A purification system of ethyl acetate and a purification method thereof

Abstract

The application relates to an ethyl acetate purification system and a purification method thereof, which comprises a reaction kettle, a first condenser, a rectifying tower, a second condenser, a reflux tank and a finished product tank connected in sequence, a plurality of tower plates are arranged in the rectifying tower, an interface plate slidingly arranged in the rectifying tower is arranged above the tower plates, a floating mechanism is arranged on the lower end surface of the interface plate, a plurality of perforations are formed in the interface plate, a diaphragm is floatingly arranged in the perforations, an actuating coil is arranged on the lower end surface of the diaphragm, a permanent magnet is arranged in the inner circle of the actuating coil, the permanent magnet is fixedly connected to the interface plate, the actuating coil is connected with a high-frequency current controller, and the diaphragm is leveled with the liquid surface above the tower plates through the floating mechanism. The high-frequency oscillation of the diaphragm can improve the mass transfer efficiency between the liquid phase and the gas phase at the liquid surface of the tower plate in the rectifying tower, promotes the separation of the azeotrope, and thus increases the effect and efficiency of the distillation process in the rectifying tower.

Description

Technical Field

[0001] This application relates to the technical field of carboxylic acid ester synthesis, and in particular to a purification system and method for ethyl acetate. Background Technology

[0002] Ethyl acetate, a type of carboxylic acid ester, is an important downstream product of acetic acid. It possesses excellent solubility and rapid drying properties, making it industrially used as a solvent for paints (varnishes, ceramic enamels), adhesives, ethyl cellulose, artificial leather, roofing felt colorants, and synthetic fibers. Acetic acid esterification is the most common method for producing ethyl acetate; it is produced by the esterification of acetic acid and ethanol in the presence of a catalyst.

[0003] The main impurities in the industrial production of ethyl acetate are water, acetic acid, alcohols, and other organic compounds. Current purification methods typically involve dehydration with anhydrous calcium sulfate followed by atmospheric distillation to obtain purified ethyl acetate. However, since ethyl acetate is produced through the esterification reaction of ethanol and acetic acid, this reaction generates water as a byproduct, creating an equilibrium reaction. Furthermore, ethanol and acetic acid can form an azeotrope in a certain ratio, making separation during distillation difficult. Similarly, ethyl acetate and water also form an azeotrope, posing challenges to traditional distillation processes and making it difficult to efficiently separate high-purity ethyl acetate from binary or ternary azeotropes using ordinary distillation methods. Summary of the Invention

[0004] To address the problem of low separation efficiency caused by the formation of azeotropes during the purification and distillation of ethyl acetate, this application provides a purification system and method for ethyl acetate.

[0005] The first aspect of this application provides an ethyl acetate purification system using the following technical solution: An ethyl acetate purification system includes a reaction vessel, a first condenser, a distillation column, a second condenser, a reflux tank, and a product tank connected in sequence. The reflux tank is connected to the top of the distillation column via a reflux pipe. The distillation column is provided with multiple trays, which form a serpentine flow path within the column. An interface plate is slidably disposed above the trays within the distillation column. A floating mechanism is provided on the lower end face of the interface plate, and the interface plate is suspended above the liquid surface above the tray by the floating mechanism. The interface plate has several perforations, and a diaphragm is floatingly mounted in the perforations. An actuation coil is mounted on the lower end face of the diaphragm. A permanent magnet is arranged in the inner circle of the actuation coil. The permanent magnet is fixedly connected to the interface plate. The actuation coil is connected to a high-frequency current controller. The diaphragm is made to be flush with the liquid surface above the tray by the floating mechanism.

[0006] Furthermore, a base is installed in the perforation of the interface plate, and the base has a mounting groove for mounting the permanent magnet. The diaphragm and the opening on the base are spaced apart, and a tightly stretched elastic mesh is connected in the gap between them.

[0007] Furthermore, a waterproof isolation membrane is fixed between the diaphragm and the opening on the base, and the outer and inner rings of the waterproof isolation membrane respectively seal and connect the base and the diaphragm; When the diaphragm is flush with the opening on the base, the waterproof isolation membrane has wrinkles.

[0008] Furthermore, both the diaphragm and the waterproof isolation membrane are made of acid-resistant materials.

[0009] Furthermore, a lubricating layer with a low coefficient of friction is provided between the actuation coil and the permanent magnet.

[0010] Furthermore, a plurality of moving plates are fixedly attached to the upper surface of the diaphragm and spaced apart along its outer edge contour. One end of the moving plate away from the middle of the diaphragm extends into the gap between the diaphragm and the wall of the perforation hole, and a disturbance plate is fixedly attached to the free end of the moving plate.

[0011] Furthermore, the disturbance piece is inclined in the vertical direction.

[0012] Furthermore, multiple protrusions are fixed to the outer periphery of the disturbance piece.

[0013] Furthermore, the diaphragm is made of a reed, and one of the vibration frequencies of the diaphragm caused by the high-frequency current controller is the same as the frequency of the diaphragm itself.

[0014] The second aspect of this application provides a method for purifying ethyl acetate using the following technical solution: A method for purifying ethyl acetate, based on the aforementioned ethyl acetate purification system, includes the following steps: S1. The industrial-grade ethyl acetate in the reactor is mixed with acetic anhydride and concentrated sulfuric acid to undergo an esterification reaction; S2. Add alkali to the reaction solution in the reactor to carry out a neutralization reaction; S3. The reaction liquid in the reactor is distilled to collect the gaseous components. The gaseous components are condensed into liquid by the first condenser and then transported to the distillation column for distillation. During the distillation process, a high-frequency pulse current is transmitted to the actuation coil through the high-frequency current controller so that the diaphragm vibrates at high frequency on the interface plate to oscillate the liquid surface above the column plate at high frequency, thereby promoting the separation of the gaseous and liquid phases in the azeotrope. S4. The gas phase at the top of the distillation column is condensed into liquid by the second condenser and then transported to the reflux tank. Part of the liquid in the reflux tank is transferred to the product tank and part is returned to the distillation column.

[0015] In summary, the beneficial technical effects of this application are as follows: 1. During distillation in a distillation column, a high-frequency oscillating current is input into the actuator coil via a high-frequency current controller, enabling high-frequency vibration of the diaphragm. This causes the diaphragm to oscillate at the surface of the reaction liquid above the tray, increasing the evaporation area and accelerating the evaporation process. Furthermore, the diaphragm oscillation can break the concentration boundary layer near the liquid surface, allowing the components in the vapor and liquid to reach equilibrium more quickly. Simultaneously, the diaphragm oscillation can promote the formation and collapse of droplets and bubbles, significantly improving the mass transfer rate. Thus, the high-frequency oscillation of the diaphragm can enhance the mass transfer efficiency between the liquid and gas phases at the liquid surface on the trays within the distillation column, promoting azeotropic separation and thereby increasing the effectiveness and efficiency of the distillation process in the distillation column. 2. By controlling the frequency and magnitude of the current supplied to the actuation coil by the high-frequency current controller, the vibration frequency and amplitude of the diaphragm can be controlled. In other words, after the high-frequency current controller is connected to a microcomputer, with the help of relevant sensors installed in the distillation column, it can be flexibly adjusted according to the reaction progress in the distillation column. For example, when the flow rate of the reaction liquid in the distillation column increases or the purity of the ethyl acetate in the outlet gas phase is low, the output current frequency and / or magnitude of the high-frequency current controller can be increased to achieve automated control of efficient distillation in the distillation column. 3. By adding multiple co-moving plates to the diaphragm, the diaphragm can vibrate at high frequency while simultaneously driving multiple co-moving plates and their disturbance plates to vibrate at high frequency. The disturbance plates can obliquely penetrate the gas phase above and the liquid phase below the liquid interface on the tray. Thus, when the disturbance plates vibrate at high frequency, they can more significantly break the laminar boundary layer in the liquid, exposing more liquid molecules to the liquid-gas interface and improving the mass transfer rate. Furthermore, the setting of multiple disturbance plates can not only expand the influence range of the diaphragm's high-frequency oscillation, but also change the vibration characteristics of the diaphragm, such as increasing the amplitude or changing the vibration frequency, thereby producing a stronger dynamic influence on the liquid layer and intensifying the separation of azeotropes. Attached Figure Description

[0016] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application; Figure 2 This is a partial cross-sectional view of the distillation column according to an embodiment of this application; Figure 3 This is a cross-sectional view of the interface panel according to an embodiment of this application; Figure 4 yes Figure 3 A magnified view of part A in the diagram.

[0017] Explanation of reference numerals in the attached figures: 11. Reactor; 12. First condenser; 13. Distillation column; 14. Second condenser; 15. Reflux tank; 16. Finished product tank; 2. Trays; 3. Interface panel; 31. Perforation; 41. Diaphragm; 42. Actuation coil; 43. Permanent magnet; 44. Base; 441. Mounting slot; 45. Elastic mesh; 46. Waterproof isolation membrane; 47. Lubricating layer; 51. Simultaneous movement plate; 52. Disturbance plate; 53. Thrust; 6. Floating mechanism. Detailed Implementation

[0018] The technical solutions of this application will now be clearly and completely described with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this application. Based on the embodiments of this application, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this application.

[0019] This application discloses a purification system for ethyl acetate. (Refer to...) Figure 1 , Figure 2 and Figure 3 The system comprises a reaction vessel 11, a first condenser 12, a distillation column 13, a second condenser 14, a reflux tank 15, and a finished product tank 16, connected in sequence. The reflux tank 15 is connected to the top of the distillation column 13 via a reflux pipe. The distillation column 13 is equipped with multiple trays 2, which form a serpentine flow path within the column. An interface plate 3 is slidably disposed within the distillation column 13 above the trays 2. The outer edge of the interface plate 3 does not extend beyond the outer edge of the tray 2. A floating mechanism 6 is provided on the lower end face of the interface plate 3, allowing the interface plate 3 to suspend above the liquid surface of the tray 2. The floating mechanism 6 can be a float, an air bladder, etc., and its outer wall material should be selected to be non-corrosive to the reaction liquid within the distillation column 13, such as stainless steel, polyetheretherketone, or polytetrafluoroethylene.

[0020] A plurality of perforations 31 are provided on the interface plate 3, arranged in an array. A diaphragm 41 is floatingly mounted in the perforations 31 on the interface plate 3. A gap is reserved between the outer edge of the diaphragm 41 and the wall of the perforation 31. An actuation coil 42 is installed on the lower end face of the diaphragm 41. A permanent magnet 43 is provided in the inner ring of the actuation coil 42. The permanent magnet 43 is fixedly connected to the interface plate 3. The actuation coil 42 is connected to a high-frequency current controller located outside the distillation column 13. The diaphragm 41 is made flush with the liquid surface above the column plate 2 by the floating mechanism 6 to minimize the resistance encountered by the diaphragm 41 during oscillation. The permanent magnet 43 can be circular, elliptical, oval, or rectangular with rounded corners. The actuation coil 42 is adapted to the shape of the permanent magnet 43.

[0021] With this setup, the gas phase generated after the raw material reacts in the reactor 11 is condensed into a liquid state by the first condenser 12 and then transported to the distillation column 13 for distillation. The gas phase at the top of the distillation column 13 is condensed into a liquid state by the second condenser 14 and then transported to the reflux tank 15. Part of the liquid product in the reflux tank 15 is transferred to the product tank 16 for storage, and the other part is refluxed back into the distillation column 13, thereby achieving the purification of ethyl acetate.

[0022] During the distillation process in the distillation column 13, a high-frequency oscillating current is input into the actuation coil 42 through the high-frequency current controller, which can cause the actuation coil 42 to generate a high-frequency magnetic field that changes with the magnitude and direction of the current. This magnetic field interacts with the constant magnetic field generated by the permanent magnet 43, which can cause the actuation coil 42 to drive the diaphragm 41 to move back and forth in the magnetic field of the permanent magnet 43, thus realizing the high-frequency vibration of the diaphragm 41. This allows the diaphragm 41 to oscillate at a high frequency above the liquid surface on the tray 2, continuously disrupting and renewing the liquid-gas interface, resulting in the continuous formation of new liquid surfaces, increasing the evaporation area, and thus accelerating the evaporation process. Furthermore, the oscillation of the diaphragm 41 at the liquid surface helps break the concentration boundary layer near the liquid surface, reducing the gradient layer that hinders mass transfer, allowing the components in the vapor and liquid to reach equilibrium more quickly. At the same time, the oscillation of the diaphragm 41 can also promote the formation and collapse of droplets and bubbles, which can greatly improve the mass transfer rate. Thus, the high-frequency oscillation of the diaphragm 41 can improve the mass transfer efficiency between the liquid and gas phases at the liquid surface on the tray 2 in the distillation column 13, promote azeotropic separation, and thereby increase the effect and efficiency of the distillation process.

[0023] Furthermore, by controlling the frequency and magnitude of the current supplied to the actuation coil 42 by the high-frequency current controller, the vibration frequency and amplitude of the diaphragm 41 can be controlled. In other words, after the high-frequency current controller is connected to the microcomputer, with the help of relevant sensors installed in the distillation column 13, it can be flexibly adjusted according to the reaction progress in the distillation column 13. For example, when the flow rate of the reaction liquid in the distillation column 13 is increased or the purity of the ethyl acetate in the outlet gas phase is low, the output current frequency and / or magnitude of the high-frequency current controller can be increased to achieve automated control of efficient distillation in the distillation column 13.

[0024] More specifically, to ensure the long-term effective vibration of the diaphragm 41, refer to Figure 3 and Figure 4 A base 44 is installed in the perforation 31 of the interface plate 3. The base 44 is fixed to the interface plate 3 and has a gap between its periphery and the wall of the perforation 31. The base 44 has a mounting groove 441 for mounting the permanent magnet 43. The diaphragm 41 and the opening on the base 44 are separated by a gap, and a tightly set elastic mesh 45 is connected in the gap between them. The elastic mesh 45 is used to float and fix the diaphragm 41 so that the diaphragm 41 can move back and forth along the winding axis of the braking coil as much as possible, but cannot move left and right, so as to ensure the vertical vibration effect of the diaphragm 41 on the interface plate 3. The elastic mesh 45 can be made of polyester fiber, polycarbonate, synthetic rubber, or heat-resistant plastics such as polyimide.

[0025] To further protect the braking coil and permanent magnet 43, refer to Figure 3 and Figure 4 A waterproof isolation membrane 46 is fixed between the diaphragm 41 and the opening on the base 44. The outer and inner rings of the waterproof isolation membrane 46 seal the base 44 and the diaphragm 41 respectively. When the diaphragm 41 is flush with the opening on the base 44, the waterproof isolation membrane 46 has wrinkles. Both the diaphragm 41 and the waterproof isolation membrane 46 are made of acid-resistant materials. The diaphragm 41 can be made of materials such as polypropylene (PP), polyester (PET), polytetrafluoroethylene (PTFE), and polyimide (PI), or it can be made of carbon fiber and Kevlar, or high-hardness materials such as aluminum, titanium, or magnesium, to better adapt to the high-frequency oscillation of the diaphragm 41 on the liquid surface. The waterproof isolation membrane 46 has lower performance requirements and can be made of polypropylene, polyester, or acid and alkali resistant rubber.

[0026] In this way, when a high-frequency current is passed through the braking coil, the braking coil drives the diaphragm 41 to oscillate at a high frequency. The elastic mesh 45 can improve the stability of the diaphragm 41 during oscillation, while the waterproof isolation membrane 46 keeps the gap between the diaphragm 41 and the base 44 waterproof and sealed during the oscillation process, preventing the reaction liquid from entering the mounting groove 441 of the base 44 and ensuring the service life of the overall structure. Since both the diaphragm 41 and the waterproof isolation membrane 46 are made of acid-resistant and heat-resistant materials, both the diaphragm 41 and the waterproof isolation membrane 46 can be in direct contact with the high-temperature reaction liquid in the distillation column 13. Furthermore, this design eliminates the need for complex mechanical structures when oscillating the surface of the reaction liquid, and allows for long-term operation in high-temperature environments, resulting in low operating costs and significant economic benefits.

[0027] In addition, to further improve the stability of diaphragm 41 during oscillation, refer to Figure 3 and Figure 4 A low-friction coefficient lubricating layer 47 is provided between the actuation coil 42 and the permanent magnet 43. The lubricating layer 47 can be provided only on the inner side of the actuation coil 42 to reduce the probability of wear during high-frequency vibration, or it can be provided only on the outer side of the permanent magnet 43 to reduce the probability of jamming during vibration of the actuation coil 42, or the lubricating layer 47 can be provided on both the braking coil and the permanent magnet 43. The lubricating layer 47 can be graphite, polytetrafluoroethylene, etc., which can not only promote the sliding effect between the actuation coil 42 and the permanent magnet 43, but also improve the insulation performance of the braking coil, and at the same time provide a certain guiding effect on the high-frequency vibration of the actuation coil 42 and the diaphragm 41.

[0028] To further improve the oscillation effect of diaphragm 41 on the liquid surface of tray 2, refer to Figure 3 Multiple moving plates 51 are fixedly attached to the upper surface of the diaphragm 41 and spaced apart along its outer edge contour. The end of the moving plate 51 away from the middle of the diaphragm 41 extends into the gap between the diaphragm 41 and the wall of the perforation 31. A disturbance plate 52 is fixedly attached to the free end of the moving plate 51. The lower end of the disturbance plate 52 is inserted below the liquid surface on the tray 2. The disturbance plate 52 is inclined in the vertical direction. For example, the upper end of the disturbance plate 52 is close to the diaphragm 41 and the lower end is close to the wall of the perforation 31.

[0029] In this way, while the diaphragm 41 is vibrating at high frequency, it can drive multiple moving plates 51 and their disturbance plates 52 to vibrate at high frequency. The disturbance plates 52 can obliquely penetrate the gas phase above the liquid interface layer on the tray 2 and the liquid phase below it. Thus, when the disturbance plates 52 vibrate at high frequency, they can more significantly break the laminar boundary layer in the liquid, allowing more liquid molecules to be exposed to the liquid-gas interface and improving the mass transfer rate. Furthermore, the arrangement of multiple disturbance plates 52 can not only expand the influence range of the high-frequency oscillation of the diaphragm 41, but also change the vibration characteristics of the diaphragm 41, such as increasing the amplitude or changing the vibration frequency, thereby producing a stronger dynamic influence on the liquid layer and intensifying the separation of azeotropes.

[0030] In another feasible embodiment, refer to Figure 3 Furthermore, multiple protrusions 53 can be fixed to the outer periphery of the disturbance plate 52. The protrusions 53 can maximize the disruption effect on the laminar boundary layer in the liquid and promote liquid-gas phase separation without excessively increasing the oscillation resistance of the disturbance plate 52 in the solution.

[0031] In other feasible embodiments, the synchronizing plate 51 can also be made of a reed. One of the vibration frequencies of the diaphragm 41 caused by the high-frequency current controller is the same as the frequency of the synchronizing plate 51 itself. In this case, the synchronizing plate 51 is only partially and completely fixed to the diaphragm 41, and the end of the synchronizing plate 51 near the disturbance plate 52 needs to be suspended for a certain length. In this way, when the high-frequency current controller controls the diaphragm 41 to vibrate until its vibration frequency is the same as the frequency of the synchronizing plate 51 itself, a resonance phenomenon will occur on the synchronizing plate 51, thereby significantly increasing the amplitude of the synchronizing plate 51 and improving the oscillation effect on the liquid surface on the tray 2. However, it should be noted that due to the resonance effect of the synchronizing plate 51, it will cause some damage to the synchronizing plate 51 and affect the normal vibration of the diaphragm 41. Therefore, the high-frequency current controller cannot maintain power supply at this frequency for a long time. It can be intermittently or controlled to enter this power supply frequency at specific times.

[0032] This application discloses a method for purifying ethyl acetate, based on the aforementioned ethyl acetate purification system, with reference to... Figure 1 , Figure 2 and Figure 3 It includes the following steps: S1. The industrial-grade ethyl acetate in reactor 11 is mixed with acetic anhydride and concentrated sulfuric acid to undergo an esterification reaction; S2. Add alkali to the reaction solution in reactor 11 to carry out a neutralization reaction; S3. The reaction liquid in the reactor 11 is distilled to collect the gas phase component. The gas phase component is condensed into liquid by the first condenser 12 and then transported to the distillation column 13 for distillation. During the distillation process, a high-frequency pulse current is sent to the actuation coil 42 through the high-frequency current controller so that the diaphragm 41 vibrates at high frequency on the interface plate 3 to oscillate the liquid surface above the column plate 2 at high frequency, thereby promoting the separation of the gas phase and liquid phase in the azeotrope. S4. The gas phase at the top of the distillation column 13 is condensed into liquid by the second condenser 14 and then transported to the reflux tank 15. Part of the liquid in the reflux tank 15 is transferred to the product tank 16 and part is returned to the distillation column 13.

[0033] Therefore, during the distillation process in the distillation column 13, a high-frequency oscillating current is input into the actuator coil 42 via a high-frequency current controller, which enables the diaphragm 41 to vibrate at a high frequency. This causes the diaphragm 41 to oscillate at a high frequency above the reaction liquid surface on the tray 2, continuously disrupting and renewing the liquid-gas interface, resulting in the continuous formation of new liquid surfaces, increasing the evaporation area, and thus accelerating the evaporation process. Furthermore, the oscillation of the diaphragm 41 at the reaction liquid surface helps to break the concentration boundary layer near the liquid surface, reducing the gradient layer that hinders mass transfer, allowing the components in the vapor and liquid to reach equilibrium more quickly. At the same time, the oscillation of the diaphragm 41 can also promote the formation and collapse of droplets and bubbles, which can greatly improve the mass transfer rate. Thus, the high-frequency oscillation of the diaphragm 41 can improve the mass transfer efficiency between the liquid and gas phases at the liquid surface on the tray 2 in the distillation column 13, promote azeotropic separation, and thereby increase the effectiveness and efficiency of the distillation process.

[0034] The implementation principle of the ethyl acetate purification system in this application embodiment is as follows: During the distillation of the reaction liquid in the distillation column 13, a high-frequency oscillating current is input into the actuator coil 42 via a high-frequency current controller, which enables the diaphragm 41 to vibrate at a high frequency. This causes the diaphragm 41 to oscillate at a high frequency above the reaction liquid surface on the tray 2, continuously disrupting and renewing the liquid-gas interface, resulting in the continuous formation of new liquid surfaces, increasing the evaporation area, and thus accelerating the evaporation process. Furthermore, the oscillation of the diaphragm 41 at the reaction liquid surface helps to break the concentration boundary layer near the liquid surface, reducing the gradient layer that hinders mass transfer, allowing the components in the vapor and liquid to reach equilibrium more quickly. At the same time, the oscillation of the diaphragm 41 can also promote the formation and collapse of droplets and bubbles, which can greatly improve the mass transfer rate. Therefore, the high-frequency oscillation of the diaphragm 41 can improve the mass transfer efficiency between the liquid and gas phases at the liquid surface on the tray 2 in the distillation column 13, promote azeotropic separation, and thus increase the effect and efficiency of the distillation process in the distillation column 13.

[0035] Furthermore, the arrangement of the diaphragm 41 and the actuation coil 42 eliminates the need for complex mechanical structures when oscillating the surface of the reaction liquid, and allows for long-term operation in high-temperature environments, resulting in low operating costs and significant economic benefits.

[0036] Unless otherwise defined, the technical or scientific terms used in this application shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "first," "second," "third," and similar terms used in this application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. The terms "an" or "a" and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms "comprising" or "including" and similar terms mean that the elements or objects preceding "comprising" or "including" encompass the elements or objects listed following "comprising" or "including" and their equivalents, and do not exclude other elements or objects. "Above," "below," "left," "right," etc., are used only to indicate relative positional relationships; when the absolute position of the described object changes, the relative positional relationship may also change accordingly.

[0037] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A purification system for ethyl acetate, comprising a reaction vessel (11), a first condenser (12), a distillation column (13), a second condenser (14), a reflux tank (15), and a product tank (16) connected in sequence, wherein the reflux tank (15) is connected to the top of the distillation column (13) via a reflux pipe, and the distillation column (13) is provided with a plurality of trays (2), wherein the plurality of trays (2) divide the distillation column (13) into serpentine flow channels, characterized in that, An interface plate (3) is provided above the tray (2) and is slidably disposed in the distillation column (13). A floating mechanism (6) is provided on the lower end face of the interface plate (3). The interface plate (3) is suspended above the liquid surface above the tray (2) by the floating mechanism (6). The interface plate (3) has several perforations (31). A diaphragm (41) is floatingly installed in the perforations (31) of the interface plate (3). An actuation coil (42) is installed on the lower end face of the diaphragm (41). A permanent magnet (43) is provided in the inner ring of the actuation coil (42). The permanent magnet (43) is fixedly connected to the interface plate (3). The actuation coil (42) is connected to a high-frequency current controller. The diaphragm (41) is made flush with the liquid surface above the tray (2) by the floating mechanism (6). The upper surface of the diaphragm (41) is fixed with a plurality of moving plates (51) spaced apart along its outer edge contour. The end of the moving plate (51) away from the middle of the diaphragm (41) extends into the gap between the diaphragm (41) and the wall of the perforation (31). The free end of the moving plate (51) is fixed with a disturbance plate (52). The co-moving plate (51) is made of a reed, and one of the vibration frequencies of the diaphragm (41) caused by the high-frequency current controller is the same as the frequency of the co-moving plate (51).

2. The ethyl acetate purification system according to claim 1, characterized in that, The interface plate (3) has a base (44) installed in the perforation (31) with a gap. The base (44) has a mounting groove (441) for the permanent magnet (43) to be installed. The diaphragm (41) and the opening on the base (44) are separated by a gap, and a tightly connected elastic mesh (45) is connected in the gap between them.

3. The ethyl acetate purification system according to claim 2, characterized in that, A waterproof isolation membrane (46) is fixed between the diaphragm (41) and the opening on the base (44), and the outer ring and inner ring of the waterproof isolation membrane (46) are respectively sealed to the base (44) and the diaphragm (41). When the diaphragm (41) is flush with the opening on the base (44), the waterproof isolation membrane (46) has wrinkles.

4. The ethyl acetate purification system according to claim 3, characterized in that, Both the diaphragm (41) and the waterproof isolation membrane (46) are made of acid-resistant materials.

5. The ethyl acetate purification system according to claim 1, characterized in that, A lubricating layer (47) with a low coefficient of friction is provided between the actuation coil (42) and the permanent magnet (43).

6. The ethyl acetate purification system according to claim 5, characterized in that, The disturbance piece (52) is inclined in the vertical direction.

7. The ethyl acetate purification system according to claim 6, characterized in that, Multiple protrusions (53) are fixed to the outer periphery of the disturbance piece (52).

8. A method for purifying ethyl acetate, based on an ethyl acetate purification system according to any one of claims 1-7, characterized in that, Includes the following steps: S1. The industrial grade ethyl acetate in the reactor (11) is mixed with acetic anhydride and concentrated sulfuric acid to undergo an esterification reaction; S2. Add alkali to the reaction liquid in the reactor (11) to carry out a neutralization reaction; S3. The reaction liquid in the reactor (11) is distilled to collect the gas phase component. The gas phase component is condensed into liquid by the first condenser (12) and then transported to the distillation column (13) for distillation. During the distillation process, the high-frequency current controller sends a high-frequency pulse current to the actuation coil (42) so that the diaphragm (41) vibrates at high frequency on the interface plate (3) to oscillate the liquid surface above the column plate (2) at high frequency, thereby promoting the separation of the gas phase and liquid phase in the azeotrope. S4. The gas phase at the top of the distillation column (13) is condensed into liquid by the second condenser (14) and then transported to the reflux tank (15). Part of the liquid in the reflux tank (15) is transferred to the finished product tank (16) and part is returned to the distillation column (13).

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