Purification device and method for malonic acid mono-p-nitrobenzyl ester

Abstract

The invention discloses a purification device and method for malonic acid mono-p-nitrobenzyl ester, and relates to the technical field of malonic acid mono-p-nitrobenzyl ester production.The purification device comprises a base, a storage barrel is installed at the top of the base, a first fan-shaped groove is formed in a rotary disc, and a second fan-shaped groove is formed in a disc-shaped frame; a box frame is fixedly arranged at the inner end of the charging barrel, an annular pushing part is arranged on the outer side of the rotary sleeve, a transmission part is arranged on the inner side of the filter cone, and a spray head is rotationally mounted on the box frame. According to the invention, firstly, through the rotation of the rotary disc and the vertical movement of the baffle disc, dynamic filtration and impurity discharge are realized, the filtration efficiency and the impurity discharge reliability are improved, secondly, through the cooperative movement of a mechanical structure, the utilization efficiency of the equipment is improved, the downtime caused by cleaning is reduced, and the production cost is reduced. For the purification process needing long-time continuous operation, the design can reduce the downtime caused by cleaning and improve the working efficiency of the equipment.

Description

Technical Field

[0001] The present invention relates to the technical field of the production of p-nitrobenzyl malonate, and particularly relates to a purification device and method for p-nitrobenzyl malonate. Background Art

[0002] P-nitrobenzyl malonate is an excellent solvent in industries such as paint making, textile, and dyeing, and is commonly used as a solvent for shellac varnish, alkyd resin, nitrocellulose, cellulose acetate, dyes, oils, and printing inks.

[0003] In the synthesis of p-nitrobenzyl malonate, by-products such as bis(p-nitrobenzyl) malonate are generated. Through purification, these impurities can be effectively removed to make the product meet higher purity standards. In the purification process of p-nitrobenzyl malonate, filtration is a key step. Through filtration, these solid impurities can be separated from the target product, thereby improving the purity of the product.

[0004] In the prior art, most often the solution is filtered while it is hot through a filter screen to remove insoluble impurities. During the filtration process, the insoluble impurities will gradually accumulate on the surface of the filter screen, resulting in a decrease in the flow-through performance of the filter screen. Over time, the impurity particles will pile up with each other, leading to a significant increase in the resistance of the filter. This not only affects the filtration speed but may also cause the filter to fail prematurely, requiring frequent replacement of the filter screen. This not only increases the operating cost but also affects the efficiency of the entire recrystallization process.

[0005] Based on the above defects, a purification device and method for p-nitrobenzyl malonate are provided. Summary of the Invention

[0006] The purpose of the present invention is to provide a purification device and method for p-nitrobenzyl malonate in order to solve the above problems.

[0007] To achieve the above purpose, the present invention adopts the following technical solution: A purification device for p-nitrobenzyl malonate, including a base, on the top of the base is installed a material cylinder and a storage cylinder communicated with the material cylinder. The top of the material cylinder is communicated with a feeding pipe. Inside the material cylinder is fixedly provided a disc-shaped frame. The bottom of the disc-shaped frame is rotatably connected with a rotating disc. A sector-shaped groove one is opened in the rotating disc, and a sector-shaped groove two is opened in the disc-shaped frame; The inner end of the material cylinder is fixedly provided with a box-shaped frame. Inside the box-shaped frame is installed a filter funnel and a driving member one for controlling the rotation of the filter funnel. The bottom of the filter funnel is communicated with a sewage discharge pipe. A blocking disc slides vertically in the filter funnel; A swivel sleeve is rotatably connected in the disc-shaped frame and penetrates downward through the swivel disc. A circumferential pushing member is arranged on the outer side of the swivel sleeve, and a transmission member is arranged on the inner side of the filter hopper. When the swivel sleeve rotates, the stop disc moves vertically under the action of the transmission member. A spray head is rotatably installed on the box frame, an air pump is installed outside the disc-shaped frame, and a second driving member is installed on the material cylinder. The swivel sleeve and the spray head are controlled to rotate synchronously by the second driving member.

[0008] Preferably, the first driving member includes a toothed disc rotatably connected inside the box frame. A second motor for controlling the rotation of the toothed disc is installed at the bottom of the box frame. A ratchet tooth is fixedly arranged on the side wall of the filter hopper, and the ratchet tooth meshes with the toothed disc.

[0009] Preferably, the circumferential pushing member includes a push rod. The push rod is fixedly arranged at the side end of the swivel sleeve through a frame plate. An arc-shaped groove one is opened at the bottom of the swivel disc, and the push rod is slidably arranged in the arc-shaped groove one.

[0010] Preferably, a sliding rod is fixedly arranged at the top of the swivel disc, and an arc-shaped groove two for cooperating with the sliding rod to slide is opened at the bottom of the disc-shaped frame.

[0011] Preferably, the second driving member includes a screw rod. The screw rod is rotatably connected in the box frame. A nut sleeve is screwed on the outer side of the screw rod. A linkage assembly is arranged on the outer side of the material cylinder. A sliding groove is opened in the box frame, and the sliding groove cooperates with the nut sleeve to penetrate and slide. An oppression assembly is arranged in the box frame. When the nut sleeve moves horizontally, the spray head is driven to rotate through the oppression assembly.

[0012] Preferably, a stop block is fixedly arranged on the box frame. The oppression assembly includes a bracket fixedly arranged on the spray head. A support rod is fixedly arranged at the side end of the bracket. A notch is opened in the nut sleeve, and the notch cooperates with the support rod to slide.

[0013] Preferably, a shell cover is fixedly arranged at the top of the disc-shaped frame. The linkage assembly includes a bevel gear ring and a bevel gear. The bevel gear ring and the bevel gear are rotatably connected in the shell cover. The bevel gear ring is fixed to the swivel sleeve. An equipment box is fixedly arranged at the outer end of the material cylinder. A belt and pulley transmission mechanism is installed in the equipment box, and the belt and pulley transmission mechanism can drive the bevel gear and the screw rod to rotate synchronously. A first motor is installed at the outer end of the equipment box.

[0014] Preferably, the transmission member includes a sliding sleeve. The sliding sleeve is fixed to the stop disc. A protrusion is fixedly arranged on the inner wall of the swivel sleeve. A sliding rail for cooperating with the protrusion to slide is opened on the side wall of the sliding sleeve.

[0015] Preferably, the sliding rail is composed of a circumferential groove and a spiral groove. A frame rod is fixedly arranged at the inner end of the shell cover. The frame rod is slidably connected with the sliding sleeve through a spline.

[0016] A purification method of p-nitrobenzyl malonate, the purification method comprising the following steps: S1. Add the crude product of p-nitrobenzyl malonate to an appropriate amount of solvent and introduce it into the purification device, and heat it until it is completely dissolved; S2. Filter the solution while it is hot to remove insoluble impurities; S3. Slowly cool the filtered hot solution to precipitate crystals; S4. Wash the crystals with a small amount of cold solvent to remove surface impurities, and dry the crystals.

[0017] In summary, due to the adoption of the above technical solutions, the beneficial effects of the present invention are as follows: 1. In this application, through the rotation of the rotating disk and the vertical movement of the blocking disk, dynamic filtration and impurity discharge are realized. This design avoids the problem of impurity blockage of the filter screen in the traditional filtration device, and improves the filtration efficiency and the reliability of impurity discharge.

[0018] 2. In this application, through the coordinated movement of the mechanical structure, during the cleaning process of the filter hopper, the heating and dissolving process of the solution above the disk-shaped frame is not affected. This design improves the utilization efficiency of the equipment, reduces the downtime caused by cleaning, and for the purification process that requires long-term continuous operation, this design can reduce the downtime caused by cleaning and improve the working efficiency of the equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 Shows a three-dimensional structural schematic diagram of the purification device provided by an embodiment of the present invention; Figure 2 Shows a cross-sectional schematic diagram of the purification device provided by an embodiment of the present invention; Figure 3 Shows a cross-sectional structural schematic diagram of the housing cover and the box frame provided by an embodiment of the present invention; Figure 4 Shows a partial enlarged schematic diagram at A provided by an embodiment of the present invention; Figure 5 Shows a matching structural schematic diagram of the rotating sleeve and the sliding sleeve provided by an embodiment of the present invention; Figure 6 Shows an exploded structural schematic diagram of the disk-shaped frame, the rotating disk and the filter hopper provided by an embodiment of the present invention.

[0020] Legend Explanation: 1. Base; 2. Barrel; 3. Filter bucket; 4. Rotary disk; 401. Sector groove one; 402. Arc groove one; 403. Slide rod; 5. Disc frame; 501. Sector groove two; 502. Arc groove two; 6. Shell cover; 7. Bevel gear ring; 8. Rotary sleeve; 801. Protrusion; 9. Push rod; 10. Slide sleeve; 11. Slide rail; 12. Baffle plate; 13. Frame rod; 14. Bevel gear; 15. Equipment box; 16. Wheel belt transmission mechanism; 17. First motor; 18. Box frame; 19. Gear; 20. Toothed disk; 21. Second motor; 22. Screw; 23. Screw sleeve; 24. Notch; 25. Nozzle; 26. Bracket; 27. Support rod; 28. Air pump; 29. ​​Block; 30. Drain pipe; 31. Storage barrel. DETAILED DESCRIPTION

[0021] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0022] The present invention provides a technical solution: please refer to Figures 1-6 A purification device for mono-p-nitrobenzyl malonate includes a base 1, a barrel 2 and a storage barrel 31 connected to the barrel 2 are installed on the top of the base 1, a feed pipe is connected to the top of the barrel 2, a disc frame 5 is fixedly arranged inside the barrel 2, a turntable 4 is rotatably connected to the bottom of the disc frame 5, a fan-shaped groove 1 401 is opened in the turntable 4, and a fan-shaped groove 2 501 is opened in the disc frame 5.

[0023] The barrel 2 is used to contain the nitrobenzyl ester solution to be purified, and the top is connected to the feed pipe for easy material input. The storage barrel 31 is connected to the barrel 2 and is used to temporarily store the purified nitrobenzyl ester for subsequent processing. The space inside the barrel 2 above the disc frame 5 is specially used for heating and dissolving the crude product and the solvent. The crude product and the solvent are heated to completely dissolve to form a uniform solution through an external heating device (such as an electric heating sleeve or an oil bath heater). The flow and residence time of the solution can be adjusted by controlling the rotation of the turntable 4. When the fan-shaped groove 1 401 is aligned with the fan-shaped groove 2 501, the solution can flow smoothly into the filter 3. When the fan-shaped groove 1 401 is staggered with the fan-shaped groove 2 501, the solution is temporarily placed in the space above the disc frame 5 for heating and dissolving.

[0024] The filter bucket 3 is connected to the barrel 2 for filtering and separation. When the fan-shaped groove 1 401 is aligned with the fan-shaped groove 2 501, the solution flows into the filter bucket 3, the impurities are filtered out, and the purified solution flows into the storage barrel 31 for temporary storage. The storage barrel 31 is used to temporarily store the purified mono-p-nitrobenzyl malonate solution for subsequent cooling crystallization and other processing steps.

[0025] By rotating the turntable 4, the flow and residence time of the solution can be flexibly controlled. This allows the dissolution and filtration processes to be adjusted according to actual needs, thereby improving the purification efficiency. In the dissolution stage, the residence time of the solution above the disc frame 5 can be appropriately extended to ensure that the crude product is completely dissolved. In the filtration stage, the solution can be quickly introduced into the filter 3 to reduce the residual impurities. The entire device has a compact structure, is easy to operate and maintain, and controls the flow of the solution by rotating the turntable 4, is simple to operate, and is easy to achieve automated control.

[0026] A box frame 18 is fixedly provided at the inner end of the barrel 2, and a filter bucket 3 and a driving member for controlling the rotation of the filter bucket 3 are installed in the box frame 18. The bottom of the filter bucket 3 is connected to a sewage pipe 30, and the output end of the sewage pipe 30 extends outward from the barrel 2. A baffle 12 that can block the input end of the sewage pipe 30 slides vertically in the filter bucket 3.

[0027] After the solution flows into the filter hopper 3, the impurities are filtered, and the purified solution flows into the storage cylinder 31. During this process, the baffle 12 blocks the input end of the sewage pipe 30 to ensure that the input end of the sewage pipe 30 is completely closed. The purpose of this step is to prevent the purified solution from flowing out through the sewage pipe 30 to ensure that only impurities can be discharged. After the filter hopper 3 completes the filtration of this part of the solution, the rotary disc 4 is controlled to rotate so that the fan-shaped groove 1 401 and the fan-shaped groove 2 501 are staggered. During this process, the baffle 12 moves upward in the vertical direction under the action of the transmission member, opens the input end of the sewage pipe 30, and the impurities are discharged through the sewage pipe 30 at the bottom of the filter hopper 3.

[0028] The scheme realizes dynamic filtration and impurity discharge through the rotation of the rotary disk 4 and the vertical movement of the baffle 12. This design avoids the problem of impurities clogging the filter screen in traditional filtering devices, and improves the filtration efficiency and the reliability of impurity discharge.

[0029] A rotary sleeve 8 penetrating downwardly through the rotary disk 4 is rotatably connected in the disc-shaped frame 5, an annular driving member for driving the rotary disk 4 to rotate is arranged on the outer side of the rotary sleeve 8, a transmission member is arranged on the inner side of the filter bucket 3, when the rotary sleeve 8 rotates, the baffle plate 12 moves vertically under the action of the transmission member, a nozzle 25 is rotatably installed on the box frame 18, an air pump 28 is installed on the outside of the disc-shaped frame 5, and a driving member 2 for controlling the synchronous rotation of the rotary sleeve 8 and the nozzle 25 is installed on the barrel 2.

[0030] After the filter 3 completes filtering the solution, the rotary sleeve 8 and the nozzle 25 are controlled to rotate synchronously by the second driving member. During this process, the baffle 12 will be lifted upward from the input end of the sewage pipe 30 under the action of the transmission member, and the sewage pipe 30 will be opened to allow impurities to be discharged. The rotary disc 4 will rotate under the action of the annular pusher, so that the fan-shaped groove 1 401 and the fan-shaped groove 2 501 are staggered. At the same time, the nozzle 25 is lifted upward and faces the filter 3. By starting the air pump 28 and the first driving member, the nozzle 25 blows air to the rotating filter 3 to achieve jet cleaning of the filter 3, which can further improve the cleanliness of the filter 3 and reduce the residual impurities. In addition, in the process of cleaning the filter 3, the fan-shaped groove 1 401 and the fan-shaped groove 2 501 are staggered, so that the space above the disc frame 5 can still heat and dissolve the solution that continues to be passed into the barrel 2. It realizes the heating and dissolving process of the solution above the disc frame 5 during the cleaning process of the filter 3 through the coordinated movement of the mechanical structure. This design improves the utilization efficiency of the equipment and reduces the downtime caused by cleaning. For purification processes that require long-term continuous operation, this design can reduce the downtime caused by cleaning and improve the working efficiency of the equipment.

[0031] Specifically, Figure 2 As shown, the driving member 1 includes a toothed disc 20 rotatably connected to the inside of the box frame 18, a second motor 21 for controlling the rotation of the toothed disc 20 is installed at the bottom of the box frame 18, and teeth 19 for engaging with the toothed disc 20 are fixed on the side wall of the filter hopper 3.

[0032] When the filter bucket 3 needs to be cleaned, the second motor 21 is started to drive the toothed disc 20 to rotate. The toothed disc 20 engages with the teeth 19 on the side wall of the filter bucket 3 to drive the filter bucket 3 to rotate. During the rotation, the nozzle 25 blows air or sprays liquid to clean the filter bucket 3 to improve the cleaning effect.

[0033] Specifically, Figure 3 and Figure 6 As shown, the annular pusher includes a push rod 9 fixed to the side end of the rotary sleeve 8 through a frame plate, and an arc groove 402 is provided at the bottom of the rotary disk 4 to cooperate with the sliding of the push rod 9; a slide bar 403 is fixed to the top of the rotary disk 4, and an arc groove 502 is provided at the bottom of the disk frame 5 to cooperate with the sliding of the slide bar 403.

[0034] When it is necessary to discharge the dissolved liquid above the disc frame 5 downward, as the rotary sleeve 8 rotates, the push rod 9 fixed on the side end of the rotary sleeve 8 first slides along the arc groove 1 402. During this process, the rotary disc 4 will remain stationary relative to the disc frame 5, and the sliding sleeve 10 will move downward under the action of the transmission member to block the input end of the sewage pipe 30. Subsequently, as the rotary disc 4 continues to rotate, the push rod 9 drives the rotary disc 4 to rotate by acting on the inner wall of the arc groove 1 402, so that the fan-shaped groove 1 401 and the fan-shaped groove 2 501 are rotated and aligned.

[0035] When the rotating disk 4 rotates, the sliding rod 403 fixed on the rotating disk 4 will rotate along the second arc-shaped groove 502. Through the sliding fit between the sliding rod 403 and the second arc-shaped groove 502, the rotation range of the rotating disk 4 is restricted, thereby ensuring that the first sector groove 401 and the second sector groove 501 maintain a stable staggered or aligned state.

[0036] The coordinated action of the push rod 9 and the sliding rod 403 ensures that the rotating disk 4 can rotate precisely, realizing the stable alignment or staggering of the first sector groove 401 and the second sector groove 501. This precise control is crucial for the smooth discharge of liquid and the filtration process. In the initial stage, the rotating disk 4 remains stationary, and only the movement of the sliding sleeve 10 blocks the sewage discharge pipe 30 to ensure the sealing before liquid discharge. Subsequently, the push rod 9 starts to push the rotating disk 4 to rotate. This step-by-step operation reduces the interference between different actions and improves the reliability of the operation.

[0037] Specifically, as Figures 1-6 shown, the second driving member includes a screw rod 22 rotatably connected in the box frame 18 and a linkage assembly that drives the screw rod 22 to rotate synchronously with the rotating sleeve 8. A nut sleeve 23 is screwed on the outer side of the screw rod 22. A sliding groove for the nut sleeve 23 to penetrate and slide is provided in the box frame 18. A pressing assembly is provided in the box frame 18. When the nut sleeve 23 moves horizontally, the spray head 25 is driven to rotate through the pressing assembly.

[0038] When the screw rod 22 and the rotating sleeve 8 rotate synchronously under the action of the linkage assembly, the nut sleeve 23 screwed on the screw rod 22 will slide along the sliding groove. During this process, the spray head 25 will rotate along the box frame 18 under the action of the pressing assembly. When the rotating sleeve 8 rotates and drives the rotating disk 4 to rotate through the circumferential pushing member, as the first sector groove 401 and the second sector groove 501 are staggered, the spray head 25 rotates and lifts under the action of the pressing assembly. When the first sector groove 401 and the second sector groove 501 are aligned, the spray head 25 will rotate so that its output end is blocked by the blocking block 29 to prevent the solution filtered by the filter hopper 3 from flowing into the spray head 25.

[0039] A blocking block 29 for blocking the output end of the spray head 25 is fixedly provided on the box frame 18. The pressing assembly includes a bracket 26 fixedly provided on the spray head 25. A support rod 27 is fixedly provided at the side end of the bracket 26. A notch 24 for the support rod 27 to slide is provided in the nut sleeve 23. When the nut sleeve 23 moves horizontally, the inner wall of the notch 24 will drive the spray head 25 to rotate through the pressing action on the support rod 27.

[0040] A housing cover 6 is fixedly installed at the top of the disc-shaped frame 5. The linkage assembly includes a bevel gear ring 7 and a bevel gear 14 rotatably connected in the housing cover 6. The bevel gear ring 7 is coaxially fixed with the swivel sleeve 8. An equipment box 15 is fixedly installed at the outer end of the barrel 2. A belt and pulley transmission mechanism 16 for driving the bevel gear 14 and the screw 22 to rotate synchronously is installed in the equipment box 15. A first motor 17 for acting on the belt and pulley transmission mechanism 16 is installed at the outer end of the equipment box 15.

[0041] The belt and pulley transmission mechanism 16 is composed of two sprockets and a chain meshed and sleeved outside the sprockets. One of the sprockets is coaxially fixed with the bevel gear 14, and the other sprocket is coaxially fixed with the screw 22. When the first motor 17 is started, the two sprockets will rotate synchronously under the action of the chain. When the bevel gear 14 rotates, it will drive the swivel sleeve 8 to rotate through the bevel gear ring 7 meshed with it.

[0042] Specifically, as Figure 5 and Figure 6 shown, the transmission part includes a sliding sleeve 10 slidably embedded inside the swivel sleeve 8 and fixed to the retaining disc 12. A protrusion 801 is fixedly installed on the inner wall of the swivel sleeve 8, and a slide rail 11 for cooperating with the protrusion 801 to slide is provided on the side wall of the sliding sleeve 10.

[0043] When the swivel sleeve 8 rotates, the protrusion 801 fixed on the inner wall of the swivel sleeve 8 will slide along the slide rail 11. When the push rod 9 fixed on the side wall of the swivel sleeve 8 slides along the arc-shaped groove 402, the protrusion 801 will slide along the spiral groove of the slide rail 11. Through the pressure transmission of the side wall of the protrusion 801 on the inner wall of the spiral groove, the sliding sleeve 10 is driven to move downward along the support rod 13. During this process, the sector-shaped groove 401 and the sector-shaped groove 501 are always in a staggered state. Until the retaining disc 12 fixed to the sliding sleeve 10 blocks the input end of the sewage discharge pipe 30. At this time, as the swivel sleeve 8 continues to rotate, the push rod 9 will act on the inner wall of the arc-shaped groove 402 to push the rotating disc 4 to rotate, so that the sector-shaped groove 401 and the sector-shaped groove 501 are aligned. During this process, the protrusion 801 will slide along the circumferential groove of the slide rail 11, and the retaining disc 12 will maintain the blocking state of the input end of the sewage discharge pipe 30.

[0044] The slide rail 11 is composed of a circumferential groove and a spiral groove. A support rod 13 is fixedly installed at the inner top end of the housing cover 6, and the support rod 13 is slidably connected with the sliding sleeve 10 through a spline. The setting of the spline on the support rod 13 restricts the relative sliding of the sliding sleeve 10, which is beneficial to the pressure transmission of the protrusion 801 fixed on the inner wall of the swivel sleeve 8 on the spiral groove of the slide rail 11.

[0045] Specifically, a purification method for p-nitrobenzyl malonate, the purification method includes the following steps: S1. Add an appropriate amount of solvent to the crude p-nitrobenzyl malonate and then introduce it into the purification device, and heat it to completely dissolve; S2. Filter the solution while it is hot to remove insoluble impurities; S3. Slowly cool the filtered hot solution to precipitate crystals; S4. Wash the crystals with a small amount of cold solvent to remove surface impurities, and dry the crystals.

[0046] When selecting a solvent, it is necessary to ensure that the solvent can completely dissolve the target substance at high temperature, while its solubility decreases significantly at low temperature. Commonly used solvents include ethyl acetate, ethanol, petroleum ether, etc. The appropriate solvent can be screened through experiments. For example, add a small amount of the sample to the solvent, heat it to dissolve, and observe whether crystals precipitate after cooling.

[0047] Add the crude product of p-nitrobenzyl malonate to an appropriate amount of solvent, heat it until completely dissolved. If there are still undissolved solids, more solvent can be added continuously until it is completely dissolved.

[0048] Filter the solution while it is hot to remove insoluble impurities. Use a preheated funnel and filter paper to prevent the solution from crystallizing during filtration. Slowly cool the filtered hot solution to precipitate crystals. The cooling rate should not be too fast to avoid the crystals enclosing impurities.

[0049] The above description of the embodiments enables those skilled in the art to implement or use the present invention. Various modifications to these embodiments will be obvious to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present invention. Therefore, the present invention will not be limited to these embodiments shown herein, but rather to the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A purification device for mono-p-nitrobenzyl malonate, comprising a base (1), characterized in that: A barrel (2) and a storage barrel (31) connected to the barrel (2) are mounted on the top of the base (1); a material delivery pipe is connected to the top of the barrel (2); a disc frame (5) is fixedly arranged inside the barrel (2); a rotating disk (4) is rotatably connected to the bottom of the disc frame (5); a first fan-shaped groove (401) is provided in the rotating disk (4); and a second fan-shaped groove (501) is provided in the disc frame (5); A box frame (18) is fixedly provided at the inner end of the barrel (2), a filter bucket (3) and a driving member for controlling the rotation of the filter bucket (3) are installed in the box frame (18), a sewage discharge pipe (30) is connected to the bottom of the filter bucket (3), and a baffle (12) is vertically slidable in the filter bucket (3); A rotary sleeve (8) which penetrates downwardly through the rotary disc (4) is rotatably connected in the disc-shaped frame (5), an annular pushing member is arranged on the outer side of the rotary sleeve (8), a transmission member is arranged on the inner side of the filter bucket (3), when the rotary sleeve (8) rotates, the baffle plate (12) moves vertically under the action of the transmission member, a nozzle (25) is rotatably mounted on the box frame (18), an air pump (28) is mounted on the outside of the disc-shaped frame (5), and a second driving member is mounted on the barrel (2), and the rotary sleeve (8) and the nozzle (25) are controlled to rotate synchronously by the second driving member.

2. A purification device for mono-p-nitrobenzyl malonate according to claim 1, characterized in that: The first driving member comprises a toothed disc (20) rotatably connected to the inside of the box frame (18); a second motor (21) for controlling the rotation of the toothed disc (20) is installed at the bottom of the box frame (18); and teeth (19) are fixedly provided on the side wall of the filter bucket (3); the teeth (19) mesh with the toothed disc (20).

3. A purification device for mono-p-nitrobenzyl malonate according to claim 1, characterized in that: The annular push member comprises a push rod (9), the push rod (9) being fixed to the side end of the rotary sleeve (8) via a frame plate, the bottom of the rotary disk (4) being provided with an arc-shaped groove (402), the push rod (9) being slidably arranged in the arc-shaped groove (402).

4. A purification device for mono-p-nitrobenzyl malonate according to claim 3, characterized in that: A sliding rod (403) is fixedly provided on the top of the rotating disk (4), and a second arc-shaped groove (502) cooperating with the sliding rod (403) is provided on the bottom of the disk frame (5).

5. A purification device for mono-p-nitrobenzyl malonate according to claim 1, characterized in that: The second driving member comprises a screw rod (22), the screw rod (22) being rotatably connected to the box frame (18), the outer side of the screw rod (22) being screwed and connected with a screw sleeve (23), the outer side of the barrel (2) being provided with a linkage component, the box frame (18) being provided with a slide groove, the slide groove being adapted to slide through the screw sleeve (23), the box frame (18) being provided with a pressing component, and when the screw sleeve (23) moves horizontally, the nozzle (25) is driven to rotate through the pressing component.

6. A purification device for mono-p-nitrobenzyl malonate according to claim 5, characterized in that: A stopper (29) is fixedly provided on the box frame (18), the pressing assembly comprises a bracket (26) fixedly provided on the nozzle (25), a support rod (27) is fixedly provided on the side end of the bracket (26), a notch (24) is provided in the screw sleeve (23), and the notch (24) cooperates with the support rod (27) to slide.

7. A purification device for mono-p-nitrobenzyl malonate according to claim 5, characterized in that: A shell cover (6) is fixedly provided on the top of the disc frame (5), and the linkage assembly comprises a bevel gear ring (7) and a bevel gear (14). The bevel gear ring (7) and the bevel gear (14) are rotatably connected in the shell cover (6), and the bevel gear ring (7) is fixed to the rotary sleeve (8). An equipment box (15) is fixedly provided on the outer end of the barrel (2), and a belt transmission mechanism (16) is installed in the equipment box (15). The belt transmission mechanism (16) can drive the bevel gear (14) and the screw (22) to rotate synchronously. A first motor (17) is installed on the outer end of the equipment box (15).

8. A purification device for mono-p-nitrobenzyl malonate according to claim 7, characterized in that: The transmission member comprises a sliding sleeve (10), the sliding sleeve (10) being fixed to a baffle (12), a protrusion (801) being fixedly provided on the inner wall of the rotating sleeve (8), and a sliding rail (11) cooperating with the protrusion (801) for sliding on the side wall of the sliding sleeve (10).

9. A purification device for mono-p-nitrobenzyl malonate according to claim 8, characterized in that: The slide rail (11) is composed of an annular groove and a spiral groove. A support rod (13) is fixedly provided at the inner end of the shell cover (6). The support rod (13) is slidably connected to the slide sleeve (10) via a spline.

10. A purification method using the purification device of mono-p-nitrobenzyl malonate according to claim 1, characterized in that: The purification method comprises the following steps: S1. Add an appropriate amount of solvent to the crude mono-p-nitrobenzyl malonate and pass it into a purification device, and heat it until it is completely dissolved; S2, filtering the solution while hot to remove insoluble impurities; S3, slowly cooling the filtered hot solution to allow crystals to precipitate; S4. Wash the crystals with a small amount of cold solvent to remove surface impurities, and then dry the crystals.

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