Sublimation purification apparatus and method

Abstract

The present application is a kind of sublimation purification equipment and method, sublimation purification equipment includes: at least one group of sublimation purification station group, each group of sublimation purification station group includes a feeding station, a defoaming station and at least two purification collection stations;Multiple heaters;Temperature control device, electrically connected with each heater;Multiple sublimation units, sublimation unit includes sublimation bottle and can be detachably covered at the bottle mouth of sublimation bottle first bottle cap or second bottle cap;At least one group of support assembly, each group of support assembly includes multiple support disc, support disc is used to support the sublimation unit placed on;Driving device, connected with each support disc, and can drive each support disc rotates in circumferential direction, to drive the sublimation unit placed on support disc in each station of corresponding sublimation purification station group is transferred in turn.The present application can effectively improve the purification production efficiency and purification degree of material, especially BHET, and realize continuous production, suitable for industrial production.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of sublimation purification, in particular to a sublimation purification device and method. BACKGROUND

[0002] At present, the purity of BHET (bis-hydroxyethyl terephthalate) formed by alcoholysis recovery of polyester is not high, and it is often yellow crystalline, containing incomplete alcoholysis generated dimers, trimers (such as cyclic oligomers) and a small amount of spinning aids.

[0003] The impurity content of BHET is a core factor for determining the economy 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. By developing a continuous purification integrated system with high efficiency and low consumption, impurities can be removed to obtain high-purity BHET. Sublimation technology is a traditional purification method, and sublimation of BHET can effectively improve product purity and remove impurities.

[0004] The traditional sublimation device is prone to impurity co-sublimation due to uneven temperature. Moreover, the traditional sublimation device usually uses a large sublimation bottle to purify the material, and the purification effect is not good. The operator can only purify one sublimation bottle at a time, and after the operation of the sublimation bottle is completed, the pure BHET is collected and the residue is cleaned before the next purification operation can be performed using the sublimation bottle. The efficiency is low, and it is not conducive to industrial production. In addition, the gas after sublimation needs to be re-condensed into a solid in a low-temperature zone, which may require manual intervention (such as collecting products and cleaning the device), making it difficult to achieve industrialization. Furthermore, the existing sublimation device cannot effectively and industrially recover BHET.

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

[0006] Therefore, the present application is designed by the present inventors on the basis of years of production and design experience in this field and related fields, and through repeated tests, in order to solve at least some of the problems existing in the prior art. SUMMARY

[0007] The present application aims to provide a sublimation purification device and method that can effectively improve the purification production efficiency and purity of the material, especially BHET, and achieve continuous production, suitable for industrial production.

[0008] The object of the present application can be achieved by using the following technical solutions:

[0009] The present application provides a sublimation purification device, comprising:

[0010] at least one set of sublimation purification stations, each set of sublimation purification stations comprising a feeding station, a defoaming station and at least two purification collection stations arranged in sequence and uniformly spaced along a circumferential direction;

[0011] a plurality of heaters, each of which is arranged below the defoaming station and the purification collection station;

[0012] a temperature control device electrically connected to each of the heaters for controlling the heating temperature of each of the heaters;

[0013] a plurality of sublimation units, each of which comprises a sublimation bottle and a first or second bottle cap detachably arranged at the bottle mouth of the sublimation bottle, a first pressure-reducing air extraction pipe arranged on the first bottle cap, a second pressure-reducing air extraction pipe and a collector arranged on the second bottle cap, and a condensate inlet pipe and a condensate outlet pipe arranged on the collector;

[0014] at least one set of support assemblies, each of which comprises a plurality of support discs arranged in sequence and uniformly spaced along the circumferential direction, and each of the support discs is used for supporting the sublimation unit;

[0015] a driving device connected to each of the support discs and capable of driving each of the support discs to rotate along the circumferential direction so as to drive the sublimation unit placed on the support disc to sequentially transfer among the stations in the corresponding set of sublimation purification stations, and the sublimation bottle is capable of being capped with the first bottle cap after completing the feeding in the feeding station and being capped with the second bottle cap when being in the purification collection station.

[0016] In a preferred embodiment of the present application, 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.

[0017] In a preferred embodiment of the present application, a spiral quantitative feeder is arranged above each of the feeding stations for feeding the material into the corresponding sublimation bottle.

[0018] In a preferred embodiment of the present application, a heater is further arranged below the feeding station.

[0019] In a preferred embodiment of the present application, 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.

[0020] In a preferred embodiment of the present application, the driving device comprises a base, a driving shaft, a driving motor, a speed reducer and a plurality of connecting rods, the driving shaft is rotatably and vertically arranged on the base, the output shaft of the driving motor is connected to the driving shaft through the speed reducer, the driving shaft is vertically fixedly connected to the plurality of connecting rods, and each of the connecting rods is connected to a corresponding support disc.

[0021] In a preferred embodiment of the present application, the sublimation purification device further comprises a robot for taking and placing the sublimation bottle on the support disc, disassembling and assembling the first bottle cap or the second bottle cap on the bottle mouth of the sublimation bottle, collecting the product on the collector, and cleaning the sublimation unit.

[0022] In a preferred embodiment of the present application, the number of groups of the sublimation purification station groups is one, and the number of purification and collection stations in the sublimation purification station group is two.

[0023] In a preferred embodiment of the present application, the number of groups of the sublimation purification station groups is multiple, and the multiple groups of the sublimation purification station groups are sequentially arranged in the circumferential direction.

[0024] The present application also provides a sublimation purification method using the above-mentioned sublimation purification device, which comprises the following steps:

[0025] S1, placing a sublimation bottle on the support disc opposite to the feeding station in each group of the sublimation purification station groups, adding material into the sublimation bottle, assembling the first bottle cap on the sublimation bottle, and stopping at the feeding station for a preset feeding time;

[0026] S2, rotating the support assembly to rotate the sublimation bottle to the defoaming station, heating the sublimation bottle, vacuumizing the sublimation bottle, and stopping at the defoaming station for a preset defoaming time;

[0027] S3, rotating the support assembly to rotate the sublimation bottle to the purification and collection station close to the defoaming station, disassembling the first bottle cap and assembling the second bottle cap with the collector on the sublimation bottle, continuing to heat the sublimation bottle, vacuumizing the sublimation bottle, circulating and injecting the condensate into the collector, and stopping at the current purification and collection station for a corresponding purification and collection preset time;

[0028] S4, rotating the support assembly to rotate the sublimation bottle to the next purification and collection station, disassembling the old second bottle cap and assembling the new second bottle cap on the sublimation bottle, collecting the condensate product on the old collector, continuing to heat the sublimation bottle, vacuumizing the sublimation bottle, circulating and injecting the condensate into the collector, and stopping at the current purification and collection station for a corresponding purification and collection preset time; if the number of purification and collection stations in each group of the sublimation purification station groups is greater than two, repeating step S4 until the sublimation bottle is rotated to the last purification and collection station;

[0029] S5, collecting the condensate product on the collector corresponding to the last purification and collection station, cleaning the sublimation unit, placing another sublimation bottle on the support disc opposite to the feeding station in each group of the sublimation purification station groups, and repeating steps S1-S4 to perform purification treatment by using the next sublimation bottle.

[0030] The present application also provides a sublimation purification method, which uses the sublimation purification device and rotates the support assembly every interval preset rotation time, and the preset rotation time is the purification treatment time required by the sublimation bottle when it is at the purification collection station close to the defoaming station.

[0031] At the feeding station in each group of sublimation purification station groups: a sublimation bottle is placed on the support disc currently facing the feeding station, material is added to the sublimation bottle, and a first bottle cap is arranged on the sublimation bottle;

[0032] At the defoaming station in each group of sublimation purification station groups: when the remaining defoaming preset time of the preset rotation time, the sublimation bottle rotated to the defoaming station is heated, and the sublimation bottle is vacuumized;

[0033] At the purification collection station close to the defoaming station in each group of sublimation purification station groups: the first bottle cap is removed and a second bottle cap with a collector is arranged on the sublimation bottle, the sublimation bottle is continuously heated, the sublimation bottle is vacuumized, and the condensate is circulated and injected into the collector;

[0034] At the other purification collection stations in each group of sublimation purification station groups: the old second bottle cap is removed and a new second bottle cap is arranged on the sublimation bottle, the condensate on the old collector is collected, the sublimation bottle is continuously heated, the sublimation bottle is vacuumized, and the condensate is circulated and injected into the collector, and the heating, vacuumizing and injecting condensate at the corresponding purification collection station are performed for a corresponding purification collection preset time; the condensate on the collector corresponding to the last purification collection station is collected, and the sublimation unit is cleaned.

[0035] As described above, the sublimation purification device and method of the present application, by arranging the feeding station, the defoaming station and the purification collection station in each group of sublimation purification station groups, the purification of the material is divided into multiple stations for processing in turn, each group of sublimation purification station groups can process one sublimation bottle first, and add material to the next sublimation bottle while cleaning the current sublimation bottle, or each group of sublimation purification station groups can simultaneously process multiple sublimation bottles, which has higher production efficiency and can realize continuous purification operation of BHET material, and is suitable for industrial production. At the same time, the volume of the sublimation bottle can be relatively small, and compared with the existing method of using only one large volume sublimation bottle, the obtained pure BHET has less impurities; the temperature control device is used to accurately control the temperature of each heating device, so that the sublimation bottle can be uniformly heated, and the uneven temperature can be avoided to cause impurities to co-sublimate; in addition, each group of sublimation purification station groups has at least two purification collection stations, so that the purification collection is more thorough and the purification rate is higher. BRIEF DESCRIPTION OF DRAWINGS

[0036] The following drawings are only intended to illustrate and explain the present application and do not limit the scope of the present application. Among them:

[0037] Figure 1 A top view schematic diagram of a sublimation purification device provided by the present application.

[0038] Figure 2 A schematic diagram of a first bottle cap provided with a first pressure reduction air extraction pipe on a sublimation bottle upper cover.

[0039] Figure 3 A schematic diagram of a second bottle cap provided with a second pressure reduction air extraction pipe and a collector on a sublimation bottle upper cover.

[0040] BRIEF DESCRIPTION OF DRAWINGS

[0041] 11, feeding station; 12, defoaming station; 13, purification collection station; 131, first purification collection station; 132, second purification collection station;

[0042] 2, sublimation unit; 21, sublimation bottle; 22, first bottle cap; 23, first pressure reduction air extraction pipe; 24, second bottle cap; 25, second pressure reduction air extraction pipe; 26, collector; 27, condensate liquid inlet pipe; 28, condensate liquid outlet pipe;

[0043] 3, support disc;

[0044] 4, driving device; 41, connecting rod;

[0045] 5, screw feeder;

[0046] 6, control panel. DETAILED DESCRIPTION

[0047] In order to have a clearer understanding of the technical features, objects and effects of the present application, the specific embodiments of the present application will be described with reference to the accompanying drawings.

[0048] As shown in Figures 1 to 3 , the present application provides a sublimation purification device, comprising:

[0049] at least one group of sublimation purification station groups, each group of sublimation purification station groups comprising a feeding station 11, a defoaming station 12 and at least two purification collection stations 13 arranged in a circumferential direction in sequence and uniformly spaced;

[0050] a plurality of heaters, each of which is arranged below the defoaming station 12 and the purification collection station 13;

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

[0052] a plurality of sublimation units 2, each of which comprises a sublimation bottle 21 and a first bottle cap 22 or a second bottle cap 24 detachably capped on the bottle mouth of the sublimation bottle 21, a first pressure-reducing air extraction pipe 23 inserted on the first bottle cap 22, a second pressure-reducing air extraction pipe 25 and a collector 26 inserted on the second bottle cap 24, and a condensate liquid inlet pipe 27 and a condensate liquid outlet pipe 28 inserted on the collector 26;

[0053] at least one set of support assemblies, each of which comprises a plurality of support plates 3 uniformly spaced in the circumferential direction and used for supporting the sublimation units 2;

[0054] a driving device 4 connected with each of the support plates 3 and capable of driving each of the support plates 3 to rotate in the circumferential direction so as to sequentially transfer the sublimation units 2 placed on the support plates 3 among the working stations in the corresponding set of sublimation purification working stations, and the sublimation bottle 21 is capable of being capped with the first bottle cap 22 after being filled in the filling working station and being capped with the second bottle cap 24 when being in the purification and collection working station 13.

[0055] Therefore, the device of the present application can sequentially process the purification of the material in multiple working stations by arranging the filling working station 11, the defoaming working station 12 and the purification and collection working station 13 in each set of sublimation purification working stations, each set of sublimation purification working stations can process one sublimation bottle 21 first and simultaneously start filling the next sublimation bottle 21 when cleaning the sublimation bottle 21, or each set of sublimation purification working stations can also simultaneously process multiple sublimation bottles 21, which is more efficient and can realize continuous purification operation of the BHET material and is suitable for industrial production. Meanwhile, the volume of the sublimation bottle 21 can be relatively small, and compared with the prior art which only uses one large-volume sublimation bottle 21, the obtained pure BHET has less impurities; the temperature of each heating device can be accurately controlled by using the temperature control device, so that the sublimation bottle 21 can be uniformly heated and the uneven temperature can be avoided to cause the co-sublimation of impurities; in addition, each set of sublimation purification working stations has at least two purification and collection working stations, so that the purification and collection are more thorough and the purification rate is higher.

[0056] In the specific implementation mode, after the second bottle cap 24 is installed on the sublimation bottle 21, the lower part of the collector 26 extends into the sublimation bottle 21 and is relatively close to the bottom of the sublimation bottle 21, so that the distance between the bottom of the collector 26 and the sublimation bottle 21 can be shortened, the gas diffusion path is reduced, and the collection effect of the purified product is improved.

[0057] Generally, the distance between the bottom end of the collector 26 and the bottom of the sublimation bottle 21 is 10-15 mm, and the specific size is determined according to actual needs. The volume of each sublimation bottle 21 is also relatively small, and the small-sized sublimation bottle 21 can reduce the interference of impurities and improve the purification effect. Generally, the sublimation bottle 21 preferably adopts a cylindrical bottle body with a bottom area of 0.5-1.5 square meters and a height of 5-15 centimeters, which can improve the efficiency of vacuum degree and is also more conducive to the sublimation of the product.

[0058] The whole device can effectively reduce the interference of impurities in the collection of pure BHET by reducing the volume of the sublimation bottle 21 and the distance between the bottom of the collector 26 and the bottle bottom of the sublimation bottle 21, improving the vacuum degree, and using the first pressurized air extraction pipe to extract the gas bubbles formed by small molecules, which is more conducive to obtaining high-purity BHET.

[0059] Referring to Figure 2 and Figure 3 , the sublimation bottle 21 is a bottle body structure with an open upper end, a first insertion hole is formed in the first bottle cap 22, the first end of the first pressure reduction air extraction pipe 23 can be sealed and inserted into the sublimation bottle 21 through the first insertion hole to communicate with the sublimation bottle 21, and can be extended near the bottle mouth of the sublimation bottle 21 to facilitate effective vacuumization. A second insertion hole and a central insertion hole are formed in the second bottle cap 24, the first end of the second pressure reduction air extraction pipe 25 can be sealed and inserted into the sublimation bottle 21 through the second insertion hole to communicate with the sublimation bottle 21, and can be extended near the bottle mouth of the sublimation bottle 21; the collector 26 can be a pipe body 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 are extended into the collector 26, and 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 used to connect a circulating liquid cooling system to circulate and pass condensate water into the collector 26, the condensate water flows into the inside of the collector 26 through the condensate inlet pipe 27, cools the outer wall of the collector 26, and then is discharged from the condensate outlet pipe 28 to maintain a low-temperature environment; the outer surface of the collector 26 constitutes a condensing surface, which can increase the sublimation contact area and improve the yield.

[0060] Generally, the first end of the condensate inlet pipe 27 is preferably arranged near the bottom of the collector 26, and the first end of the condensate outlet pipe 28 is preferably arranged near the top of the collector 26 to improve the condensation effect. The second end of the first pressure reduction air extraction pipe 23 and the second end of the second pressure reduction air extraction pipe 25 can be connected to corresponding vacuum pumps to perform vacuumization to corresponding vacuum degrees, maintain a certain system pressure in the sublimation bottle 21, and reduce the sublimation temperature of BHET. Switch valves are also provided on the first pressure reduction air extraction pipe 23, the second pressure reduction air extraction pipe 25, the condensate inlet pipe 27, and the condensate outlet pipe 28 to facilitate the control of the on-off of each part.

[0061] In use, the first bottle cap 22 and the first pressure reduction air extraction pipe 23 can be integrated together, the condensate inlet pipe 27 and the condensate outlet pipe 28 can be integrated with the collector 26, and the second bottle cap 24 can be integrated with the collector 26 and the second pressure reduction air extraction pipe 25, which can be assembled in advance, and during work, the first pressure reduction air extraction pipe 23 and the first bottle cap 22 assembled in advance can be sealed and installed at the bottle mouth of the sublimation bottle 21, or the second pressure reduction air extraction pipe 25, the collector 26, and the second bottle cap 24 assembled in advance can be sealed and installed at the bottle mouth of the sublimation bottle 21, which is more convenient.

[0062] Further, referring to Figure 1 A spiral dosing feeder 5 is arranged above each feeding station 11 for adding materials into the corresponding sublimation bottle 21. In the feeding station 11, the spiral dosing 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 is further arranged below the feeding station 11 to improve efficiency.

[0064] For the heater, a disc heating structure is generally adopted, and heating wires in a spiral arrangement can be arranged in the disc heating structure to ensure the uniformity of heating 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 to ensure that the liquid BHET can better move towards the collector 26 after being gasified into a liquid gas, so that the liquid gas can better adhere to the outer wall surface of the collector 26 after being sublimated into a solid, which is more conducive to collection.

[0065] Further optionally, the driving device 4 comprises a base, a driving shaft, a driving motor, a speed reducer and a plurality of connecting rods 41. The driving shaft is rotatably and vertically inserted into the base, the output shaft of the driving motor is connected with the driving shaft through the speed reducer, the driving shaft is vertically fixed with the plurality of connecting rods 41, and each connecting rod 41 is connected with a corresponding support disc 3.

[0066] The support disc 3 can adopt a circular bottom disc and be made of stainless steel. A clamping groove is further arranged on the support disc 3, and the sublimation bottle 21 can be clamped in the clamping groove of the support disc 3 to stabilize the sublimation bottle 21. The driving shaft can be connected with the base through a bearing, the speed reducer can adopt a worm gear reducer, the driving motor drives the driving shaft to rotate through the worm gear reducer, thereby driving all the support discs 3 arranged uniformly and at intervals in the circumferential direction to rotate together, and the rotation angle can be accurately positioned. The heaters of all the stations can be heated to the same temperature, for example, 200-250°C, or can be heated to respective temperatures according to actual needs. The driving device 4 can also adopt other structures according to needs, and the present embodiment is only for illustration. The first and second vacuum exhaust pipes 23 and 25 can be used to exhaust the sublimation bottle 21 to the same vacuum degree, or can be exhausted to the required vacuum degree according to needs, so that the vacuum degree in the sublimation bottle 21 is 100 Pa-2 kPa.

[0067] Further optionally, the sublimation purification equipment further comprises a robot for taking and placing the sublimation bottle 21 on the support disc 3, disassembling and assembling the first bottle cap 22 or the second bottle cap 24 on 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 disc 3 corresponding to the feeding station, the first bottle cap 22 with the first pressure-reducing air extraction pipe 23 is installed on the sublimation bottle 21 after the sublimation bottle 21 is filled, the first bottle cap 22 with the first pressure-reducing air extraction pipe 23 is removed and the second bottle cap 24 with the second pressure-reducing air extraction pipe 25 and the collector 26 is installed when the sublimation bottle 21 moves to the purification and collection station 13 close to the defoaming station 12, the old second bottle cap 24 with the second pressure-reducing air extraction pipe 25 and the collector 26 is removed and the new second bottle cap 24 with the second pressure-reducing air extraction pipe 25 and the collector 26 is installed when the sublimation bottle 21 moves to the next purification and collection station 13, the sublimation bottle 21 on the last purification and collection station 13 is taken off the support disc 3, the product in each collector 26 is collected, and each part of the sublimation unit 2 is cleaned, all of which can be automatically completed by the robot, so that the automatic continuous operation of the equipment can be realized, the manual participation is reduced, and the purification efficiency is improved.

[0069] The number of the support assemblies is the same as that of the sublimation purification station groups, and the number of the support discs 3 in each support assembly is the same as the total number of the stations in each sublimation purification station group. Each support disc 3 can face the corresponding station, and the support disc 3 can drive the sublimation unit 2 above to move to face the next station by rotating the support assembly. The support assembly and the sublimation purification station group can be one group or multiple groups. When they are multiple groups, the multiple sublimation purification station groups are sequentially arranged in the circumferential direction, so that more sublimation bottles 21 can be placed at the same time, and more materials can be purified at the same time. The number of the purification and collection stations 13 in each sublimation purification station group is at least two, so that the materials can be sufficiently purified and collected.

[0070] The specific number is determined according to actual needs. For example, in a preferred example, the support assembly and the sublimation purification station group can be one group, the number of the purification and collection stations 13 in the group is two, and the four stations in the sublimation purification station group are uniformly arranged at intervals of 90° in the circumferential direction. The whole sublimation purification device constitutes a four-heating-rotary-pressure-reducing-sublimation purification device. When in use, the driving motor is precisely rotated by 90° each time to switch a station, so that the sublimation bottle 21 moves to the four stations in turn. An independent heater is arranged below each station, and each heater is independently controlled by the temperature control device. In actual application, the temperature control device also has a control panel 6, and each heater can be independently controlled by the control panel 6 to realize precise temperature control of the station.

[0071] Further, the sublimation purification device described above can have the following two sublimation purification methods when in use, which are as follows:

[0072] The first method includes the following steps:

[0073] S1, place a sublimation bottle 21 on the support disc 3 opposite each set of sublimation and purification work station group, add material into the sublimation bottle 21, cover the sublimation bottle 21 with a first bottle cap 22, and stay in the feeding work station 11 for a preset time;

[0074] S2, rotate the support assembly to rotate the sublimation bottle 21 to the defoaming work station 12, heat the sublimation bottle 21, and vacuumize the sublimation bottle 21, and stay in the defoaming work station 12 for a preset time;

[0075] S3, rotate the support assembly to rotate the sublimation bottle 21 to the purification and collection work station 13 close to the defoaming work station 12, remove the first bottle cap 22 and cover the sublimation bottle 21 with a second bottle cap 24 with a collector 26, continue to heat the sublimation bottle 21, vacuumize the sublimation bottle 21, and circulate and inject condensate into the collector 26, and stay in the current purification and collection work station 13 for a corresponding purification and collection preset time;

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

[0077] S5, collect the condensate on the collector 26 corresponding to the last purification and collection work station 13, clean the sublimation unit 2, place another sublimation bottle 21 on the support disc 3 opposite each set of sublimation and purification work station group, and repeat steps S1-S4 to perform purification treatment with the next sublimation bottle 21.

[0078] The first method is to make only one work station in each set of sublimation and purification work station group work, that is, only one work station in each set of sublimation and purification work station group has a corresponding sublimation bottle 21, and multiple work stations do not have sublimation bottles 21 at the same time. After one sublimation bottle 21 is transferred from the feeding work station 11 to the last purification and collection work station 13 in each set of sublimation and purification work station group and the treatment is completed, the next sublimation bottle 21 is placed in the feeding work station 11 of the set of sublimation and purification work station group.

[0079] In this method, refer to Figure 1, the above-mentioned four heating rotary reduced-pressure sublimation purification equipment is taken as an example, namely, the sublimation purification station group is one group, the purification collection stations 13 are two and are respectively recorded as a first purification collection station 131 and a second purification collection station 132, according to the first method, the working process of the equipment is specifically as follows:

[0080] A sublimation bottle 21 is placed on the support disc 3 opposite to the feeding station 11, crude BHET material to be purified is added into the sublimation bottle 21, then the first bottle cap 22 provided with the first reduced-pressure air exhaust pipe 23 is sealed and covered on the sublimation bottle 21, and the sublimation bottle 21 after the material is added is stayed at the feeding station 11 for a preset feeding time (for example, 5-15 seconds).

[0081] Then the support assembly is rotated, the sublimation bottle 21 after the material is added is rotated to the defoaming station 12, the heater directly below the defoaming station 12 is used to heat the sublimation bottle 21, the first reduced-pressure air exhaust pipe 23 is used to exhaust the sublimation bottle 21, the sublimation bottle 21 is stayed at the defoaming station 12 for a preset defoaming time (for example, 1-3 minutes), so that the BHET in the material is melted into a liquid state, small molecules of water or other small molecules in the material become bubbles and are exhausted by the first reduced-pressure air exhaust pipe 23, the impurities doped in the BHET can be reduced, and the gas in the molten liquid is exhausted, so that spattering during sublimation can be prevented.

[0082] Then the support assembly is rotated, the sublimation bottle 21 is rotated to the first purification collection station 131, the first bottle cap 22 provided with the first reduced-pressure air exhaust pipe 23 on the sublimation bottle 21 is removed, and the second bottle cap 24 provided with the collector 26 and the second reduced-pressure air exhaust pipe 25 is covered, the heater directly below the first purification collection station 131 is used to continue heating the sublimation bottle 21, the second reduced-pressure air exhaust pipe 25 is used to exhaust the sublimation bottle 21, the condensate liquid inlet pipe 27 and the condensate liquid outlet pipe 28 are used to circulate and pass the condensate liquid (such as condensed water) into the collector 26, and the sublimation bottle 21 is stayed at the first purification collection station 131 for a corresponding purification collection preset time (for example, 15-45 minutes), in this period of time, during the heating process, the liquid-state BHET in the sublimation bottle 21 is gasified into liquid gas, the liquid gas moves upward, and under the condensation effect of the condensed water in the collector 26, the liquid gas is sublimated into a solid and adheres to the outer wall of the collector 26.

[0083] Next, the support assembly rotates the sublimation bottle 21 to the second purification collection station 132. At this station, the second bottle cap 24 and the collector 26 installed at the first purification collection station 131 are removed (the condensed product in the collector 26 can be collected), and a new second bottle cap 24 with a collector 26 and a second vacuum pipe 25 is installed on the sublimation bottle 21. The work process is the same as that at the first purification collection station 131. The heater directly below the second purification collection station 132 continues to heat the sublimation bottle 21. The second vacuum pipe 25 is used to vacuum the sublimation bottle 21. The condensate inlet pipe 27 and the condensate outlet pipe 28 are used to circulate the condensate into the collector 26. The sublimation bottle 21 stays at the second purification collection station 132 for a predetermined time (for example, 10-30 minutes). During this period, the liquid BHET in the sublimation bottle 21 continues to vaporize into liquid gas under heating. The liquid gas moves upward and condenses into solid on the outer wall of the collector 26 under the condensation of the condensate in the collector 26.

[0084] Since the purification and collection of BHET at the first purification collection station 131 may not be complete or the collector 26 may be full, the purification and collection of BHET continue at the second purification collection station 132, which can improve the purification and collection rate. After the second purification collection station 132, the purification is complete, and the solid condensed on the outer wall of the second collector 26 is collected. The product collected in each collector 26 is the purified BHET. The used sublimation unit 2 is cleaned for reuse.

[0085] After the sublimation bottle 21 stays at the second purification collection station 132 for a predetermined time, the purification and collection of the sublimation bottle 21 are complete. While the collector 26 on the sublimation bottle 21 is collecting the product and the sublimation bottle 21 is being cleaned, another sublimation bottle 21 can be placed on the support disc 3 directly opposite the current charging station 11 for the next set of purification operations.

[0086] It can be understood that in the method, if there are multiple groups of sublimation purification work station groups, the support disc 3 corresponding to the feeding work station 11 in the multiple groups of sublimation purification work station groups can simultaneously place a sublimation bottle 21, and the sublimation bottles 21 corresponding to each group of sublimation purification work station groups are sequentially transferred to the work stations in the respective sublimation purification work station groups. If the number of the purification collection work stations 13 in each group of sublimation purification work station groups is greater than or equal to three, after being processed in the second purification collection work station 132, the sublimation bottle 21 is rotated to the third purification collection work station, a new second bottle cap 24 with a collector 26 is replaced, and the purification collection is continued. In addition, in the method, each heater can be in a heating state at all times, or can be started after the sublimation bottle 21 is rotated to the corresponding work station. Each heater is controlled to be turned on and the heating temperature is adjusted by the temperature control device described above. Each vacuum exhaust pipe is started after the sublimation bottle 21 is moved to the corresponding work station, so that the corresponding vacuum pump is used to reduce the air pressure.

[0087] Second: rotating the support assembly every interval preset rotation time, the preset rotation time is the purification processing time required when the sublimation bottle 21 is in the purification collection work station 13 close to the defoaming work station 12; the sublimation purification method comprises:

[0088] In the feeding work station 11 in each group of sublimation purification work station groups: a sublimation bottle 21 is placed on the support disc 3 currently facing the feeding work station 11, material is added to the sublimation bottle 21, and a first bottle cap 22 is provided on the sublimation bottle 21;

[0089] In the defoaming work station 12 in each group of sublimation purification work station groups: when the remaining defoaming preset time of the preset rotation time, the sublimation bottle 21 rotated to the defoaming work station 12 is heated, and the sublimation bottle 21 is vacuumized;

[0090] In the purification collection work station 13 close to the defoaming work station 12 in each group of sublimation purification work station groups: the first bottle cap 22 is removed and the second bottle cap 24 with the collector 26 is provided on the sublimation bottle 21, the sublimation bottle 21 is continuously heated, the sublimation bottle 21 is vacuumized, and the condensate is circulated and injected into the collector 26;

[0091] In the other purification collection work stations 13 in each group of sublimation purification work station groups: the old second bottle cap 24 is removed and the new second bottle cap 24 is provided on the sublimation bottle 21, the condensate on the old collector 26 is collected, the sublimation bottle 21 is continuously heated, the sublimation bottle 21 is vacuumized, and the condensate is circulated and injected into the collector 26, the heating, vacuumizing and injecting of the condensate in the corresponding purification collection work station 13 are performed for a corresponding purification collection preset time; the condensate on the collector 26 corresponding to the last purification collection work station 13 is collected, and the sublimation unit 2 is cleaned.

[0092] The second method is to rotate all the support plates 3 together according to a fixed preset rotation time. Since the purification collection time at the purification collection station 13 near the defoaming station 12 is the longest (15-45 minutes), the purification collection time at the remaining purification collection stations 13 is relatively short (10-30 minutes), the defoaming treatment time at the defoaming station 12 is also short (1-3 minutes), and the defoaming treatment needs to be rotated to the purification collection station 13 immediately for purification treatment. Therefore, the preset rotation time is determined according to the purification treatment time (15-45 minutes) required by the purification collection station 13 near the defoaming station 12 with the longest time, for example, the preset rotation time is designed to be 30 minutes.

[0093] In this way, the support plates 3 are rotated every preset rotation time, and a new sublimation bottle 21 can be placed in the corresponding support plate 3 of the feeding station 11 whenever it is empty. When the sublimation bottle 21 is filled with materials, it is rotated to the defoaming station 12 at the rotation period, and then waits until the remaining defoaming preset time is reached before heating and vacuumizing, for example, when the preset rotation time is 30 minutes and the defoaming preset time is 20 minutes, the sublimation bottle 21 is rotated to the defoaming station 12 and waits for 10 minutes, and then heats and vacuums for 20 minutes when the remaining time of the next rotation is 20 minutes. The defoaming treatment is 20 minutes, and then rotates to the first purification collection station 131.

[0094] When it reaches the purification collection station 13, it can start heating, vacuumizing, and circulating condensed water into the collector 26. After 30 minutes of purification collection, it rotates to the second purification collection station 132, where it can first heat, vacuumize, and circulate condensed water into the collector 26. After 20 minutes of purification collection, stop heating, vacuumizing, and circulating condensed water into the collector 26. If the second purification collection station 132 is not the last purification collection station 13, wait for 30 minutes and then rotate to the next purification collection station 13 for further processing in the same way. If the second purification collection station 132 is the last purification collection station 13, stop heating, vacuumizing, and circulating condensed water into the collector 26 after 20 minutes of purification collection, and then directly take away the sublimation bottle 21 to collect the product in the collector 26 and clean the sublimation bottle 21.

[0095] If a heater is also provided below the feeding station 11, after placing the sublimation bottle 21 at the feeding station 11, the sublimation bottle 21 needs to be filled with materials and the first bottle cap 22 needs to be placed on it at a remaining feeding preset time (5-15 seconds) from the preset rotation time.

[0096] In the second method, the specific feeding, defoaming, purification and collection processes are the same as those in the first method, and will not be described again. The only difference is when to rotate, place several sublimation bottles 21, and open the heating, vacuumizing and circulating condensing.

[0097] In the first method, the purification treatment of the BHET material is divided into feeding, defoaming and at least two purification and collection processes, a total of at least four workstations, which are processed in turn. When the purification and collection of the sublimation bottle 21 is completed, the product on the collector 26 is collected, and the sublimation bottle 21 is cleaned, the next sublimation bottle 21 can be used for purification operation, which can achieve high purification efficiency. In the second method, the purification treatment of the BHET material is also divided into feeding, defoaming and at least two purification and collection processes, a total of at least four workstations, and a new sublimation bottle 21 can be placed on the support disc 3 corresponding to the feeding workstation 11 when the support disc 3 is empty. The multiple sublimation bottles 21 in the entire device can perform corresponding operations simultaneously, which is more efficient, and significantly improves the production efficiency.

[0098] At the same time, in both methods, the sublimation bottle 21 has a relatively small volume, and compared with the prior art which only uses one large-volume sublimation bottle 21, the obtained pure BHET has fewer impurities. The temperature control device is used to accurately control the temperature of each heating device, so that the sublimation bottle 21 can be uniformly heated, and the uneven temperature can be avoided to cause the co-sublimation of impurities. Each group of sublimation and purification workstations has at least two purification and collection processes, which can achieve more thorough purification and higher purification rate. In addition, the collector 26 is closer to the sublimation bottle 21, which is also more conducive to reducing impurities and improving the purity of the collected product. Both methods can realize continuous purification operation of the BHET material, and are suitable for industrial production.

[0099] It should be noted that the above device and purification method are actually not a sublimation process for the purification of BHET, but a process of melting, gasification and condensation, which is a process from solid to liquid, to liquid gas, and then to solid. Therefore, the entire device and method can also be called a material purification device and a material purification method. It is particularly suitable for purifying BHET monomers of polyester textiles and blended fabrics, purifying BHET obtained by alcoholysis of polyester, solving the problem of low-purity BHET formed by alcoholysis of polyester, and achieving continuous production. Of course, the device is not limited to the purification of BHET material, but can also be used for the purification treatment of other materials.

[0100] The above is only a specific embodiment of the present application, and is not intended to limit the scope of the present application. Any equivalent changes and modifications made by those skilled in the art without departing from the concept and principles of the present application shall fall within the scope of the present application.

Claims

1. A sublimation purification apparatus, characterized by, The device comprises: at least one set of sublimation purification stations, each set of sublimation purification stations comprising a feeding station, a defoaming station and at least two purification and collection stations arranged in sequence and uniformly spaced along a circumferential direction; a plurality of heaters, each of which is arranged below the defoaming station and the purification and collection stations; a temperature control device electrically connected to each of the heaters for controlling the heating temperature of each of the heaters; a plurality of sublimation units, each of which comprises a sublimation bottle and a first or second bottle cap detachably arranged at the mouth of the sublimation bottle, a first pressure-reducing air extraction tube arranged on the first bottle cap, a second pressure-reducing air extraction tube and a collector arranged on the second bottle cap, and a condensate inlet tube and a condensate outlet tube arranged on the collector; at least one set of support assemblies, each of which comprises a plurality of support discs arranged uniformly along the circumferential direction, and each of the support discs is used to support the sublimation units; a driving device connected to each of the support discs and capable of driving each of the support discs to rotate along the circumferential direction, so as to drive the sublimation units placed on the support discs to sequentially transfer among the stations in the corresponding set of sublimation purification stations, and the sublimation bottle is capable of being capped with the first bottle cap when it is in the feeding station and completes feeding, and is capable of being capped with the second bottle cap when it is in the purification and collection station.

2. The sublimation purification device according to claim 1, wherein 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 device according to claim 1, wherein a screw feeder is arranged above each of the feeding stations for feeding materials into the corresponding sublimation bottle.

4. The sublimation purification device according to claim 1, wherein a heater is further arranged below the feeding station.

5. The sublimation purification device according to claim 1, wherein the heater is a disc heater, and the heating area of the disc heater is larger than the bottom area of the sublimation bottle.

6. The sublimation purification device according to claim 1, wherein the driving device comprises a base, a driving shaft, a driving motor, a speed reducer and a plurality of connecting rods, the driving shaft is rotatably and vertically arranged on the base, the output shaft of the driving motor is connected to the driving shaft through the speed reducer, the driving shaft is vertically fixed to the plurality of connecting rods, and each of the connecting rods is connected to a corresponding support disc.

7. The sublimation purification device according to claim 1, wherein the sublimation purification device further comprises a robot for picking and placing the sublimation bottles on the support discs, disassembling and assembling the first or second bottle cap on the mouth of the sublimation bottle, collecting the products in the collector, and cleaning the sublimation units.

8. The sublimation purification device according to claim 1, wherein the number of the sets of sublimation purification stations is one, and the number of the purification and collection stations in each set of sublimation purification stations is two.

9. The sublimation purification device according to claim 1, wherein The number of the sublimation purification station groups is multiple groups, and the multiple groups of the sublimation purification station groups are sequentially arranged along the circumferential direction.

10. A sublimation purification process characterized by, The sublimation purification method comprises: S1, placing a sublimation bottle on the support disc opposite to each group of sublimation purification station groups, adding materials into the sublimation bottle, covering the sublimation bottle with a first bottle cap, and staying at the feeding station for a preset feeding time; S2, rotating the support assembly to rotate the sublimation bottle to a degassing station, heating the sublimation bottle, vacuumizing the sublimation bottle, and staying at the degassing station for a preset degassing time; S3, rotating the support assembly to rotate the sublimation bottle to a purification collection station close to the degassing station, removing the first bottle cap and covering the sublimation bottle with a second bottle cap with a collector, continuing to heat the sublimation bottle, vacuumizing the sublimation bottle, and circulating and injecting condensate into the collector, and staying at the current purification collection station for a corresponding purification collection preset time; S4, rotating the support assembly to rotate the sublimation bottle to the next purification collection station, removing the old second bottle cap and covering the sublimation bottle with a new second bottle cap, collecting the condensate on the old collector, continuing to heat the sublimation bottle, vacuumizing the sublimation bottle, and circulating and injecting condensate into the collector, and staying at the current purification collection station for a corresponding purification collection preset time; if the number of the purification collection stations in each group of sublimation purification station groups is greater than two, repeating step S4 until the sublimation bottle is rotated to the last purification collection station; S5, collecting the condensate on the collector corresponding to the last purification collection station, cleaning the sublimation unit, placing another sublimation bottle on the support disc opposite to each group of sublimation purification station groups, and repeating steps S1-S4 to use the next sublimation bottle for purification treatment.

11. A sublimation purification process characterized by, The sublimation purification method comprises: The sublimation purification method comprises: At the feeding station in each group of sublimation purification station groups: placing a sublimation bottle on the support disc opposite to the feeding station, adding materials into the sublimation bottle, and covering the sublimation bottle with a first bottle cap; At the degassing station in each group of sublimation purification station groups: when the remaining degassing preset time of the preset rotation time is reached, heating the sublimation bottle rotated to the degassing station, and vacuumizing the sublimation bottle; At the purification collection station close to the degassing station in each group of sublimation purification station groups: removing the first bottle cap and covering the sublimation bottle with a second bottle cap with a collector, continuing to heat the sublimation bottle, vacuumizing the sublimation bottle, and circulating and injecting condensate into the collector; At other purification collection stations in each group of sublimation purification stations: remove the old second bottle cap and cover the new second bottle cap on the sublimation bottle, collect the condensate on the old collector, continue heating the sublimation bottle, vacuumize the sublimation bottle, circulate and inject the condensate into the collector, heat, vacuumize and inject the condensate at the corresponding purification collection station for a predetermined time; collect the condensate on the collector corresponding to the last purification collection station, and clean the sublimation unit.

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