阅读说明：本技术 熔融结晶器 (Melt crystallizer ) 是由 史佳林 姚蔚明 于 2015-03-31 设计创作，主要内容包括：本发明涉及一种熔融结晶器,其包括外壳、结晶管和设置在结晶管的入口处的分配件,其中,在外壳的顶端设置上封盖,并在外壳的底端设置下封盖,外壳通过上封盖和下封盖形成封闭空间,上封盖上设置有安装孔,结晶管设置在安装孔处且与安装孔连通,结晶管竖向延伸而穿过下封盖,分配件包括能插入到结晶管内的锥形本体,锥形本体构造为在由上到下的方向上直径逐渐增大,锥形本体与结晶管之间形成间隙。该熔融结晶器反应易于控制,提纯效率高。(The invention relates to a melt crystallizer, which comprises a shell, a crystallization tube and a distribution piece arranged at the inlet of the crystallization tube, wherein an upper sealing cover is arranged at the top end of the shell, a lower sealing cover is arranged at the bottom end of the shell, the shell forms a closed space through the upper sealing cover and the lower sealing cover, a mounting hole is formed in the upper sealing cover, the crystallization tube is arranged at the mounting hole and is communicated with the mounting hole, the crystallization tube vertically extends to penetrate through the lower sealing cover, the distribution piece comprises a conical body capable of being inserted into the crystallization tube, the diameter of the conical body is gradually increased in the direction from top to bottom, and a gap is formed between the conical body and the crystallization tube. The melt crystallizer is easy to control the reaction and high in purification efficiency.)

1. A melt crystallizer, comprising:

the device comprises a shell, an upper sealing cover is arranged at the top end of the shell, a lower sealing cover is arranged at the bottom end of the shell, the shell forms a closed space through the upper sealing cover and the lower sealing cover, a mounting hole is formed in the upper sealing cover,

a crystallization tube disposed at the mounting hole and communicating with the mounting hole, the crystallization tube extending vertically to pass through the lower cap, an

A distribution member disposed at an inlet of the crystallization tube and connectable with the upper cap, the distribution member comprising a tapered body insertable into the crystallization tube, the tapered body being configured to gradually increase in diameter in a top-to-bottom direction, a gap being formed between the tapered body and the crystallization tube;

wherein, the distribution part still include with toper body fixed connection and ability lock are in cover piece on the upper cover, be provided with on the cover piece can with the groove of clearance intercommunication, the groove structure is the cross.

2. The melt crystallizer of claim 1, wherein a ratio of a diameter of a lower end surface of the conical body to an inner diameter of the crystallization tube is from 0.75:1 to 0.95: 1.

3. The melt crystallizer as claimed in claim 1, wherein an upper enclosure is provided at a top end of the outer shell to form a distribution chamber with the upper cover, a top end of the upper enclosure is provided with a feed port communicating with the distribution chamber, and a first temperature control member for controlling a temperature of the distribution chamber is provided on the upper enclosure,

and/or a lower sealing shell is arranged at the bottom end of the shell to form a discharge chamber together with the lower sealing cover, a discharge hole communicated with the discharge chamber is formed in the bottom end of the discharge chamber, and a second temperature control component used for controlling the temperature of the discharge chamber is arranged on the lower sealing shell.

4. A melt crystallizer as claimed in claim 3, wherein the upper enclosure is configured in the shape of a semi-arc with a first intermediate layer, the feed inlet is disposed at the arc apex of the upper enclosure, and the first temperature control means comprises a first inlet communicating with the first intermediate layer for the passage of a heating medium, a first intermediate layer, and a first outlet communicating with the first intermediate layer,

and/or the lower capsule is configured in a semi-arc shape with a second interlayer, the discharge port is arranged at the arc top of the lower capsule, and the second temperature control component comprises a second inlet communicated with the second interlayer for a heating medium to pass through, a second interlayer and a second outlet communicated with the second interlayer.

5. The melt crystallizer of claim 4, wherein the first inlet is disposed in a lower portion of the upper enclosure, the first outlet is disposed in an upper portion of the upper enclosure on an opposite side of the first inlet,

and/or the second inlet is disposed in a lower portion of the lower enclosure, and the second outlet is disposed in an upper portion of the lower enclosure on an opposite side of the second inlet.

6. The melt crystallizer of claim 4, wherein a baffle plate is detachably disposed in the distribution chamber, the baffle plate extending in a radial direction and being connected to an inner wall of the distribution chamber, the baffle plate being provided with a through hole,

and/or be in the detachable setting cylinder manifold in the ejection of compact room, the cylinder manifold extends and with the inner wall connection of ejection of compact room in radial direction.

7. The melt crystallizer of claim 1, wherein a heat transfer medium inlet and a heat transfer medium outlet are provided on the enclosure in communication with the enclosed space, the heat transfer medium inlet being provided at an upper portion of the enclosure, the heat transfer medium outlet being provided at a lower portion of the enclosure, the enclosed space between the heat transfer medium inlet and the heat transfer medium outlet forming a heat exchange chamber.

8. The melt crystallizer of claim 7, wherein the heat transfer medium inlet is spaced from the upper cover by a distance 1/6-1/3 of a height of the enclosure.

9. The melt crystallizer of claim 7, wherein the heat transfer medium inlets are uniformly arranged in a circumferential direction of the shell,

and/or the heat transfer medium outlets are arranged uniformly in the circumferential direction of the housing.

10. The melt crystallizer of claim 7, wherein a flow guide assembly is disposed in the heat exchange chamber, the flow guide assembly comprising first and second flow guide members spaced apart, the first flow guide member extending radially in contact with an inner wall of the heat exchange chamber, a flow guide hole being disposed at a center of the first flow guide member, and the second flow guide member being radially disposed and having a flow guide gap with the inner wall of the heat exchange chamber.

11. The melt crystallizer as claimed in claim 7, wherein a partition is provided in the closed space above the heat transfer medium inlet to form a soaking chamber with the upper cover, and a soaking inlet and a soaking outlet for communicating a heat transfer medium are provided on a sidewall of the soaking chamber.

Technical Field

The present invention relates to a melt crystallizer.

Background

With the development of chemical industry, the purity requirements of polymer monomers and raw materials are higher and higher. These monomers are usually present as isomeric mixtures, and therefore these mixtures must be purified to the desired chemical and optical purity of the polymer monomer.

While for isomers and heat sensitive materials, such as lactide, coking and hydrolysis are prone to occur at high temperatures. If the rectification technology is adopted, the operation conditions are harsh, and the requirements on equipment materials and processing precision are high. Even so, phenomena such as carbonization, coking, polymerization and the like in the rectifying still can not be avoided, and the product yield is very low.

Melt crystallization techniques can be applied to separate heat sensitive systems and isomeric systems. However, the melt crystallization device in the prior art has a complex structure and low purification efficiency.

Disclosure of Invention

Aiming at the technical problems in the prior art, the invention provides a melt crystallizer. It can purify the polymer monomer and raw material by using melt crystallization technology, and is especially suitable for thermosensitive polymer monomer and raw material. Moreover, the melt crystallizer has the advantages of simple structure and easy industrial amplification.

According to the invention, a melting crystallizer is provided, which comprises a shell, an upper sealing cover is arranged at the top end of the shell, a lower sealing cover is arranged at the bottom end of the shell, the shell forms a closed space through the upper sealing cover and the lower sealing cover, the upper sealing cover is provided with a mounting hole,

a crystallization tube disposed at the mounting hole and communicating with the mounting hole, the crystallization tube extending vertically to pass through the lower cap, an

A distributing member arranged at the entrance of the crystallization tube and capable of being connected with the upper cover, the distributing member comprises a conical body capable of being inserted into the crystallization tube, the conical body is configured to gradually increase in diameter in the direction from top to bottom, and a gap is formed between the conical body and the crystallization tube.

In one embodiment, the dispensing member further comprises a cover member fixedly attached to the conical body and adapted to snap fit over the upper closure, the cover member having a channel adapted to communicate with the gap. Preferably, the groove is configured as a cross.

In one embodiment, the ratio of the diameter of the lower end surface of the conical body to the inner diameter of the crystallization tube is from 0.75:1 to 0.95: 1.

In one embodiment, an upper capsule is provided at the top end of the housing to form a distribution chamber with the upper cap, the top end of the upper capsule is provided with a feed port communicating with the distribution chamber, and a first temperature control member for controlling the temperature of the distribution chamber is provided on the upper capsule,

and/or a lower sealing shell is arranged at the bottom end of the shell to form a discharge chamber with the lower sealing cover, a discharge hole communicated with the discharge chamber is arranged at the bottom end of the discharge chamber, and a second temperature control component used for controlling the temperature of the discharge chamber is arranged on the lower sealing shell.

In one embodiment, the upper capsule is configured in a semi-circular arc shape having a first intermediate layer, the feed inlet is disposed at the arc apex of the upper capsule, and the first temperature-control member includes a first inlet communicating with the first intermediate layer for the passage of the heating medium, a first intermediate layer, and a first outlet communicating with the first intermediate layer,

and/or the lower capsule is configured in a semi-arc shape with a second interlayer, the discharge port is arranged at the arc top of the lower capsule, and the second temperature control part comprises a second inlet communicated with the second interlayer for the heat medium to pass through, the second interlayer and a second outlet communicated with the second interlayer.

In one embodiment, the first inlet is disposed in a lower portion of the upper enclosure, the first outlet is disposed in an upper portion of the upper enclosure on an opposite side of the first inlet,

and/or the second inlet is disposed in a lower portion of the lower enclosure and the second outlet is disposed in an upper portion of the lower enclosure on an opposite side of the second inlet.

In one embodiment, a buffer plate is detachably provided in the distribution chamber, the buffer plate extending in a radial direction and being connected to an inner wall of the distribution chamber, the buffer plate being provided with a through-hole,

and/or a bus board is detachably arranged in the discharge chamber, extends in the radial direction and is connected with the inner wall of the discharge chamber.

In one embodiment, a heat transfer medium inlet and a heat transfer medium outlet are provided on the housing in communication with the enclosed space, the heat transfer medium inlet being provided at an upper portion of the housing, the heat transfer medium outlet being provided at a lower portion of the housing, the enclosed space between the heat transfer medium inlet and the heat transfer medium outlet forming a heat exchange chamber.

In one embodiment, the heat transfer medium inlet is spaced from the upper cover by a distance 1/6-1/3 of the height of the enclosure.

In one embodiment, the heat transfer medium inlets are evenly arranged in the circumferential direction of the casing,

and/or the heat transfer medium outlets are arranged uniformly in the circumferential direction of the housing.

In one embodiment, a flow guide assembly is arranged in the heat exchange chamber, the flow guide assembly comprises a first flow guide part and a second flow guide part which are arranged at intervals, the first flow guide part extends radially to be in contact with the inner wall of the heat exchange chamber, a flow guide hole is arranged at the center of the first flow guide part, and the second flow guide part is arranged radially and has a flow guide gap with the inner wall of the heat exchange chamber.

In one embodiment, a partition plate is arranged in the closed space above the heat-conducting medium inlet to form a heat preservation chamber with the upper sealing cover, and a heat preservation inlet and a heat preservation outlet which are used for communicating the heat-conducting medium are arranged on the side wall of the heat preservation chamber.

In the present application, the terms "upper" and "lower" are used with reference to the working orientation of the melt crystallizer.

Compared with the prior art, the melt crystallizer has the advantages that the melt crystallizer meets the requirements of a high-light purity and high-chemistry purification process of polymer monomers. Meanwhile, the melting crystallizer has simple structure, easy control of reaction and high purity of the purified product.

Drawings

Preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings. In the figure:

fig. 1 shows a block diagram of a melt crystallizer according to the present invention.

Fig. 2 shows a cross-sectional view at B from fig. 1.

Fig. 3 shows a top view from fig. 1 at B.

Fig. 4 shows a cross-sectional view from a-a of fig. 1.

In the drawings, like parts are provided with like reference numerals. The figures are not drawn to scale.

Detailed Description

The invention will be further explained with reference to the drawings.

Fig. 1 shows a melt crystallizer 100 according to the present invention. As shown in fig. 1, the melt crystallizer 100 includes a housing 1, and an upper cover 2 is provided at a top end of the housing 1, and a lower cover 3 is provided at a bottom end of the housing 1, the housing 1 forming a closed space 4 by the upper cover 2 and the lower cover 3. An upper capsule 5 is also removably arranged at the top end of the casing 1, a distribution chamber 6 being formed between the upper capsule 5 and the upper cover 2. A lower sealing shell 7 is detachably arranged at the bottom end of the shell 1, and a discharge chamber 8 is formed between the lower sealing shell 7 and the lower sealing cover 3. The upper cover 2 is provided with mounting holes 21 (shown in fig. 2). The crystallization tube 9 communicating with the mounting hole 21 is provided in the mounting hole 21. The crystallization tube 9 is arranged vertically, extending through the lower cover 3 into the outfeed chamber 8. At the top end of the upper enclosure 5, a feed opening 51 is provided for communication with the distribution chamber 6. Meanwhile, a discharge port 71 is provided at the bottom end of the lower capsule 7 to communicate with the discharge chamber 8.

Thus, the material mother liquor enters the distribution chamber 6 through the feed inlet 51 and then enters the crystallization tube 9 through the mounting hole 21, a certain substance in the material mother liquor can be crystallized on the inner wall of the crystallization tube 9, and the material mother liquor which is not crystallized is discharged into the discharge chamber 8 from the lower end of the crystallization tube 9 and finally discharged out of the melt crystallizer 100 through the discharge hole 71. The melt crystallizer 100 has a simple structure and a wide application range, and can realize large-scale industrialization.

Preferably, crystallization tube 9 is a falling film crystallization tube. Thereby increasing the crystallization area and preventing entrainment when the material mother liquid flows along the inner wall of the crystallization tube 9. In addition, in order to ensure that the mother liquor overflows on the inner wall of the crystallization pipe 9 to form a film, a distributing member 10 is arranged at the inlet of the crystallization pipe 9. In a preferred embodiment, as shown in fig. 2, the dispensing member 10 comprises a conical body 11 and a cap 12. Wherein, the conical body 11 can be inserted into the crystallization tube 9 and forms a gap 16 for guiding the mother liquid of the material with the inner wall of the crystallization tube 9. And the cover member 12 is fixedly connected with the conical body 11 and is in covering and overlapping connection with the inlet of the crystallization tube 9. A groove 13 is arranged at the top end of the cover component 12, and the groove 13 is communicated with the gap 16, so that the material mother liquid in the distribution chamber 6 enters the gap 16 after passing through the groove 13 to overflow on the inner wall of the crystallization tube 9 to form a film, as shown in figure 3. In a further preferred embodiment, the slot 13 is a cross-slot provided on the cover member 12. And the ratio of the diameter of the lower end surface of the conical body 11 to the inner diameter of the crystallization tube 9 is 0.75:1-0.95: 1. Through set up distribution part 10 at the entrance of crystallization pipe 9 for the material mother liquor does not receive the influence of the liquid level of the material mother liquor in distribution chamber 6, and flows along the inner wall of crystallization pipe 9 uniformly, helps the overflow film forming, makes the material mother liquor fully contact with the inner wall of crystallization pipe 9, has guaranteed the product purity of crystallization effect and purification. Meanwhile, the flow velocity of the material mother liquor is reduced through the distribution part 10, and the buffering effect is achieved, so that entrainment is prevented, and the crystallization efficiency is ensured.

According to the invention, a first temperature-control member 17 for controlling the temperature of the distribution chamber 6 is provided on the upper enclosure 5. For example, the upper envelope 5 is configured with a first interlayer 52. The first temperature-controlling member 17 includes a first inlet 53 communicating with the first interlayer 52 for passing a heating medium therethrough, the first interlayer 52, and a first outlet 54 communicating with the first interlayer 52. Thus, a heat medium may be employed to flow within first inlet 53, first interlayer 52 and first outlet 54 to heat and insulate distribution chamber 6 to prevent premature crystallization of the material mother liquor in distribution chamber 6. In addition, in order to ensure the everywhere uniformity of the temperature within the distribution chamber 6 and the smooth flow of the heat medium in the first interlayer 52, the upper capsule 5 is configured in a semicircular arc shape so that the inner wall of the first interlayer 52 is smooth. Preferably, the first inlet 53 is disposed in a lower portion of the upper enclosure 5, and the first outlet 54 is disposed in an upper portion of the upper enclosure 5 on an opposite side of the first inlet 53. The arrangement mode is beneficial to improving the energy utilization rate and reducing the energy consumption. The upper capsule 5 is not limited to a semicircular structure, and may have other structures. For example, the shape is conical, or conical in the upper part and cylindrical in the lower part. To further ensure uniform heating of the distribution chamber 6, a diversion member 55 is further disposed in the first interlayer 52 to divert the heat medium in the first interlayer 52.

Similarly, a second temperature control member 18 for controlling the temperature of the discharge chamber 8 is provided on the lower capsule 7. For example, the lower envelope 7 is constructed with a second interlayer 72. The second temperature-control member 18 comprises a second inlet 73 communicating with the second interlayer 72 for the passage of a heating medium, the second interlayer 72 and a second outlet 74 communicating with the second interlayer 72. Therefore, the heat medium can be adopted to flow in the second inlet 73, the second interlayer 72 and the second outlet 74 to heat and insulate the discharging chamber 8, thereby preventing the problem that the crystallization pipe 9 is blocked by the crystallization of the material mother liquor at the outlet of the crystallization pipe 9. In addition, in order to ensure the uniformity of the temperature throughout within the discharge chamber 8 and the smooth flow of the heat medium in the second interlayer 72, the lower capsule 7 is configured in a semicircular arc shape so that the inner wall of the second interlayer 72 is smooth. Preferably, the second inlet 73 is arranged in a lower portion of the lower enclosure 7 and the second outlet 74 is arranged in an upper portion of the lower enclosure 7 on the opposite side of the second inlet 73. The arrangement mode is beneficial to improving the energy utilization rate and reducing the energy consumption. The lower capsule 7 is not limited to a semicircular structure, and may have other structures. For example, the shape is conical, or conical in the upper part and cylindrical in the lower part.

A first mounting port 56 is provided on the upper enclosure 5 for placing a temperature sensor to sense the temperature within the distribution chamber 6, thereby sensing the temperature of the distribution chamber 6 or directing operation to obtain a desired temperature based on the temperature results measured thereby. Similarly, a second mounting opening 75 is provided in the lower enclosure 7 for placing a temperature sensor to sense the temperature within the discharge chamber 8.

According to the invention, a buffer plate 19 is provided in the distribution chamber 6. The buffer plate 19 is detachably provided on the inner wall of the upper enclosure 5. Through holes 20 are provided in the buffer plate 19 so that the material mother liquor entering the distribution chamber 6 from the feed opening 51 flows onto the buffer plate 19 and flows down from the through holes 20. The impact of the material mother liquor on the liquid level of the material mother liquor is reduced by arranging the buffer plate 19. Meanwhile, due to the detachable arrangement of the buffer plate 19, the buffer plate 19 is convenient to clean and replace. Meanwhile, a bus bar 22 is detachably provided in the discharge chamber 8. The bus bar plate 22 is used for merging the material mother liquid flowing out from the crystallization pipe 9, and the bus bar plate 22 is connected with the inner wall of the discharging chamber 8, so that the material mother liquid flows to the discharging port 71 from a gap formed by the bus bar plate 22 and the inner wall of the discharging chamber 8 or from a through hole arranged on the bus bar plate 22.

A heat transfer medium inlet 24 and a heat transfer medium outlet 25 communicating with the enclosed space 4 are provided on the housing 1. Wherein a heat transfer medium inlet 24 is provided at an upper portion of the housing 1, a heat transfer medium outlet 25 is provided at a lower portion of the housing 1 near the lower cover 3, and a heat exchange chamber 26 is formed in the enclosed space 4 between the heat transfer medium inlet 24 and the heat transfer medium outlet 25. When the material mother liquor enters the crystallization pipe 9 and needs to be crystallized, the low-temperature heat medium enters the heat exchange chamber 26 from the heat transfer medium inlet 24 and flows out from the heat transfer medium outlet 25, so that the temperature in the heat exchange chamber 26 is reduced to a set value, and a certain substance in the material mother liquor starts to crystallize on the inner wall of the crystallization pipe 9. At this time, the mother liquor of the material which is not crystallized is discharged from the lower end of the crystallization tube 9. The seed layer on the inner wall of the crystallization tube 9 reaches a certain thickness and the feed port 51 stops feeding. And the high-temperature heat medium enters the heat exchange chamber 26 through the heat medium inlet 24 and flows out from the heat medium outlet 25 to melt the crystal layer in the crystallization tube 9. The melted melt is discharged into a collecting container through a discharging chamber 8.

In order to ensure uniform flow of the heat medium in the heat exchange chamber 26, the heat transfer medium inlet 24 and the heat transfer medium outlet 25 may be plural and uniformly arranged in the circumferential direction of the housing 1. This multiple in and multiple out arrangement allows for more uniform flow of the heat medium in the heat exchange chamber 26 with less heat exchange difference with the crystallization tubes 9, while helping to control the reaction environment in the heat exchange chamber 26.

A flow guide assembly 31 is provided in the heat exchange chamber 26. The flow guide assembly 31 includes a first flow guide member 32 and a second flow guide member 33 arranged at intervals. Wherein the first flow guide 32 radially extends to contact the inner wall of the heat exchange chamber 26, and a flow guide hole 34 is provided at the center of the first flow guide 32. The second flow guide 33 is radially arranged and has a flow guide gap 35 with the inner wall of the heat exchange chamber 26. The crystallization tube 9 is sealingly passed through a first flow guide 32 and a second flow guide 33. Thereby, the heat medium flows from the heat transfer medium inlet 24 onto the first flow guide 32, flows from the flow guide holes 34 to the second flow guide 33, and then flows downward from the gap 35. Preferably, a plurality of sets of flow guide assemblies 31 may be provided in the heat exchange chamber 26 as needed to allow the heat medium to continuously flow from the periphery to the middle and then from the middle to the periphery, thereby improving heat exchange efficiency in the heat exchange chamber 26. The arrangement improves the heat exchange rate, reduces the energy consumption and is beneficial to large-scale industrialization.

According to a preferred embodiment of the present invention, the heat transfer medium inlet 24 is spaced from the upper cover 2 by a distance 1/6-1/3 of the height of the housing 1. And a partition plate 27 is provided in the closed space 4 above the heat transfer medium inlet 2 to form a soak chamber 28 between the partition plate 27 and the upper lid 2. Wherein the distribution member 10 is located at the upper end of the partition 27 and the crystallization tubes 9 are sealingly passed through the partition 27. A soak inlet 29 for communicating the heat medium is provided on the side wall of the soak chamber 28 to introduce the heat medium into the soak chamber 28 to maintain the temperature of the soak chamber 28, after which the heat medium flows out from the soak outlet 30. This arrangement prevents the mother liquor from starting to crystallize in the distributor 10 and blocking the crystallization tube 9.

Preferably, a plurality of crystallization tubes 9 may be provided within the enclosed space 4. In order to ensure a small difference in heat exchange between the crystallization tubes 9, a plurality of crystallization tubes 9 are spatially arranged uniformly on the cover 2, as shown in FIG. 4. This improves the crystallization efficiency of the melt crystallizer 100, and is advantageous for large-scale industrialization.

The use of the melt crystallizer 100 is described in detail below with reference to fig. 1 to 4.

The material mother liquor enters the distribution chamber 6 from the feed inlet 51 through the buffer plate 19. In order to prevent the material in the material mother liquor from being crystallized in advance, the distribution chamber 6 is maintained at a certain temperature by the first temperature control member 17, that is, the heat medium may be passed through the first inlet 53, the first interlayer 52 and the first outlet 54 in order. The mother liquor flows down the inner wall of the crystallization tube 9 uniformly through the distribution member 10. Meanwhile, the low-temperature heat medium enters the heat exchange chamber 26 through the heat-conducting medium inlet 24, passes through the flow guide assembly 31, and is led out through the heat-conducting medium outlet 25. The temperature of the material mother liquor in the crystallization pipe 9 is reduced to a certain set value under the action of a low-temperature heat medium, and a certain substance in the material mother liquor is crystallized on the inner wall of the crystallization chamber 9. While the mother liquid of the uncrystallized material is discharged from the lower end of the crystallization pipe 9 and is converged by the confluence plate 22 in the discharge chamber 4, and finally discharged from the discharge port 71 out of the melt crystallizer 100. Wherein, the arrows in fig. 1 show the flowing direction of the material mother liquid and the heat medium.

The mother liquor exiting the melt crystallizer 100 may be re-fed into the feed port 51 for re-crystallization until the material in the mother liquor is substantially crystallized.

On the inner wall of the crystallization tube 9, when the crystal layer reaches a certain thickness, the feeding port 51 stops feeding the material mother liquor. Meanwhile, the low-temperature heat medium entering the heat exchange chamber 26 is switched to the high-temperature heat medium to melt the crystal layer on the inner wall of the crystallization tube 9, and the melted crystal layer is discharged to the collection container through the discharge chamber 8.

After the crystal layer on the inner wall of the crystallization tube 9 is melted, the feed port 51 is opened again to allow the material mother liquid to enter the distribution chamber 6. The high temperature heat medium entering the heat exchange chamber 26 is switched to the low temperature heat medium again, and a new cycle of crystallization process is started. Thus, the crystallization → melting → recrystallization → remelting is continuously circulated, so as to achieve the purpose of extracting the required substances.

The above description is only a preferred embodiment of the present invention, but the scope of the present invention is not limited thereto, and any person skilled in the art can easily make changes or variations within the technical scope of the present invention disclosed, and such changes or variations should be covered within the scope of the present invention. Therefore, the protection scope of the present invention shall be subject to the protection scope of the claims.