Alpha-pyrrolidone crude product purification device and control method

Abstract

This invention relates to the field of purification equipment technology, and more particularly to a purification equipment and control method for crude α-pyrrolidone. The technical solution includes a tower body, multiple trays fixedly installed inside the tower body, and a liquid storage plate fixedly installed inside the tower body and above the trays. The liquid storage plate stores liquid. Multiple air holes are provided on the trays. Floating valves, corresponding to the air holes and rising and falling according to the air pressure, are installed on the trays. Drainage holes, corresponding to the air holes and coaxially arranged, are provided on the liquid storage plate. A variable valve mechanism is fixedly installed on the drainage holes. This invention, through intelligent linkage between the float valve lift and the drainage hole diameter, allows for real-time liquid replenishment under high-speed gas impact, completely eliminating dry zones on the trays, ensuring uniform gas-liquid contact, improving mass transfer efficiency, and featuring a design that adjusts the drainage flow rate to avoid flooding caused by excessive liquid replenishment. This expands operational flexibility and is particularly suitable for the thermosensitive characteristics of α-pyrrolidone.

Description

Technical Field

[0001] This invention relates to the field of extraction equipment technology, and in particular to an extraction equipment and control method for crude α-pyrrolidone. Background Technology

[0002] In the purification process of α-pyrrolidone, its physicochemical properties have a significant impact on the separation process. α-Pyrrolidone is a highly polar, high-boiling-point organic solvent with strong hygroscopicity and heat sensitivity. Because it forms near-boiling compounds with water, conventional vacuum distillation, while able to lower the operating temperature and reduce the risk of thermal decomposition to some extent, still struggles to achieve efficient removal of water to the required electronic-grade purity. Furthermore, α-pyrrolidone is prone to dimerization, oxidation, or decomposition at high temperatures, generating colored or high-boiling-point impurities that affect product quality.

[0003] To overcome the aforementioned problems, azeotropic distillation is commonly used in industry as the mainstream process for dehydrating α-pyrrolidone. This technology introduces an azeotropic agent, which forms a low-boiling-point azeotrope with water, which is then distilled off at the top of the distillation column, effectively removing water. After condensation, the azeotropic agent and water separate into layers, with the organic phase flowing back into the column to maintain compositional stability; the bottom of the column yields dehydrated α-pyrrolidone. This process is typically carried out in a multi-plate column, where the gas and liquid phases come into countercurrent contact on the plates, completing mass and heat transfer.

[0004] However, traditional trays are prone to problems such as liquid splashing, mist entrainment, and dry zone formation at high gas velocities, leading to a decrease in actual mass transfer area, product contamination, and limited operational flexibility. The purification device and control method proposed in this patent address these pain points by achieving dynamic balance and efficient mass transfer of gas-liquid contact through intelligently linked float valves and venting mechanisms. It is particularly suitable for the precision separation of thermosensitive and highly polar systems such as α-pyrrolidone. Summary of the Invention

[0005] The purpose of this invention is to address the problems existing in the prior art by proposing a refining apparatus and control method for crude α-pyrrolidone that avoids reducing the actual contact area between the liquid and the gas while ensuring high-speed gas flow.

[0006] On one hand, the present invention proposes a purification apparatus for crude α-pyrrolidone, comprising a column body, multiple trays fixedly installed inside the column body, and further comprising: A liquid storage plate is fixedly installed inside the tower body and located above the tower plate, and the liquid storage plate stores liquid. Multiple air holes are provided on the tower plate; float valves are installed on the tower plate that correspond one-to-one with the air holes and rise and fall according to the air pressure; and drain holes are provided on the liquid storage plate that correspond one-to-one with the air holes and are coaxially arranged. A variable valve port mechanism is fixedly installed on the drain hole, and the variable valve port mechanism controls the size of the flow orifice diameter of the drain hole; The splash-proof compensation component includes a drive assembly connected to the variable valve port mechanism and controlling the size of the flow orifice of the variable valve port mechanism, and an actuation assembly connected to the float valve and moving according to the rise and fall of the float valve. The height position of the actuation assembly controls the on / off state of the drive assembly circuit. Optionally, the variable valve mechanism includes a valve body fixedly mounted on a liquid storage plate, the valve body having a conical hole, a slide rod slidably mounted on the valve body via a support frame, and a sealing plate for sealing the conical hole being fixedly mounted at one end of the slide rod.

[0007] Optionally, a spring is fixedly installed between the sealing plate and the support frame, and a sealing ring is fixedly installed on the edge of the sealing plate.

[0008] Optionally, the drive assembly includes a connecting plate fixedly mounted on the slide bar, a magnetic block fixedly mounted at one end of the connecting plate, and an electromagnet fixedly mounted on the liquid storage plate.

[0009] Optionally, the starting assembly includes a synchronization plate fixedly mounted on the float valve, a support rod fixedly mounted on the synchronization plate, a cylinder fixedly mounted on the tower plate via a base, a connecting rod slidably mounted inside the cylinder, a first contact point fixedly mounted on the support rod, and a second contact point fixedly mounted on the connecting rod.

[0010] Optionally, a power source is installed on the outside of the tower body. The power source, the first contact, the electromagnet, and the second contact form a closed circuit. A controller is installed on the closed circuit, and the controller controls the power output of the power source according to the circuit connection time.

[0011] Optionally, a first corrugated pipe is fixedly installed between the liquid storage plate and the connecting plate, the magnetic block and the electromagnet are both located inside the first corrugated pipe, a second corrugated pipe is fixedly installed between the tower plate and the base, and the support rod, cylinder, connecting rod, first contact and second contact are all located inside the second corrugated pipe.

[0012] Optionally, the tray includes a first plate body, one end of which is fixedly fitted with a first containment dam, and the pores are evenly distributed on the surface of the first plate body; The float valve includes multiple limiting rods slidably mounted on the first plate, and a circular plate is fixedly mounted on each of the multiple limiting rods. The bottom of each limiting rod is provided with a curved portion.

[0013] Optionally, the liquid storage plate includes a second plate body fixedly installed inside the tower body, with a second cofferdam fixedly installed at both ends of the second plate body, and the drain holes are evenly distributed on the surface of the second plate body; The second plate is provided with multiple flow guide holes, and flow guide pipes are fixedly installed on the flow guide holes. The flow guide pipes are higher than the second cofferdam.

[0014] On the other hand, this application proposes a method for controlling crude α-pyrrolidone, based on the above-described refining apparatus for crude α-pyrrolidone, specifically including the following steps: Step 1: Gas moves upward from the bottom of the tower, and liquid moves downward from the top of the tower. A portion of the liquid is stored on the tower plates and the liquid storage plate. Step 2: Under the action of gas pressure, the gas passes through the gas pores and comes into contact with the liquid on the tray and reacts. When the gas flow rate is high, it will drive the float valve to rise, and at the same time, the liquid on the tray is prone to splashing. Step 3: After the float valve rises, the vent hole is opened by the starting and driving components, allowing the liquid on the storage plate to flow downwards and come into contact with the rapidly rising liquid, thereby compensating for the liquid when the gas flows rapidly. In summary, this application includes at least one of the following beneficial technical effects: This invention utilizes the intelligent linkage between the float valve lift and the vent orifice diameter to replenish liquid in real time under high-speed gas impact, completely eliminating the dry zone on the tray, ensuring uniform gas-liquid contact, improving mass transfer efficiency, and featuring a design that allows for adjustable vent flow to avoid flooding caused by excessive replenishment. This expands operational flexibility and is particularly suitable for the thermosensitive properties of α-pyrrolidone. Attached Figure Description

[0015] Figure 1 This is a structural diagram of the tower. Figure 2 This is a schematic diagram of the internal structure of the tower. Figure 3 for Figure 2 A magnified view of a section at point A in the middle; Figure 4 This is a schematic diagram showing the installation positions of the trays and the liquid storage trays; Figure 5 This is a schematic diagram of the tower plate structure; Figure 6 for Figure 5 A magnified view of a section at point B in the middle; Figure 7 for Figure 5 A magnified view of a section at point C; Figure 8 A schematic diagram of the variable valve port mechanism and drive assembly; Figure 9 This diagram shows the installation locations of the driver and startup components. Figure 10 This is a schematic diagram of the liquid storage plate.

[0016] Attached reference numerals: 1. Tower body; 11. Liquid outlet; 12. Steam inlet; 13. Gas outlet; 14. Liquid inlet; 2. Tower plate; 21. First plate body; 22. First cofferdam; 23. Vent hole; 24. Float valve; 241. Limiting rod; 242. Circular plate; 243. Bend section; 3. Liquid storage plate; 31. Second plate; 32. Second cofferdam; 33. Drainage hole; 4. Variable valve port mechanism; 41. Valve body; 42. Tapered orifice; 43. Support frame; 44. Slide rod; 45. Sealing plate; 46. Spring; 5. Splash-proof compensation component; 51. Drive assembly; 511. Connecting plate; 512. Magnetic block; 513. Electromagnet; 52. Starting assembly; 521. Synchronization plate; 522. Support rod; 523. Cylinder; 524. Connecting rod; 525. First contact; 526. Second contact; 53. First bellows; 54. Second bellows; 6. Flow guide hole; 61. Flow guide tube; 7. Triangle ruler. Detailed Implementation

[0017] The technical solution of this application will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0018] The components of the embodiments of this application described and shown in the accompanying drawings can be arranged and designed in a variety of different configurations. Therefore, the following detailed description of the embodiments of this application provided in the drawings is not intended to limit the scope of the claimed application, but merely to illustrate selected embodiments of the application.

[0019] Based on the embodiments in this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0020] In the description of this application, it should be noted that the terms "upper," "lower," "inner," "outer," "front end," "rear end," "both ends," "one end," and "the other end," etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, and are only for the convenience of describing the present invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention. Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance.

[0021] In the description of this application, it should be noted that, unless otherwise expressly specified and limited, the terms "installation," "connection," and "joining" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; and they can refer to the internal connection between two components. Those skilled in the art can understand the specific meaning of the above terms in this application based on the specific circumstances.

[0022] like Figure 1 and Figure 2 As shown, the present invention proposes a purification apparatus for crude α-pyrrolidone, comprising a column body 1. The bottom of the column body 1 is provided with a steam inlet 12 and a liquid outlet 11, and the top of the column body 1 is provided with a gas outlet 13 and a liquid inlet 14. The steam inlet 12 is connected to the steam outlet of the reboiler, and the steam inlet 12 sends the steam generated by heating and boiling in the reboiler back to the bottom of the column body 1, driving the gas phase to rise. The liquid outlet 11 is connected to a purification unit and a reboiler circulation pump, which transports the dehydrated crude α-pyrrolidone. Part of the liquid is pumped into the reboiler for heating, and the heavy component product is discharged through the liquid outlet 11. The gas outlet 13 is connected to a main condenser, which condenses the steam into liquid. The liquid inlet 14 is connected to a reflux pump, which pumps the organic phase in the phase separator into the top of the column. The organic phase in the phase separator is the azeotropic agent enriched phase obtained by condensing the azeotropic steam at the top of the column and separating it from water. It is refluxed into the column to replenish the liquid phase at the top of the column and maintain the distillation separation efficiency.

[0023] As one implementation method, such as Figures 3 to 6 As shown, the purification device in this embodiment also includes multiple trays 2 fixedly installed inside the column body 1. As the core internal component of the distillation column, the tray 2 plays a key role in forming a stable liquid layer by blocking and accumulating the liquid phase through the overflow weir structure, forcing the rising gas to pass through the sieve holes and disperse into a group of bubbles. During the process of passing through the liquid layer, efficient mass and heat transfer between the gas and liquid phases is achieved. The high-boiling-point components in the gas condense and migrate to the liquid phase, while the low-boiling-point components in the liquid phase evaporate and transfer to the gas phase. In this dynamic contact, the bursting and regeneration of bubbles continuously renew the phase interface, greatly improving the mass transfer efficiency.

[0024] Furthermore, the tray 2 includes a first plate body 21, and a first weir 22 is fixedly installed at one end of the first plate body 21. The first weir 22 allows liquid to accumulate on the first plate body 21 to form a stable liquid phase. The tray 2 is provided with a plurality of vent holes 23, which are evenly distributed on the surface of the first plate body 21. The rising gas will pass through the vent holes 23, pass through the first plate body 21, and come into contact with the liquid phase on the first plate body 21.

[0025] The tower plate 2 is equipped with float valves 24 that correspond one-to-one with the gas holes 23 and rise and fall according to the gas pressure. The float valves 24 include multiple limiting rods 241 that are slidably installed on the first plate 21. A circular plate 242 is fixedly installed on the multiple limiting rods 241. The bottom of the limiting rods 241 is provided with a bending part 243. The circular plate 242 will move up and down under the action of gas pressure and the guiding action of the limiting rods 241. The bending part 243 restricts the highest position of the circular plate 242 to prevent the circular plate 242 from slipping off. The circular plate 242 falls on the first plate 21 by gravity. When the gas rises, the gas pressure pushes up the circular plate 242. The opening increases with the gas velocity. The gas is ejected from the annular gap between the circular plate 242 and the first plate 21, forming small bubbles. The bubble group passes through the liquid layer, that is, the liquid on the tower plate 2, forming a foam zone. The circular plate 242 dynamically floats to balance the gas pressure and gravity.

[0026] As one implementation method, such as Figure 9 and Figure 10 As shown, the purification device also includes a liquid storage plate 3 fixedly installed inside the tower body 1 and located above the tower plate 2. The liquid storage plate 3 stores liquid, and the liquid storage plate 3 is provided with drain holes 33 that correspond one-to-one with the gas holes 23 and are coaxially arranged. When the gas velocity through the first tower plate 2 is high, liquid splashing is likely to occur, resulting in a decrease in the effective gas-liquid contact area. At this time, the liquid phase is released to the lower first plate 21 through the drain holes 33, which can quickly replenish the liquid phase in the "dry zone" on the lower first plate 21 caused by the rising gas, ensuring that the gas and liquid can effectively enter and exit the tower. To prevent a decrease in the gas-liquid contact area and thus a reduction in exchange efficiency, the liquid storage plate 3 includes a second plate 31 fixedly installed inside the tower body 1. Both ends of the second plate 31 are fixedly installed with second weirs 32. The second weirs 32 allow liquid to accumulate to a certain height on the second plate 31. The height of the second weirs 32 is higher than that of the first weir 22, resulting in higher hydraulic pressure in the drain holes 33. This prevents gas from passing through the drain holes 33 and ensures that the drain holes 33 can flow downwards. The drain holes 33 are evenly distributed on the surface of the second plate 31.

[0027] The second plate 31 is provided with multiple guide holes 6, and a guide pipe 61 is fixedly installed on the guide holes 6. The rising gas will pass through the second plate 31 through the multiple guide holes 6 and the guide pipe 61, and the guide pipe 61 is higher than the second cofferdam 32 to prevent the liquid on the second plate 31 from flowing out through the guide holes 6.

[0028] As one implementation method, such as Figure 8As shown, the refining device in this embodiment also includes a variable valve mechanism 4 fixedly installed on the drain hole 33. The variable valve mechanism 4 controls the size of the flow orifice diameter of the drain hole 33. When the gas velocity through the first plate 21 is greater, the gas volume passing through per unit time is greater, which makes it easier to cause liquid splashing. Therefore, the drain hole 33 needs to have a larger flow area to ensure that more liquid flows out per unit time and can accommodate a larger gas volume. The variable valve mechanism 4 includes a valve body 41 fixedly installed on the liquid storage plate 3. The valve body 41 is provided with a conical hole 4. 2. A slide rod 44 is slidably installed inside the valve body 41 via a support frame 43. A sealing plate 45 is fixedly installed at one end of the slide rod 44 to block the conical hole 42. Under the action of gravity, the sealing plate 45 will contact the conical hole 42, thereby blocking the conical hole 42 and preventing the liquid on the second plate 31 from flowing out. When the sealing plate 45 rises, it will separate from the conical hole 42. The greater the rising height, the larger the gap between the sealing plate 45 and the conical hole 42, and the more liquid passes through the drain hole 33 per unit time.

[0029] A spring 46 is fixedly installed between the sealing plate 45 and the support frame 43, and a sealing ring is fixedly installed on the edge of the sealing plate 45. The pressure between the sealing plate 45 and the conical hole 42 is increased by the spring 46, which can ensure the sealing effect, and the sealing ring further ensures the sealing performance.

[0030] like Figures 5 to 9 As shown, in this embodiment, the refining device also includes a splash-proof compensation component 5. The splash-proof compensation component 5 includes a drive component 51 connected to the variable valve port mechanism 4 and controlling the size of the flow orifice of the variable valve port mechanism 4, and an activation component 52 connected to the float valve 24 and moving according to the rise and fall of the float valve 24. The height position of the activation component 52 controls the on / off state of the circuit of the drive component 51. The greater the gas velocity, the greater the height the float valve 24 rises. When the float valve 24 rises to a certain height, it will inevitably cause liquid splashing. At this time, the drive component 51 is activated to release the drain hole 33 to compensate for the liquid phase and prevent the problem of insufficient gas-liquid contact area.

[0031] Furthermore, the drive assembly 51 includes a connecting plate 511 fixedly mounted on the slide bar 44. A magnetic block 512 is fixedly mounted on one end of the connecting plate 511, and an electromagnet 513 is fixedly mounted on the liquid storage plate 3. When the electromagnet 513 is energized, it will generate an attractive or repulsive force on the magnetic block 512. Depending on the position of the electromagnet 513, the electromagnet 513 will generate an attractive or repulsive force on the magnetic block 512, which will drive the sealing plate 45 to move.

[0032] Furthermore, the starting component 52 includes a synchronization plate 521 fixedly installed on the float valve 24, a support rod 522 fixedly installed on the synchronization plate 521, a cylinder 523 fixedly installed on the tower plate 2 via a base, a connecting rod 524 slidably installed inside the cylinder 523, a first contact 525 fixedly installed on the support rod 522, and a second contact 526 fixedly installed on the connecting rod 524. When the first contact 525 and the second contact 526 come into contact, the circuit connected to the electromagnet 513 is connected, which can generate an interaction force between the electromagnet 513 and the magnetic block 512, thereby driving the sealing plate 45 to move.

[0033] It should be noted that a power supply is installed on the outside of the tower body 1. The power supply, the first contact 525, the electromagnet 513, and the second contact 526 form a closed circuit. A controller is installed on the closed circuit. The controller controls the power output according to the circuit connection time. The controller can gradually increase the repulsive force generated by the electromagnet 513, which can gradually increase the gap between the sealing plate 45 and the conical hole 42, thereby controlling the effective flow area of ​​the vent hole 33. The power of the electromagnet 513 can be controlled by detecting the height of the second contact 526. The flow area of ​​the vent hole 33 can be controlled in real time according to the gas volume.

[0034] A first corrugated pipe 53 is fixedly installed between the liquid storage plate 3 and the connecting plate 511. The magnetic block 512 and the electromagnet 513 are both located inside the first corrugated pipe 53. The first corrugated pipe 53 prevents the liquid from interfering with the magnetic block 512 and the electromagnet 513. A second corrugated pipe 54 is fixedly installed between the tower plate 2 and the base. The support rod 522, the cylinder 523, the connecting rod 524, the first contact 525 and the second contact 526 are all located inside the second corrugated pipe 54. The second corrugated pipe 54 prevents the liquid from affecting the first contact 525 and the second contact 526.

[0035] Multiple triangular plates 7 are fixedly installed inside the tower body 1. The triangular plates 7 are located between the tower plate 2 and the liquid storage plate 3. The liquid flowing out from one side of the liquid storage plate 3 will come into contact with the triangular plates 7, and a part of the liquid will enter the lower liquid storage plate 3, while the other part of the liquid will enter the lower tower plate 2.

[0036] On the other hand, this application proposes a method for controlling crude α-pyrrolidone, based on the above-mentioned purification apparatus for crude α-pyrrolidone, specifically including the following steps: Step 1: Gas moves upward from the bottom of tower 1, and liquid moves downward from the top of tower 1. A portion of the liquid is stored on tower plate 2 and liquid storage plate 3. Step 2: Under the action of gas pressure, the gas passes through the gas hole 23 and comes into contact with the liquid on the tray 2 and reacts. When the gas flow rate is high, it will drive the float valve 24 to rise, and at the same time, the liquid on the tray 2 is prone to splashing. Step 3: When the float valve 24 rises, the drain hole 33 is opened by the starting component 52 and the driving component 51, so that the liquid on the liquid storage plate 3 flows downward and comes into contact with the rapidly rising liquid, thereby compensating for the liquid when the gas flows rapidly.

[0037] In this embodiment, fresh steam, serving as the driving force, enters from the bottom steam inlet 12 and flows upward, while the organic phase rich in azeotropic agent, serving as the reflux liquid, enters from the top liquid inlet 14 and flows downward. The downward flowing liquid forms a liquid layer on the tray 2, and the upward flowing gas, under the action of gas pressure, passes through the vents 23 on the tray 2 and opens the float valve 24, making full contact with the liquid on the tray in the form of bubbles. During this process, mass and heat transfer occur, and the high-boiling-point components in the gas, such as water, condense and transfer to the liquid phase, while the low-boiling-point components in the liquid phase, such as azeotropic agent, volatilize and transfer to the gas phase. After contacting the gas, some components of the liquid undergo phase change and continue to flow downward. Finally, the dehydrated α-pyrrolidone product is discharged from the bottom liquid outlet 11. The gas that has not contacted the liquid continues to rise, and finally, the mixed steam rich in water and azeotropic agent is discharged from the top gas outlet 13. After condensation and phase separation, the azeotropic agent is recycled back into the tower as reflux liquid, and the water is discharged from the system as waste liquid, thus forming a continuous closed-loop dehydration and refining process.

[0038] The above specific embodiments are merely several optional embodiments of the present invention. Based on the technical solutions of the present invention and the relevant teachings of the above embodiments, those skilled in the art can make various alternative improvements and combinations to the above specific embodiments.

Claims

1. A device for refining crude α-pyrrolidone, comprising a tower body (1) and a plurality of tower plates (2) fixedly installed inside the tower body (1), characterized in that, Also includes: A liquid storage plate (3) is fixedly installed inside the tower body (1) and located above the tower plate (2), and the liquid storage plate (3) stores liquid. Multiple air holes (23) are provided on the tower plate (2), a float valve (24) is installed on the tower plate (2) corresponding to the air holes (23) and rising and falling according to the air pressure, and a drain hole (33) is provided on the liquid storage plate (3) corresponding to the air holes (23) and coaxially arranged. A variable valve port mechanism (4) is fixedly installed on the drain hole (33), the variable valve port mechanism (4) controlling the size of the flow orifice diameter of the drain hole (33); The splash compensation component (5) includes a drive assembly (51) connected to the variable valve port mechanism (4) and controlling the size of the flow orifice of the variable valve port mechanism (4), and an activation assembly (52) connected to the float valve (24) and moving according to the rise and fall of the float valve (24). The height position of the activation assembly (52) controls the on / off state of the circuit of the drive assembly (51).

2. The device for purifying crude α-pyrrolidone according to claim 1, wherein The variable valve mechanism (4) includes a valve body (41) fixedly installed on the liquid storage plate (3). The valve body (41) has a conical hole (42) inside. A slide rod (44) is slidably installed inside the valve body (41) via a support frame (43). A sealing plate (45) for sealing the conical hole (42) is fixedly installed at one end of the slide rod (44).

3. The purification apparatus for crude α-pyrrolidone according to claim 2, characterized in that, A spring (46) is fixedly installed between the sealing plate (45) and the support frame (43), and a sealing ring is fixedly installed on the edge of the sealing plate (45).

4. The purification apparatus for crude α-pyrrolidone according to claim 3, characterized in that, The drive assembly (51) includes a connecting plate (511) fixedly installed on the slide bar (44), a magnetic block (512) fixedly installed at one end of the connecting plate (511), and an electromagnet (513) fixedly installed on the liquid storage plate (3).

5. The purification apparatus for crude α-pyrrolidone according to claim 4, characterized in that, The starting assembly (52) includes a synchronization plate (521) fixedly installed on the float valve (24), a support rod (522) fixedly installed on the synchronization plate (521), a cylinder (523) fixedly installed on the tower plate (2) via a base, a connecting rod (524) slidably installed inside the cylinder (523), a first contact point (525) fixedly installed on the support rod (522), and a second contact point (526) fixedly installed on the connecting rod (524).

6. The purification apparatus for crude α-pyrrolidone according to claim 5, characterized in that, A power source is installed on the outside of the tower body (1). The power source, the first contact (525), the electromagnet (513), and the second contact (526) form a closed circuit. A controller is installed on the closed circuit. The controller controls the power output of the power source according to the circuit connection time.

7. The apparatus for refining crude α-pyrrolidone according to claim 6, characterized in that, A first corrugated pipe (53) is fixedly installed between the liquid storage plate (3) and the connecting plate (511). The magnetic block (512) and the electromagnet (513) are both located inside the first corrugated pipe (53). A second corrugated pipe (54) is fixedly installed between the tower plate (2) and the base. The support rod (522), the cylinder (523), the connecting rod (524), the first contact point (525), and the second contact point (526) are all located inside the second corrugated pipe (54).

8. The apparatus for refining crude α-pyrrolidone according to claim 7, characterized in that, The tower plate (2) includes a first plate body (21), a first dam (22) is fixedly installed at one end of the first plate body (21), and the air holes (23) are evenly distributed on the surface of the first plate body (21); The float valve (24) includes multiple limiting rods (241) slidably mounted on the first plate (21), and a circular plate (242) is fixedly mounted on the multiple limiting rods (241). The bottom of the limiting rods (241) is provided with a curved part (243).

9. The apparatus for refining crude α-pyrrolidone according to claim 8, characterized in that, The liquid storage plate (3) includes a second plate (31) fixedly installed inside the tower body (1), and a second cofferdam (32) is fixedly installed at both ends of the second plate (31). The drain holes (33) are evenly distributed on the surface of the second plate (31). The second plate (31) is provided with a plurality of flow guide holes (6), and a flow guide pipe (61) is fixedly installed on the flow guide hole (6). The flow guide pipe (61) is higher than the second cofferdam (32).

10. A method for controlling crude α-pyrrolidone, based on the refining apparatus for crude α-pyrrolidone according to any one of claims 1-9, characterized in that, Specifically, the following steps are included: Step 1: Gas moves upward from the bottom of the tower body (1), and liquid moves downward from the top of the tower body (1). A portion of the liquid is stored on the tower plate (2) and the liquid storage plate (3). Step 2: Under the action of gas pressure, the gas passes through the gas hole (23) and comes into contact with the liquid on the tray (2) and reacts. When the gas flow rate is high, it will drive the float valve (24) to rise, and at the same time the liquid on the tray (2) is prone to splashing. Step 3: When the float valve (24) rises, the drain hole (33) is opened by the starting component (52) and the driving component (51), so that the liquid on the liquid storage plate (3) flows downward and comes into contact with the rapidly rising liquid, and the liquid is compensated when the gas flows rapidly.

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