Continuous efficient crystallization device

Abstract

The utility model relates to a continuous high-efficiency crystallization device which comprises a shell, n-1 longitudinal baffling partition plates are arranged in the shell, an inner cavity of the shell is divided into n cavity bodies by the n-1 baffling partition plates, a rotary heat exchange body and a fixed scraper are respectively arranged in each cavity body, the fixed scraper is in contact with the outer surface of the rotary heat exchange body, and the n is larger than or equal to 1. At least one stirring paddle is arranged on the surface of the outer wall of the rotary heat exchange body, a combined opening for the stirring paddle to pass through is formed in the fixed scraper, a hollow rotating shaft extending out of the side wall of the shell is arranged at one end of the rotary heat exchange body, and the hollow rotating shaft is connected with the shell through a rotary sealing device; a cold source inlet inner pipe with the outer diameter smaller than the inner diameter of the hollow rotating shaft is arranged in the hollow rotating shaft, the cold source inlet inner pipe extends into an inner cavity of the rotary heat exchange body, and the hollow rotating shaft, the cold source inlet inner pipe and the rotary heat exchange body are coaxially arranged. The surface of the rotary heat exchange body is not hung on a wall, the heat exchange coefficient is basically not attenuated, and the heat exchange efficiency is high.

Description

Technical Field

[0001] The utility model relates to a crystallization device, in particular to a continuous and efficient crystallization device. Background Art

[0002] Cooling crystallization is a common unit operation in pharmaceutical and chemical production, a process closely tied to temperature, time, and agitation. Different products have distinct crystallization curves, and even for the same product, varying crystallization processes can significantly impact both its intrinsic and external quality.

[0003] Currently, the most commonly used cooling crystallization equipment is a stirred kettle crystallizer, which uses either an external kettle jacket or internal cooling coils for cooling. Using a jacket for cooling, crystals tend to adhere to the inner walls of the kettle, resulting in severe wall formation, which affects heat transfer efficiency and reduces crystallization efficiency. Although agitation is provided, it is impossible to remove the thick crystals adhering to the inner walls of the kettle. Even though stirring blades can scrape off some of the attached crystals, this does not completely solve the problem of crystallization kettle wall adhesion and can even cause blockage in the discharge pipe at the bottom of the kettle. Similarly, using internal cooling coils for cooling will also cause wall formation on the coils, further affecting crystallization efficiency.

[0004] In response to the problems encountered during the crystallization process, various spiral cooling crystallizers have emerged, including horizontal internal rotating discs, horizontal internal rotating pipes, horizontal internal rotating spiral ribbons, vertical internal rotating pipes, and vertical internal rotating spiral ribbons. These have improved crystallization efficiency and reduced energy consumption and crystal growth time. Compared with ordinary kettle crystallizers, spiral crystallizers have improved crystallization efficiency. However, during the crystallization process, the cooling surface of the rotating moving parts will still have a wall hanging phenomenon, affecting the crystallization efficiency. For continuous crystallization processes, the cooling effect will deteriorate as the crystallization time increases, requiring frequent shutdown and maintenance, which in turn affects the equipment's production capacity.

[0005] Patent CN 201524442 U discloses an efficient scraping wall type hollow plate cooling continuous crystallizer, which includes a plurality of hollow cooling plates arranged in combination in a U-shaped horizontal long trough container. A rotating shaft passes through all the cooling plates. A barrier disc is installed between every two cooling plates, and an adjustable scraping wall type stirring device is installed on the barrier disc and the rotating shaft. All the barrier discs and the scraping wall type stirring devices are installed on the rotating shaft and are driven to rotate and stir by a motor and a speed reducer. The scraping wall type stirring device plays a role in cleaning the wall, quickly scraping off the crystallized substances on the surfaces of all the cooling plates. Not only is the cooling area large, but also the heat transfer and cooling efficiency are greatly improved. Compared with the existing crystallization equipment in the market, this patented technology has a large cooling area and a greatly improved heat transfer effect. However, during the crystallization process, due to the circular rotation of the stirring, thick crystallized substances will accumulate in the places that cannot be stirred at the top of the U-shaped horizontal long trough container, which is difficult to remove. The removed crystal blocks are easy to block the subsequent conveying pipelines and require frequent shutdowns for cleaning, affecting production capacity. Moreover, it is impossible to have a seamless connection between the cooling plate and the scraper, and there will still be a small layer of crystallized substances on the cooling plate, resulting in a lower heat transfer efficiency, which in turn affects the crystallization process. Moreover, as the crystallization time prolongs, the hardness of the crystallized substances becomes higher and higher, the rotation of the scraper becomes more and more difficult, the resistance of the rotating shaft becomes larger and larger, the scraper is easily broken, the rotating shaft is easily deformed and cracked, resulting in fracture, and the maintenance cost is high. Moreover, most of the crystallization occurs on the cooling plate wall, and the crystallized substances are scraped off by the scraper, and the crystal form is easily damaged, resulting in uneven particle size of the product and affecting the product quality.

[0006] Therefore, there is an urgent need to develop a continuous high-efficiency crystallization device with high crystallization efficiency and no wall sticking phenomenon. Summary of the Utility Model

[0007] One of the purposes of the present utility model is to provide a continuous high-efficiency crystallization device to solve the problem that the existing cooling crystallization device has a wall sticking phenomenon, which affects the crystallization efficiency.

[0008] Another purpose of the present utility model is to provide a continuous high-efficiency crystallization method to solve the problems of low efficiency, uneven crystal grains and poor product quality in the existing cooling crystallization process.

[0009] One of the objectives of the present utility model is achieved as follows: A continuous and efficient crystallization device includes a housing. At one end of the housing, a feed inlet is provided. At the other end of the housing, a crystallization liquid outlet is provided. Inside the housing, n - 1 longitudinal baffle plates are provided. The n - 1 baffle plates divide the inner cavity of the housing into n cavities, namely the first cavity, the second cavity, ……, the nth cavity, where n ≥ 1. In each cavity, a set of rotary heat exchangers and fixed scrapers are respectively provided. The rotary heat exchangers are driven by driving elements to rotate around their own axes. The fixed scrapers are in contact with the outer wall surfaces of the rotary heat exchangers. On the outer wall surfaces of the rotary heat exchangers, at least one stirring paddle is provided. On the fixed scrapers, a combined opening for the stirring paddle to pass through is provided. At one end of the rotary heat exchanger, a hollow rotating shaft extending out of the side wall of the housing is provided. The hollow rotating shaft is connected to the housing through a rotary sealing device. Inside the hollow rotating shaft, a cold source inlet inner tube with an outer diameter smaller than the inner diameter of the hollow rotating shaft is provided. The cold source inlet inner tube extends into the inner cavity of the rotary heat exchanger. The hollow rotating shaft, the cold source inlet inner tube, and the rotary heat exchanger are coaxially arranged. The fixed scraper can be fixed at any position inside the housing as long as it ensures that the fixed scraper is in contact with the outer wall surface of the rotary heat exchanger in the same group. The length of the fixed scraper is greater than or equal to the length of the rotary heat exchanger cylinder body.

[0010] The baffle plates are at a certain distance from both the top and the bottom inside the housing; or starting from the feed inlet end inside the housing, the odd - numbered baffle plates are at a certain distance from both the top and the bottom of the housing, and the distance from the baffle plates to the top of the housing is greater than the distance to the bottom of the housing. The even - numbered baffle plates have no gap with the top of the housing and are at a certain distance from the bottom of the housing.

[0011] The baffle plates are solid plates; or the baffle plates are of a hollow structure.

[0012] On the inner wall of the rotary heat exchanger, several inner baffle plates are provided. The inner baffle plates are cross - standing plates. The cross - standing plates include vertical plates perpendicular to the inner wall of the rotary heat exchanger and horizontal plates located in the middle of the vertical plates.

[0013] The stirring paddle includes paddle blades and support plates. The paddle blades are connected to the outer surface of the rotary heat exchanger through the support plates. The support plates are perpendicular to the axis of the rotary heat exchanger. The combined opening includes a first opening for the paddle blades to pass through and a second opening for the support plates to pass through.

[0014] At the bottom of the housing, a discharge port is provided; and / or at the bottom of the housing, a heat exchange interlayer is provided. The heat exchange interlayer is provided with a heat exchange inlet and a heat exchange outlet; and / or on the peripheral side walls of the housing, a jacket is provided. The jacket is provided with a jacket cold source inlet and a jacket cold source outlet.

[0015] The blade and the support plate are of solid structure; or the support plate is of hollow structure, and the internal space of the support plate communicates with the inner cavity of the rotary heat exchanger, and the blade is of solid structure; or both the support plate and the blade are of hollow structure, and the inner cavity of the rotary heat exchanger, the internal space of the support plate and the internal space of the blade communicate with each other.

[0016] A rotary joint is provided at the outer end of the hollow rotating shaft, a cold source outlet is provided on the rotary joint, and the cold source inlet pipe passes through the rotary joint and is connected to the cold source inlet.

[0017] The second object of the present invention is achieved as follows: A continuous and efficient crystallization method, which is realized based on the aforementioned continuous and efficient crystallization device, includes the following steps:

[0018] a. Continuously add liquid material into the first cavity of the shell through the feed port at a certain flow rate, and at the same time start all driving elements to drive the rotary heat exchanger to rotate, and at the same time continuously add cold source into all rotary heat exchangers through the cold source inlet pipe at a certain flow rate, and control the cold source to be discharged through the gap between the hollow rotating shaft and the cold source inlet pipe at the same flow rate as the added cold source to establish a cold source cycle.

[0019] b. When the liquid material is added into the shell and the liquid level of the liquid material reaches above the upper surface of the rotary heat exchanger, close the feed port, and control the temperature of the material in the shell to reach the temperature required by the crystallization process through the cold source.

[0020] c. After the crystallization temperature reaches the process requirements and the crystallization and crystal growth processes are completed, open the feed port and the crystallization liquid outlet, control the flow rate of the continuously added liquid material, and at the same time in the nth cavity, the crystallization liquid continuously overflows and discharges from the crystallization liquid outlet at the same flow rate to realize the continuous crystallization process of the liquid material.

[0021] When the crystallization process ends, discharge the remaining crystallization liquid from the discharge port at the bottom of the shell. If there are crystallization substances that are not easily discharged, a heat source can be introduced into the bottom heat exchange sandwich layer to melt the crystallization substances and then discharge them from the discharge port. If there are crystallization substances on the inner walls around the shell, a heat source can also be introduced into the jacket to melt the crystallization substances and then discharge them from the discharge port.

[0022] Control the crystallization temperature of the liquid material in the second cavity to be 0 - 2 °C lower than the crystallization temperature of the liquid material in the first cavity, control the crystallization temperature of the liquid material in the third cavity to be 0 - 2 °C lower than the crystallization temperature of the liquid material in the second cavity,..., control the crystallization temperature of the liquid material in the nth cavity to be 0 - 2 °C lower than the crystallization temperature of the liquid material in the n - 1th cavity, and the crystallization temperatures in each cavity meet the process control requirements.

[0023] The beneficial effects of the present invention:

[0024] The heat exchanger of the present utility model always maintains dynamic movement (i.e., the heat exchanger is always in a dynamic contact process with the liquid material), which can ensure that the liquid material is in a completely mixed flow state during the crystallization process in its respective cavity, and the crystallization temperature is balanced, effectively reducing the crystallization of the liquid material on the surface of the heat exchanger. And by controlling the temperature during the crystallization process through the heat exchanger and scraping the crystallization on the surface of the heat exchanger with a fixed scraper, the surface of the heat exchanger does not hang the wall and always remains clean. Ensure that the basic heat transfer coefficient of the heat exchanger remains unchanged and the heat transfer efficiency hardly decays.

[0025] At the same time, through the cooperation of the combined opening on the fixed scraper and the stirring paddle on the heat exchanger, it is ensured that the stirring action of the liquid material and the action of the fixed scraper removing the crystallization on the surface of the heat exchanger are carried out synchronously, improving the heat transfer efficiency of the continuous crystallization equipment and also improving the output and quality of the product.

[0026] The inner baffle inside the heat exchanger can effectively ensure the uniform distribution of the cold source in the heat exchanger and the requirement of high residence time, reduce energy consumption, and improve the heat transfer efficiency at the same time.

[0027] The technology of the present utility model has high heat transfer efficiency, the crystallization temperature is easy to control, it can meet the high residence time required by the crystallization process, the crystal form is full, the crystal grains are uniform, the product quality is good, and the continuous crystallization of the material can also be realized. Compared with the existing crystallization technology of the scraping wall type hollow plate cooling continuous crystallizer, the surface of the heat exchanger does not hang the wall, always remains clean, the heat transfer coefficient hardly decays, with the same heat transfer area, the output doubles, and the production capacity increases by 50%. And it is convenient for overhaul and maintenance, the equipment has high cost performance, and the industrialization effect is remarkable. Brief Description of the Drawings

[0028] Figure 1 It is a front sectional view of the continuous high-efficiency crystallization device provided by the present utility model.

[0029] Figure 2 It is a side sectional view of the continuous high-efficiency crystallization device provided by the present utility model.

[0030] Figure 3 It is another side sectional view of the continuous high-efficiency crystallization device provided by the present utility model.

[0031] Figure 4 It is a front sectional view of another external structure of the continuous high-efficiency crystallization device provided by the present utility model.

[0032] Figure 5 It is another structural schematic diagram of the baffle of the continuous high-efficiency crystallization device provided by the present utility model.

[0033] Figure 6Schematic diagram of the transverse combined opening on the fixed scraper, the transverse stirring paddle of the heat exchanger with rotary regenerator, and the support body of the continuous and efficient crystallization device provided by the present utility model.

[0034] Figures 7 - 10 Cross-sectional views of different structural forms in the longitudinal direction of the heat exchanger with rotary regenerator of the continuous and efficient crystallization device provided by the present utility model.

[0035] Figure 11 Another schematic diagram of the inner pipe of the cold source inlet of the continuous and efficient crystallization device provided by the present utility model.

[0036] In the figure: 1. Housing; 2. Baffle plate; 3. Heat exchanger with rotary regenerator; 4. Observation port; 5. Fixed scraper; 6. Outlet of jacket cold source; 7. Feed inlet; 8. Heat exchange inlet; 9. First cavity; 10. Second cavity; 11. nth cavity; 12. Heat exchange interlayer; 13. Heat exchange outlet; 14. Inlet of jacket cold source; 15. Temperature monitoring port; 16. Crystallized liquid outlet; 17. Jacket; 18. Rotary sealing device; 19. Driving element; 20. Discharge port; 21. Support leg; 22. Inner pipe of cold source inlet; 23. Outlet of cold source; 24. Inlet of cold source; 25. Rotary joint; 26. Hollow rotating shaft; 27. Combined opening; 27-1. First opening; 27-2. Second opening; 28. Cylinder body of heat exchanger with rotary regenerator; 29. Stirring paddle; 29-1. Support plate; 29-2. Blade; 30. Inner baffle. Detailed implementation manners

[0037] In order to make the technical problems, technical solutions and beneficial effects to be solved by the present utility model clearer, the present utility model will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present utility model and are not used to limit the present utility model.

[0038] As Figure 1 、 Figure 2 shown, the continuous and efficient crystallization device of the present utility model includes a housing 1, a feed inlet 7 is provided at one end of the housing 1, a crystallized liquid outlet 16 is provided at the other end of the housing 1, and n - 1 longitudinal baffle plates 2 are provided in the housing 1. The n - 1 baffle plates 2 divide the inner cavity of the housing 1 into n cavities, namely the first cavity 9, the second cavity 10,..., the nth cavity 11, where n ≥ 1. That is, there is at least one cavity. At this time, no baffle plate 2 is provided inside the housing 1, and the inner cavity of the housing 1 is this cavity.

[0039] In each cavity, a set of rotary heat exchangers 3 and fixed scrapers 5 are respectively arranged. The rotary heat exchanger 3 is driven by a driving element 19 to rotate around its own axis. The fixed scraper 5 is in contact with the outer wall surface of the rotary heat exchanger 3. At least one stirring paddle 29 is arranged on the outer wall surface of the rotary heat exchanger 3. A combined opening 27 for the stirring paddle 29 to pass through is formed on the fixed scraper 5. A hollow rotating shaft 26 extending out of the side wall of the housing 1 is arranged at one end of the rotary heat exchanger 3. The hollow rotating shaft 26 is connected to the housing 1 through a rotary sealing device 18. An inner cold source pipe 22 with an outer diameter smaller than the inner diameter of the hollow rotating shaft 26 is arranged in the hollow rotating shaft 26. The inner cold source pipe 22 extends into the inner cavity of the rotary heat exchanger 3. The hollow rotating shaft 26, the inner cold source pipe 22 and the rotary heat exchanger 3 are coaxially arranged; the fixed scraper 5 can be fixed at any position in the housing 1, as long as it is ensured that the fixed scraper 5 is in contact with the outer wall surface of the rotary heat exchanger 3 of the same group. The length of the fixed scraper is greater than or equal to the length of the rotary heat exchanger cylinder body.

[0040] The rotary heat exchanger 3 is of a hollow cylinder structure and is connected to the side walls on both sides of the housing 1 through rotating shafts at both ends. In order to ensure the sealing performance, a rotary sealing device 18 is provided between the rotating shaft and the housing 1. The rotary sealing device 18 includes a bearing system and a sealing system, which can ensure the sealing performance while the rotating shaft rotates freely. The rotary sealing device 18 is a prior art and will not be described in detail in this specific embodiment.

[0041] The rotary heat exchanger 3 has a certain distance from both the bottom and the top of the housing 1.

[0042] Preferably, the distance between the rotary heat exchanger 3 and the top of the housing 1 is greater than the distance between the rotary heat exchanger 3 and the bottom of the housing 1.

[0043] The rotating shaft at one end of the rotary heat exchanger 3 is a hollow rotating shaft 26. The hollow rotating shaft 26 is communicated with the inner cavity of the rotary heat exchanger 3. The hollow rotating shaft 26 serves as both the channel for the cold source and the rotating shaft for the rotary heat exchanger to rotate; the rotating shaft at the other end of the rotary heat exchanger 3 is a solid rotating shaft.

[0044] The driving element 19 is connected to the rotating shaft at one end of the rotary heat exchanger 3. The driving element 19 can be connected to the hollow rotating shaft 26. Generally, the driving element 19 is connected to the rotating shaft on the opposite side of the hollow rotating shaft 26, and the rotary heat exchanger 3 is driven to rotate by the driving element 19. Among them, the driving element 19 can be a variable frequency speed regulation motor, etc.

[0045] The cold source inlet inner pipe 22 is located inside the hollow rotating shaft 26. The inner end of the cold source inlet inner pipe 22 extends into the inner cavity of the rotary heat exchanger 3. The outer end of the cold source inlet inner pipe 22 is connected to the cold source inlet 24 outside the housing 1. The cold source inlet inner pipe 22 is used to input the cold source into the inner cavity of the rotary heat exchanger 3. The outer diameter of the cold source inlet inner pipe 22 is smaller than the inner diameter of the hollow rotating shaft 26. The gap between the outer wall of the cold source inlet inner pipe 22 and the inner wall of the hollow rotating shaft 26 is used for the cold source to output from the inner cavity of the rotary heat exchanger 3.

[0046] Furthermore, a rotary joint 25 is provided at the outer end of the hollow rotating shaft 26. A cold source outlet 23 is provided on the rotary joint 25. The cold source inlet inner pipe 22 passes through the rotary joint 25 and is connected to the cold source inlet 24.

[0047] Through the above structure, it can not only ensure the stable rotation of the rotary heat exchanger 3 around the rotating shaft, but also realize the input and output of the cold source, so as to establish the circulation of the cold source while the rotary heat exchanger 3 rotates, thereby ensuring the temperature stability of the liquid material outside the rotary heat exchanger 3 and facilitating the control of the temperature of the liquid material outside the rotary heat exchanger 3.

[0048] The housing 1 is used for the crystallization and crystal growth of the material to be crystallized inside it.

[0049] Among them, as Figure 1 , Figure 2 shown, the outer shape structure of the housing 1 is a cuboid.

[0050] As Figure 3 shown, as another embodiment of the present invention, the outer shape structure type of the housing 1 is a horizontal cylinder, and its front sectional view is as Figure 1 shown.

[0051] As Figure 4 shown, as another embodiment of the present invention, the outer shape structure type of the housing 1 is a horizontal cylinder with another structure.

[0052] Support legs 21 are provided at the bottom of the housing for supporting the housing.

[0053] In this embodiment, the housing 1 only includes one cavity and one rotary heat exchanger 3. The rotary heat exchanger 3 is coaxial with the housing 1. The fixed scraper is located inside the housing 1 and is adjacent to the outer wall surface of the rotary heat exchanger 3. A jacket 17 is provided on the outer wall of the housing 1. A feed inlet 7 is provided on one side of the upper part of the housing 1. A crystal liquid outlet 16 is provided on the other side of the upper part of the housing 1. The crystal liquid outlet 16 is lower than the feed inlet 7. After the liquid material enters the housing 1 from the feed inlet 7, it rotates and mixes downward around the rotary heat exchanger 3 under the stirring action of the stirring paddle 29 on the rotary heat exchanger 3. When the crystallization and crystal growth process is over, it is discharged from the crystal liquid outlet 16.

[0054] At the same time, a discharge port 20 is provided at the bottom of the housing 1.

[0055] As another embodiment of the present utility model, the outer shape structure type of the housing 1 can also be a horizontal ellipsoid.

[0056] In the inner cavity of the housing 1 of the present utility model, it is divided into several cavities by a vertical baffle plate 2. The cavities communicate with each other. The baffle plate 2 plays a role in deflecting the material, enabling the material to flow along a set trajectory. At the same time, it can increase the residence time of the liquid material in each cavity. Cooperating with the stirring action of the stirring paddle 29, after the liquid material fully contacts the surface of the heat exchanger 3 in the cavity, the heat exchange efficiency of the heat exchanger 3 is fully exerted.

[0057] Among them, there are various arrangement ways for the baffle plate 2.

[0058] The first way, as Figure 1 shown, there is a certain distance between the baffle plate 2 and the top and bottom inside the housing 1. A part of the liquid material in the previous cavity flows to the next cavity through the top of the baffle plate 2, and another part flows to the next cavity through the bottom of the baffle plate 2.

[0059] The second way, as Figure 5 shown, at one end of the housing 1 from the feed port, for the odd-numbered baffle plates 2, there is a certain distance between them and the top and bottom of the housing 1, and the distance between the baffle plate 2 and the top of the housing 1 is greater than the distance between the baffle plate 2 and the bottom of the housing 1. For the even-numbered baffle plates 2, there is no gap with the top of the housing 1 and there is a certain distance from the bottom of the housing 1. In this arrangement, most of the liquid material in the first cavity overflows from the top of the first baffle plate 2 to the second cavity 10, and a small part of the liquid material flows from the bottom of the first baffle plate 2 to the second cavity 10; all the liquid material in the second cavity 10 flows from the bottom of the second baffle plate 2 to the third cavity, and so on, until the liquid material flows into the nth cavity 11.

[0060] Among them, the baffle plate 2 is a solid plate structure, and the baffle plate 2 can also be a hollow plate structure. A cold source is introduced into the internal space of the baffle plate 2 to increase the heat exchange area.

[0061] The temperature of the cold source introduced into the internal space of the baffle plate 2 is slightly higher than the temperature of the cold source in the heat exchanger cylinder 28 of the heat exchanger to prevent crystallization on the surface of the baffle plate 2.

[0062] A discharge port 20 is provided at the bottom of the housing 1 for discharging the remaining material in the housing 1 after crystallization.

[0063] Further, an independent heat exchange interlayer 12 can be provided at the bottom of the housing 1, and a heat exchange inlet 8 and a heat exchange outlet 13 are provided on the heat exchange interlayer 12. During the crystallization process of the liquid material, a cold source can be introduced into the heat exchange interlayer 12 to improve the crystallization efficiency. At the end of the crystallization of the liquid material, a heat source is introduced to melt the crystals deposited at the bottom of the housing 1, facilitating the discharge of the remaining material.

[0064] Further, a jacket 17 can be provided on the peripheral side walls of the housing 1, and the jacket 17 is provided with a jacket cold source inlet 14 and a jacket cold source outlet 6. During the crystallization process of the liquid material, a cold source is introduced to improve the crystallization efficiency.

[0065] During the crystallization process of the liquid material, the temperature of the cold source introduced into the jacket 17 and the independent heat exchange interlayer 12 is slightly higher than the temperature of the cold source introduced into the rotary heat exchange body cylinder 28, so as to prevent the liquid material from crystallizing on the inner surfaces of the jacket 17 and the heat exchange interlayer 12.

[0066] As another embodiment of the present application, a temperature monitoring port 15 is further provided outside each cavity of the housing 1, and a temperature sensor is installed on the temperature monitoring port 15. The temperature monitoring port 15 is used to detect the instantaneous temperature of the material in each cavity.

[0067] An observation port 4 is further provided outside the housing 1, and the height of the observation port 4 is higher than the height of the feed port 7. The observation port 4 is used to observe the crystallization process of the liquid material.

[0068] As Figure 6 shown, n fixed scrapers 5 are welded side by side at any position inside the housing 1, and one edge of each fixed scraper 5 is transversely and closely adjacent to the outer surface of the rotary heat exchange body 3 in the same group. Each fixed scraper 5 is provided with a combination opening 27 having the same size and transverse quantity as the stirring paddle 29.

[0069] At least one group of stirring paddles 29 is uniformly arranged in a direction parallel to the axis of the rotary heat exchange body 3, Figure 6 FIG. is a structural diagram of three groups of stirring paddles 29 provided; at least one paddle blade 29-2 is included in each group of stirring paddles 29, and the stirring paddles 29 in a group are axially equidistantly distributed along the outer surface of the rotary heat exchange body 3.

[0070] Among them, the stirring paddle 29 specifically includes a paddle blade 29-2 and a support plate 29-1. The paddle blade 29-2 is connected to the outer surface of the rotary heat exchange body 3 through the support plate 29-1. The support plate 29-1 is perpendicular to the axis of the rotary heat exchange body 3, and the paddle blade 29-2 is vertically cross-arranged on the support plate 29-1. Correspondingly, the combination opening 27 includes a first opening 27-1 for the paddle blade 29-2 to pass through and a second opening 27-2 for the support plate 29-1 to pass through.

[0071] When the rotating heat transfer body 3 rotates, the stirring paddle 29 on the rotating heat transfer body 3 rotates synchronously with the rotating heat transfer body 3. The rotating stirring paddle 29 can just pass through the combined opening 27 on the fixed scraper 5, ensuring that the rotating heat transfer body 3 can achieve continuous rotation. At the same time, the fixed scraper 5 can scrape off a small amount of crystals attached to the surface of the rotating heat transfer body 3, ensuring that the heat exchange area is basically not attenuated.

[0072] On the one hand, the support plate 29-1 can stably support the paddle 29-2. On the other hand, since the support plate 29-1 is perpendicular to the axis of the rotating heat transfer body 3, the second opening 27-2 required for the fixed scraper 5 to pass through is a gap with a very small width, which basically does not affect the scraping of crystals on the outer surface of the rotating heat transfer body 3 by the lower edge of the fixed scraper 5, and minimizes the area that the fixed scraper 5 cannot scrape, thereby reducing the residue of crystals on the outer surface of the rotating heat transfer body 3.

[0073] Figure 7 、 8 , 9, 10 are several different structures of a group of stirring paddles 29, Figure 7 、 8 9 are structural diagrams showing two, three and six groups of stirring paddles 29 arranged on the outer surface of the rotary heat transfer body 3 in a direction perpendicular to the axis.

[0074] Furthermore, if Figure 9 As shown, the support plate 29-1 may be an annular ring structure sleeved on the outer surface of the rotating heat transfer body 3. This ensures that there is no crystal residue at the position on the outer surface of the rotating heat transfer body 3 corresponding to the second opening 27-2.

[0075] As an embodiment of the present invention, the support plate 29 - 1 and the paddle 29 - 2 are solid structures.

[0076] As another embodiment of the present invention, the support plate 29 - 1 is a hollow structure, and the space inside the support plate 29 - 1 is connected to the inner cavity of the heat transfer body 3 , and the blade 29 - 2 is a solid structure.

[0077] As another embodiment of the present invention, the support plate 29-1 and the paddle 29-2 on the rotating heat exchanger 3 are both hollow structures, and the inner cavity of the rotating heat exchanger 3, the internal space of the support plate 29-1, and the internal space of the paddle 29-2 are all connected.

[0078] The hollow structure of the support plate 29-1 and the blade 29-2 can further increase the heat exchange area, improve the crystallization efficiency, reduce the amount of cold source used, reduce production costs, and increase the production capacity of a single device.

[0079] A number of internal baffles 30 are provided on the inner wall of the heat exchanger 3 for heat exchange during rotation. When the heat exchanger 3 for heat exchange during rotation rotates in a certain direction, the internal baffles 30 can drive the cold source continuously added through the cold source inlet 24 and the inner cold source inlet pipe 22 inside to rotate with it, so that the cold source is evenly distributed in the heat exchanger 3 for heat exchange during rotation, while increasing the residence time of the cold source in the heat exchanger 3 for heat exchange during rotation, reducing energy consumption, and at the same time increasing the crystallization efficiency. It can also enable the cold source to be continuously and smoothly discharged through the transverse gap and the cold source outlet 23, realizing the continuity of the cold source inlet and outlet, and further controlling the temperature of the liquid material in the housing 1 to be in an equilibrium state, realizing the precise control of the temperature during crystallization and the technological requirements of the residence time required for crystal growth during crystallization.

[0080] Further, the internal baffle 30 is a cross-shaped vertical plate, and the cross-shaped vertical plate includes a vertical plate perpendicular to the inner wall of the heat exchanger 3 for heat exchange during rotation and a horizontal plate located in the middle of the vertical plate. The vertical plate and the horizontal plate are arranged along the entire length of the inner wall of the heat exchanger 3 for heat exchange during rotation.

[0081] In the present utility model, the inner cold source inlet pipe 22 is an important component for inputting the cold source into the interior of the heat exchanger 3 for heat exchange during rotation. The inner cold source inlet pipe 22 can be a fixed pipe and does not rotate together with the hollow rotating shaft 26; the inner cold source inlet pipe 22 can also be a movable pipe and rotates with the hollow rotating shaft 26.

[0082] As an embodiment of the present application, one end of the inner cold source inlet pipe 22 extending into the interior of the heat exchanger 3 for heat exchange during rotation cylinder 28 is open, and the distance from the open end to the other end inside the heat exchanger 3 for heat exchange during rotation cylinder 28 is relatively close.

[0083] As another embodiment of the present application, as Figure 10 shown, the part of the inner cold source inlet pipe 22 extending into the interior of the heat exchanger 3 for heat exchange during rotation cylinder 28 is a hollow pipe with uniformly distributed holes. The other end of the hollow pipe can be provided with holes or not, and the present utility model does not make any restrictions.

[0084] The continuous and efficient crystallization method of the present utility model is realized based on the aforementioned continuous and efficient crystallization device, and includes the following steps.

[0085] a. Continuously add liquid material into the first cavity 9 of the housing 1 through the feed port 7 at a certain flow rate, and at the same time start all the driving elements 19 to drive the heat exchanger 3 for heat exchange during rotation to rotate. At the same time, continuously add cold source into all the heat exchangers 3 for heat exchange during rotation through the inner cold source inlet pipe 22 at a certain flow rate, and control the cold source to be discharged through the gap between the hollow rotating shaft 26 and the inner cold source inlet pipe 22 at the same flow rate as the added cold source to establish a cold source cycle.

[0086] b. When the liquid material is added into the housing 1 and when the liquid level of the liquid material reaches above the upper surface of the heat exchanger 3 for heat exchange during rotation, close the feed port 7, and control the temperature of the material in the housing 1 to reach the temperature required by the crystallization process through the cold source.

[0087] When the crystallization temperature reaches the process requirements and the crystallization and crystal growth processes are completed, open the feed inlet 7 and the crystallization liquid outlet 16, control the flow rate of the liquid material feed to be the same as the flow rate of the discharged crystallization liquid, and control the flow rate and velocity of the liquid material to reach a stable crystallization temperature under the action of the cold source.

[0088] The time from when the liquid material starts to be added until the liquid level reaches above the upper surface of the heat exchange rotor 3 is the residence time of the liquid material in the housing 1. The residence time can be adjusted by the variable frequency speed regulating motor to adjust the rotation speed of the heat exchange rotor 3 and the flow velocity of the liquid material, so as to achieve the time requirements for controlling the crystallization and crystal growth of the liquid material.

[0089] c. After the crystallization temperature reaches the process requirements, open the feed inlet 7 and the crystallization liquid outlet 16, control the continuous addition of the liquid material, and at the same time, in the nth cavity 11, the crystallization liquid continuously overflows and discharges from the crystallization liquid outlet 16.

[0090] Control the crystallization temperature of the liquid material in the second cavity 10 to be 0 - 2 °C lower than that of the liquid material in the first cavity 9, control the crystallization temperature of the liquid material in the third cavity to be 0 - 2 °C lower than that of the liquid material in the second cavity 10, ……, control the crystallization temperature of the liquid material in the nth cavity 11 to be 0 - 2 °C lower than that of the liquid material in the (n - 1)th cavity, and the crystallization temperatures in each cavity meet the process control requirements. By controlling the gradual decrease of the temperature in the cavity, the cooling rate of the liquid material is further ensured to meet the process requirements.

[0091] When the added liquid material flows above the upper surface of the heat exchange rotor 3, after multi-stage crystallization in n cavities, control process parameters such as the crystallization temperature and crystal growth time in each cavity, complete the growth of the crystal grains, reach crystallization saturation, and the crystallization liquid continuously overflows and discharges from the crystallization liquid outlet 16. Control the flow velocity of the continuous addition of the liquid material and the flow velocity of the continuous discharge of the crystallization liquid, so as to realize the continuous crystallization process.

[0092] Among them, the setting of the fixed scraper 5 can scrape off the crystals that instantaneously crystallize on the surface of the heat exchange rotor cylinder 28 by the fixed scraper 5 in contact with the surface of the heat exchange rotor cylinder 28, ensuring efficient and balanced heat exchange of the heat exchange rotor 3 and improving the heat exchange efficiency.

[0093] When the crystallization process ends, discharge the remaining crystallization liquid from the discharge port 20 at the bottom of the housing 1. If there are crystallization substances that are not easily discharged, a heat source can be introduced into the bottom heat exchange interlayer 12 to melt the crystallization substances and then discharge them from the discharge port 20. If there are crystallization substances on the inner walls around the housing 1, a heat source can also be introduced into the jacket to melt the crystallization substances and then discharge them from the discharge port.

Claims

1. A continuous and efficient crystallization device, characterized in that, It includes a housing, with a feed inlet provided at one end of the housing, a crystallization liquid outlet provided at the other end of the housing, and n - 1 longitudinal baffle plates arranged inside the housing. The n - 1 baffle plates divide the inner cavity of the housing into n cavities, namely the first cavity, the second cavity, ……, the nth cavity, where n ≥ 1; a set of rotary heat exchangers and fixed scrapers are respectively arranged in each cavity. The rotary heat exchanger is driven by a driving element to rotate around its own axis. The fixed scraper is in contact with the outer wall surface of the rotary heat exchanger. At least one stirring paddle is arranged on the outer wall surface of the rotary heat exchanger. A combined opening for the stirring paddle to pass through is provided on the fixed scraper. A hollow rotating shaft extending out of the side wall of the housing is arranged at one end of the rotary heat exchanger. The hollow rotating shaft is connected to the housing through a rotary sealing device. An inner pipe for introducing a cold source with an outer diameter smaller than the inner diameter of the hollow rotating shaft is arranged inside the hollow rotating shaft. The inner pipe for introducing a cold source extends into the inner cavity of the rotary heat exchanger. The hollow rotating shaft, the inner pipe for introducing a cold source, and the rotary heat exchanger are coaxially arranged; the fixed scraper can be fixed at any position inside the housing as long as it ensures that the fixed scraper is in contact with the outer wall surface of the rotary heat exchanger in the same group as it, and the length of the fixed scraper is greater than or equal to the length of the cylinder body of the rotary heat exchanger.

2. The continuous high-efficiency crystallization device according to claim 1, wherein The baffle plate has a certain distance from both the top and the bottom inside the housing; or Starting from the feed inlet end of the housing, for the odd - numbered baffle plates, they have a certain distance from both the top and the bottom of the housing, and the distance from the baffle plate to the top of the housing is greater than the distance to the bottom of the housing. For the even - numbered baffle plates, there is no gap with the top of the housing and there is a certain distance from the bottom of the housing.

3. The continuous and efficient crystallization device according to claim 1 or 2, characterized in that, The baffle plate is a solid plate; or The baffle plate is of a hollow structure.

4. The continuous high-efficiency crystallization device according to claim 1, characterized in that, A number of inner baffle plates are arranged on the inner wall of the rotary heat exchanger; the inner baffle plates are cross - vertical plates, and the cross - vertical plates include vertical plates perpendicular to the inner wall of the rotary heat exchanger and horizontal plates located in the middle of the vertical plates.

5. The continuous high-efficiency crystallization device according to claim 1, characterized in that, The stirring paddle includes paddle blades and a support plate. The paddle blades are connected to the outer surface of the rotary heat exchanger through the support plate. The support plate is perpendicular to the axis of the rotary heat exchanger. The combined opening includes a first opening for the paddle blades to pass through and a second opening for the support plate to pass through.

6. The continuous high-efficiency crystallization device according to claim 1, wherein, A discharge port is provided at the bottom of the housing; and / or a heat exchange interlayer is provided at the bottom of the housing, and a heat exchange inlet and a heat exchange outlet are provided on the heat exchange interlayer; and / or a jacket is provided on the peripheral side walls of the housing, and a jacket cold source inlet and a jacket cold source outlet are provided on the jacket.

7. The continuous and efficient crystallization device according to claim 5, characterized in that The paddle blades and the support plate are of a solid structure; or the support plate is of a hollow structure, and the internal space of the support plate is communicated with the inner cavity of the rotary heat exchanger, and the paddle blades are of a solid structure; or both the support plate and the paddle blades are of a hollow structure, and the inner cavity of the rotary heat exchanger, the internal space of the support plate, and the internal space of the paddle blades are mutually communicated.

8. The continuous high-efficiency crystallization device according to claim 1, characterized in that A rotary joint is provided at the outer end of the hollow rotating shaft. A cold source outlet is provided on the rotary joint. The inner pipe for introducing a cold source passes through the rotary joint and is connected to a cold source inlet.

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