A continuous solvus crystallization device with V-shaped connecting pipe structure

Abstract

This invention relates to a continuous dissolution crystallization apparatus with a V-shaped connecting pipe structure. The technical solution specifically includes a V-shaped connecting pipe structure dissolution crystallizer assembly, an oscillating flow pump drive mechanism, a feeding mechanism, a discharging mechanism, a circulating cooling mechanism, and an intelligent control system. The V-shaped connecting pipe structure design creates periodic circulation within the chamber, significantly enhancing radial mixing intensity. This not only effectively solves the technical bottleneck of uneven crystal suspension at high solid-liquid ratios but also strengthens mass transfer during continuous crystallization. The absence of internal stirring paddles or moving mechanical parts effectively prevents the breakage and nucleation of suspended crystal particles. In the nucleation-dominant region, alternating heating and dissolution, along with increasing the solvent flow rate, enhances nucleation, dissolving scale on the pipe wall and fine crystals in the mother liquor. This regulates the number of crystal nuclei in the mother liquor, thereby achieving controllable production of the crystallized product with the desired particle size distribution and effectively solving the problem of scale buildup on the pipe wall.

Description

Technical Field

[0001] This invention belongs to the field of industrial crystallization technology, specifically relating to a continuous dissolution crystallization device with a V-shaped connecting pipe structure. Background Technology

[0002] Dissolution crystallization is a crucial process technology in fine chemical production, particularly widely used in pharmaceuticals and energetic materials. It can generally be carried out at room temperature, making it advantageous for crystallizing temperature-sensitive compounds. Traditional dissolution crystallization processes are typically semi-continuous, involving a single addition of the mother liquor while the solvent is continuously added, creating supersaturation that promotes solute nucleation and crystal growth.

[0003] Currently, there is no dedicated dissolution crystallizer. Existing dissolution crystallization processes generally use a jacketed stirred tank. First, the mother liquor is added to the tank, then several times the volume of the mother liquor of the solvent is continuously added. To ensure uniform solid-liquid mixing in the later stages of crystallization, multiple stirring layers can be installed. While the semi-continuous batch process offers greater operational flexibility, it also suffers from excessive nucleation due to localized supersaturation. Furthermore, with the surge in demand for some fine chemicals, scaling up existing semi-continuous batch dissolution crystallization processes often fails to balance the contradictions between production capacity, product quality, and process efficiency. Simultaneous multi-line operations, on the other hand, present problems such as large online material volumes (posing significant risks for recrystallization processes using organic solvents or energetic materials) and operational complexity, which have become constraints on capacity expansion. Therefore, developing a continuous dissolution crystallization device with an optimized structure based on the traditional semi-continuous batch dissolution crystallizer is of great significance. Summary of the Invention

[0004] The present invention aims to overcome the technical defects of existing semi-continuous dissolution crystallizers and provides a continuous dissolution crystallization device with a V-shaped connecting pipe structure, which can realize the continuous addition of crystallization mother liquor.

[0005] To achieve the above objectives, the technical solution adopted by the present invention specifically includes a crystallizer assembly with a V-shaped connecting pipe structure, an oscillating flow pump drive mechanism, a feeding mechanism, a discharging mechanism, a circulating cooling mechanism, and an intelligent control system.

[0006] The V-shaped connecting pipe structure of the crystallizer assembly consists of N-stage V-shaped connecting pipe structure crystallizers (1) connected in series via jacketed U-shaped elbows (2); the oscillating flow pump drive mechanism consists of an oscillating flow pump (3), a hose assembly (4), and an isolation assembly (5) connected in series; the feeding mechanism consists of a mother liquor feeding pump (9) and (N-2) solvent feeding pumps (10); the discharging mechanism consists of an S-shaped jacket assembly (6) and a jacketed stirring vessel (7) with stirring connected in series; the circulating cooling mechanism consists of four program-controlled external circulating water baths (8), the temperature and external circulation flow rate of each program-controlled external circulating water bath (8) can be individually controlled by the circulating cooling mechanism; the intelligent control system consists of an online particle size analyzer probe (11), an online Raman test probe (12), an online temperature measurement probe (13), and an expert system (14);

[0007] The V-shaped connecting tube is formed by connecting two straight round tubes, and the included angle of the V-shape of the axes of the two straight round tubes is θ; the crystallizer (1) with the V-shaped connecting tube structure consists of a coaxial shell and a tube side, the inlet and outlet of the shell are connected to the circulating cooling mechanism, and the tube side is composed of repeated units connected in series with coaxial cylindrical chambers and V-shaped connecting tubes alternately, wherein each repeated unit contains 2 V-shaped connecting tubes and 2 coaxial cylindrical chambers, one end of the first V-shaped connecting tube is connected to the bottom of the first cylindrical chamber, and the second V-shaped connecting tube is connected to the top of the first and second cylindrical chambers respectively; the next repeated unit rotates (360 degrees) along the tube side axis. / M) after which it is connected in series with the previous repeating unit, where M is a positive integer; the inner diameter of the tube side outlet of the V-shaped connecting tube structure of the crystallizer (1) is preferably equal to the inner diameter of the coaxial cylindrical cavity; the jacketed U-shaped elbow (2) is composed of a coaxial sleeve shell and tube side, the shell inlet and outlet are connected to the circulating cooling mechanism, and round hole baffles are uniformly arranged in the tube side, wherein the outer diameter of the round hole baffle is equal to the inner diameter of the tube side of the jacketed U-shaped elbow (2), and the inner diameter of the round hole baffle is equal to the inner diameter of the V-shaped connecting tube; a feeding pipe is set at the arc apex of the jacketed U-shaped elbow (2), and the feeding pipe passes horizontally through the shell side of the jacketed U-shaped elbow (2) and then directly through its tube side;

[0008] The isolation component (5) uses an elastic membrane to physically separate the working medium in the oscillating pump (3) from the crystallization mother liquor in the V-shaped connecting pipe structure of the crystallizer assembly, so as to avoid contact and corrosion between suspended particles and solvent in the crystallization mother liquor in the crystallizer assembly and the moving parts of the oscillating pump (3). The hose assembly (4) can realize the soft connection between the oscillating pump (3) and the isolation component (5), so as to avoid resonance between the oscillating pump (3) and the V-shaped connecting pipe structure of the crystallizer assembly. The tube side inlet of the V-shaped connecting pipe structure of the crystallizer assembly is connected to the isolation component (5), and the tube side outlet is connected to the S-shaped jacket assembly (6).

[0009] The S-type jacket assembly (6) consists of a coaxial sleeve-type shell and tube side. The shell inlet and outlet are connected to the circulating cooling mechanism. The tube side inlet of the S-type jacket assembly (6) is connected to the tube side outlet of the V-type connecting pipe structure of the dissolution crystallizer assembly. The tube side outlet straight pipe of the S-type jacket assembly (6) passes horizontally through the jacket of the jacketed stirred tank (7) with stirring and is inserted into the tank. The tube side inlet section of the S-type jacket assembly (6) is uniformly provided with round hole type baffles, and the outlet section is not provided with round hole type baffles. The jacket inlet and outlet of the jacketed stirred tank (7) with stirring are connected to the circulating cooling mechanism.

[0010] Following the direction from the tube-side inlet to the tube-side outlet of the V-shaped connecting tube structure precipitator assembly, the V-shaped connecting tube structure precipitators (1) are numbered sequentially from the 2nd to the (N-1)th V-shaped connecting tube structure precipitators (1). Each precipitator (1) has a solvent feed pipe evenly arranged along the tube-side direction. The solvent feed pipe passes vertically downward through the shell side of the precipitator (1) and then directly into the cylindrical cavity of its tube side. Each precipitator... The number of solvent feeding pipes in the crystallizer (1) is preferably 1 to 7, and most preferably 3 to 5. The solvent feeding pipes of each crystallizer (1) are connected in series and then connected to a solvent feeding pump (10). The shell side inlet and outlet of the first, second and third crystallizers (1) with V-shaped connecting pipe structure are respectively connected to three program-controlled external circulating water baths (8). The shell side inlet and outlet of the remaining crystallizers (1) are connected in series and then connected to a program-controlled external circulating water bath (8).

[0011] Following the direction from the tube-side inlet to the tube-side outlet of the V-shaped connecting tube structure of the leaching crystallizer assembly, the jacketed U-shaped elbows (2) are numbered sequentially. The feed pipe at the apex of the arc of the first jacketed U-shaped elbow (2) is connected to the mother liquor feed pump (9). The feed pipes at the apex of the arc of the second and third jacketed U-shaped elbows (2) are connected to two online particle size analyzer probes (11) respectively. The feed pipe at the apex of the arc of the fourth jacketed U-shaped elbow (2) is connected to an online Raman spectroscopy probe. Connect the test probe (12), and connect the feed pipes at the top of the arc of the 5th to (N-1)th jacketed U-shaped elbows (2) to the online temperature probe (13) respectively; input the Raman data, particle size data and temperature data collected online into the expert system (14), and the expert system (14) feeds back and adjusts the frequency of the oscillating flow pump (3), the flow rate of the mother liquor feed pump (9), the flow rate of the solvent feed pump (10), and the temperature and flow rate of the program-controlled external circulating water bath (8);

[0012] The series number N is a positive integer, preferably N is greater than or equal to 4; the second and third V-shaped connecting tube structure dissolution crystallizers (1) are the crystal nucleation advantage regions, and the fourth and subsequent V-shaped connecting tube structure dissolution crystallizers (1) are the crystal growth advantage regions. The shell side of the second and third V-shaped connecting tube structure dissolution crystallizers (1) in the crystal nucleation advantage regions suppresses the formation of scale on the inner wall of the tube side and regulates the number of crystal nuclei in the nucleation region through alternating heating and cooling operations.

[0013] The preferred values ​​for M are 2, 4, 6, 8, 10, and 12; the next preferred values ​​are 2 and 4; and the most preferred value is 4.

[0014] The included angle θ of the V-shaped connecting pipe preferably satisfies 90 degrees ≤ θ ≤ 180 degrees, and most preferably satisfies 120 degrees ≤ θ ≤ 180 degrees.

[0015] The number of round hole baffles provided in the pipe side of the jacketed U-shaped elbow (2) is preferably no less than 2, secondly preferably no less than 4, and most preferably no less than 6.

[0016] The inlet and outlet diameters of the V-shaped connecting pipe structure of the crystallizer (1), the jacketed U-shaped elbow (2), and the S-shaped jacket assembly (6) are equal.

[0017] The oscillating flow pump (3) can generate periodic oscillating flow, the oscillation frequency of which is preferably not less than 1 Hz and the oscillation frequency is adjustable.

[0018] The V-shaped connecting pipe structure of the crystallizer (1), the jacketed U-shaped elbow (2), the oscillating pump (3), the hose assembly (4), the isolation assembly (5), and the S-shaped jacket assembly (6) are equipped with flanges at their ports and are connected in series through the flanges.

[0019] By adopting the above technical solution, the present invention has the following advantages compared with the prior art:

[0020] (1) The continuous dissolution crystallization device with V-shaped connecting pipe structure involved in this invention can transform the traditional semi-continuous dissolution crystallization production in a batch process into a continuous dissolution crystallization process, which significantly improves production efficiency. The mother liquor for crystallization is added continuously, and the dissolving agent is also added continuously. The operating conditions of the entire material are consistent during the continuous dissolution crystallization process. Therefore, the performance of the crystallized product is stable and consistent, eliminating the persistent problem of "batch-to-batch differences" in batch crystallization processes.

[0021] (2) The continuous dissolution crystallization device with V-shaped connecting tube structure involved in the present invention adopts a non-axial connecting tube design. Through the V-shaped connecting tube structure, and the position of the connecting chambers before and after the connection is symmetrically distributed along the axial position, the fluid in the chamber can form a circulation in one oscillation cycle. Compared with the traditional batch crystallizer, it can significantly enhance the radial mixing intensity. It not only effectively solves the technical bottleneck of uneven crystal suspension when the solid-liquid ratio is high, but also enhances mass transfer, avoids excessive local supersaturation, and improves the quality of crystal products.

[0022] (3) The continuous dissolution crystallization device with V-shaped connecting tube structure involved in the present invention has no mechanical stirring paddle or moving mechanical parts inside, which can effectively avoid the collision and breakage between the crystal particles and the stirring paddle. Therefore, it is especially suitable for producing energetic crystals or crystal products with narrow particle size distribution requirements.

[0023] (4) The continuous dissolution crystallization device with V-shaped connecting pipe structure involved in the present invention can efficiently dissolve the scale on the pipe wall and the fine crystals in the mother liquor by alternating cooling crystallization and heating dissolution operations in the nucleation advantage region, thereby controlling the number of crystal nuclei in the crystallization mother liquor and thus achieving controllable production of the expected particle size distribution of the crystallized product. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of the structure of the present invention. Detailed Implementation

[0025] The present invention will be further described below with reference to specific embodiments, but this is not intended to limit the scope of protection thereof.

[0026] Example 1

[0027] A continuous dissolution crystallization device with a V-shaped connecting tube structure specifically includes a dissolution crystallizer assembly with a V-shaped connecting tube structure, an oscillating flow pump drive mechanism, a feeding mechanism, a discharging mechanism, a circulating cooling mechanism, and an intelligent control system;

[0028] The V-shaped connecting pipe structure of the crystallizer assembly consists of a 7-stage V-shaped connecting pipe structure crystallizer (1) connected in series via a jacketed U-shaped elbow (2); the oscillating flow pump drive mechanism consists of an oscillating flow pump (3), a hose assembly (4), and an isolation assembly (5) connected in series; the feeding mechanism consists of a mother liquor feeding pump (9) and 5 solvent feeding pumps (10); the discharging mechanism consists of an S-shaped jacket assembly (6) and a jacketed stirring vessel (7) with stirring connected in series; the circulating cooling mechanism consists of 4 program-controlled external circulating water baths (8), the temperature and external circulation flow rate of each program-controlled external circulating water bath (8) can be individually controlled by the circulating cooling mechanism; the intelligent control system consists of an online particle size analyzer probe (11), an online Raman test probe (12), an online temperature measuring probe (13), and an expert system (14);

[0029] The V-shaped connecting tube is formed by connecting two straight round tubes, and the V-shaped angle between the axes of the two straight round tubes is 120 degrees; the V-shaped connecting tube structure of the crystallizer (1) consists of a coaxial sleeve shell and a tube side, the shell inlet and outlet are connected to the circulating cooling mechanism, and the tube side is formed by repeated units connected in series with coaxial cylindrical chambers and V-shaped connecting tubes alternately, wherein each repeated unit contains 2 V-shaped connecting tubes and 2 coaxial cylindrical chambers, one end of the first V-shaped connecting tube is connected to the bottom of the first cylindrical chamber, and the second V-shaped connecting tube is connected to the top of the first and second cylindrical chambers respectively; the next repeated unit is along the tube side axis After the line rotates 90 degrees, it is connected in series with the previous repeating unit; the inner diameter of the tube side outlet of the V-shaped connecting tube structure of the crystallizer (1) is preferably equal to the inner diameter of the coaxial cylindrical cavity; the jacketed U-shaped elbow (2) is composed of a coaxial sleeve shell and tube side, the shell inlet and outlet are connected to the circulating cooling mechanism, and 6 round hole baffles are evenly arranged in the tube side, wherein the outer diameter of the round hole baffle is equal to the inner diameter of the tube side of the jacketed U-shaped elbow (2), and the inner diameter of the round hole baffle is equal to the inner diameter of the V-shaped connecting tube; a feeding pipe is set at the arc apex of the jacketed U-shaped elbow (2), and the feeding pipe passes horizontally through the shell side of the jacketed U-shaped elbow (2) and then directly through its tube side;

[0030] The isolation component (5) uses an elastic membrane to physically separate the working medium in the oscillating pump (3) from the crystallization mother liquor in the V-shaped connecting pipe structure of the crystallizer assembly, so as to avoid contact and corrosion between suspended particles and solvent in the crystallization mother liquor in the crystallizer assembly and the moving parts of the oscillating pump (3). The hose assembly (4) can realize the soft connection between the oscillating pump (3) and the isolation component (5), so as to avoid resonance between the oscillating pump (3) and the V-shaped connecting pipe structure of the crystallizer assembly. The tube side inlet of the V-shaped connecting pipe structure of the crystallizer assembly is connected to the isolation component (5), and the tube side outlet is connected to the S-shaped jacket assembly (6).

[0031] The S-type jacket assembly (6) consists of a coaxial sleeve-type shell and tube side. The shell inlet and outlet are connected to the circulating cooling mechanism. The tube side inlet of the S-type jacket assembly (6) is connected to the tube side outlet of the V-type connecting pipe structure of the dissolution crystallizer assembly. The tube side outlet straight pipe of the S-type jacket assembly (6) passes horizontally through the jacket of the jacketed stirred tank (7) with stirring and is inserted into the tank. The tube side inlet section of the S-type jacket assembly (6) is uniformly provided with round hole type baffles, and the outlet section is not provided with round hole type baffles. The jacket inlet and outlet of the jacketed stirred tank (7) with stirring are connected to the circulating cooling mechanism.

[0032] The V-shaped connecting tube structure of the precipitator crystallizer assembly is numbered sequentially from the tube side inlet to the tube side outlet. From the 2nd to the 6th V-shaped connecting tube structure precipitator crystallizer (1), each precipitator crystallizer (1) is uniformly provided with a solvent feed pipe along the tube side. The solvent feed pipe passes vertically downward through the shell side of the precipitator crystallizer (1) and then directly into the cylindrical cavity of its tube side. The number of solvent feed pipes in each precipitator crystallizer (1) is 3 to 5. The solvent feed pipes of each precipitator crystallizer (1) are connected in series and then connected to a solvent feed pump (10). The shell side inlet and outlet of the 1st, 2nd and 3rd V-shaped connecting tube structure precipitator crystallizer (1) are connected to 3 program-controlled external circulating water baths (8) respectively. The shell side inlet and outlet of the remaining precipitator crystallizer (1) are connected in series and then connected to a program-controlled external circulating water bath (8).

[0033] Following the direction from the tube-side inlet to the tube-side outlet of the V-shaped connecting tube structure of the leaching crystallizer assembly, the jacketed U-shaped elbows (2) are numbered sequentially. The feed pipe at the apex of the arc of the first jacketed U-shaped elbow (2) is connected to the mother liquor feed pump (9). The feed pipes at the apex of the arc of the second and third jacketed U-shaped elbows (2) are connected to two online particle size analyzer probes (11) respectively. The feed pipe at the apex of the arc of the fourth jacketed U-shaped elbow (2) is connected to an online Raman spectroscopy probe. Connect the test probe (12), and connect the feed pipes at the top of the arc of the 5th to (N-1)th jacketed U-shaped elbows (2) to the online temperature probe (13) respectively; input the Raman data, particle size data and temperature data collected online into the expert system (14), and the expert system (14) feeds back and adjusts the frequency of the oscillating flow pump (3), the flow rate of the mother liquor feed pump (9), the flow rate of the solvent feed pump (10), and the temperature and flow rate of the program-controlled external circulating water bath (8);

[0034] The second and third V-shaped connecting tube structures of the soluble crystallizer (1) are the nucleation advantage regions, while the fourth to seventh V-shaped connecting tube structures of the soluble crystallizer (1) are the crystal growth advantage regions. The shell side of the second and third V-shaped connecting tube structures of the soluble crystallizer (1) in the nucleation advantage regions suppresses the formation of scale on the inner wall of the tube side and regulates the number of crystal nuclei in the nucleation region through alternating heating and cooling operations.

[0035] The inlet and outlet diameters of the V-shaped connecting pipe structure of the crystallizer (1), the jacketed U-shaped elbow (2), and the S-shaped jacket assembly (6) are equal.

[0036] The oscillating flow pump (3) can generate periodic oscillating flow, with its oscillation frequency set to 3 Hz and adjustable.

[0037] The V-shaped connecting pipe structure of the crystallizer (1), the jacketed U-shaped elbow (2), the oscillating pump (3), the hose assembly (4), the isolation assembly (5), and the S-shaped jacket assembly (6) are equipped with flanges at their ports and are connected in series through the flanges.

[0038] The implementation process of the continuous dissolution and crystallization apparatus with the V-shaped connecting tube structure described in this invention for the continuous dissolution and crystallization of erythritol is described below, taking into account specific process operating conditions:

[0039] First, a saturated erythritol solution at room temperature is fed into a V-shaped connecting tube crystallizer assembly via a mother liquor feed pump (9). After the crystallizer assembly is filled with liquid and the venting operation is completed, the feed rate of the mother liquor feed pump (9) is set to 100 mL / min. The shell-side inlet temperature of the first V-shaped connecting tube crystallizer (1) is set to 5 °C higher than room temperature, and the shell-side inlet temperature of the second to seventh V-shaped connecting tube crystallizers (1) is room temperature. The jacket inlet temperature of the jacketed stirred tank (7) is also room temperature. The online particle size analyzer probe (11), online Raman test probe (12), online temperature probe (13), and expert system (14) belonging to the intelligent control system are turned on. Turn on the solvent feed pump (10), and control the flow rates of the first to fourth solvent feed pumps (10) to be 25~75 mL / min, 50~150 mL / min, 100~200 mL / min and 200~300 mL / min respectively. The number of crystals set in the expert system (14) is 5000~10000. If the measured value of the online particle size analyzer probe (11) is greater than 10000, the inlet temperature and flow rate of the shell side of the second V-shaped connecting tube structure of the solvent crystallizer (1) are increased, and the flow rate of the first solvent feed pump (10) is decreased. If the measured value of the online particle size analyzer probe (11) is less than 5000, the flow rate of the first solvent feed pump (10) is increased. The crystal slurry is continuously filtered, washed, and dried to obtain erythritol crystal products. The yield of erythritol by continuous dissolution and crystallization reaches 95-100% of the theoretical yield, of which 60-80 mesh crystal products account for more than 90% of the total crystal mass.

Claims

1. A continuous dissolution crystallization apparatus with a V-shaped connecting pipe structure, characterized in that, Specifically, it includes a V-shaped connecting pipe structure for the crystallizer assembly, an oscillating flow pump drive mechanism, a feeding mechanism, a discharging mechanism, a circulating cooling mechanism, and an intelligent control system; The V-shaped connecting pipe structure of the precipitator crystallizer assembly consists of N-stage V-shaped connecting pipe structure precipitators (1) connected in series via jacketed U-shaped elbows (2); the oscillating flow pump drive mechanism consists of an oscillating flow pump (3), a hose assembly (4), and an isolation assembly (5) connected in series; the feeding mechanism consists of a mother liquor feeding pump (9) and (N-2) solvent feeding pumps (10); the discharging mechanism consists of an S-shaped jacket assembly (6) and a jacketed stirring vessel (7) with stirring connected in series; the circulating cooling mechanism consists of four program-controlled external circulating water baths (8), the temperature and external circulation flow rate of each program-controlled external circulating water bath (8) are individually controlled by the circulating cooling mechanism; the intelligent control system consists of an online particle size analyzer probe (11), an online Raman test probe (12), an online temperature measuring probe (13), and an expert system (14); The V-shaped connecting tube is formed by connecting two straight round tubes, and the included angle of the V-shape of the axes of the two straight round tubes is θ; the crystallizer (1) with the V-shaped connecting tube structure consists of a coaxial shell and a tube side, the inlet and outlet of the shell are connected to the circulating cooling mechanism, and the tube side is formed by repeated units connected in series with coaxial cylindrical chambers and V-shaped connecting tubes alternately, wherein each repeated unit contains 2 V-shaped connecting tubes and 2 coaxial cylindrical chambers, one end of the first V-shaped connecting tube is connected to the bottom of the first cylindrical chamber, and the second V-shaped connecting tube is connected to the top of the first and second cylindrical chambers respectively; the next repeated unit rotates 360 degrees along the tube side axis. After degree / M, it is connected in series with the previous repeating unit, where M is a positive integer; the inner diameter of the tube side outlet of the V-shaped connecting tube structure of the crystallizer (1) is equal to the inner diameter of the coaxial cylindrical cavity; the jacketed U-shaped elbow (2) is composed of a coaxial sleeve shell and tube side, the shell inlet and outlet are connected to the circulating cooling mechanism, and the tube side is uniformly provided with round hole baffles, wherein the outer diameter of the round hole baffle is equal to the inner diameter of the tube side of the jacketed U-shaped elbow (2), and the inner diameter of the round hole baffle is equal to the inner diameter of the V-shaped connecting tube; a feeding pipe is provided at the arc apex of the jacketed U-shaped elbow (2), and the feeding pipe passes horizontally through the shell side of the jacketed U-shaped elbow (2) and then directly through its tube side; The isolation component (5) uses an elastic membrane to physically separate the working medium in the oscillating pump (3) from the crystallization mother liquor in the V-shaped connecting pipe structure of the crystallizer assembly, so as to avoid contact and corrosion between suspended particles and solvent in the crystallization mother liquor in the crystallizer assembly and the moving parts of the oscillating pump (3). The hose assembly (4) can realize the soft connection between the oscillating pump (3) and the isolation component (5), so as to avoid resonance between the oscillating pump (3) and the V-shaped connecting pipe structure of the crystallizer assembly. The tube side inlet of the V-shaped connecting pipe structure of the crystallizer assembly is connected to the isolation component (5), and the tube side outlet is connected to the S-shaped jacket assembly (6). The S-type jacket assembly (6) consists of a coaxial sleeve-type shell and tube side. The shell inlet and outlet are connected to the circulating cooling mechanism. The tube side inlet of the S-type jacket assembly (6) is connected to the tube side outlet of the V-type connecting pipe structure of the dissolution crystallizer assembly. The tube side outlet straight pipe of the S-type jacket assembly (6) passes horizontally through the jacket of the jacketed stirred tank (7) with stirring and is inserted into the tank. The tube side inlet section of the S-type jacket assembly (6) is uniformly provided with round hole type baffles, and the outlet section is not provided with round hole type baffles. The jacket inlet and outlet of the jacketed stirred tank (7) with stirring are connected to the circulating cooling mechanism. Based on the direction from the tube-side inlet to the tube-side outlet of the V-shaped connecting tube structure precipitator crystallizer assembly, the V-shaped connecting tube structure precipitators (1) are numbered sequentially from the 2nd to the (N-1)th V-shaped connecting tube structure precipitators (1). Each precipitator (1) has a solvent feed pipe evenly arranged along the tube-side direction. The solvent feed pipe passes vertically downward through the shell side of the precipitator (1) and then directly into the cylindrical cavity of its tube side. The number of solvent feed pipes in each solvent crystallizer (1) is 1 to 7; the solvent feed pipes of each solvent crystallizer (1) are connected in series and then connected to a solvent feed pump (10); the shell side inlet and outlet of the first, second and third V-shaped connecting pipe structure solvent crystallizers (1) are connected to three program-controlled external circulating water baths (8) respectively; the shell side inlet and outlet of the remaining solvent crystallizers (1) are connected in series and then connected to a program-controlled external circulating water bath (8); Following the direction from the tube-side inlet to the tube-side outlet of the V-shaped connecting tube structure of the leaching crystallizer assembly, the jacketed U-shaped elbows (2) are numbered sequentially. The feed pipe at the apex of the arc of the first jacketed U-shaped elbow (2) is connected to the mother liquor feed pump (9). The feed pipes at the apex of the arc of the second and third jacketed U-shaped elbows (2) are connected to two online particle size analyzer probes (11) respectively. The feed pipe at the apex of the arc of the fourth jacketed U-shaped elbow (2) is connected to an online Raman spectroscopy probe. Connect the test probe (12), and connect the feed pipes at the top of the arc of the 5th to (N-1)th jacketed U-shaped elbows (2) to the online temperature probe (13) respectively; input the Raman data, particle size data and temperature data collected online into the expert system (14), and the expert system (14) feeds back and adjusts the frequency of the oscillating flow pump (3), the flow rate of the mother liquor feed pump (9), the flow rate of the solvent feed pump (10), and the temperature and flow rate of the program-controlled external circulating water bath (8); The series number N is a positive integer, and N is greater than or equal to 4; the second and third V-shaped connecting tube structure soluble crystallizers (1) are the crystal nucleation advantage regions, and the fourth and subsequent V-shaped connecting tube structure soluble crystallizers (1) are the crystal growth advantage regions. The shell side of the second and third V-shaped connecting tube structure soluble crystallizers (1) in the crystal nucleation advantage regions suppresses the formation of scale on the inner wall of the tube side and regulates the number of crystal nuclei in the nucleation region through alternating heating and cooling operations.

2. The continuous dissolution crystallization apparatus with a V-shaped connecting tube structure according to claim 1, characterized in that, The value of M is 2, 4, 6, 8, 10, or 12.

3. The continuous dissolution crystallization apparatus with a V-shaped connecting tube structure according to claim 1, characterized in that, The included angle θ of the V-shaped connecting pipe satisfies 90 degrees ≤ θ ≤ 180 degrees.

4. The continuous dissolution crystallization apparatus with a V-shaped connecting tube structure according to claim 1, characterized in that, The number of round hole baffles installed in the pipe side of the jacketed U-shaped elbow (2) shall not be less than 2.

5. The continuous dissolution crystallization apparatus with a V-shaped connecting tube structure according to claim 1, characterized in that, The inlet and outlet diameters of the V-shaped connecting pipe structure of the crystallizer (1), the jacketed U-shaped elbow (2), and the S-shaped jacket assembly (6) are equal.

6. The continuous dissolution crystallization apparatus with a V-shaped connecting tube structure according to claim 1, characterized in that, The oscillating flow pump (3) can generate periodic oscillating flow with an oscillation frequency of not less than 1 Hz and its oscillation frequency is adjustable.

7. The continuous dissolution crystallization apparatus with a V-shaped connecting tube structure according to claim 1, characterized in that, The V-shaped connecting pipe structure of the crystallizer (1), the jacketed U-shaped elbow (2), the oscillating pump (3), the hose assembly (4), the isolation assembly (5), and the S-shaped jacket assembly (6) are equipped with flanges at their ports and are connected in series through the flanges.

Images