, The surface of the crystallizing plate (2) is also provided with a cleaning assembly for cleaning the flow port (2-2). The cleaning assembly includes several grooves (2-3) disposed on the outside of each group of flow ports and a movable plate (2-4) hinged to one side of each groove (2-3). The grooves (2-3) are longitudinally arranged elongated structures. A movable plate (2-4) is hinged to one side of each groove (2-3) near the protrusion (3-1) of the baffle plate (3). The movable plate (2-4) moves outward under the support of the elastic element (2-5) and presses against one side of the protrusion (3-1) of the baffle plate (3). On the side, a number of protrusions (2-4-1) are arranged longitudinally on the inner surface of the movable plate (2-4). The position of each protrusion (2-4-1) corresponds to the position of a flow port (2-2). The baffles (3) are all driven to move laterally by the displacement driving device (5) set in the crystallizer box (1). When the baffles (3) move laterally, they push the movable plate (2-4) to flip into the groove (2-3) and make the protrusions (2-4-1) embedded into the flow port (2-2). Thus, the protrusions (2-4-1) clean the crystal blocks blocking the flow port (2-2).

5. The intelligent wastewater treatment equipment for extracting N-methylpyrrolidone as described in claim 4, characterized in that, The displacement driving device (5) includes a positioning frame (51), a lead screw (52), a drive motor (53), and a guide rail (54). There are two positioning frames (51) arranged longitudinally at the front and rear ends of the crystallizing plate assembly. Each baffle plate (3) has a flat plate portion (3-2) at both its front and rear ends. The two flat plate portions (3-2) extend towards the two positioning frames (51) and are connected and fixed to the surface of the positioning frames (51). Both sides of the positioning frames (51) are horizontally slidably connected to the inner walls of the crystallizer box (1) via the guide rail (54). The left and right sides of the crystallizer box (1) have outwardly protruding cavities (14), which are in the shape of an "I". Each positioning frame... The frame (51) has fixed plates (51-2) on both sides and extends into the accommodating cavities (14) on both sides respectively. The fixed plates (51-2) are threadedly connected to the screws (52) that are horizontally rotated in the accommodating cavities (14). One end of the screws (52) passes through one end of the accommodating cavity (14) and is driven to rotate by the drive motors (53) set on the outer wall of the crystallizer box (1). This causes the two positioning frames (51) to drive several baffles (3) to move back and forth synchronously under the action of the screws (52). This causes the baffles (3) to press against the movable plate (2-4) and drive the movable plate (2-4) to flip and clear the flow port (2-2) through the protrusion (2-4-1).

6. The intelligent wastewater treatment equipment for extracting N-methylpyrrolidone as described in claim 5, characterized in that, The positioning frame (51) has a square frame structure. Several plug-in seats (51-1) are arranged horizontally at the upper and lower ends of the positioning frame (51) for plugging and fixing one end of the baffle plate (3). The plug-in seats (51-1) are fixed by fasteners that horizontally penetrate one end of the baffle plate (3).

7. The intelligent wastewater treatment equipment for extracting N-methylpyrrolidone as described in claim 1, characterized in that, It also includes a control system, which includes a PLC controller and a flow meter (61) installed on the circulation pipe (6). The PLC controller is connected to the flow meter (61), the drive motor (53), the circulation pump (7), and two three-way solenoid valves (103).

8. The treatment method of the intelligent wastewater treatment equipment for extracting N-methylpyrrolidone as described in any one of claims 1-7 specifically includes the following steps: Step 1: Inject the wastewater extract into the crystallizer box (1) and circulate it in the crystallizer box (1) under the drive of the circulation pump (7); Step 2: The heating temperature of the circulating medium flowing in the crystallization plate (2) is controlled to be between 100°C and 120°C by the heat exchange system in order to evaporate the water contained in the wastewater extract. Step 3: The cooling temperature of the circulating medium flowing in the crystallization plate (2) is controlled to be between -10°C and -5°C by the heat exchange system so that the NMP solvent contained in the wastewater extract crystallizes out and the remaining uncrystallized wastewater extract is discharged from the outlet pipe (102). Step 4: Finally, the heating temperature of the circulating medium flowing in the crystallization plate (2) is controlled by the heat exchange system to be maintained between 5°C and 15°C, so that the NMP solvent crystallized on the crystallization plate (2) melts and the NMP solvent is discharged through the drain pipe (13).

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