Sublimation purification equipment and method

Abstract

The invention relates to sublimation purification equipment and method, and the sublimation purification equipment comprises at least one sublimation purification station group, each sublimation purification station group comprises a feeding station, a defoaming station and at least two purification collection stations; a plurality of heaters; the temperature control device is electrically connected with each heater; each sublimation unit comprises a sublimation bottle and a first bottle cap or a second bottle cap detachably covering a bottle opening of the sublimation bottle; each supporting assembly comprises a plurality of supporting discs, and the supporting discs are used for supporting and placing the sublimation units; and the driving device is connected with each supporting disc and can drive each supporting disc to rotate along the circumferential direction so as to drive the sublimation units placed on the supporting discs to sequentially transfer at each station in the corresponding sublimation purification station group. According to the invention, the purification production efficiency and purification degree of the material, especially BHET, can be effectively improved, continuous production is realized, and the method is suitable for industrial production.

Description

Technical Field

[0001] This invention relates to the field of sublimation purification, and more particularly to a sublimation purification apparatus and method. Background Technology

[0002] Currently, the purity of BHET (dihydroxyethyl terephthalate) formed from polyester through alcoholysis is not high. It is often a yellow crystal containing dimers, trimers (such as cyclic oligomers) and a small amount of spinning auxiliaries generated from incomplete alcoholysis.

[0003] The impurity content of BHET is a core factor determining the economics of polyester chemical recycling and the performance of recycled PET. High-quality BHET can be used to synthesize recycled PET for food-grade packaging and fibers. High-purity BHET can be obtained by removing impurities through the development of efficient, low-consumption, continuous purification integrated systems. Sublimation technology is a traditional purification method; its application in BHET can effectively improve product purity and remove impurities.

[0004] Traditional sublimation apparatuses are prone to impurity co-sublimation due to uneven temperature distribution. Furthermore, they typically use large sublimation bottles for purification, resulting in poor purification efficiency. Operators in traditional sublimation apparatuses can only perform purification operations in one bottle at a time; after processing that bottle, collecting pure BHET, and cleaning residue, the bottle can be used for the next purification cycle, leading to low efficiency and hindering industrial production. Additionally, the sublimated gas needs to be recondensed into a solid at low temperatures, a process that may require manual intervention (such as product collection and equipment cleaning), making industrial-scale implementation difficult. Therefore, existing sublimation apparatuses cannot achieve effective and industrial-scale BHET recovery.

[0005] For example, the existing patent CN2873284Y discloses a sublimation device for separating and purifying natural products, which can purify materials, but it has low efficiency, low purification degree, and is not conducive to industrial production.

[0006] In view of this, based on years of experience in production design in this and related fields, the inventor has designed a sublimation purification device and method through repeated experiments, in order to solve at least some of the problems existing in the prior art. Summary of the Invention

[0007] The purpose of this invention is to provide a sublimation purification device and method, which can effectively improve the purification efficiency and purity of materials, especially BHET, and realize continuous production, making it suitable for industrial production.

[0008] The objective of this invention can be achieved using the following technical solutions:

[0009] This invention provides a sublimation purification apparatus, comprising:

[0010] At least one set of sublimation and purification station group, each set of sublimation and purification station group includes a feeding station, a degassing station and at least two purification and collection stations arranged sequentially and evenly at intervals along a circumferential direction.

[0011] Multiple heaters are provided, one below each of the degassing station and the purification and collection station;

[0012] Temperature control device, electrically connected to each heater, is used to control the heating temperature of each heater;

[0013] Multiple sublimation units, each sublimation unit includes a sublimation bottle and a first or second cap that can be detachably placed on the bottle mouth of the sublimation bottle. A first pressure-reducing suction pipe is inserted into the first cap, and a second pressure-reducing suction pipe and a collector are inserted into the second cap. A condensate inlet pipe and a condensate outlet pipe are inserted into the collector.

[0014] At least one set of support components, each set of support components including multiple support disks evenly spaced along the circumferential direction, the support disks being used to support and place the sublimation unit;

[0015] The driving device is connected to each support plate and can drive each support plate to rotate in a circumferential direction, so as to drive the sublimation unit placed on the support plate to move sequentially to each station in the corresponding sublimation purification station group. When the sublimation bottle is in the feeding station and the feeding is completed, the first bottle cap can be closed, and when it is in the purification and collection station, the second bottle cap can be closed.

[0016] In a preferred embodiment of the present invention, the lower part of the collector extends into the sublimation flask and the distance between the bottom end of the collector and the bottom of the sublimation flask is 10-15 mm.

[0017] In a preferred embodiment of the present invention, a screw metering feeder is provided above each feeding station for adding materials into the corresponding sublimation bottle.

[0018] In a preferred embodiment of the present invention, a heater is provided below the feeding station.

[0019] In a preferred embodiment of the present invention, the heater is a disc heating structure, and the heating area of ​​the disc heating structure is larger than the bottom area of ​​the sublimation flask.

[0020] In a preferred embodiment of the present invention, the driving device includes a base, a drive shaft, a drive motor, a reducer, and a plurality of connecting rods. The drive shaft is rotatably and vertically inserted into the base. The output shaft of the drive motor is connected to the drive shaft through the reducer. The drive shaft is vertically fixed to the plurality of connecting rods, and each connecting rod is connected to a corresponding support plate.

[0021] In a preferred embodiment of the present invention, the sublimation purification apparatus further includes a robot for picking up and placing sublimation bottles on a support plate, attaching or removing a first or second cap from the bottle neck, collecting the product on the collector, and cleaning the sublimation unit.

[0022] In a preferred embodiment of the present invention, the number of sublimation purification workstations is one set, and the number of purification and collection workstations in the sublimation purification workstations is two.

[0023] In a preferred embodiment of the present invention, there are multiple sublimation purification workstations, which are arranged sequentially along the circumferential direction.

[0024] The present invention also provides a sublimation purification method, using the above-mentioned sublimation purification equipment, the sublimation purification method comprising:

[0025] S1. Place a sublimation bottle on the support plate of the feeding station in each sublimation purification station group, add material into the sublimation bottle, put the first bottle cap on the sublimation bottle, and stay at the feeding station for a preset feeding time.

[0026] S2. The rotating support assembly rotates the sublimation bottle to the degassing station, heats the sublimation bottle, evacuates the sublimation bottle, and degassing it for a preset time at the degassing station.

[0027] S3. Rotate the support assembly to rotate the sublimation bottle to the purification and collection station close to the degassing station, remove the first bottle cap and place the second bottle cap with the collector on the sublimation bottle, continue to heat the sublimation bottle, evacuate the sublimation bottle, circulate and inject condensate into the collector, and stay at the current purification and collection station for the corresponding preset purification and collection time.

[0028] S4. Rotate the support assembly to rotate the sublimation bottle to the next purification and collection station, remove the old second bottle cap and place the new second bottle cap on the sublimation bottle, collect the condensate on the old collector, continue heating the sublimation bottle, evacuate the sublimation bottle, circulate condensate into the collector, and stay at the current purification and collection station for the corresponding preset purification and collection time; if the number of purification and collection stations in each sublimation purification station group is more than two, repeat step S4 until the sublimation bottle is rotated to the last purification and collection station;

[0029] S5. Collect the condensed product on the collector corresponding to the last purification collection station and clean the sublimation unit; place another sublimation bottle on the support plate of the feeding station in each sublimation purification station group, and repeat steps S1-S4 to use the next sublimation bottle for purification.

[0030] The present invention also provides a sublimation purification method, employing the aforementioned sublimation purification equipment, and rotating the support assembly at preset rotation intervals, wherein the preset rotation interval is the purification processing time required when the sublimation bottle is at the purification collection station near the degassing station; the sublimation purification method includes:

[0031] In each sublimation and purification station group, at the feeding station: a sublimation bottle is placed on the support plate facing the current feeding station, material is added into the sublimation bottle, and the first bottle cap is placed on the sublimation bottle.

[0032] In the degassing station of each sublimation purification station group: when there is a preset degassing time remaining before the preset rotation time, the sublimation bottle rotated to the degassing station is heated and the sublimation bottle is evacuated.

[0033] In each sublimation purification station group, near the degassing station, the purification collection station is as follows: the first bottle cap is removed and the second bottle cap with the collector is placed on the sublimation bottle, the sublimation bottle is heated, the sublimation bottle is evacuated, and the condensate is circulated into the collector.

[0034] In each sublimation purification station group, at other purification and collection stations: remove the old second bottle cap and place the new second bottle cap on the sublimation bottle; collect the condensate on the old collector; continue heating the sublimation bottle; evacuate the sublimation bottle; circulate condensate into the collector; perform the corresponding purification and collection preset time for heating, evacuation, and condensate injection at the corresponding purification and collection station; collect the condensate on the collector corresponding to the last purification and collection station; and clean the sublimation unit.

[0035] As described above, the sublimation purification equipment and method of the present invention, by setting up a feeding station, a degassing station, and a purification collection station in each sublimation purification station group, divides the purification of materials into multiple stations for sequential processing. Each sublimation purification station group can process one sublimation bottle first, and while cleaning that sublimation bottle, the next sublimation bottle is simultaneously fed. Alternatively, each sublimation purification station group can operate on multiple sublimation bottles simultaneously, resulting in higher production efficiency and enabling continuous purification of BHET materials, making it suitable for industrial production. Simultaneously, the sublimation bottle volume can be relatively small, resulting in less impurities in the obtained pure BHET compared to existing methods that use only one large-volume sublimation bottle. Precise temperature control of each heating device ensures uniform heating of the sublimation bottle, avoiding uneven temperature leading to co-sublimation of impurities. Furthermore, each sublimation purification station group has at least two purification collection stations, resulting in more thorough purification and collection, and a higher purification rate. Attached Figure Description

[0036] The following figures are intended only to illustrate and explain the present invention and do not limit the scope of the invention. Wherein:

[0037] Figure 1 This is a top view schematic diagram of the sublimation purification equipment provided by the present invention.

[0038] Figure 2 This is a schematic diagram of the first bottle cap provided by the present invention, which is equipped with a first pressure-reducing suction pipe.

[0039] Figure 3 This is a schematic diagram of the sublimation bottle cap provided by the present invention, which is equipped with a second pressure-reducing suction pipe and a collector.

[0040] Explanation of icon numbers:

[0041] 1. Feeding station; 12. Defoaming station; 13. Purification and collection station; 131. First purification and collection station; 132. Second purification and collection station;

[0042] 2. Sublimation unit; 21. Sublimation bottle; 22. First cap; 23. First pressure-reducing suction pipe; 24. Second cap; 25. Second pressure-reducing suction pipe; 26. Collector; 27. Condensate inlet pipe; 28. Condensate outlet pipe;

[0043] 3. Support plate;

[0044] 4. Drive unit; 41. Connecting rod;

[0045] 5. Screw metering feeder;

[0046] 6. Control Panel. Detailed Implementation

[0047] To provide a clearer understanding of the technical features, objectives, and effects of the present invention, specific embodiments of the present invention will now be described with reference to the accompanying drawings.

[0048] like Figures 1 to 3 As shown, this application provides a sublimation purification apparatus, comprising:

[0049] At least one set of sublimation and purification stations, each set of sublimation and purification stations includes a feeding station 1, a defoaming station 12 and at least two purification and collection stations 13 arranged sequentially and evenly along a circumferential direction.

[0050] Multiple heaters are provided, one below each of the degassing station 12 and the purification and collection station 13;

[0051] Temperature control device, electrically connected to each heater, is used to control the heating temperature of each heater;

[0052] Multiple sublimation units 2, each sublimation unit 2 includes a sublimation bottle 21 and a first cap 22 or a second cap 24 that is detachably attached to the mouth of the sublimation bottle 21. A first pressure-reducing suction pipe 23 is inserted into the first cap 22, and a second pressure-reducing suction pipe 25 and a collector 26 are inserted into the second cap 24. A condensate inlet pipe 27 and a condensate outlet pipe 28 are inserted into the collector 26.

[0053] At least one set of support components, each set of support components including multiple support disks 3 evenly spaced along the circumferential direction, the support disks 3 being used to support and place the sublimation unit 2;

[0054] The driving device 4 is connected to each support plate 3 and can drive each support plate 3 to rotate in the circumferential direction, so as to drive the sublimation unit 2 placed on the support plate 3 to move sequentially to each station in the corresponding sublimation purification station group. When the sublimation bottle 21 is in the feeding station and the feeding is completed, the first bottle cap 22 can be closed. When it is in the purification and collection station 13, the second bottle cap 24 can be closed.

[0055] Therefore, the equipment of this application, by setting up a feeding station 1, a degassing station 12, and a purification and collection station 13 in each sublimation purification station group, divides the purification of materials into multiple stations for sequential processing. Each sublimation purification station group can process one sublimation bottle 21 first, and while cleaning the sublimation bottle 21, the next sublimation bottle 21 is simultaneously fed. Alternatively, each sublimation purification station group can operate on multiple sublimation bottles 21 simultaneously, resulting in higher production efficiency and enabling continuous purification of BHET materials, suitable for industrial production. Simultaneously, the volume of the sublimation bottle 21 can be relatively small, resulting in less impurities in the obtained pure BHET compared to existing methods that use only one large-volume sublimation bottle 21. Precise temperature control of each heating device using a temperature control device ensures uniform heating of the sublimation bottle 21, avoiding uneven temperature leading to co-sublimation of impurities. Furthermore, each sublimation purification station group has at least two purification and collection stations, resulting in more thorough purification and collection, and a higher purification rate.

[0056] In a specific implementation, after the second cap 24 is installed on the sublimation bottle 21, the lower part of the collector 26 extends into the sublimation bottle 21 and is close to the bottom of the sublimation bottle 21. This can shorten the distance between the bottom of the collector 26 and the sublimation bottle 21, reduce the gas diffusion path, and improve the collection effect of the purified product.

[0057] The distance between the bottom of the collector 26 and the bottom of the sublimation flask 21 is generally 10-15 mm, with the specific dimensions depending on actual needs. Each sublimation flask 21 also has a relatively small volume; the miniaturized sublimation flask 21 reduces impurity interference and improves purification efficiency. The sublimation flask 21 is preferably cylindrical, with a base area of ​​0.5-1.5 square meters and a height of 5-15 centimeters, which improves vacuum efficiency and facilitates product sublimation.

[0058] The entire device increases the vacuum level by reducing the volume of the sublimation bottle 21 and the distance between the bottom of the collector 26 and the bottom of the sublimation bottle 21. The first pressurized suction tube removes the bubbles formed by small molecules, which can effectively reduce the interference of impurities in the collection of pure BHET and make it easier to obtain high-purity BHET.

[0059] Reference Figure 2 and Figure 3 The sublimation bottle 21 has an open top and a first insertion hole on the first cap 22. The first end of the first pressure reducing suction tube 23 can be sealed and inserted into the sublimation bottle 21 through the first insertion hole to communicate with the sublimation bottle 21. It can extend into the vicinity of the bottle mouth of the sublimation bottle 21 to facilitate effective vacuuming. A second insertion hole and a central insertion hole are provided on the second cap 24. The first end of the second pressure-reducing suction pipe 25 can be sealed and inserted into the sublimation bottle 21 through the second insertion hole and communicate with the sublimation bottle 21. It can extend into the vicinity of the bottle mouth of the sublimation bottle 21. The collector 26 can be a tube structure with both ends closed. The lower part of the collector 26 is sealed and inserted into the sublimation bottle 21 through the central insertion hole. The first end of the condensate inlet pipe 27 and the first end of the condensate outlet pipe 28 extend into the collector 26. The second end of the condensate inlet pipe 27 and the second end of the condensate outlet pipe 28 are located outside the collector 26 and are used to connect to the circulating liquid cooling system to circulate condensate into the collector 26. The condensate flows into the interior of the collector 26 through the condensate inlet pipe 27, cools the outer wall of the collector 26, and is discharged from the condensate outlet pipe 28 to maintain a low temperature environment. The outer surface of the collector 26 forms a condensation surface, which can increase the sublimation contact area and improve the yield.

[0060] Generally, it is preferable to position the first end of the condensate inlet pipe 27 near the bottom of the collector 26, and the first end of the condensate outlet pipe 28 near the top of the collector 26, to improve the condensation effect. The second ends of the first pressure-reducing suction pipe 23 and the second pressure-reducing suction pipe 25 can be connected to corresponding vacuum pumps to evacuate to the appropriate vacuum level, maintain a certain system pressure inside the sublimation bottle 21, and reduce the BHET sublimation temperature. Corresponding switching valves are also provided on the first pressure-reducing suction pipe 23, the second pressure-reducing suction pipe 25, the condensate inlet pipe 27, and the condensate outlet pipe 28 to facilitate the control of the on / off state at each point.

[0061] In use, the first cap 22 can be integrated with the first pressure-reducing suction pipe 23, the condensate inlet pipe 27 and the condensate outlet pipe 28 can be integrated with the collector 26, and the second cap 24 can be integrated with the collector 26 and the second pressure-reducing suction pipe 25. These can be pre-assembled. During operation, the pre-assembled first pressure-reducing suction pipe 23 and the first cap 22 can be directly sealed and installed at the mouth of the sublimation bottle 21, or the assembled second pressure-reducing suction pipe 25, the collector 26 and the second cap 24 can be sealed and installed at the mouth of the sublimation bottle 21, which is more convenient.

[0062] Furthermore, refer to Figure 1 Above each feeding station 1, a screw metering feeder 5 is provided for adding material into the corresponding sublimation bottle 21. At the feeding station 1, the screw metering feeder 5 can quantitatively and stably deliver the crude BHET material to be sublimated into the sublimation bottle 21; then, the first bottle cap 22 is installed on the bottle mouth of the sublimation bottle 21 to ensure a good seal at the interface and prevent gas leakage.

[0063] Optionally, a heater can be installed below the feeding station 1 to improve efficiency.

[0064] For the heater, a disc heating structure is generally adopted, and the disc heating structure may be equipped with spirally arranged heating wires to ensure uniform heating of the sublimation bottle 21. At the same time, the heating area of ​​the disc heating structure is larger than the bottom area of ​​the sublimation bottle 21, so as to ensure that the liquid BHET can move better towards the collector 26 after vaporizing into liquid gas, so that the liquid gas can better adhere to the outer wall of the collector 26 after condensing into solid, which is more conducive to collection.

[0065] Alternatively, the drive unit 4 includes a base, a drive shaft, a drive motor, a reducer, and multiple connecting rods 41. The drive shaft is rotatably and vertically inserted into the base. The output shaft of the drive motor is connected to the drive shaft through the reducer. The drive shaft is vertically fixed to the multiple connecting rods 41, and each connecting rod 41 is connected to a corresponding support plate 3.

[0066] The support plate 3 can be a circular base, made of stainless steel. A slot is provided on the support plate 3, allowing the sublimation bottle 21 to be securely held within it. The drive shaft is connected to the base via bearings. The reducer can be a worm gear reducer, and the drive motor drives the drive shaft to rotate via the worm gear reducer, thereby rotating all the support plates 3 evenly spaced along the circumference, with precise rotation angle positioning. All heaters at all stations can heat to the same temperature, for example, 200-250℃, or to their respective temperatures as needed. Other structures can be used for the drive device 4 as required; this embodiment is merely illustrative. The first and second pressure-reducing suction pipes 23 and 25 can be used to create a uniform vacuum within the sublimation bottle 21, or a desired vacuum level of 100Pa-2kPa can be achieved.

[0067] Further optionally, the sublimation purification equipment also includes a robot for picking up and placing sublimation bottles 21 on the support plate 3, removing and attaching the first cap 22 or the second cap 24 to the bottle mouth of the sublimation bottle 21, collecting the product on the collector 26, and cleaning the sublimation unit 2.

[0068] In this way, the sublimation bottle 21 is placed on the support plate 3 corresponding to the feeding station. After the sublimation bottle 21 is fed, the first bottle cap 22 with the first pressure-reducing suction pipe 23 is placed on the sublimation bottle 21. When the sublimation bottle 21 moves to the purification and collection station 13 near the degassing station 12, the first bottle cap 22 with the first pressure-reducing suction pipe 23 is removed and a second bottle cap 24 with a second pressure-reducing suction pipe 25 and a collector 26 is installed. When the sublimation bottle 21 moves to the next purification and collection station 13, the old second bottle cap 24 with the second pressure-reducing suction pipe 25 and a collector 26 is removed and a new second bottle cap 24 with the second pressure-reducing suction pipe 25 and a collector 26 is installed. The sublimation bottle 21 on the last purification and collection station 13 is removed from the support plate 3. The products on each collector 26 are collected, and each part of the sublimation unit 2 is cleaned. All these operations can be completed automatically by the robot, which can realize the automated continuous operation of the equipment, reduce manual intervention, and improve purification efficiency.

[0069] The number of support components is the same as the number of sublimation purification station groups. The number of support plates 3 in each support component group is the same as the total number of stations in each sublimation purification station group. Each support plate 3 can face its corresponding station. By rotating the support component, the support plate 3 can move the sublimation unit 2 above it to face the next station. The support components and sublimation purification station groups can each be a single group or multiple groups. When there are multiple groups, the multiple sublimation purification station groups are arranged sequentially along the circumference, which can simultaneously place more sublimation bottles 21 and purify more materials at the same time. Each sublimation purification station group has at least two purification collection stations 13 to facilitate sufficient purification and collection of materials.

[0070] The specific number depends on actual needs. For example, in a preferred embodiment, the support components and the sublimation purification station group can each be a group. The number of purification collection stations 13 in this sublimation purification station group is two. The four stations in the sublimation purification station group are evenly spaced at 90° intervals along the circumference. The entire sublimation purification equipment constitutes a four-heating rotary decompression sublimation purification equipment. In use, the drive motor rotates precisely 90° each time to switch one station, so that the sublimation bottle 21 is transferred sequentially to these four stations. Each station is equipped with an independent heater, and each heater is independently controlled by a temperature control device. In actual applications, the temperature control device also has a control panel 6, and each heater can be independently controlled by the control panel 6 to achieve precise temperature control of the station.

[0071] Furthermore, the aforementioned sublimation purification equipment can be used in practice for the following two sublimation purification methods, as follows:

[0072] The first method: Sublimation purification methods include:

[0073] S1. Place a sublimation bottle 21 on the support plate 3 facing the feeding station 1 in each sublimation purification station group, add material into the sublimation bottle 21, cover the sublimation bottle 21 with the first bottle cap 22, and stay at the feeding station 1 for a preset feeding time.

[0074] S2. Rotate the support assembly to rotate the sublimation bottle 21 to the degassing station 12, heat the sublimation bottle 21, evacuate the sublimation bottle 21, and degas for a preset time at the degassing station 12.

[0075] S3. Rotate the support assembly to rotate the sublimation bottle 21 to the purification and collection station 13 near the degassing station 12, remove the first bottle cap 22 and place the second bottle cap 24 with the collector 26 on the sublimation bottle 21, continue to heat the sublimation bottle 21, evacuate the sublimation bottle 21, circulate condensate into the collector 26, and stay at the current purification and collection station 13 for the corresponding preset purification and collection time.

[0076] S4. Rotate the support assembly to rotate the sublimation bottle 21 to the next purification and collection station 13, remove the old second bottle cap 24 and put the new second bottle cap 24 on the sublimation bottle 21, collect the condensed product on the old collector 26, continue to heat the sublimation bottle 21, evacuate the sublimation bottle 21, circulate the condensate into the collector 26, and stay at the current purification and collection station 13 for the corresponding preset purification and collection time; if the number of purification and collection stations 13 in each sublimation purification station group is greater than two, repeat step S4 until the sublimation bottle 21 is rotated to the last purification and collection station 13;

[0077] S5. Collect the condensed product on the collector 26 corresponding to the last purification collection station 13 and clean the sublimation unit 2. Place another sublimation bottle 21 on the support plate 3 of the feeding station 1 in each sublimation purification station group, and repeat steps S1-S4 to use the next sublimation bottle 21 for purification.

[0078] The first method ensures that only one station in each sublimation purification station group is in operation, meaning that only one station in each sublimation purification station group corresponds to a sublimation bottle 21, preventing multiple stations from having sublimation bottles 21 simultaneously. After one sublimation bottle 21 is sequentially transferred from the feeding station 1 to the last purification and collection station 13 for processing, the next sublimation bottle 21 is placed at the feeding station 1 in that sublimation purification station group.

[0079] In this method, refer to Figure 1Taking the aforementioned four-heating rotary decompression sublimation purification equipment as an example, that is, the sublimation purification station group is a group, and the purification collection station 13 is two, respectively referred to as the first purification collection station 131 and the second purification collection station 132, the working process of the equipment according to the first method is as follows:

[0080] Place a sublimation bottle 21 on the support plate 3 facing the feeding station 1, add the crude BHET material to be purified into the sublimation bottle 21, and then seal the first bottle cap 22 with the first pressure reducing suction tube 23 on the sublimation bottle 21. Stay at the feeding station 1 for a preset feeding time (e.g., 5-15 seconds).

[0081] Then, the rotating support assembly rotates the sublimation bottle 21 after the material is added to the degassing station 12. The heater directly below the degassing station 12 heats the sublimation bottle 21, and the first depressurization suction pipe 23 is used to evacuate the sublimation bottle 21. The bottle stays in the degassing station 12 for a preset degassing time (e.g., 1-3 minutes), which allows the BHET in the material to melt into a liquid state, and the small water molecules or other small molecules in the material to turn into bubbles, which are then removed by the first depressurization suction pipe 23. This reduces the impurities in the BHET and removes the gas from the molten liquid, preventing splashing during sublimation.

[0082] The rotating support assembly then rotates the sublimation bottle 21 to the first purification and collection station 131. The first bottle cap 22, which is equipped with the first pressure-reducing suction pipe 23, is removed from the sublimation bottle 21, and the second bottle cap 24, which is equipped with the collector 26 and the second pressure-reducing suction pipe 25, is installed. The sublimation bottle 21 is then heated using the heater directly below the first purification and collection station 131. The sublimation bottle 21 is evacuated using the second pressure-reducing suction pipe 25. Condensate (such as condensate water) is circulated into the collector 26 using the condensate inlet pipe 27 and the condensate outlet pipe 28. The sublimation bottle 21 is then kept in the first purification and collection station 131 for a predetermined purification and collection time (e.g., 15-45 minutes). During this time, the liquid BHET in the sublimation bottle 21 will vaporize into liquid gas during the heating process. The liquid gas moves upward and, under the condensation effect of the condensate water in the collector 26, the liquid gas condenses into a solid and adheres to the outer wall of the collector 26.

[0083] Next, the rotating support assembly rotates the sublimation bottle 21 to the second purification and collection station 132. At this station, the second bottle cap 24 and collector 26 installed at the first purification and collection station 131 need to be removed together (after removal, the condensate on the collector 26 can be collected). Then, the new second bottle cap 24, equipped with the collector 26 and the second pressure-reducing suction pipe 25, is installed on the sublimation bottle 21. The working process is the same as at the first purification and collection station 131. The heater directly below the second purification and collection station 132 is used to continue heating the sublimation bottle 21. Heating is performed by using the second pressure-reducing suction pipe 25 to evacuate the sublimation bottle 21. Condensate is circulated into the collector 26 through the condensate inlet pipe 27 and the condensate outlet pipe 28. The sample stays at the second purification and collection station 132 for a preset purification and collection time (e.g., 10-30 minutes). During this time, the liquid BHET in the sublimation bottle 21 will continue to vaporize into liquid gas during the heating process. The liquid gas moves upward and, under the condensation effect of the condensate in the collector 26, the liquid gas condenses into a solid and adheres to the outer wall of the collector 26.

[0084] Since the purification and collection of BHET at the first purification and collection station 131 may not be thorough or the collector 26 may be full, the purification and collection of BHET is continued at the second purification and collection station 132 to improve the purification and collection rate. After the second purification and collection station 132, purification ends, and the solids condensed on the outer wall of the second collector 26 are collected. The products collected on each collector 26 are the purified BHET. The used sublimation unit 2 is cleaned for reuse.

[0085] After the sublimation bottle 21 has been in the second purification and collection station 132 for a set time, and the purification and collection of the sublimation bottle 21 is completed, while the collector 26 on the sublimation bottle 21 collects the product and cleans the sublimation bottle 21, another sublimation bottle 21 can be placed on the support plate 3 opposite the current feeding station 1 for the next set of purification operations.

[0086] It is understandable that in this method, if there are multiple sublimation purification stations, the support plate 3 of the corresponding feeding station 1 in each sublimation purification station can simultaneously place one sublimation bottle 21. The sublimation bottle 21 corresponding to each sublimation purification station is sequentially moved to the next station in its respective sublimation purification station. If the number of purification collection stations 13 in each sublimation purification station is greater than or equal to three, after processing at the second purification collection station 132, the sublimation bottle 21 is rotated to the third purification collection station, a new second bottle cap 24 with a collector 26 is replaced, and purification and collection continue. In addition, in this method, each heater can be continuously heated, or the heater corresponding to the station can be started after the sublimation bottle 21 is rotated to the corresponding station; the opening and heating temperature of each heater are controlled and adjusted by the aforementioned temperature control device. After the sublimation bottle 21 moves to the corresponding station, the corresponding vacuum pump is started to reduce the gas pressure using the corresponding pressure reducing pipe.

[0087] The second method involves rotating the support assembly at preset rotation intervals, where the preset rotation time is the purification processing time required when the sublimation bottle 21 is near the purification collection station 13 close to the degassing station 12; the sublimation purification method includes:

[0088] In each sublimation and purification station group, at feeding station 1: a sublimation bottle 21 is placed on the support plate 3 facing feeding station 1, material is added into the sublimation bottle 21, and the first bottle cap 22 is placed on the sublimation bottle 21.

[0089] In each sublimation purification station group, at the degassing station 12: when there is a preset degassing time remaining before the preset rotation time, the sublimation bottle 21 that has been rotated to the degassing station 12 is heated and a vacuum is drawn inside the sublimation bottle 21.

[0090] In each sublimation purification station group, near the degassing station 12, at the purification collection station 13: remove the first bottle cap 22 and place the second bottle cap 24 with the collector 26 on the sublimation bottle 21, continue to heat the sublimation bottle 21, evacuate the sublimation bottle 21, and circulate condensate into the collector 26.

[0091] In other purification and collection stations 13 within each sublimation and purification station group: remove the old second bottle cap 24 and place the new second bottle cap 24 on the sublimation bottle 21; collect the condensed product on the old collector 26; continue heating the sublimation bottle 21; evacuate the sublimation bottle 21; circulate and inject condensate into the collector 26; perform the corresponding purification and collection preset time for heating, evacuating, and injecting condensate at the corresponding purification and collection station 13; collect the condensed product on the collector 26 corresponding to the last purification and collection station 13; and clean the sublimation unit 2.

[0092] The second method involves rotating all the support plates 3 together for a fixed preset rotation time. Since the purification and collection time at the purification and collection station 13, which is closest to the degassing station 12, is the longest (15-45 minutes), while the other purification and collection stations 13 have relatively shorter times (10-30 minutes), and the degassing time at the degassing station 12 is also very short (1-3 minutes), and the plates need to be rotated to the purification and collection station 13 immediately after degassing for further purification, the preset rotation time is determined based on the required purification time (15-45 minutes) at the purification and collection station 13 closest to the degassing station 12, for example, a preset rotation time of 30 minutes.

[0093] In this way, the support plate 3 rotates at preset rotation intervals. Whenever the corresponding support plate 3 on the feeding station 1 becomes empty, a new sublimation bottle 21 can be added. After the sublimation bottle 21 is filled, when it rotates to the degassing station 12 during the rotation cycle, it waits until there is still a preset degassing time remaining before heating and vacuuming. For example, if the preset rotation time is 30 minutes and the preset degassing time is 20 minutes, when the sublimation bottle 21 rotates to the degassing station 12, it waits for 10 minutes. When there are still 20 minutes left before the next rotation, it rotates to the first purification and collection station 131 after 20 minutes of heating and vacuuming and 20 minutes of degassing.

[0094] Upon reaching purification and collection station 13, heating, vacuuming, and circulating condensate into collector 26 can begin. After 30 minutes of purification and collection, the device rotates to the second purification and collection station 132. At the second purification and collection station 132, heating, vacuuming, and circulating condensate into collector 26 can be performed for the corresponding preset purification and collection time (10-30 minutes, taking 20 minutes as an example). After 20 minutes, heating, vacuuming, and circulating condensate into collector 26 are stopped. If the second purification and collection station 132 is not the last purification and collection station 13, the rotation cycle is completed after 30 minutes before rotating to the next purification and collection station 13 and continuing the same process. If the second purification and collection station 132 is the last purification and collection station 13, after 20 minutes of purification and collection, heating, vacuuming, and circulating condensate into collector 26 are stopped. Then, the sublimation bottle 21 is directly removed, the product in collector 26 is collected, and the sublimation bottle 21 is cleaned.

[0095] If a heater is also provided below the feeding station 1, then after placing the sublimation bottle 21 at the feeding station 1, it is necessary to add material to the sublimation bottle 21 and cover it with the first bottle cap 22 when there is a remaining feeding preset time (5-15 seconds) after the preset rotation time.

[0096] In the second method, the specific processes of adding materials, degassing, purification and collection are the same as those in the first method, and will not be repeated here. The only difference is when to rotate, how many sublimation bottles 21 to place, and when to start heating, vacuuming and circulating condensation.

[0097] In the first method, the purification process of BHET material is divided into at least four stations: feeding, degassing, and at least two purification collections, which are processed sequentially. While the product on the collector 26 is collected and the sublimation bottle 21 is cleaned after purification collection in the sublimation bottle 21, the next sublimation bottle 21 can be used for purification, resulting in high purification efficiency. In the second method, the purification process of BHET material is also divided into at least four stations: feeding, degassing, and at least two purification collections, which are processed sequentially. Furthermore, when the support plate 3 corresponding to the feeding station 1 becomes empty, a new sublimation bottle 21 can be placed. Multiple sublimation bottles 21 in the entire equipment can perform corresponding operations simultaneously, resulting in higher operating efficiency and significantly improved production efficiency.

[0098] Meanwhile, in both methods, the sublimation flask 21 has a relatively smaller volume, resulting in less impurities in the pure BHET compared to existing methods that use only a large-volume sublimation flask 21. Precise temperature control of each heating element ensures uniform heating of the sublimation flask 21, preventing uneven temperature distribution that could lead to co-sublimation of impurities. Each sublimation purification station group has at least two purification collection units, resulting in more thorough purification and a higher purification rate. Furthermore, placing the collector 26 closer to the sublimation flask 21 further reduces impurities and improves the purity of the collected product. Both methods enable continuous purification of BHET materials and are suitable for industrial production.

[0099] It should be noted that the above-described equipment and purification method, strictly speaking, is not a sublimation process for BHET purification. Instead, it involves melting, vaporization, and deposition—a process from solid to liquid, to liquid-gas, and back to solid. Therefore, the entire equipment and method can also be called material purification equipment and method. It is particularly suitable for purifying BHET monomers from recycled polyester textiles and blended fabrics, used to purify BHET recovered from polyester alcoholysis, solving the problem of low-purity BHET formed during polyester alcoholysis recovery while achieving continuous production. Of course, this equipment is not limited to the purification of BHET materials and can also be used for the purification of other materials.

[0100] The above are merely illustrative embodiments of the present invention and are not intended to limit the scope of the invention. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present invention should fall within the scope of protection of the present invention.

Claims

1. A sublimation purification device, characterized in that, include: At least one set of sublimation and purification station group, each set of sublimation and purification station group includes a feeding station, a degassing station and at least two purification and collection stations arranged sequentially and evenly at intervals along a circumferential direction. Multiple heaters are provided, one below each of the degassing station and the purification and collection station; A temperature control device, electrically connected to each of the heaters, is used to control the heating temperature of each of the heaters; Multiple sublimation units, each sublimation unit includes a sublimation bottle and a first or second cap that can be detachably placed on the bottle mouth of the sublimation bottle. A first pressure-reducing suction pipe is inserted into the first cap, and a second pressure-reducing suction pipe and a collector are inserted into the second cap. A condensate inlet pipe and a condensate outlet pipe are inserted into the collector. At least one set of support components, each set of support components including a plurality of support disks evenly spaced along the circumferential direction, the support disks being used to support and place the sublimation unit; A driving device is connected to each of the support plates and can drive each of the support plates to rotate along the circumferential direction, so as to drive the sublimation unit placed on the support plate to move sequentially to each station in the corresponding sublimation purification station group. When the sublimation bottle is in the feeding station and the feeding is completed, the first bottle cap can be closed, and when it is in the purification and collection station, the second bottle cap can be closed.

2. The sublimation purification equipment as described in claim 1, characterized in that, The lower part of the collector extends into the sublimation bottle, and the distance between the bottom end of the collector and the bottom of the sublimation bottle is 10-15 mm.

3. The sublimation purification equipment as described in claim 1, characterized in that, A screw feeder is provided above each of the feeding stations for adding materials into the corresponding sublimation bottles.

4. The sublimation purification equipment as described in claim 1, characterized in that, A heater is also provided below the feeding station.

5. The sublimation purification equipment as described in claim 1, characterized in that, The heater is a disc heating structure, and the heating area of ​​the disc heating structure is larger than the bottom area of ​​the sublimation bottle.

6. The sublimation purification equipment as described in claim 1, characterized in that, The driving device includes a base, a drive shaft, a drive motor, a reducer, and multiple connecting rods. The drive shaft is rotatably and vertically inserted into the base. The output shaft of the drive motor is connected to the drive shaft through the reducer. The drive shaft is vertically fixed to the multiple connecting rods, and each connecting rod is connected to a corresponding support plate.

7. The sublimation purification equipment as described in claim 1, characterized in that, The sublimation purification equipment also includes a robot for picking up and placing the sublimation bottle on the support plate, removing or attaching the first or second cap to the bottle mouth of the sublimation bottle, collecting the product on the collector, and cleaning the sublimation unit.

8. The sublimation purification equipment as described in claim 1, characterized in that, The number of sublimation and purification workstations is one group, and the number of purification and collection workstations in the sublimation and purification workstation group is two.

9. The sublimation purification equipment as described in claim 1, characterized in that, The number of sublimation and purification workstations is multiple, and the multiple sublimation and purification workstations are arranged sequentially along the circumferential direction.

10. A method for sublimation and purification, characterized in that, Using the sublimation purification equipment as described in any one of claims 1-9, the sublimation purification method includes: S1. Place a sublimation bottle on the support plate facing the feeding station in each sublimation purification station group, add material into the sublimation bottle, cover the sublimation bottle with the first bottle cap, and stay at the feeding station for a preset feeding time. S2. Rotate the support assembly to rotate the sublimation bottle to the degassing station, heat the sublimation bottle, evacuate the sublimation bottle, and degas for a preset time at the degassing station; S3. Rotate the support assembly to rotate the sublimation bottle to a purification and collection station close to the degassing station, remove the first bottle cap and place the second bottle cap with the collector on the sublimation bottle, continue to heat the sublimation bottle, evacuate the sublimation bottle, circulate and inject condensate into the collector, and stay at the current purification and collection station for a corresponding preset purification and collection time. S4. Rotate the support assembly to rotate the sublimation bottle to the next purification and collection station, remove the old second cap and place the new second cap on the sublimation bottle, collect the condensed product on the old collector, continue heating the sublimation bottle, evacuate the sublimation bottle, circulate condensate into the collector, and stay at the current purification and collection station for the corresponding preset purification and collection time; if the number of purification and collection stations in each sublimation purification station group is greater than two, repeat step S4 until the sublimation bottle is rotated to the last purification and collection station; S5. Collect the condensed product on the collector corresponding to the last purification collection station and clean the sublimation unit; place another sublimation bottle on the support plate of the feeding station in each sublimation purification station group, and repeat steps S1-S4 to use the next sublimation bottle for purification.

11. A sublimation purification method, characterized in that, The sublimation purification equipment as described in any one of claims 1-9 is used, and the support assembly is rotated at preset rotation times, wherein the preset rotation time is the purification processing time required when the sublimation bottle is at the purification collection station near the degassing station. The sublimation and purification method includes: In each sublimation and purification station group, at the feeding station: a sublimation bottle is placed on the support plate facing the current feeding station, material is added into the sublimation bottle, and the first bottle cap is placed on the sublimation bottle. In the degassing station of each sublimation purification station group: when there is a preset degassing time remaining before the preset rotation time, the sublimation bottle rotated to the degassing station is heated and the sublimation bottle is evacuated. In each sublimation purification station group, near the degassing station, the purification collection station is as follows: the first bottle cap is removed and the second bottle cap with a collector is placed on the sublimation bottle, the sublimation bottle is continued to be heated, the sublimation bottle is evacuated, and condensate is circulated into the collector. In other purification and collection stations within each sublimation purification station group: remove the old second bottle cap and place the new second bottle cap on the sublimation bottle; collect the condensate on the old collector; continue heating the sublimation bottle; evacuate the sublimation bottle; circulate condensate into the collector; perform the corresponding purification and collection preset time for heating, evacuation, and condensate injection at the corresponding purification and collection station; collect the condensate on the collector corresponding to the last purification and collection station; and clean the sublimation unit.

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