Centrifugal sedimentation continuous sweating purification tower and purification method

Abstract

The invention relates to a centrifugal sedimentation continuous sweating purification tower and a purification method.The sweating purification tower comprises a sweating purification tower body, the sweating purification tower body comprises a centrifugal sedimentation section, a purification section and a melting section, the centrifugal sedimentation section is arranged at the uppermost end of the sweating purification tower body, a rotary drum is arranged in the centrifugal sedimentation section, a spiral conveyor is arranged in the rotary drum, and the melting section is arranged in the spiral conveyor; the rotary drum and the spiral conveyor rotate at a differential speed, a feeding port is formed in the center of the top end of the centrifugal settling section, a plurality of material distribution ports are formed in the cavity wall of a cavity I of the spiral conveyor, a solid phase outlet is formed in the lower end of the rotary drum, and a mother liquor outlet is formed in the bottom end of a shell of the centrifugal settling section; the melting section is arranged below the purification section, a stirring shaft and a stirring paddle are arranged in the sweating purification tower body, a heating device is arranged at the bottom of the melting section, and a product outlet is formed in the bottom of the melting section. The device disclosed by the invention has the beneficial effects of more compact structure, higher purification efficiency and better purification effect.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of chemical separation technology, and in particular to a centrifugal settling continuous sweating purification column and a purification method. BACKGROUND

[0002] The sweating purification column is a chemical purification equipment used for further purifying the molten crystals after crystallization by heat mass exchange to achieve high-purity product separation. The applicant has been committed to the research and development of continuous suspension melting crystallization process, and first provided the concept of sweating tower in Chinese patent CN202111514595.9, which disclosed the structure and working principle of the solid-liquid countercurrent heat mass exchange purification tower. In order to further optimize the mass transfer effect in the sweating tower, improve the separation efficiency of the equipment, and avoid problems such as liquid short circuit, channeling, back mixing, and solid phase coalescence, the applicant disclosed a solid-liquid countercurrent heat mass exchange purification tower and a purification method in Chinese patent CN202311259710.1. The purification tower is divided into a bottom melting section, a main body countercurrent heat mass exchange section, and a top overflow section. The crystals form a crystal bed layer at the bottom of the tower under the action of gravity after entering the purification tower, and the liquid phase forms a clear zone at the top of the tower. A heating jacket is provided at the bottom of the tower to melt the crystals into molten liquid by inputting heat, and the proportion of the product outlet taken out is controlled to make part of the molten liquid flow upward along the body of the sweating purification tower, and the crystals move downward along the body of the sweating purification tower. Due to the temperature and concentration difference between the molten liquid and the crystals, heat mass exchange occurs continuously when the two flow in opposite directions, resulting in continuous purification of the crystals during their downward movement along the body of the sweating purification tower, and finally reaching the product purity requirement at the bottom of the tower. However, the technical solution in patent CN202311259710.1 only relies on gravity settling to achieve solid-liquid separation and establish a crystal bed layer, and when the solid-liquid density difference of the crystal slurry is small, the crystal morphology is poor, and the settling rate is slow, the separation and purification efficiency decreases. SUMMARY

[0003] The present application aims to provide a centrifugal settling continuous sweating purification column and a purification method to solve the problems existing in the prior art. The technical problems to be solved by the present application are solved by the following technical solutions.

[0004] A centrifugal sedimentation continuous sweating purification column comprises a sweating purification column body, the sweating purification column body comprises a centrifugal sedimentation section, a purification section and a melting section, the centrifugal sedimentation section is arranged at the uppermost end of the sweating purification column body, a rotating drum is arranged in the centrifugal sedimentation section, a spiral conveyor is arranged in the rotating drum, the rotating drum and the spiral conveyor rotate at different speeds, a feeding port is arranged at the center of the top end of the centrifugal sedimentation section, the lower end of the feeding port extends into a cavity I inside the spiral conveyor and communicates with the cavity I of the spiral conveyor, a plurality of distribution ports are arranged on the cavity wall of the cavity I of the spiral conveyor, the distribution ports make the cavity I of the spiral conveyor communicate with a cavity II of the rotating drum, a solid phase outlet is arranged at the lower end of the rotating drum, the top end of the rotating drum is open and communicates with a cavity III of the centrifugal sedimentation section, a mother liquor outlet is arranged at the bottom of the shell of the centrifugal sedimentation section, the purification section is arranged below the centrifugal sedimentation section, the solid phase outlet communicates with the purification section, the melting section is arranged below the purification section, a stirring shaft is arranged in the sweating purification column body, the stirring shaft penetrates through the purification section and the melting section, stirring paddles are arranged on the stirring shaft, a heating device is arranged at the bottom of the melting section, and a product outlet is arranged at the bottom of the melting section.

[0005] Preferably, the edge of the spiral flow channel of the spiral conveyor is adjacent to the inner wall of the rotating drum.

[0006] Preferably, the rotating drum is conical as a whole, or the upper part is cylindrical and the lower part is conical, and the spiral conveyor is matched with the rotating drum.

[0007] Preferably, the spiral belt of the spiral conveyor is a variable-pitch spiral.

[0008] Preferably, the inner wall of the purification section is provided with turbulence baffles at positions between adjacent two layers of stirring paddles.

[0009] Preferably, the turbulence baffles are circular ring structures with a conical cross section, the connection between the turbulence baffles and the inner wall of the purification section is a conical bottom, and the conical top of the turbulence baffles points to the axis of the purification section.

[0010] Preferably, the conical top angle of the turbulence baffles is 60°-120°.

[0011] Preferably, a plurality of temperature control units are arranged on the purification section to control the temperature of different parts of the purification section.

[0012] This invention also provides a purification method, comprising the following steps: injecting the crystal slurry obtained by suspension crystallization into the cavity I of the screw conveyor in the centrifugal settling section through the feed inlet; under the action of centrifugal force, the crystal slurry enters the cavity II between the inner wall of the drum and the outer wall of the screw conveyor through the distribution port; the crystal slurry undergoes solid-liquid separation in the drum due to centrifugal force, wherein the solid phase forms a crystal layer along the inner wall of the drum, the liquid phase is located on the surface of the crystal layer, and overflows from the top of the drum along the spiral flow channel into the cavity III of the centrifugal settling section, and is discharged through the mother liquor outlet; the crystal layer on the inner wall of the drum is pushed downward by the spiral flow channel of the screw conveyor. The crystals are pushed to the solid phase outlet and then enter the purification and melting sections, where a continuous and stable crystal bed is established. The rotating screw conveyor continuously provides a certain downward pressure to the crystal bed. Under the action of the heating device in the melting section, the crystal bed melts at the bottom of the tower. The product output is controlled to be less than the amount of molten liquid, so that the molten liquid in the melting section flows upward under the pressure of the crystal bed. The upward-flowing molten liquid undergoes a reverse heat and mass exchange with the downward-moving crystals, so that the crystals are continuously purified as they move downward along the body of the sweating purification tower, eventually meeting the product purity requirements.

[0013] Preferably, the residence time of the material in the sweating purification tower body is adjusted by adjusting the feed rate at the feed inlet and the power of the heating device, and the reflux ratio of the molten liquid in the sweating purification tower body is adjusted by adjusting the product outlet output, thereby adjusting the purification efficiency of the sweating purification tower body.

[0014] The present invention provides a centrifugal sedimentation continuous sweating purification tower and purification method, which have the following beneficial effects: 1) Compared with the existing technology that relies solely on gravity sedimentation to achieve solid-liquid separation, the present invention sets up a centrifugal sedimentation section, which enhances the pre-separation effect of solid and liquid through centrifugal sedimentation, resulting in better solid-liquid separation and thus further improving the purity of crystal products.

[0015] 2) The rotating pushing action of the screw conveyor continuously provides a certain downward pressure to the crystal bed. By controlling the crystallization temperature, the feed rate at the inlet, and the extraction ratio of the mother liquor outlet and the product outlet, a suitable density of the suspended crystal slurry and crystal bed can be established, which can further improve the purification efficiency and purity of the sweating purification tower.

[0016] 3) By incorporating a screw conveyor and a rotating drum, the separation and purification efficiency is improved while the equipment structure becomes more compact. When processing the same crystal slurry material, the equipment volume can be reduced by 10% to 30% compared to existing sweating purification towers. When processing crystal slurry systems with slow solid-phase sedimentation rates, the sweating purification tower in this embodiment has higher applicability and higher separation efficiency.

[0017] 4) Through the combined action of the temperature control unit, heating device, rotating drum and screw conveyor, a stable concentration and temperature gradient is established within the sweating purification tower, providing multiple theoretical equilibrium stages within a single device, resulting in better purification effect. Attached Figure Description

[0018] Figure 1 This is a schematic diagram of the structure of the present invention.

[0019] The reference numerals in the attached figures are as follows: 1. Centrifugal sedimentation section, 2. Purification section, 3. Melting section, 4. Feed inlet, 5. Rotary drum, 6. Screw conveyor, 7. Distribution port, 8. Mother liquor outlet, 9. Stirring shaft, 10. Heating device, 11. Supporting filter screen, 12. Product outlet. Detailed Implementation

[0020] It should be noted that, unless otherwise specified, the embodiments and features described in this application can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0021] Example 1: Reference Figure 1 As shown, a centrifugal sedimentation continuous diaphoretic purification tower is improved in that it includes a diaphoretic purification tower body, which comprises a centrifugal sedimentation section 1, a purification section 2, and a melting section 3. The centrifugal sedimentation section 1 is located at the uppermost end of the diaphoretic purification tower body. A rotating drum 5 is installed inside the centrifugal sedimentation section 1, and a screw conveyor 6 is installed inside the rotating drum 5. The rotating drum 5 and the screw conveyor 6 rotate at different speeds. A feed inlet 4 is located at the center of the top of the centrifugal sedimentation section 1. The lower end of the feed inlet 4 extends into the cavity I inside the screw conveyor 6 and communicates with the cavity I of the screw conveyor 6. Several distribution ports 7 are provided on the cavity wall of the cavity I of the screw conveyor 6. The distribution ports 7 allow the screw conveyor to... The cavity I of the conveyor 6 is connected to the cavity II of the drum 5. The lower end of the drum 5 is provided with a solid phase outlet. The top of the drum 5 is open and connected to the cavity III of the centrifugal sedimentation section 1. The bottom end of the shell of the centrifugal sedimentation section 1 is provided with a mother liquor outlet 8. The purification section 2 is located below the centrifugal sedimentation section 1. The solid phase outlet is connected to the purification section 2. The melting section 3 is located below the purification section 2. The diaphoretic purification tower body is provided with a stirring shaft 9. The stirring shaft 9 passes through the purification section 2 and the melting section 3. The stirring shaft 9 is provided with a stirring paddle. The bottom of the melting section 3 is provided with a heating device 10. The bottom of the melting section 3 is provided with a product outlet 12.

[0022] In this embodiment, when the sweating purification tower is working, the crystal slurry obtained by suspension crystallization is injected into the cavity I of the screw conveyor 6 in the centrifugal settling section 1 through the feed inlet 4. The screw conveyor 6 rotates around its central axis at a set speed. Under the action of centrifugal force, the crystal slurry enters the cavity II between the inner wall of the drum 5 and the outer wall of the screw conveyor 6 through the distribution port 7. The drum 5 rotates around its central axis at a set speed. The crystal slurry undergoes solid-liquid separation in the cavity II due to centrifugal force. The solid phase forms a crystal layer along the inner wall of the drum 5, and the liquid phase is located on the surface of the crystal layer and overflows from the top of the drum 5 along the spiral flow channel into the cavity III of the centrifugal settling section 1, and is discharged through the mother liquor outlet 8. Since the drum 5 and the screw conveyor 6 rotate at different speeds, the crystal layer in the cavity II is pushed downward to the solid phase outlet by the spiral flow channel of the screw conveyor 6. Then, the crystals enter the purification section 2 and the melting section 3, where a continuous and stable crystal bed is established. The rotating screw conveyor 6 continuously provides downward pressure to the crystal bed, resulting in a more suitable density and higher product purity. The crystal bed melts at the bottom of the tower under the action of the heating device 10 in the melting section 3. The output of the product outlet 12 is controlled to be less than the amount of molten liquid, causing the molten liquid in the melting section 3 to flow upwards under the pressure of the crystal bed. A temperature and concentration difference exists between the upward-flowing molten liquid and the downward-moving crystals, resulting in continuous reverse heat and mass exchange between the crystals and the molten liquid. The rising molten liquid recrystallizes on the crystal surface due to the heat transfer from the falling crystals. As the crystals move downwards along the main body of the evaporation purification tower, they are continuously purified, ultimately meeting the product purity requirements.

[0023] Furthermore, the edge of the spiral channel of the spiral conveyor 6 is adjacent to the inner wall of the drum 5.

[0024] Furthermore, the drum 5 is generally conical, or has a cylindrical upper part and a conical lower part, and the screw conveyor 6 is matched with the drum 5.

[0025] Furthermore, the spiral belt of the spiral conveyor 6 is a variable pitch spiral.

[0026] Furthermore, the pitch of the spiral belt of the spiral conveyor 6 gradually decreases from top to bottom.

[0027] Furthermore, a baffle is provided on the inner wall of the purification section 2 at the position between the stirring paddles of adjacent layers.

[0028] Furthermore, the baffle is a conical ring structure with a cone-shaped cross-section. The connection between the baffle and the inner wall of the purification section 2 is the bottom of the cone, and the top of the cone points to the axis of the purification section 2.

[0029] Furthermore, the cone apex angle of the baffle is 60°~120°.

[0030] Furthermore, the purification section 2 is equipped with several temperature control units to control the temperature of different parts of the purification section 2.

[0031] Furthermore, the temperature controlled by the temperature control unit gradually increases from top to bottom.

[0032] In this embodiment, the combined action of the temperature control unit, heating device, rotating drum and screw conveyor establishes a stable concentration and temperature gradient within the sweating purification tower, providing multiple theoretical equilibrium stages within a single device, resulting in better purification effect.

[0033] Example 2: An improvement to a purification method using a centrifugal sedimentation continuous sweating purification tower as described in Example 1 includes the following steps: The crystal slurry obtained through suspension crystallization is injected through inlet 4 into cavity I of the screw conveyor 6 within the centrifugal sedimentation section 1; under centrifugal force, the slurry enters cavity II between the inner wall of the drum 5 and the outer wall of the screw conveyor 6 through outlet 7; the slurry undergoes solid-liquid separation within the drum 5 due to centrifugal force, wherein the solid phase forms a crystal layer along the inner wall of the drum 5, the liquid phase is located on the surface of the crystal layer, and overflows from the top of the drum 5 along the spiral flow channel into cavity III of the centrifugal sedimentation section 1, and is discharged through mother liquor outlet 8; the crystals on the inner wall of the drum 5... The crystal bed is pushed downwards by the spiral channel of the screw conveyor 6 to the solid phase outlet, and then enters the purification section 2 and the melting section 3, where a continuous and stable crystal bed is established. As the screw conveyor 6 rotates and pushes, it continuously provides a certain downward pressure to the crystal bed. The crystal bed melts at the bottom of the tower under the action of the heating device 10 in the melting section 3. The output of the product outlet 12 is controlled to be less than the amount of molten liquid, so that the molten liquid in the melting section 3 flows upwards under the pressure of the crystal bed. The upward-flowing molten liquid undergoes a reverse heat and mass exchange with the downward-moving crystals, so that the crystals are continuously purified as they move downwards along the body of the sweating purification tower, and finally meet the product purity requirements.

[0034] Furthermore, the residence time of the material in the sweating purification tower body is adjusted by adjusting the feed rate at the feed inlet 4 and the power of the heating device 10, and the reflux ratio of the molten liquid in the sweating purification tower body is adjusted by adjusting the output rate at the product outlet 12, thereby adjusting the purification efficiency of the sweating purification tower body.

[0035] Example 3: Based on Example 1 or 2, crude ethylene carbonate was prepared via the ethylene oxide method. Separation and purification were achieved using continuous suspension melt crystallization, with a reaction tower output concentration of approximately 80%. After crystallization, a slurry with a suspension density of approximately 20% was formed. The slurry was further separated and purified using the sweating purification tower body of this invention. The time from start-up to product quality stabilization was shortened by approximately 4 hours compared to Example 1 of CN202311259710.1, the equipment holding volume was reduced by approximately 25%, and the purity of the extracted product was approximately 99.9983%.

[0036] Example 4: Based on Example 1 or 2, isomers of dichlorotoluene were separated. 2,4-Dichlorotoluene and 2,6-Dichlorotoluene are two isomers of dichlorotoluene with a boiling point difference of less than 1°C, making them difficult to separate using conventional distillation methods. Adsorption separation is energy-intensive, while melt crystallization is a more suitable method for separating and purifying dichlorotoluene isomers. However, since the solid-liquid equilibrium phase diagrams of 2,4-dichlorotoluene and 2,6-dichlorotoluene are eutectic solutions, obtaining high-purity 2,4-dichlorotoluene often requires multi-stage recrystallization. For example, using a 90% 2,4-dichlorotoluene mixture as raw material for separation and purification, using a centrifuge for solid-liquid separation, combined with a crystal washing process, four stages of crystallization are required to obtain a product with a purity of over 99.5%. Furthermore, by controlling the crystallization temperature and the amount of mother liquor and product return, the crystal slurry suspension density is maintained at approximately 40%, and the slurry is further purified using the sweating purification tower body provided by this invention. Purification section 2 is equipped with three temperature control units, which control the temperature of the units from top to bottom at -18℃, -16℃, and -14℃, respectively, and control the temperature of heating device 10 to be higher than the melting point of 2,4-dichlorotoluene. After 48 hours of continuous and stable operation, product samples were taken for analysis, and the purity was 99.92%.

[0037] It should be noted that the above detailed descriptions are exemplary and intended to provide further explanation of this application. Unless otherwise specified, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains.

[0038] It should be noted that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the exemplary embodiments described in this application. As used herein, the singular form is intended to include the plural form as well, unless the context clearly indicates otherwise. Furthermore, it should be understood that when the terms "comprising" and / or "including" are used in this specification, they indicate the presence of features, steps, operations, devices, components, and / or combinations thereof.

[0039] It should be noted that the terms "first," "second," etc., used in the specification, claims, and accompanying drawings of this application are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such terms can be used interchangeably where appropriate so that the embodiments of this application described herein can be implemented in sequences other than those illustrated or described herein.

[0040] Furthermore, the terms “comprising” and “having”, and any variations thereof, are intended to cover non-exclusive inclusion. For example, a process, method, system, product, or apparatus that includes a series of steps or units is not necessarily limited to those steps or units that are explicitly listed, but may include other steps or units that are not explicitly listed or that are inherent to such process, method, product, or apparatus.

[0041] For ease of description, spatial relative terms such as "above," "on top of," "on the upper surface of," "above," etc., are used herein to describe the spatial positional relationship of a device or feature as shown in the figures to other devices or features. It should be understood that spatial relative terms are intended to encompass different orientations in use or operation beyond the orientation of the device as described in the figures. For example, if the device in the figures were inverted, a device described as "above" or "on top of" other devices or structures would subsequently be positioned as "below" or "under" other devices or structures. Thus, the exemplary term "above" can include both "above" and "below." The device may also be positioned in other different ways, such as rotated 90 degrees or in other orientations, and the spatial relative descriptions used herein will be interpreted accordingly.

[0042] In the detailed description above, reference has been made to the accompanying drawings, which form part of this document. In the drawings, similar symbols typically identify similar parts unless the context otherwise indicates otherwise. The illustrated embodiments described in the detailed specification, drawings, and claims are not intended to be limiting. Other embodiments may be used and other changes may be made without departing from the spirit or scope of the subject matter presented herein.

[0043] The above description is merely a preferred embodiment of the present invention and is not intended to limit the invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A centrifugal sedimentation continuous sweating purification tower, characterized in that: The structure includes a diaphoretic purification tower body, which comprises a centrifugal settling section (1), a purification section (2), and a melting section (3). The centrifugal settling section (1) is located at the uppermost end of the diaphoretic purification tower body. A rotating drum (5) is installed inside the centrifugal settling section (1), and a screw conveyor (6) is installed inside the rotating drum (5). The rotating drum (5) and the screw conveyor (6) rotate at a differential speed. A feed inlet (4) is located at the center of the top of the centrifugal settling section (1). The lower end of the feed inlet (4) extends into the cavity I inside the screw conveyor (6) and communicates with the cavity I of the screw conveyor (6). Several material distribution ports (7) are provided on the cavity wall of the cavity I of the screw conveyor (6). The material distribution ports (7) connect the cavity I of the screw conveyor (6) with the rotating drum. (5) is connected to cavity II. The bottom of the drum (5) is provided with a solid phase outlet. The top of the drum (5) is open and connected to cavity III of the centrifugal sedimentation section (1). The bottom of the shell of the centrifugal sedimentation section (1) is provided with a mother liquor outlet (8). The purification section (2) is located below the centrifugal sedimentation section (1). The solid phase outlet is connected to the purification section (2). The melting section (3) is located below the purification section (2). The sweating purification tower body is provided with a stirring shaft (9). The stirring shaft (9) passes through the purification section (2) and the melting section (3). The stirring shaft (9) is provided with a stirring paddle. The bottom of the melting section (3) is provided with a heating device (10). The bottom of the melting section (3) is provided with a product outlet (12).

2. The centrifugal sedimentation continuous sweating purification tower according to claim 1, characterized in that: The edge of the spiral channel of the spiral conveyor (6) is adjacent to the inner wall of the drum (5).

3. The centrifugal sedimentation continuous sweating purification tower according to claim 1, characterized in that: The drum (5) is conical in shape, or cylindrical at the top and conical at the bottom, and the screw conveyor (6) is matched with the drum (5).

4. The centrifugal sedimentation continuous sweating purification tower according to claim 1, characterized in that: The spiral belt of the spiral conveyor (6) is a variable pitch spiral.

5. The centrifugal sedimentation continuous sweating purification tower according to claim 1, characterized in that: A turbulence baffle is provided on the inner wall of the purification section (2) between the stirring paddles of two adjacent layers.

6. The centrifugal sedimentation continuous sweating purification tower according to claim 5, characterized in that: The baffle is a conical ring structure with a cone-shaped cross section. The connection between the baffle and the inner wall of the purification section (2) is the bottom of the cone, and the top of the cone points to the axis of the purification section (2).

7. A centrifugal sedimentation continuous sweating purification tower according to claim 6, characterized in that: The conical apex angle of the turbulence baffle is 60°~120°.

8. The centrifugal sedimentation continuous sweating purification tower according to claim 1, characterized in that: The purification section (2) is equipped with several temperature control units to control the temperature of different parts of the purification section (2).

9. A purification method using any one of the centrifugal sedimentation continuous sweating purification towers according to claims 1-8, characterized in that: The process includes the following steps: the crystal slurry obtained by suspension crystallization is injected into the cavity I of the screw conveyor (6) in the centrifugal settling section (1) through the feed inlet (4); under the action of centrifugal force, the crystal slurry enters the cavity II between the inner wall of the drum (5) and the outer wall of the screw conveyor (6) through the feed inlet (7); the crystal slurry undergoes solid-liquid separation in the drum (5) due to centrifugal action, wherein the solid phase forms a crystal layer along the inner wall of the drum (5), the liquid phase is located on the surface of the crystal layer, and overflows from the top of the drum (5) along the spiral flow channel into the cavity III of the centrifugal settling section (1), and is discharged through the mother liquor outlet (8); the crystal layer on the inner wall of the drum (5) is pushed downward by the spiral flow channel of the screw conveyor (6). The crystals are pushed to the solid outlet and then enter the purification section (2) and the melting section (3). A continuous and stable crystal bed is established in the purification section (2) and the melting section (3). The rotating push of the screw conveyor (6) continuously provides a certain downward pressure to the crystal bed. The crystal bed melts at the bottom of the tower under the action of the heating device (10) in the melting section (3). The output of the product outlet (12) is controlled to be less than the amount of molten liquid, so that the molten liquid in the melting section (3) flows upward under the pressure of the crystal bed. The upward flowing molten liquid undergoes reverse heat and mass exchange with the downward moving crystals, so that the crystals are continuously purified as they move downward along the body of the sweating purification tower, and finally meet the product purity requirements.

10. The purification method according to claim 9, characterized in that: The residence time of the material in the sweating purification tower body is adjusted by adjusting the feed rate at the feed inlet (4) and the power of the heating device (10). The reflux ratio of the molten liquid in the sweating purification tower body is adjusted by adjusting the output rate at the product outlet (12), thereby adjusting the purification efficiency of the sweating purification tower body.

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