A multi-stage purification tower for sodium methoxide production

Abstract

This invention discloses a multi-stage purification tower for sodium methoxide production, comprising a feed heater and multiple distillation towers connected in series. Each distillation tower has a feed inlet, a top exhaust port, a bottom drain port, and a top reflux port. Each distillation tower is also equipped with a bottom reboiler and a top condenser. A demister is installed between the top condenser and the top exhaust port, and a buffer tank is installed between the top condenser and the top reflux port. The bottom drain port of the previous distillation tower is connected to the feed inlet of the next distillation tower via a pipeline. This invention, through a cascade purification structure with multiple distillation towers connected in series, allows the material initially purified at the bottom of the previous tower to be continuously fed into the next distillation tower, progressively removing moisture and light component impurities from the system, continuously promoting the forward reaction of sodium methoxide synthesis, fundamentally suppressing the hydrolysis side reaction of sodium methoxide, and improving the purity of the sodium methoxide product.

Description

Technical Field

[0001] This invention relates to the field of sodium methoxide production technology, and in particular to a multi-stage purification tower for sodium methoxide production. Background Technology

[0002] Sodium methoxide is a core organic synthesis intermediate widely used in chemical industries such as pharmaceutical synthesis, pesticide production, biodiesel preparation, and fragrance processing. It is also a commonly used strong base catalyst in organic reactions, and its industrial market demand continues to expand. Currently, the mainstream production process for sodium methoxide in China is the alkaline synthesis process, using methanol and sodium hydroxide as raw materials to produce sodium methoxide and water through a reversible reaction. The core limiting factor of this reaction is that the product sodium methoxide readily undergoes hydrolysis and reverse reaction upon contact with water. Therefore, continuous and efficient removal of moisture from the system through distillation purification is essential to drive the reaction forward. The efficiency and stability of the distillation purification process directly determine the purity, production cost, and production continuity of the sodium methoxide product.

[0003] The existing demisting process at the top of distillation columns has significant defects. During the production of sodium methoxide, the vapor phase at the top of the column carries highly alkaline sodium methoxide mist that is prone to crystallization and scaling. Traditional fixed baffle and wire mesh demisters are easily clogged by scaling, causing a continuous increase in system pressure drop and a rapid decrease in demisting efficiency. This requires frequent shutdowns for disassembly and cleaning, which not only interrupts the continuous production process but also allows air and moisture to enter the system, further aggravating the hydrolysis side reaction of sodium methoxide. At the same time, fixed-structure demisters have a large number of cleaning dead zones, making thorough cleaning impossible.

[0004] In response to the above problems, some patented technologies related to sodium methoxide distillation have been disclosed in the industry. However, most of them focus on the structural optimization of single-tower reactive distillation and have not solved the problem of coordinated operation of multi-tower series continuous purification. They have not proposed effective online cleaning and operating condition adaptation solutions for the core pain points of demisters, such as easy scaling, difficulty in cleaning, and poor operational stability. They cannot simultaneously meet the requirements of efficient demisting, dead-angle online cleaning, and wide production load adaptation, and are difficult to meet the requirements of large-scale, continuous, and high-purity sodium methoxide industrial production. Summary of the Invention

[0005] To address the problems mentioned in the background section, this invention provides a multi-stage purification tower for sodium methoxide production.

[0006] To achieve the above objectives, the present invention adopts the following technical solution:

[0007] A multi-stage purification tower for sodium methoxide production includes a feed heater and a distillation tower, wherein multiple distillation towers are provided and connected in series with each other.

[0008] The distillation column is equipped with a feed inlet, a top exhaust outlet, a bottom liquid outlet, and a top reflux outlet;

[0009] The distillation column is also equipped with a bottom reboiler and a top condenser. A demister is provided between the top condenser and the top exhaust port, and a buffer tank is provided between the top condenser and the top reflux port.

[0010] The drain outlet at the bottom of the previous distillation column is connected to the feed inlet of the next distillation column via a pipeline.

[0011] Preferably, the distillation column is provided with multiple trays from top to bottom, and multiple air holes are opened on the trays, with float valves installed on the air holes.

[0012] Preferably, the tray has a liquid overflow notch on one side, and an overflow weir and a guide plate are provided on the side of the liquid overflow notch.

[0013] Preferably, the demister has an air inlet on one side and an air outlet on the other side, a drain outlet near the bottom on one side, a baffle blocking mechanism inside the demister, and a cleaning mechanism inside the demister.

[0014] Preferably, the folding plate blocking mechanism includes multiple sets of baffles, each set of baffles has two baffles, and the two baffles are hinged to each other on the side that is close to each other, and a threaded sleeve is hinged to the side that is far from each other. Multiple threaded rods are rotatably installed inside the demister, and the multiple sets of baffles are equidistantly arranged on the threaded rods. The threaded sleeve is threadedly installed on the outside of the threaded rods.

[0015] Preferably, the two threaded sleeves on each set of baffles are installed on opposite threads on the threaded rod, and each threaded rod is also equipped with two guide rods. A guide sleeve is also hinged on the baffle at the position corresponding to the guide rod, and the guide sleeve is slidably installed on the outside of the guide rod.

[0016] Preferably, the bottom end of the demister is fixed with a drive box, the bottom end of the threaded rod extends into the drive box and is fixed with a first bevel gear, a horizontally arranged drive shaft is rotatably installed in the drive box, the drive shaft is driven to rotate by a rotary motor, and a plurality of second bevel gears are fixed on the drive shaft, the plurality of second bevel gears meshing with a plurality of first bevel gears in a first corresponding manner.

[0017] Preferably, the cleaning mechanism includes a horizontal water inlet pipe, the inlet end of which is connected to a water supply device via a hose, and a plurality of lifting vertical pipes are fixed at the bottom end of the horizontal water inlet pipe. The bottom end of the lifting vertical pipes slides into the demister, and a row of cleaning nozzles is connected to the bottom end of the lifting vertical pipes. The cleaning nozzles are equipped with counterweights.

[0018] Preferably, the top end of the horizontal water inlet pipe is connected to a traction rope, the top end of the demister is fixed with a mounting bracket, and a first reversing pulley and a second reversing pulley are rotatably mounted on the mounting bracket. After passing through the first reversing pulley and the second reversing pulley, one end of the traction rope faces downward and is fixed with a pull ring.

[0019] Preferably, a hook corresponding to the pull ring is fixed on one side of the demister, and a gas distributor is connected to one end of the air inlet located inside the demister.

[0020] Compared with the prior art, the beneficial effects of the present invention are:

[0021] 1. Through a cascade purification structure with multiple distillation columns connected in series, the material that has undergone preliminary purification at the bottom of the previous column can be continuously fed into the next distillation column to remove moisture and light component impurities from the system step by step, continuously promoting the forward reaction of sodium methoxide synthesis, suppressing the side reaction of sodium methoxide hydrolysis from the source, improving the purity of sodium methoxide product, fully meeting the quality requirements of pharmaceutical-grade high-purity products, and realizing continuous operation of the entire sodium methoxide purification process, which improves production efficiency and capacity compared with traditional batch process.

[0022] 2. Through the coordinated design of the angle-adjustable baffle blocking mechanism and the matching lifting cleaning mechanism, under normal production conditions, the baffle bends to form a continuous baffle channel, which can efficiently capture sodium methoxide mist entrained in the gas phase, effectively avoiding material loss and corrosion and blockage of downstream condensers and pipelines; under cleaning conditions, the baffle can be rotated to a straight state, opening up an unobstructed cleaning channel, and together with the lifting cleaning nozzle, it can achieve online cleaning of the entire area inside the demister without dead angles, without the need to stop the equipment for disassembly. Attached Figure Description

[0023] To more clearly illustrate the technical solutions in the embodiments of the present invention or the prior art, the drawings used in the description of the embodiments or the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0024] Figure 1 This is an overall flowchart of the present invention;

[0025] Figure 2 This is a front-view sectional view of the distillation column of the present invention;

[0026] Figure 3 This is a three-dimensional sectional view of the distillation column of the present invention;

[0027] Figure 4 This is a front-view sectional view of the demister of the present invention;

[0028] Figure 5 for Figure 4 Enlarged detail image of position A in the middle;

[0029] Figure 6 for Figure 4 Enlarged detail image of position B in the middle;

[0030] Figure 7 Left view of the mounting structure of a set of baffles according to the present invention;

[0031] In the diagram: 1. Distillation column; 101. Top exhaust port; 102. Bottom drain port; 103. Feed inlet; 104. Top reflux port; 105. Tray; 1051. Float valve; 1052. Overflow weir; 1053. Guide plate; 2. Bottom reboiler; 3. Feed heater; 4. Demister; 401. Air inlet; 402. Air outlet; 403. Drain; 404. Drive box; 405. Rotary motor; 406. Drive shaft; 407. Second bevel gear 408. Wheel; 5. Hook; 6. Tower top condenser; 7. Buffer tank; 8. Threaded rod; 901. Guide rod; 10. Baffle; 11. Threaded sleeve; 12. Guide sleeve; 13. First bevel gear; 14. Horizontal water inlet pipe; 15. Hose; 16. Lifting riser; 17. Cleaning nozzle; 18. Counterweight; 19. Traction rope; 10. Mounting bracket; 10. First reversing pulley; 11. Second reversing pulley; 12. Pull ring. Detailed Implementation

[0032] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0033] Example

[0034] Reference Figure 1-7 Referring to Figures 1-7, a multi-stage purification tower for sodium methoxide production includes a feed heater 3 and a distillation tower 1. The feed heater 3 raises the temperature of the feed material through heat exchange with a heat medium, bringing it to the saturation state of the distillation feed. This ensures that the material entering the distillation tower can quickly achieve gas-liquid separation, improving the initial efficiency of distillation purification. The distillation tower 1 achieves multiple countercurrent contact mass transfers between the gas and liquid phases through its internal tower structure, providing the core reaction and separation space for the multi-stage continuous purification of sodium methoxide. Multiple distillation towers 1 are provided, and these towers 1 are connected in series. Through the series connection of multiple towers, the material is purified step by step to gradually remove light component impurities and moisture from the material, avoiding the problem of insufficient separation capacity of a single tower leading to substandard purity of the sodium methoxide product.

[0035] The distillation column 1 is equipped with a feed inlet 103, a top exhaust port 101, a bottom liquid outlet 102, and a top reflux port 104. The feed inlet 103 receives the material processed in the previous stage and sends it into the designated mass transfer separation area inside the column, ensuring that the material accurately enters the corresponding position inside the column and ensuring the stable progress of the distillation mass transfer process. The top exhaust port 101 discharges the light component gas phase separated inside the column, continuously sending the removed methanol, water, and other light components out of the column, promoting the forward reaction of sodium methoxide synthesis and suppressing hydrolysis side reactions. The bottom liquid outlet 102 discharges the purified heavy component sodium methoxide material inside the column, sending the material purified step by step to the next distillation unit to achieve continuous series purification. The top reflux port 104 refluxes the liquid phase condensed at the top of the column back into the column, forming a downward flow of the liquid phase inside the column, which forms a countercurrent contact with the rising gas phase, ensuring the continuous progress of distillation mass transfer separation.

[0036] The distillation column 1 is also equipped with a bottom reboiler 2 and a top condenser 5. The bottom reboiler 2 provides heat to the bottom material through heat exchange with a heat medium, causing partial vaporization of the liquid phase material to form an upward gas phase, providing continuous gas phase power for gas-liquid mass transfer in the column and ensuring stable circulation of the distillation process. The top condenser 5 condenses the top gas phase into a liquid phase through heat exchange with a cold medium, realizing the liquefaction and recovery of the light component gas phase, providing a liquid phase source for the reflux in the column, and simultaneously realizing the recovery and recycling of methanol solvent. A demister 4 is installed between the top condenser 5 and the top exhaust port 101. The demister 4 captures liquid droplets entrained in the gas phase through its internal structure, intercepting sodium methoxide material droplets entrained in the gas phase, avoiding material loss and corrosion and blockage of downstream equipment, while ensuring the cleanliness of the gas phase entering the condenser. A buffer tank 6 is installed between the top condenser 5 and the top reflux port 104. The condensed liquid phase is temporarily stored and pressure stabilized to stabilize the flow rate and pressure of the liquid phase refluxed from the top of the column, avoid the disruption of the distillation conditions in the column caused by fluctuations in the reflux flow rate, and ensure the stability of mass transfer and separation in the column.

[0037] The bottom drain port 102 of the previous distillation column 1 is connected to the feed port 103 of the next distillation column 1 through a pipeline, so as to realize the continuous conveying of purified materials step by step, ensure the continuous operation of the multi-column series purification process, and realize the deep step-by-step purification of materials.

[0038] The distillation column 1 is provided with multiple trays 105 from top to bottom, providing a place for contact and mass transfer between the gas and liquid phases inside the column. Multiple trays form multiple continuous mass transfer separation stages, improving the separation and purification efficiency of the distillation column. Multiple gas holes are opened on the trays 105, and float valves 1051 are installed on the gas holes. The float valves 1051 automatically adjust their opening height according to the gas flow rate, ensuring sufficient gas-liquid contact within a wide gas load range, avoiding leakage at low gas velocities and flooding at high gas velocities, and improving the operational flexibility of the distillation column.

[0039] One side of the tray 105 is provided with a liquid overflow notch, and the side of the liquid overflow notch of the tray 105 is provided with an overflow weir 1052 and a guide plate 1053. The overflow weir 1052 maintains a stable liquid layer thickness on the tray, ensuring sufficient contact time between the gas and liquid phases on the tray and improving the mass transfer separation effect. The guide plate 1053 guides the liquid phase of the upper tray to flow smoothly into the lower tray, avoiding splashing and deflection during the liquid phase falling, ensuring uniform liquid phase distribution on the tray and stabilizing the distillation conditions in the column.

[0040] The demister 4 has an inlet 401 on one side and an outlet 402 on the other side. A drain outlet 403 is located near the bottom on one side of the demister 4. The inlet 401 receives the gas phase discharged from the top of the distillation column and sends it into the demister. The outlet 402 sends the cleaned gas phase after demisting out of the demister, smoothly transporting the demisted gas phase to the downstream condenser. The drain outlet 403 discharges the collected droplets and cleaning waste liquid inside the demister, promptly discharging the collected sodium methoxide material droplets and scaling cleaning waste liquid to prevent the accumulated liquid from being re-entrained by the gas phase, while ensuring the cleanliness of the demister's interior. The demister 4 has an internal baffle blocking mechanism. The device is equipped with a cleaning mechanism. The baffle plate blocking mechanism changes the direction of gas flow through the baffle structure and uses inertial force to capture mist droplets in the gas phase, effectively removing sodium methoxide mist entrained in the gas phase and achieving efficient gas-liquid separation. The cleaning mechanism washes the internal structure of the demister by spraying cleaning media, removing scale and crystals on the baffle plate blocking mechanism online, avoiding structural blockage that leads to decreased demister efficiency and increased system pressure drop, and ensuring long-term stable operation of the demister.

[0041] The baffle blocking mechanism includes multiple sets of baffles 8, with two baffles in each set. The two baffles 8 are hinged together on their closest sides, allowing relative rotation of the two baffles through the hinge structure. This creates an adjustable deflection angle, enabling flexible switching between the defogging working state and the cleaning preparation state, thus meeting the dual requirements of efficient defogging and convenient cleaning. In the bent state, a deflection channel is formed to capture mist droplets, while in the straight state, a cleaning channel is opened to achieve thorough rinsing. A threaded sleeve 801 is hinged to the far side of the two baffles 8. The linear movement of the threaded sleeve drives the baffle to rotate around the hinge point, converting linear motion into rotational motion of the baffle, achieving precise adjustment of the baffle angle and stable switching between the two working states. Multiple threaded rods 7 are rotatably installed inside the demister 4, with multiple sets of baffles 8 equidistantly arranged on the threaded rods 7. The threaded sleeve 801 is threadedly installed on the threaded rods 7. Externally, the rotation of the threaded rod drives the threaded sleeve to move linearly along the rod body. The rotation of a single threaded rod synchronously drives the two baffles in the same group to move synchronously, ensuring that the state switching of multiple baffles is synchronized and consistent, and avoiding action deviation.

[0042] The two threaded sleeves 801 on each set of baffles 8 are installed on opposite threads on the threaded rod 7. The opposing threads enable the two threaded sleeves to move synchronously towards or away from each other, ensuring that when the threaded rod rotates, the two baffles in the same set can bend or flatten synchronously, achieving synchronous switching of states and avoiding jamming caused by asynchronous movements. This ensures precise positioning of both bending defogging and straight cleaning states. In addition, each threaded rod 7 is also equipped with two guide rods 701. A guide sleeve 802 is hinged to the baffle 8 at the corresponding position of the guide rod 701. The guide sleeve 802 is slidably installed outside the guide rod 701. The guide rod 701 and the guide sleeve 802 provide radial limit and guidance for the movement of the baffle, preventing the baffle from circumferentially deflecting when the threaded rod rotates, ensuring that the baffle always rotates within the specified plane, and improving the stability and smoothness of the structure's operation.

[0043] The bottom end of the demister 4 is fixed with a drive box 404. The bottom end of the threaded rod 7 extends into the drive box 404 and is fixed with a first bevel gear 803. A horizontally arranged drive shaft 406 is rotatably installed inside the drive box 404. The drive shaft 406 is driven to rotate by a rotary motor 405. Multiple second bevel gears 407 are fixed on the drive shaft 406. The multiple second bevel gears 407 mesh with the multiple first bevel gears 803 one by one. The rotary motor drives the drive shaft to rotate. The horizontal rotational motion is converted into the synchronous vertical rotational motion of multiple threaded rods through the bevel gear meshing transmission. The synchronous rotation of multiple threaded rods is achieved by a single drive motor, ensuring that the state switching of all baffle groups is completely synchronized, and improving the linkage and control accuracy of the structure.

[0044] The cleaning mechanism includes a horizontal water inlet pipe 9, which receives and distributes the cleaning medium, evenly distributing it to each cleaning point to ensure full-area cleaning coverage. The inlet end of the horizontal water inlet pipe 9 is connected to a water supply device via a flexible hose 901. The hose 901 flexibly delivers the cleaning medium, adapting to the lifting and lowering movements of the horizontal water inlet pipe, ensuring a continuous and stable supply of the cleaning medium during the lifting and lowering process of the cleaning mechanism, avoiding pipe breakage due to tension. Multiple lifting vertical pipes 902 are fixed to the bottom of the horizontal water inlet pipe 9, driving the cleaning nozzles to move vertically, achieving full vertical coverage of the cleaning points and eliminating cleaning dead zones. The bottom end of the lifting vertical pipes 902 slides into the demister 4, and a row of cleaning nozzles 903 is connected to the bottom end of the lifting vertical pipes 902. The cleaning nozzles 903 atomize and spray the cleaning medium onto the surface to be cleaned. The high-pressure spray of the cleaning medium fully dissolves and washes away scale and crystals on the structural surface, achieving efficient online cleaning and adapting to full-surface rinsing when the baffle is in a straight position. The cleaning nozzles 903... The upper part is equipped with a counterweight 904, which drives the cleaning nozzle and the lifting vertical pipe to move downward through gravity, ensuring that the cleaning mechanism can descend smoothly by gravity and achieve full coverage rinsing from top to bottom, avoiding the problem of jamming and inability to descend.

[0045] The top of the horizontal water pipe 9 is connected to a traction rope 905. The traction force drives the horizontal water pipe to move upward, realizing the upward reset of the cleaning mechanism. Combined with the downward movement, it realizes reciprocating rinsing and improves the cleaning effect. The top of the demister 4 is fixed with a mounting bracket 906. The mounting bracket 906 is rotatably mounted with a first reversing pulley 9061 and a second reversing pulley 9062. By changing the direction of the traction rope's tension through the pulleys, the vertical traction action is converted into a downward pulling force that is easy to operate, realizing flexible control of the lifting and lowering of the cleaning mechanism. After passing through the first reversing pulley 9061 and the second reversing pulley 9062, one end of the traction rope 905 faces downward and is fixed with a pull ring 9063, which allows the operator to control the lifting and lowering of the cleaning mechanism by pulling the pull ring, realizing flexible adjustment of the rinsing position.

[0046] A hook 408 corresponding to the pull ring 9063 is fixed on one side of the demister 4 to hook and fix the pull ring. After the cleaning mechanism moves upward and resets, the position is locked to prevent the cleaning mechanism from affecting the gas flow under normal demisting conditions. The air inlet 401 is connected to a gas distributor at one end inside the demister 4 to evenly distribute the incoming gas phase, ensuring that the gas phase can flow evenly across the entire cross-section of the baffle blocking mechanism, avoiding the decrease in demisting efficiency caused by gas phase deviation, and improving the overall demisting effect.

[0047] In the description of this invention, it should be understood that the terms "center," "longitudinal," "lateral," "length," "width," "thickness," "upper," "lower," "front," "rear," "left," "right," "vertical," "horizontal," "top," "bottom," "inner," "outer," "clockwise," "counterclockwise," "axial," "radial," and "circumferential" indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are used only for the convenience of describing this 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. Therefore, they should not be construed as limitations on this invention.

[0048] In this invention, unless otherwise explicitly specified and limited, the terms "set," "install," "connect," "link," and "fix" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral part; they can refer to a mechanical connection, a direct connection, or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.

[0049] The control method of this invention is automatic control through a controller. The control circuit of the controller can be implemented by simple programming by those skilled in the art. The power supply is also common knowledge in the art. Furthermore, since this invention is mainly used to protect mechanical devices, the control method and circuit connection will not be explained in detail here.

[0050] The above description is only a preferred embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.

Claims

1. A multi-stage purification column for sodium methoxide production, comprising a feed heater (3) and a rectification column (1), characterized in that: The distillation column (1) is provided in multiple units, and the multiple distillation columns (1) are connected in series with each other; The distillation column (1) is provided with a feed inlet (103), a top exhaust port (101), a bottom liquid outlet (102), and a top reflux port (104). The distillation column (1) is also equipped with a bottom reboiler (2) and a top condenser (5). A demister (4) is provided between the top condenser (5) and the top exhaust port (101), and a buffer tank (6) is provided between the top condenser (5) and the top reflux port (104). The bottom drain (102) of the previous distillation column (1) is connected to the feed inlet (103) of the next distillation column (1) via a pipeline.

2. The multi-stage purification column for producing sodium methoxide according to claim 1, characterized in that: The distillation column (1) is provided with multiple trays (105) from top to bottom. Multiple air holes are provided on the trays (105), and float valves (1051) are installed on the air holes.

3. The multi-stage purification column for producing sodium methoxide according to claim 2, characterized in that: The tray (105) is provided with a liquid overflow notch on one side, and an overflow weir (1052) and a guide plate (1053) are provided on the side of the liquid overflow notch of the tray (105).

4. The multi-stage purification tower for sodium methoxide production according to claim 1, characterized in that: The demister (4) has an air inlet (401) on one side and an air outlet (402) on the other side. A drain outlet (403) is located near the bottom on one side of the demister (4). The demister (4) has a baffle blocking mechanism inside and a cleaning mechanism inside.

5. A multi-stage purification tower for sodium methoxide production according to claim 4, characterized in that: The folding plate blocking mechanism includes multiple sets of baffles (8), each set of baffles (8) has two, and the two baffles (8) are hinged to each other on the side that is close to each other, and a threaded sleeve (801) is hinged to the side that is far from each other. Multiple threaded rods (7) are rotatably installed inside the demister (4). Multiple sets of baffles (8) are equidistantly arranged on the threaded rods (7), and the threaded sleeve (801) is threadedly installed on the outside of the threaded rods (7).

6. The multi-stage purification column for producing sodium methoxide according to claim 5, characterized in that: The two threaded sleeves (801) on each set of baffles (8) are installed on opposite threads on the threaded rod (7), and each threaded rod (7) is also equipped with two guide rods (701). A guide sleeve (802) is also hinged on the baffle (8) at the position corresponding to the guide rod (701). The guide sleeve (802) is slidably installed on the outside of the guide rod (701).

7. The multi-stage purification column for producing sodium methoxide according to claim 5, characterized in that: The bottom end of the demister (4) is fixed with a drive box (404), the bottom end of the threaded rod (7) extends into the drive box (404) and is fixed with a first bevel gear (803), a horizontally arranged drive shaft (406) is rotatably installed in the drive box (404), the drive shaft (406) is driven to rotate by a rotary motor (405), and a plurality of second bevel gears (407) are fixed on the drive shaft (406), and the plurality of second bevel gears (407) mesh with the plurality of first bevel gears (803) in the first corresponding manner.

8. The multi-stage purification column for producing sodium methoxide according to claim 7, characterized in that: The cleaning mechanism includes a horizontal water inlet pipe (9), the water inlet end of which is connected to a water supply device via a hose (901), and a plurality of lifting vertical pipes (902) are fixed at the bottom end of the horizontal water inlet pipe (9). The bottom end of the lifting vertical pipe (902) slides into the demister (4), and a row of cleaning nozzles (903) is connected to the bottom end of the lifting vertical pipe (902). A counterweight (904) is provided on the cleaning nozzle (903).

9. The multi-stage purification column for producing sodium methoxide according to claim 8, characterized in that: The top end of the horizontal water pipe (9) is connected to a traction rope (905), and the top end of the demister (4) is fixed with a mounting bracket (906). The mounting bracket (906) is rotatably mounted with a first reversing pulley (9061) and a second reversing pulley (9062). After the traction rope (905) passes through the first reversing pulley (9061) and the second reversing pulley (9062), one end faces downward and is fixed with a pull ring (9063).

10. The multi-stage purification column for producing sodium methoxide according to claim 9, characterized in that: The demister (4) has a hook (408) fixed on one side corresponding to the pull ring (9063), and the air inlet (401) is connected to a gas distributor at one end inside the demister (4).

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