Static crystallizer

Abstract

The utility model belongs to the technical field of static crystallization, and relates to a static crystallizer. The static crystallizer comprises a crystallizer body, the crystallizer body comprises an outer jacketed pipe and an inner jacketed pipe which are in a straight sleeve shape, and an annular jacketed cavity between the outer jacketed pipe and the inner jacketed pipe forms a temperature control medium flowing cavity; and the rotational flow component is used for separating a spiral flow channel which winds the outer peripheral wall of the inner jacketed pipe in the temperature control medium flowing cavity, so that the temperature control medium can flow downwards along the spiral flow channel in a rotational flow manner. Efficient melt crystallization heat exchange can be achieved, and the crystallization process efficiency and the product quality are improved.

Description

Technical Field

[0001] The present application belongs to the technical field of static crystallization, and specifically relates to a static crystallizer. Background Art

[0002] A static crystallizer is a device used to separate and purify substances, crystallizing solutes from a solution by controlling temperature. Unlike dynamic crystallizers, static crystallizers do not rely on mechanical stirring, but instead rely on natural convection and diffusion to achieve crystallization. In cooling crystallization and melt crystallization, no other substances are introduced. Cooling the solution in the crystallizer causes it to reach a supersaturated state, allowing the solute to precipitate and form crystals. This crystallization process offers low energy consumption, simple steps, and high product purity. However, it also suffers from low heat exchange efficiency, large temperature differences, and uneven crystallization.

[0003] It can be seen that heat exchange performance is the most important parameter indicator for the design of static crystallizers, especially the heat exchange efficiency and temperature control in the crystallizer. Precise heat exchange control of the melt crystallizer can ensure that the material crystallizes at an appropriate temperature, thereby obtaining ideal crystal quality. Precise heat exchange control can also realize the "sweating" process to wash away impurities wrapped and adhered to the crystals, thereby achieving the purification of the crystal product. In addition, heat exchange efficiency directly affects crystallization efficiency. Efficient heat exchange can achieve faster cooling and supersaturation of the material, thereby improving the crystallization rate and production efficiency. Reasonable heat exchange design can reduce energy consumption, improve energy utilization efficiency, reduce the energy required for cooling or heating, and thus reduce production costs. Utility Model Content

[0004] The purpose of this application is to provide a static crystallizer to achieve efficient melt crystallization heat exchange, improve the efficiency of the crystallization process and product quality.

[0005] To achieve the above objectives, the present application provides a static crystallizer, comprising:

[0006] The crystallizer body includes an outer jacket tube in the shape of a straight sleeve and an inner jacket tube for introducing crystallization raw materials, and the annular jacket cavity between the outer jacket tube and the inner jacket tube forms a temperature control medium flow cavity;

[0007] The swirl component is used to separate a swirling flow channel that winds around the outer peripheral wall of the inner jacket tube in the temperature control medium flow cavity, so that the temperature control medium can flow in a swirling shape along the swirling flow channel.

[0008] In some embodiments, the swirl member is a spiral fin, the inner edge of the spiral fin is in contact with the outer circumferential wall of the inner jacket tube, and the outer edge of the spiral fin is in contact with the inner circumferential wall of the inner jacket tube.

[0009] In some embodiments, the spiral fin has a helix angle of 15° to 45° and a pitch of 5 to 20 cm.

[0010] In some embodiments, the static crystallizer further comprises:

[0011] A temperature controller is connected to both ends of the temperature control medium flow chamber and is used to sustainably provide the temperature control medium.

[0012] In some embodiments, the inner jacket tube comprises:

[0013] A straight tube section, wherein the top end of the straight tube section is provided with a feed port for the crystallization raw material;

[0014] The reducing pipe section is funnel-shaped and integrally extends downward from the bottom end of the straight pipe section;

[0015] The material supporting component is arranged at the bottom end of the straight tube section, and the material supporting component is penetrated by a plurality of flow micropores.

[0016] In some embodiments, the material supporting member is a porous plate that separates the straight tube section and the reduced diameter tube section in a partition shape.

[0017] In some embodiments, the pore size of the flow-through micropores is 1-8 mm; and / or the total pore area of ​​several of the flow-through micropores accounts for 10-30% of the plate area of ​​the material support component, and / or several of the flow-through micropores are arranged in a square or diamond shape on the material support component.

[0018] In some embodiments, the static crystallizer further comprises:

[0019] A pressure source is connected to the reducing lumen of the reducing pipe section and provides positive pressure or negative pressure to the reducing lumen.

[0020] In some embodiments, the outlet of the reducing pipe section is provided with an outlet valve.

[0021] In some embodiments, the static crystallizer further includes a raw material collector connected to the pressure source, and the bottom end outlet of the reducing pipe section is inserted into the raw material collector.

[0022] In the static crystallizer of the present application, by adding a swirl member coiled around the outer wall of the inner jacketed tube, a spiral flow channel can be formed around the inner jacketed tube, thereby guiding the flow of the temperature-control medium fluid, increasing the flow rate, and further enhancing the contact heat exchange area, thereby achieving an enhanced heat exchange effect, making the supersaturation of the melt crystallization more uniform and the crystal column quality higher during the crystallization process. On this basis, the maximum design diameter of a single tube can be increased, making the single batch crystallization efficiency higher, and improving the process efficiency while ensuring the quality of the crystal product.

[0023] Other features and advantages of the embodiments of the present application will be described in detail in the subsequent detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] The accompanying drawings are used to provide a further understanding of the embodiments of the present application and constitute a part of the specification. Together with the following specific embodiments, they are used to explain the embodiments of the present application, but do not constitute a limitation on the embodiments of the present application. For those skilled in the art, other drawings can be obtained based on the structures shown in these drawings without inventive work. In the drawings:

[0025] Figure 1 This is a schematic diagram of the structure of the inner jacket pipe after the swirl component is added;

[0026] Figure 2 Schematic diagram of the structure of a crystallizer body according to a specific embodiment of the present application;

[0027] Figure 3 Schematic diagram of the structure of a crystallizer body according to another specific embodiment of the present application;

[0028] Figure 4 Schematic diagram of the structure of a static crystallizer according to a specific embodiment of the present application;

[0029] Figure 5 Schematic diagram of the steps of the crystallization purification method according to a specific embodiment of the present application.

[0030] Description of Reference Numerals

[0031] 1. Inner jacketed tube; 2. Temperature control medium inlet; 3. Swirl component; 4. Outer jacketed tube; 5. Material support component; 6. Reducer section; 7. Outlet valve; 8. Discharge port; 9. Raw material collector; 10. Temperature controller; 11. Temperature control medium outlet; 12. Pressure source. DETAILED DESCRIPTION

[0032] The following describes the specific embodiments of the present application in detail with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only used to illustrate and explain the present application and are not intended to limit the present application.

[0033] In the static crystallizers of the prior art, there are generally various shortcomings in terms of heat exchange performance or heat exchange technology. For example, the first is low heat exchange efficiency. The heat exchange efficiency of the static crystallizer is relatively low because the material is stationary outside the heat exchange plate or heat exchange tube, resulting in low heat and mass transfer efficiency, slow crystallization speed, and long operation cycle; secondly, the operation cycle of the crystallization process of the static crystallizer is long, and one operation cycle can be as long as more than ten hours. For materials that need to be recrystallized, the entire cycle may exceed forty hours, which is not conducive to materials with poor timeliness; thirdly, the equipment investment is large and the structure is complex, including circulation pumps, heat exchangers, circulation pipelines, etc., which occupy a large area; fourthly, there is the problem of flow field deviation. When the crystallization mother liquor containing fine crystals is extracted from the crystallizer through the circulation pipeline, the outlet can only be at the circumference of the crystallizer. At a certain point, the extraction effect is not ideal due to the deviation of the flow field; fifthly, the energy consumption is high. Due to the limitation of the heat exchange temperature difference, the external circulation type fine crystal elimination system often requires a large circulation volume, which increases the energy consumption of the equipment operation; sixthly, the flow field inside the crystallizer generally forms a fully mixed state. Excessive circulation volume can easily cause the flow field inside the crystallizer to form a fully mixed state, and it is impossible to achieve a true fine crystal elimination cycle; seventhly, the material distribution is uneven. Uneven material distribution may lead to differences in crystallization effect and affect product purity; eighthly, crystals are easy to clog pipelines. In the processing of heat-sensitive and easy-to-crystallize materials, crystals are easy to deposit on the heating surface, hindering heat transfer, affecting product quality and yield, and easily clogging pipelines. The above-mentioned shortcomings have limited the efficiency and effect of current static crystallizers in certain applications to varying degrees.

[0034] This application aims to improve and optimize the design of the static crystallizer in a targeted manner to enhance its performance, especially the heat exchange performance, thereby improving the efficiency of the crystallization process and the quality of the product. First, in response to the problem of low heat exchange efficiency and slow crystallization process of the static crystallizer, the inventors, through continuous experiments and observations, realized that this is not only caused by the poor fluidity of the material, but also by the poor utilization of the heat exchange contact area, poor precise control of temperature and speed, and other problems. Therefore, they creatively proposed to achieve enhanced heat exchange effect by adding a swirl component 3. Figure 1 As shown, as a basic concept, after the swirl member 3 is coiled around the outer wall of the inner jacket tube 1, the swirl member 3 guides the flow of the heat exchange medium (i.e., the temperature-control fluid) and restricts the flow space, thereby increasing the circulation rate of the temperature-control fluid at the same flow rate. The increased fluid flow rate leads to an increase in the heat transfer coefficient. Moreover, the temperature-control fluid fills the swirling flow channel, resulting in a larger contact heat exchange area and maximum coverage of the outer wall of the inner jacket tube 1, thereby enhancing the heat transfer effect. The enhanced heat transfer effect makes the supersaturation of the melt crystallization more uniform, and the crystal column quality of the crystallization process is higher.

[0035] like Figures 2 to 4 As shown, the present application discloses a static crystallizer, which includes:

[0036] The crystallizer body includes an outer jacket tube 4 in the shape of a straight sleeve and an inner jacket tube 1 for introducing crystallization raw materials. The annular jacket cavity between the outer jacket tube 4 and the inner jacket tube 1 forms a temperature control medium flow cavity; and a swirl component 3, which is used to separate a spiral flow channel that winds around the outer peripheral wall of the inner jacket tube 1 in the temperature control medium flow cavity, so that the temperature control medium can flow in a swirling manner along the swirl flow channel.

[0037] See also Figure 2 The temperature-control medium fluid enters the crystallizer from the temperature-control medium inlet 2 and flows into the annular jacket cavity between the outer jacket tube 4 and the inner jacket tube 1. By providing the swirl component 3, the temperature-control medium flow cavity is divided into a spiral flow channel. The temperature-control medium fluid can flow downward in a swirling manner along the spiral flow channel, with the flow rate gradually increasing. The spiral flow path is long, and the temperature-control medium fluid can fully contact the outer peripheral wall of the inner jacket tube 1. Therefore, for the same flow rate of temperature-control medium, a faster flow rate, longer heat exchange time, and larger heat exchange contact area can be obtained, thereby increasing the heat transfer coefficient and achieving a better heat exchange effect.

[0038] It can be seen that due to the low heat exchange efficiency of the existing crystallizer, on the one hand, it will lead to poor crystallization heat transfer effect, inaccurate control of crystallization and sweating temperature, which generally causes low purity and yield of crystal products; on the other hand, the diameter size of the tubular crystallizer is limited in design, making it difficult to scale up the crystallization equipment and the efficiency of the equipment is low. The present application designs a high-efficiency static crystallizer with a spiral fin heat exchange structure. The enhanced heat exchange effect formed will make the supersaturation of the melt crystallization more uniform, and the quality of the crystal column during the crystallization process is higher. Accordingly, under the premise of achieving a certain heat exchange effect, the maximum design diameter of a single tube can be increased for the tubular crystallizer, and the single batch processing capacity is in a cubic relationship with the crystallizer diameter. The single batch crystallization efficiency is higher, and the process efficiency is improved while ensuring the quality of the crystal product.

[0039] Among them, the swirl component 3 and the spiral flow channel arranged around the outer wall of the inner tube can be of various shapes and structures as required. For example, the swirl component 3 shown in the figure is a spiral fin, the inner edge of the spiral fin is in contact with the outer peripheral wall of the inner jacket tube 1, and the outer edge of the spiral fin is in contact with the inner peripheral wall of the inner jacket tube 1, thereby completely dividing the temperature control medium flow cavity into a spiral flow channel. Such a design can meet the above-mentioned requirements of enhancing the heat transfer coefficient, and the material collection, processing and installation of the spiral fin are also relatively convenient. Moreover, the direction of rotation, rotation inclination angle, drop, etc. of the spiral flow channel can also be specifically set and adjusted according to the size of the temperature control medium flow cavity, design requirements for flow rate, etc.

[0040] When using spiral fins, pre-design and simulation can be performed to adjust various parameters. In this embodiment, as an example, the spiral fins are designed with a helix angle of 15° to 45° and a pitch of 5 to 20 cm. It is well known to those skilled in the art that the helix angle is the angle between the tangent of the helix line of the spiral fin and a plane perpendicular to the helix axis, and the pitch is the axial spacing between adjacent threads. These details will not be elaborated upon here.

[0041] It will be understood by those skilled in the art that the swirl member 3 is not limited to the spiral fins of the above specifications, and may also be a flat fin with one section being horizontal and another section being an inclined fin. The number of swirl members 3 is also not limited to the one shown in the figure, and may also be a multi-section type, or a double spiral fin to form a double spiral flow channel. In addition, the inner edge of the spiral fin may be fitted or directly welded to the outer circumferential wall of the inner jacket tube 1, but the outer edge of the spiral fin may not be in contact with the inner circumferential wall of the inner jacket tube 1. The blade surface of the spiral fin is shaped to be radially inward and downward to facilitate directing the fluid to the inner side of the fin.

[0042] See also Figure 4 The static crystallizer of this embodiment may also include a temperature controller 10, which is connected to both ends of the temperature control medium flow cavity and is used to sustainably provide the temperature control medium. The temperature control medium provided by the temperature controller 10 enters the crystallizer from the temperature control medium inlet 2 and is recovered from the temperature control medium outlet 11. Through the temperature controller 10, precise heat exchange control of the melt crystallizer can be achieved to ensure that the material can crystallize at a suitable temperature, thereby obtaining ideal crystal quality, and precise heat exchange control can also realize the "sweating" process to wash away impurities wrapped in the crystals and impurities adhering to the crystals, thereby achieving purification of the crystal products. This temperature controller 10 can adjust the temperature, flow rate, etc. of the temperature control medium and control the circulation of the temperature control medium.

[0043] It can be seen that by designing the above-mentioned spiral fin heat exchange structure, compared with the traditional double-jacketed crystallizer, the heat exchange efficiency can be effectively improved, the crystallizer temperature control efficiency is higher, and the temperature distribution is more uniform.

[0044] See also Figure 3 Furthermore, the inner jacket tube 1 may include:

[0045] A straight tube section, the top of which is provided with a feed port for the crystallization raw material;

[0046] The reducing pipe section 6 is in the shape of a closed funnel and extends downward from the bottom end of the straight pipe section;

[0047] The material supporting member 5 is arranged at the bottom end of the straight tube section, and a plurality of flow-through micropores are provided through the material supporting member 5 .

[0048] The reducing pipe section 6 is funnel-shaped, with a discharge port 8 at its bottom. This collects fluid that permeates through the micropores of the material support member 5 and discharges it through the discharge port 8. Furthermore, the material support member 5, physically supporting the crystal layer, is installed at the bottom of the inner jacketed tube 1. This effectively supports the crystal columnar layer during the filtration and sweating stages, significantly improving the effectiveness and efficiency of mother liquor and sweat removal. Furthermore, the reducing pipe section 6 at the bottom of the inner jacketed tube 1 (i.e., below the material support member 5) further enhances temperature control, as will be explained in detail below.

[0049] Specifically, adding a perforated support structure at the bottom of the straight tube section of the crystallizer can not only effectively support the crystal column layer physically, but also the crystallized mother liquor and sweat can be pre-separated into solid and liquid before negative pressure filtration, effectively enhancing the efficiency of the negative pressure filtration process and significantly improving the effect after sweating.

[0050] In this embodiment, the material support member 5 is a porous plate that separates the straight tube section and the diameter-reducing tube section 6 in a partition shape. Figure 3 As shown, the material support member 5 can be a circular plate embedded in the inner jacket tube 1, and a ceramic sand core can be selected, and the size of the flow micropores therein can be selected according to the size of the material to be processed. During operation, positive pressure is first introduced and then the crystallization raw material is added, so that the liquid raw material does not leak through the support member under a certain positive pressure condition, and crystal columns are crystallized as much as possible in the straight tube section. The crystal columns after crystallization stay on the support member, and after the crystallization is completed, the crystallization mother liquor is removed by negative pressure filtration. Then the sweating process can form a uniform crystal layer channel under the condition of efficient heat transfer, and then the sweat is removed by negative pressure filtration. The role of the support member can effectively improve the effect and efficiency of removing the mother liquor and sweat.

[0051] The reducing pipe section 6 collects the crystallization mother liquor or sweat from the pre-permeation through the micropores, and finally collects it into the raw material collector 9 through the discharge port 8. In this embodiment, the height of the reducing pipe section 6 can be 2-10 cm, and the inner diameter of the discharge port 8 can be about 1 / 2 of the inner diameter of the straight pipe section, which can be adjusted and set according to specific requirements or effects.

[0052] In this embodiment, the pore size of the flow micropores in the material support member 5 can be selected to be 1-8 mm, depending on the size of the crystallization raw material and the crystals. The total pore area of ​​all the flow micropores can account for 10-30% of the plate surface area of ​​the material support member 5. Moreover, a plurality of flow micropores can be arranged in a square or diamond shape on the material support member 5. Parameters such as the pore size, total pore area, and pore arrangement of the flow micropores can be designed according to process requirements to ensure that the liquid raw material does not leak through the support member under certain positive pressure conditions, that the crystal column channels formed during the sweating stage are more uniform, that impurities are more thoroughly removed, and that the resulting product has a higher purity. Products of the same purity can also achieve a higher yield.

[0053] Based on the design of the reducing pipe section 6, the jacket temperature can also be controlled. That is, the static crystallizer of this embodiment can also include a pressure source 12, which is connected to the reducing pipe cavity of the reducing pipe section 6 and provides positive pressure or negative pressure to the reducing pipe cavity. The pressure source 12 can be an air pump, etc. The discharge port 8 of the reducing pipe section 6 can also be provided with an outlet valve 7. In the prior art, due to the lack of temperature control at the bottom end of the jacket pipe, scaling is easily generated at the end of sweating, that is, the high-temperature operation stage. In this embodiment, in combination with the material support member 5, the reducing pipe section 6, the air pump, etc., positive pressure or negative pressure can be introduced into the reducing section in a timely manner, and the liquid control valve (i.e., the outlet valve 7) can be further used to control the jacket temperature, so as to effectively avoid scaling problems in the mother liquor and sweat removal stage, so that the operational stability and crystallization effect of the crystallization process are improved.

[0054] exist Figure 4 In the embodiment, the static crystallizer may further include a raw material collector 9 connected to a pressure source 12. The bottom outlet 8 of the reducing pipe section 6 is inserted into the raw material collector 9. The raw material collector 9 can collect the filtered crystallization mother liquor or sweat. The pressure source 12 can apply positive or negative pressure to the reducing pipe section 6 through the raw material collector 9 and the outlet valve 7.

[0055] In summary, the improved static crystallizer of the present application can enhance the heat exchange efficiency, make the crystallization supersaturation in the tubular crystallizer more uniform, and the crystal quality is higher. The same static crystallization process, the heat exchange energy consumption is reduced. Moreover, the diameter of the static tubular crystallizer can break through the limitation of heat exchange efficiency, the single batch crystal volume can be increased proportionally with the cube of the diameter, and the single batch production capacity can reach twice that of the prior art. In addition, the crystal column channels formed in the sweating stage are more uniform, the impurities are removed more thoroughly, the higher the purity of the product obtained, and the higher the yield of products with the same purity.

[0056] This application also discloses a crystallization purification method accordingly. Figure 5 As shown, the method adopts the static crystallizer described above and includes the steps of:

[0057] S100: adding liquid initial crystallization raw materials into the inner jacket tube of the static crystallizer, and supplying a temperature control medium to the temperature control medium flow chamber through the temperature controller 10, so that the initial crystallization raw materials crystallize in the static crystallizer and obtain coarse crystal columns;

[0058] S200: sweating the crude crystal column to obtain a purified crystal column;

[0059] S300: The purified crystal column is heated until it is completely melted to obtain a liquid purified product.

[0060] The crystallization purification method of the present application utilizes the above-mentioned high-efficiency static crystallizer equipment with a spiral fin heat exchange structure. By arranging a spiral fin heat exchange structure between the jackets, the heat exchange medium can form a swirl or turbulent flow in the jacket, significantly improving the heat exchange efficiency. By optimizing the fin angle and spacing, the heat transfer effect can be further enhanced. Specifically, see Figure 4 , the liquid initial crystallization raw material is added to the inner jacket tube from the top of the straight tube section. Then, the temperature-controlled medium fluid with set temperature, flow rate and flow rate can be introduced into the annular jacket cavity, that is, the temperature-controlled medium flow cavity, through the temperature controller 10. The introduced temperature-controlled medium fluid swirls along the swirl component 3 in the temperature-controlled medium flow cavity, thereby cooling the crystallization raw material in the straight tube section of the inner jacket tube 1 through full contact and heat exchange with the outer peripheral wall of the inner jacket tube 1, causing it to gradually crystallize and obtain a coarse crystal column. Then, the crystallization mother liquor can be discharged by suction filtration. Then, a sweating process is carried out to adjust the temperature and other parameters of the introduced temperature-controlled medium fluid, and the obtained coarse crystal column is heated to the sweating temperature at a set heating rate, while gradually discharging sweat to obtain a purified crystal column. Finally, the purified crystal column is heated and melted to obtain a liquid purified product.

[0061] It can be seen that in this crystallization purification process, precise temperature control and efficient and uniform contact heat exchange are crucial. After obtaining the preliminary crystallization purification product, for some products with high purity requirements, the crystallization purification method of this application may also include the following steps:

[0062] S400: adding the liquid purified product after the crystal column is melted into the static crystallizer as the purified crystallization raw material, and repeating steps S100 to S300 for further crystallization purification until a product meeting the purity requirements is obtained.

[0063] That is, by repeating the crystallization purification steps S100 to S300, crystallization purification can be repeated until a product meeting the purity requirements is obtained.

[0064] In adopting Figure 3 、 Figure 4 In the case of the static crystallizer shown with the material support member 5, step S100 may further include: applying a set positive pressure to the reducing pipe section 6 before adding the crystallization material, so that the crystallization material does not leak through the material support member 5 under the set positive pressure. This concentrates the crystallization material within the straight pipe section, allowing the resulting crystal column to be supported by the material support member 5. Furthermore, mother liquor or sweat can be pumped into the reducing pipe section 6 through the flow-through micropores of the material support member 5, achieving solid-liquid pre-separation during the crystallization process.

[0065] In addition, in steps S100 and S200, the raw material mother liquid or sweat can be removed by negative pressure filtration of the reducing pipe section 6. When the outlet valve 7 is opened and the reducing pipe section 6 is negatively suctioned, the discharge efficiency of the mother liquid or sweat can be accelerated and clogging is less likely to occur.

[0066] The existing static crystallization equipment has no temperature control design at the material outlet, which makes the pipeline easy to clog, and the sweat in the sweating process is not easy to be discharged cleanly. Therefore, in addition to setting a spiral fin heat exchange structure between the jackets, the present application also sets a material support component 5, a reducing pipe section 6, an outlet valve 7, a pressure source 12, etc. at the bottom of the tubular crystallizer to realize the temperature control design of the reducing section, thereby avoiding scaling and clogging, and facilitating the discharge of sweat in the sweating process. By setting a porous plate to distribute the material in layers, the crystal column layer in the filtration and sweating stages can be effectively supported, solid-liquid pre-separation can be achieved, and the effect and efficiency of removing the mother liquor and sweat can be effectively improved. At the same time, the stability of the crystal column layer can be ensured to prevent the collapse of the crystal layer.

[0067] The bottom of the straight tube section adopts a variable diameter temperature control design, which uses local temperature control to achieve precise control of the mother liquor and sweat, effectively avoiding the scaling problem in the mother liquor and sweat removal stage, which is beneficial to the operation stability of the crystallization process, improves the crystallization effect, and increases the separation efficiency.

[0068] As an example, when the above crystallization purification method is specifically applied, the following specific processes may be mainly included:

[0069] 1) Add the liquid crystal raw material into the inner jacket tube of the crystallizer, and control the temperature of the system at the starting temperature of crystallization by the temperature controller 10, and stay for 10-30 minutes to allow the temperature to stabilize;

[0070] 2) Cooling the raw material to the crystallization temperature at a constant cooling rate, maintaining the temperature at the crystallization temperature after the cooling is completed, and draining the mother liquor by filtration through the pressure source 12 after equilibration for 60-120 minutes, to obtain a coarse crystal column in the straight tube section of the crystallizer;

[0071] 3) heating the crude crystal column obtained in step 2) at a constant heating rate to the sweating temperature, maintaining the temperature at the sweating temperature after the heating is completed, equilibrating for 60-120 minutes, and filtering out the sweat through a pressure source 12 to obtain a further purified crystal column;

[0072] 4) heating the crystalline product obtained in step 3) until it is completely melted to obtain a liquid product;

[0073] 5) Using the product obtained in step 4) as a raw material, repeat the above steps to perform multi-stage melt crystallization until a product meeting the purity requirements is obtained.

[0074] Through multi-stage melt crystallization, the final product purity can reach over 99.99%. Compared with conventional static crystallizers without spiral fin heat exchange structures, its heat exchange efficiency is greatly improved, the process completion time is reduced by at least one-third, and the crystallized product is of higher quality and more uniformly distributed.

[0075] This application innovatively designs a fin heat exchange structure with spiral crystallization, which can effectively improve the heat exchange efficiency compared to the traditional double-jacketed crystallizer, and the crystallizer temperature control efficiency is higher and the temperature distribution is more uniform. For tubular crystallizers, the maximum design diameter of a single tube can be increased, that is, the amount of material processed at a single time is increased in proportion to the cube of the diameter, thereby improving the process efficiency while ensuring the quality of the crystal product. In addition, a material support component and a variable diameter section temperature control design are set at the bottom of the vertical tubular crystallizer, that is, a crystal layer physical support component is added to the bottom of the straight tube section, and the variable diameter section between the straight tube section and the discharge port is double-jacketed for temperature control, thereby solving the problem that the existing crystallization equipment is easily blocked and sweat cannot be completely removed, affecting the purity of the crystal.

[0076] In the description of this application, it should be understood that the terms "first" and "second" are used for descriptive purposes only and should not be understood to indicate or imply relative importance or implicitly specify the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include at least one of such features. In the description of this application, "plurality" means at least two, for example, two, three, etc., unless otherwise specifically defined.

[0077] In this application, unless otherwise specified or limited, the terms "installed," "connected," "connect," "fixed," etc. should be understood in a broad sense. For example, they can refer to fixed connection, detachable connection, or integration; mechanical connection, electrical connection, or communication; direct connection or indirect connection through an intermediate medium; internal communication between two elements or interaction between two elements, unless otherwise specified. Those skilled in the art will understand the specific meanings of the above terms in this application based on specific circumstances.

[0078] In the description of this specification, the description with reference to the terms "one embodiment", "some embodiments", "example", "specific example", or "some examples" means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present application. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner. In addition, those skilled in the art can combine and combine different embodiments or examples described in this specification and features of different embodiments or examples without contradiction.

[0079] Although the embodiments of the present application have been shown and described above, it can be understood that the above embodiments are exemplary and cannot be understood as limitations on the present application. Ordinary technicians in this field can change, modify, replace and modify the above embodiments within the scope of the present application.

Claims

1. A static crystallizer, characterized in that: The static crystallizer comprises: The crystallizer body comprises an outer jacket tube (4) in the shape of a straight sleeve and an inner jacket tube (1) for introducing crystallization raw materials, wherein an annular jacket cavity between the outer jacket tube (4) and the inner jacket tube (1) forms a temperature control medium flow cavity; The swirl component (3) is used to separate a swirling flow channel in the temperature control medium flow cavity, which is wound around the outer peripheral wall of the inner jacket tube (1), so that the temperature control medium can flow in a swirling manner along the swirling flow channel.

2. The static crystallizer according to claim 1, characterized in that The swirl component (3) is a spiral fin, the inner edge of the spiral fin is in contact with the outer peripheral wall of the inner jacket tube (1), and the outer edge is in contact with the inner peripheral wall of the inner jacket tube (1).

3. The static crystallizer according to claim 2, characterized in that The spiral fin has a helix angle of 15° to 45° and a pitch of 5 to 20 cm.

4. The static crystallizer according to claim 1, characterized in that The static crystallizer also includes: A temperature controller (10) is connected to both ends of the temperature control medium flow chamber and is used to continuously provide the temperature control medium.

5. The static crystallizer according to any one of claims 1 to 4, characterized in that The inner jacket tube (1) comprises: A straight tube section, wherein the top end of the straight tube section is provided with a feed port for the crystallization raw material; A reducing pipe section (6) extending downward from the bottom end of the straight pipe section in a funnel-shaped manner; A material support member (5) is provided at the bottom end of the straight tube section, and a plurality of flow-through micropores are provided through the material support member (5).

6. The static crystallizer according to claim 5, characterized in that The material supporting member (5) is a porous plate that separates the straight tube section and the diameter-reducing tube section (6) in a partition shape.

7. The static crystallizer according to claim 5, characterized in that The pore diameter of the flow micropores is 1-8 mm; and / or the total pore area of ​​a plurality of the flow micropores accounts for 10-30% of the plate surface area of ​​the material support member (5); and / or the plurality of the flow micropores are arranged in a square or diamond shape on the material support member (5).

8. The static crystallizer according to claim 5, characterized in that The static crystallizer also includes: A pressure source (12) is connected to the variable diameter lumen of the variable diameter pipe section (6) and provides positive pressure or negative pressure to the variable diameter lumen.

9. The static crystallizer according to claim 8, characterized in that The discharge port (8) of the reducing pipe section (6) is provided with an outlet valve (7).

10. The static crystallizer according to claim 9, characterized in that The static crystallizer further comprises a raw material collector (9) connected to the pressure source (12), and the bottom end discharge port (8) of the reducing pipe section (6) is inserted into the raw material collector (9).

Images