A cyclone rectification column, acrylic acid decontaminating system and purification process

Abstract

A cyclone rectifying tower, comprising a cylindrical tower body, a gas phase outlet connected with a negative pressure drainage device at the top of the tower body, a kettle liquid outlet at the bottom of the tower body, and a heterogeneous system generator, a feed pipe being tangentially arranged at the lower section of the tower body, the heterogeneous system generator comprising a conveying pipeline connected with the feed pipe, a feed spray device for high-purity raw materials in atomized state being arranged in the conveying pipeline, the tangential arrangement of the feed pipe enabling the heterogeneous system to obtain a centrifugal force for helical rising when entering the tower through the feed pipe, and more easily enabling mist, droplets and liquid beads to be thrown to the inner wall of the tower to collide with the tower wall to form a liquid film, the high-purity raw materials being sprayed by the feed spray device when passing through the conveying pipeline to form the heterogeneous system, and the heterogeneous system formed by spraying being able to form an acceleration in the conveying pipeline to enter the tower.

Description

Technical Field

[0001] This invention relates to a cyclone distillation column that can be used in the purification process of acrylic acid. Background Technology

[0002] High-purity acrylic acid mainly refers to an acrylic acid monomer that has had aldehyde compounds removed from acrylic acid products. According to GB / T 17529.1-2008 "Industrial Acrylic Acid and Esters", its basic technical indicators include five items: acrylic acid purity ≥99.5wt%, hue ≤10APHA, moisture ≤0.15wt%, total aldehyde content ≤10ppm, and polymerization inhibitor (hydroquinone monomethyl ether) content 200±20ppm.

[0003] Existing acrylic acid purification processes use through-flow sieve tray distillation columns. In the liquid phase of the through-flow sieve tray column, water and hydrazine hydrate ionize, generating hydrogen ions and hydrazine ions that have an initiator effect. Therefore, through-flow sieve tray columns are prone to ionic polymerization reactions, which affects the purification effect of acrylic acid. Summary of the Invention

[0004] The purpose of this invention is to provide a cyclone distillation column that can remove heavy components and purify acrylic acid.

[0005] The objective of this invention is achieved through the following technical solution:

[0006] A cyclone distillation column includes a cylindrical column body, a gas phase outlet connected to a negative pressure diversion device at the top of the column body, a bottom liquid outlet at the bottom of the column body, and a heterogeneous system generator. A feed pipe is arranged tangentially along the lower section of the column body. The heterogeneous system generator includes a conveying pipe connected to the feed pipe. A feed sprayer capable of generating atomized high-purity raw materials is installed in the conveying pipe. The tangential arrangement of the feed pipe along the column body allows the heterogeneous system to obtain centrifugal force that causes it to spiral upwards when entering the column. This makes it easier to throw the mist, droplets, and liquid droplets in the heterogeneous system onto the inner wall of the column, where they collide and form a liquid film. When the feed passes through the conveying pipe, the high-purity raw material is sprayed by the feed sprayer to form a heterogeneous system, and the sprayed heterogeneous system can create an acceleration in the conveying pipe to enter the column.

[0007] The tower body is equipped with a sprayer located above the feed pipe. The sprayer sprays the feed that has already undergone gas-liquid separation inside the tower body to maintain the heterogeneous system state.

[0008] The inner wall of the tower has a guide channel extending along its height. When the heterogeneous system rises at high speed in a spiral, the mist, droplets and liquid droplets in the heterogeneous system are separated from the cyclone under the action of centrifugal force and collide with the inner wall of the tower to form a liquid film. The liquid film continues to make circular motion under the drive of the cyclone. When it flows through the guide channel, it is intercepted and forms a liquid accumulation. The liquid accumulation settles to the bottom of the tower under the action of gravity and is discharged from the outlet of the bottom liquid.

[0009] The upper section of the tower body is equipped with a flow stabilizing and equalizing grid plate. When the cyclone rises at high speed to the flow stabilizing and equalizing grid plate, it is broken by the flow stabilizing and equalizing grid plate, and the feeding stops the high-speed spiral motion and rises steadily.

[0010] The flow stabilizing and equalizing grid plate includes multiple skeletons arranged circumferentially extending radially along the tower body and multiple annular plates arranged concentrically and connected to the skeletons. The annular plates are arranged horizontally in the width direction. The skeletons are arranged at equal intervals around the circumference to stably support the annular plates. The concentric arrangement of the annular plates can play a role in breaking the rotation.

[0011] A demister is installed above the flow stabilizing and equalizing grid plate. The demister can remove mist, thereby obtaining acrylic acid vapor with a very small amount of heavy components.

[0012] A sprayer is installed above the demister to further spray the acrylic vapor.

[0013] Another object of the present invention is to provide an acrylic acid purification process, which is achieved through the following techniques:

[0014] An acrylic acid purification process, employing the aforementioned cyclone distillation column, includes the following steps:

[0015] A. Acrylic acid vapor is formed into a heterogeneous system by the heterogeneous system generator and enters the tower. After entering the tower tangentially, the high-speed heterogeneous system begins to move in a high-speed spiral motion in the upward direction. The mist, droplets and liquid droplets in the heterogeneous system are separated from the cyclone under the action of centrifugal force and collide with the inner wall of the tower to form a liquid film. Then, it moves in a circular motion under the drive of the cyclone. When it flows through the guide channel, it is intercepted and forms liquid accumulation. The liquid accumulation settles to the bottom of the tower under the action of gravity and is discharged from the bottom liquid outlet.

[0016] B. The upward cyclone is humidified in the opposite direction by the sprayer, maintaining the heterogeneous system state, and the heterogeneous system is separated under the action of centrifugal force. The cyclone is broken by the flow equalization grid plate and then the mist is removed by the wire mesh demister, resulting in acrylic acid vapor with extremely small heavy component content. The working pressure of the negative pressure diversion device is 2.93~4.67kPaA.

[0017] Another object of the present invention is to provide a high-purity acrylic acid debinding component system, which is achieved through the following technology:

[0018] A high-purity acrylic acid debinding component system includes a scraped-film distillation column and a cyclone distillation column. The scraped-film distillation column includes a cylindrical first column body and a scraper frame rotatably disposed within the first column body. The first column body includes a feed section and an evaporation section arranged vertically. The scraper frame is disposed in the evaporation section, which is equipped with a heating component. An annular feed trough is provided in the feed section, and the annular feed trough has multiple circumferentially arranged overflow ports. The raw material overflowing from the overflow ports flows downward along the inner wall of the evaporation section and forms a thin film under the action of the scraper frame to promote evaporation. The first column body of the scraped-film distillation column also includes a rectification section located below the evaporation section and a reboiler located below the rectification section. A cylindrical guide hood is provided in the rectification section, with an open lower end and a closed upper end. A second sprayer capable of spraying high-purity raw material is disposed in the guide hood. An annular first... A plurality of first vapor guide pipes arranged in a circular pattern are connected between the vapor collection pipe, the flow guide hood, and the first vapor collection pipe. One end of the first vapor guide pipe is connected to the outer circumferential surface of the flow guide hood, and the other end is connected to the first vapor collection pipe. The first vapor collection pipe is connected to the conveying pipe of the cyclone distillation column. A collection port is provided at the upper end of the washing liquid collection section, which is opposite to the lower port of the flow guide hood. A concentrated liquid collection tank surrounding the collection port is provided inside the first column body. A concentrated liquid discharge pipe connected to the concentrated liquid collection tank is provided on the side wall of the first column body. A washing liquid discharge pipe connected to the washing liquid collection section is provided at the bottom of the first column body. The acrylic acid content of the de-heavy components from the scraped film distillation column can reach more than 99.0 wt%. The cyclone distillation column can further purify the de-heavy acrylic acid solution, so that the acrylic acid content can reach more than 99.95 wt%.

[0019] A high-purity acrylic acid debinding process, employing the aforementioned high-purity acrylic acid debinding system, includes the following steps:

[0020] A. Acrylic acid raw material containing heavy components enters the annular feed tank from the feed section. The acrylic acid raw material in the annular feed tank flows out from the overflow port and flows downward along the inner wall of the evaporation section. Under the action of the rotating scraper frame, a thin film is formed, and the film evaporates to form vapor under the heating of the heating component. The working temperature of the heating component is 53-63℃.

[0021] B. Under the negative pressure of the negative pressure diversion device, the steam spirals downward and rises into the diversion hood after descending to the bottom of the diversion hood. During this process, the steam is washed by the sprayed high-purity acrylic acid to form a heterogeneous system. The heterogeneous system settles into the tower bottom and is transported to the annular material tank. The washed steam enters the first steam collection pipe from the first steam guide pipe. The acrylic acid steam in the first steam collection pipe enters the conveying pipe of the heterogeneous system generator.

[0022] C. Acrylic acid vapor is formed into a heterogeneous system by the heterogeneous system generator and enters the tower. After entering the tower tangentially, the high-speed heterogeneous system begins to move in a high-speed spiral motion in the upward direction. The mist, droplets and liquid droplets in the heterogeneous system are separated from the cyclone under the action of centrifugal force and collide with the inner wall of the tower to form a liquid film. Then, it moves in a circular motion under the drive of the cyclone. When it flows through the guide channel, it is intercepted and forms a liquid accumulation. The liquid accumulation settles to the bottom of the tower under the action of gravity and is discharged from the bottom liquid outlet.

[0023] D. The upward cyclone is humidified in the opposite direction by the sprayer, maintaining the heterogeneous system state, and the heterogeneous system is separated under the action of centrifugal force. The cyclone is broken by the flow equalization grid plate and then the mist is removed by the wire mesh demister to obtain acrylic acid vapor with extremely small amount of heavy components. The working pressure of the negative pressure diversion device is 2.93~4.67kPaA. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of a cyclone distillation column.

[0025] Figure 2 for Figure 1 A sectional view along the AA direction.

[0026] Figure 3 for Figure 2 A sectional view along the BB direction.

[0027] Figure 4 This is a schematic diagram of the acrylic acid debinding component system.

[0028] Figure 5 This is a schematic diagram of the annular baffle plate in a scraped film distillation column. Detailed Implementation

[0029] Reference Figures 1 to 4 As shown, a cyclone distillation column D includes a cylindrical column body 4 and a heterogeneous system generator 5. The top of the column body 4 is provided with a gas phase outlet 43 connected to a negative pressure diversion device. The lower section of the column body 4 is provided with a feed pipe 41 arranged tangentially along the column body 4. The bottom of the column body 4 is provided with a bottom liquid outlet 44. The interior of the column body 4 includes a sprayer 8, a demister, a flow stabilizing and equalizing grid plate 6, a sprayer 9 arranged sequentially from top to bottom, and a flow guide groove 42 arranged on the inner wall of the column body 4 along its height direction.

[0030] The heterogeneous system generator 5 includes a conveying pipe 51 connected to the feed pipe 41. A feed sprayer 52 capable of generating atomized high-purity acrylic acid is installed in the conveying pipe 51. The conveying pipe 51 is horizontally arranged outside the tower body 4, with one end connected to the feed pipe 41 and the other end connected to the side outlet 33 of the scraped film distillation tower C. When the acrylic acid vapor in the scraped film distillation tower C is introduced into the cyclone distillation tower D, it passes through the conveying pipe 51 and isothermally humidifies the acrylic acid vapor with the feed sprayer 52 to form a heterogeneous system. The initial velocity of the feed to the heterogeneous system generator 5 is determined by the diameter of the conveying pipe 51, and the mass of the heterogeneous system is determined by the length of the conveying pipe 51, the spray volume of the feed sprayer 52, and the spraying effect.

[0031] The tower body 4 is equipped with at least one sprayer 9. The sprayer 9 sprays high-purity acrylic acid to humidify the high-speed spiral rising cyclone in the opposite direction, so that the feed is kept in a heterogeneous system state and the heterogeneous system continues to be separated under the action of centrifugal force, which can achieve the effect of further deweighting.

[0032] The upper section of the tower body 4 is provided with a flow stabilizing and equalizing grid plate 6. The flow stabilizing and equalizing grid plate 6 includes multiple skeletons 61 arranged in a circular pattern extending radially along the tower body 4 and multiple annular plates 62 arranged concentrically and connected to the skeletons 61. The annular plates 62 are arranged horizontally in the width direction. The skeletons 61 are arranged at equal intervals around the circumference to stably support the annular plates 62. When the cyclone rises at high speed to the flow stabilizing and equalizing grid plate 6, it is broken by the densely arranged annular plates 62, and the rising airflow stops its high-speed spiral motion and rises stably.

[0033] The demister is located inside the upper part of the tower body 4 and below the sprayer 8. The demister is a wire mesh demister 7. When the airflow broken by the flow stabilizing and equalizing grid plate 6 passes through the wire mesh demister 7, the mist can be removed, thus obtaining acrylic acid vapor with a very small amount of heavy components. At this time, most of the heavy components have been removed.

[0034] The sprayer 8 is located inside the upper part of the tower body 4 near the gas phase outlet 43, and can further spray the acrylic acid vapor.

[0035] An acrylic acid purification process, using the aforementioned cyclone distillation column D, includes the following steps:

[0036] A. When acrylic acid vapor with an acrylic acid content of 99.0 wt% or more passes through the heterogeneous system generator 5 of the cyclone distillation column D, it is humidified by the feed sprayer 52 to form a heterogeneous system. The high-speed heterogeneous system moves along the conveying pipe 51 and enters the cyclone distillation column D tangentially after reaching the feed pipe 41. It then begins to move in a high-speed spiral motion in the upward direction. The mist, droplets and liquid droplets in the heterogeneous system are separated from the cyclone under the action of centrifugal force. After colliding with the inner wall of the column body 4, they form a liquid film. Then, driven by the cyclone, they make a circular motion. When they flow through the guide channel 42, they are intercepted and form a liquid accumulation. The liquid accumulation settles to the bottom of the column under the action of gravity and is discharged from the bottom liquid outlet 44.

[0037] B. The upward cyclone is counter-humidified by the sprayer 9 inside the tower, maintaining the heterogeneous system state. Under the action of centrifugal force, the heterogeneous system is separated. When the high-speed spiraling cyclone passes through the flow stabilizing and equalizing grid plate 6, it is broken by the concentrically arranged dense annular plates 62, ending the spiral motion and rising steadily. Then, the mist is removed by the wire mesh demister 7, resulting in acrylic acid vapor with an extremely small amount of heavy components. Finally, the acrylic acid vapor is discharged from the gas phase outlet 43. At this time, the acrylic acid content in the acrylic acid vapor can reach more than 99.95 wt%. The working pressure of the negative pressure diversion device is 2.93~4.67 kPaA.

[0038] A high-purity acrylic acid debinding component system includes a scraped film distillation column C and a cyclone distillation column D. The scraped film distillation column C includes a cylindrical first column body 1 and a scraper frame 2 rotatably disposed in the first column body 1. The first column body 1 includes a feed section 11 and an evaporation section 12 arranged vertically. The scraper frame 2 is rotatably disposed in the evaporation section 12. The scraper frame 2 includes a vertically arranged rotating shaft 21, a cylindrical support 22 disposed on the rotating shaft 21, and a scraper disposed on the outer circumference of the cylindrical support 22 and arranged vertically. A drive motor 24 connected to drive the rotating shaft 21 is provided at the top of the first column body 1. The specific structure of the scraper frame 2 is known prior art and will not be described in detail here. The lower end of the rotating shaft 21 is rotatably supported in the first column body 1 by a support 23, which can position the lower end of the rotating shaft 21 and prevent the scraper frame 2 from shaking during rotation.

[0039] The evaporation section 12 is equipped with a heating component, which is a heating steam jacket 121 disposed on the outer peripheral surface of the evaporation section 12. During operation, the evaporation section 12 is heated by supplying circulating heating steam to the heating steam jacket 121, so that the raw material on the inner wall of the evaporation section 12 evaporates.

[0040] The feeding section 11 is provided with an annular material trough 113, which is used to store raw materials and distribute them to the inner wall of the evaporation section 12. Specifically, the feeding section 11 includes a conical sidewall 111 and an annular baffle plate 112. The conical sidewall 111 and the annular baffle plate 112 form an annular material trough 113. Multiple overflow ports 1121 are formed on the annular baffle plate 112. The overflow ports 1121 have a V-shaped structure and roughly penetrate the height of the annular baffle plate 112. The V-shaped overflow ports can distribute the raw materials to the inner wall of the evaporation section 12 more evenly and stably. The raw materials overflowing from the overflow ports 1121 flow down the inner wall of the evaporation section 12 and form a thin film under the action of the scraper frame 2 to promote evaporation. The feeding section 11 is provided with a feeding pipe 114 located above the annular material trough 113.

[0041] The first column body 1 of the scraped-film distillation column C also includes a rectification section 13 located below the evaporation section 12 and a reboiler 14 located below the rectification section 13. A cylindrical guide hood 3 is installed in the rectification section 13, with an open lower end and a closed upper end. An upper first sprayer 131 and a lower first sprayer 132, capable of spraying high-purity raw materials, are installed within the guide hood 3. A first wire mesh demister 134 is installed between the upper first sprayer 131 and the lower first sprayer 132. An annular first vapor collecting pipe 31 is installed outside the rectification section 13. Multiple circumferentially arranged first vapor guiding pipes 32 connect the guide hood 3 and the first vapor collecting pipe 31. One end of each first vapor guiding pipe 32 is connected to the outer circumferential surface of the guide hood 3, and the other end is connected to the first vapor collecting pipe 31. 31 is connected to a negative pressure diversion device to draw out the vapor in the first tower body 1. The upper end of the tower bottom 14 is provided with a collection port 141 that is spaced apart from the lower port of the diversion hood 3. The inside of the first tower body 1 is provided with a concentrated liquid collection tank 137 surrounding the collection port 141. The side wall of the first tower body 1 is provided with a concentrated liquid discharge pipe 138 that connects to the concentrated liquid collection tank 137. The evaporated concentrated liquid can flow along the inner wall of the first tower body 1 into the concentrated liquid collection tank 137. The concentrated liquid can be discharged periodically through the concentrated liquid discharge pipe 138. The acrylic acid content in the acrylic acid solution de-weighted from the scraped film distillation tower C can reach more than 99.0 wt%. The cyclone distillation tower D can further purify the acrylic acid solution de-weighted, so that the acrylic acid content can reach more than 99.95 wt%.

[0042] A high-purity acrylic acid debinding process, employing a high-purity acrylic acid debinding system, includes the following steps:

[0043] A. Acrylic acid raw material containing heavy components is discharged into an annular feed tank 113 through feed pipe 114. The acrylic acid raw material in the annular feed tank 113 flows out from overflow port 1121 and flows downward along the inner wall of evaporation section 12. Under the action of rotating scraper frame 2, a thin film is formed. The film evaporates to form acrylic acid vapor under the heating of steam in heating steam jacket 121. The heating temperature is 53-63℃. This heating temperature will not promote the large-scale generation of acrylic acid dimers. The acrylic acid dimer generation rate is less than 0.1wt% / h.

[0044] B. Acrylic acid vapor spirals downward under the negative pressure of the negative pressure diversion device, and after descending to below the diversion hood 3, it rises and enters the diversion hood 3. During this process, the vapor is washed by the sprayed high-purity acrylic acid to form a heterogeneous system. The heterogeneous system settles into the tower 14 and is transported to the annular material tank 113. The washed vapor enters the first vapor collection pipe 31 from the first vapor guide pipe 32. The acrylic acid vapor in the first vapor collection pipe 31 enters the conveying pipe 51 of the heterogeneous system generator 5.

[0045] C. Acrylic acid vapor is formed into a heterogeneous system by the heterogeneous system generator 5 and enters the column body 4 of the cyclone distillation column D. After entering the column body 4 in a tangential direction, the high-speed heterogeneous system begins to move in a high-speed spiral motion in an upward direction. The mist, droplets and liquid droplets in the heterogeneous system are separated from the cyclone under the action of centrifugal force and collide with the inner wall of the column body 4 to form a liquid film. Then, it moves in a circular motion under the drive of the cyclone. When it flows through the guide channel 42, it is intercepted and forms a liquid accumulation. The liquid accumulation settles to the bottom of the column under the action of gravity and is discharged from the bottom liquid outlet 44.

[0046] D. The upward cyclone is humidified in the opposite direction by the sprayer 9, maintaining the heterogeneous system state, and the heterogeneous system is separated under the action of centrifugal force. The cyclone is broken by the flow equalization grid plate 6, and then the mist is removed by the wire mesh demister 7 to obtain acrylic acid vapor with extremely small amount of heavy components. The working pressure of the negative pressure diversion device is 2.93~4.67kPaA.

[0047] Existing technologies use cross-flow sieve tray columns as distillation columns. Cross-flow sieve tray columns are prone to ionic polymerization reactions because water and hydrazine hydrate in the liquid phase of the trays ionize, generating hydrogen ions and hydrazine ions, which have an initiator effect. Compared to cross-flow sieve tray columns, the distillation process of the scraped film distillation column C is carried out in a near-gaseous state. At the same time, compared to acrylic acid, water and hydrazine hydrate are both light components, with a lower possibility of liquefaction and ionization. This eliminates the problem of hydrogen ions and hydrazine ions initiating ionic polymerization reactions in acrylic acid. Therefore, choosing the scraped film distillation column C as the distillation column eliminates the difficulty in preventing the polymerization reaction of acrylic acid.

[0048] The above description is merely a preferred embodiment of the present invention and should not be construed as limiting the scope of the present invention. All equivalent changes and modifications made in accordance with the scope of the patent application and the contents of the specification of the present invention should still fall within the scope of the patent of the present invention.

Claims

1. A high-purity acrylic acid debinding component system, comprising a scraped-film distillation column and a cyclone distillation column, characterized in that: Cyclone distillation column includes a cylindrical column body, a gas phase outlet connected to a negative pressure diversion device at the top of the column body, a bottom liquid outlet at the bottom of the column body, and a heterogeneous system generator. The lower section of the column body is provided with a feed pipe arranged tangentially along the column body. The heterogeneous system generator includes a conveying pipe connected to the feed pipe, and a feed sprayer capable of generating atomized high-purity raw materials is provided in the conveying pipe. A scraped-film distillation column includes a cylindrical first column body and a scraper frame rotatably mounted within the first column body. The first column body includes a feed section and an evaporation section arranged vertically. The scraper frame is located in the evaporation section, which is equipped with a heating element. An annular feed trough is provided in the feed section, with multiple overflow ports arranged circumferentially. The raw material overflowing from the overflow ports flows downwards along the inner wall of the evaporation section and forms a thin film under the action of the scraper frame to promote evaporation. The first column body of the scraped-film distillation column also includes a rectification section located below the evaporation section and a reboiler located below the rectification section. A cylindrical flow guide hood is provided in the rectification section, with an open lower end and a closed upper end. A second sprayer capable of spraying high-purity raw material is installed inside the flow guide hood. An annular flow guide hood is provided outside the rectification section. The first vapor collecting pipe is connected to the first vapor guiding pipe in a circular arrangement. One end of the first vapor guiding pipe is connected to the outer circumferential surface of the guiding hood, and the other end is connected to the first vapor collecting pipe. The first vapor collecting pipe is connected to the conveying pipe of the cyclone distillation column. The vapor spirals downward under the negative pressure of the negative pressure guiding device, and rises into the guiding hood after descending to the bottom of the guiding hood. The upper end of the washing liquid collecting section is provided with a collecting port opposite to the lower port of the guiding hood. The first column body is provided with a concentrated liquid collecting tank surrounding the collecting port. The side wall of the first column body is provided with a concentrated liquid discharge pipe communicating with the concentrated liquid collecting tank. The bottom of the first column body is provided with a washing liquid discharge pipe communicating with the washing liquid collecting section.

2. The high-purity acrylic acid debinding component system according to claim 1, characterized in that: The tower body is equipped with a sprayer located above the feed pipe.

3. The high-purity acrylic acid debinding component system according to claim 1, characterized in that: The inner wall of the tower has guide grooves extending along its height direction.

4. A high-purity acrylic acid debinding component system according to claim 1, 2, or 3, characterized in that: The upper section of the tower body is equipped with a flow stabilizing and equalizing grid.

5. The high-purity acrylic acid debinding component system according to claim 4, characterized in that: The flow stabilization and equalization grid plate includes multiple skeletons arranged circumferentially extending radially along the tower body and multiple annular plates arranged concentrically and connected to the skeletons, with the annular plates arranged horizontally in the width direction.

6. The high-purity acrylic acid debinding component system according to claim 4, characterized in that: A demister is installed above the flow stabilizing and equalizing grid plate.

7. The high-purity acrylic acid debinding component system according to claim 6, characterized in that: A sprayer is installed above the demister.

8. A process for removing heavy components from high-purity acrylic acid, employing the high-purity acrylic acid deweighting system as described in any one of claims 1 to 7, comprising the following steps: A. Acrylic acid raw material containing heavy components enters the annular feed tank from the feed section. The acrylic acid raw material in the annular feed tank flows out from the overflow port and flows downward along the inner wall of the evaporation section. Under the action of the rotating scraper frame, a thin film is formed, and the film evaporates to form vapor under the heating of the heating component. The working temperature of the heating component is 53-63℃. B. Under the negative pressure of the negative pressure diversion device, the steam spirals downward and rises into the diversion hood after descending to the bottom of the diversion hood. During this process, the steam is washed by the sprayed high-purity acrylic acid to form a heterogeneous system. The heterogeneous system settles into the tower bottom and is transported to the annular material tank. The washed steam enters the first steam collection pipe from the first steam guide pipe. The acrylic acid steam in the first steam collection pipe enters the conveying pipe of the heterogeneous system generator. C. Acrylic acid vapor is formed into a heterogeneous system by the heterogeneous system generator and enters the tower. After entering the tower tangentially, the high-speed heterogeneous system begins to move in a high-speed spiral motion in the upward direction. The mist, droplets and liquid droplets in the heterogeneous system are separated from the cyclone under the action of centrifugal force and collide with the inner wall of the tower to form a liquid film. Then, it moves in a circular motion under the drive of the cyclone. When it flows through the guide channel, it is intercepted and forms a liquid accumulation. The liquid accumulation settles to the bottom of the tower under the action of gravity and is discharged from the bottom liquid outlet. D. The upward cyclone is humidified in the opposite direction by the sprayer, maintaining the heterogeneous system state, and the heterogeneous system is separated under the action of centrifugal force. The cyclone is broken by the flow equalization grid plate and then the mist is removed by the wire mesh demister to obtain acrylic acid vapor with extremely small amount of heavy components. The working pressure of the negative pressure diversion device is 2.93~4.67kPaA.

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