Continuous oscillatory flow crystallization device with V-shaped connecting pipe structure

Abstract

The invention relates to a continuous oscillatory flow crystallization device with a V-shaped connecting pipe structure. According to the technical scheme, the device specifically comprises a tubular crystallizer assembly of a V-shaped connecting pipe structure, an oscillatory flow pump driving mechanism, a feeding mechanism, a discharging mechanism, a circulating cooling mechanism and an intelligent control system. Through the structural design of the V-shaped connecting pipe, periodic circulation can be formed in the chamber, the radial mixing strength is remarkably enhanced, the impact force of fluid on the wall surface is increased, and a heat transfer boundary layer is thinned, so that the technical bottleneck of non-uniform crystal suspension at a high solid-to-liquid ratio is effectively solved, and heat transfer and mass transfer in the continuous crystallization process can be enhanced; no stirring paddle or moving mechanical part is arranged inside, so that suspended crystal particles are effectively prevented from being broken and nucleated; and in the nucleation dominant area, through alternate cooling crystallization and heating dissolution operation, crystal scales on the pipe wall and fine grains in the mother liquor can be dissolved, and the number of crystal nucleuses in the crystallization mother liquor can be regulated and controlled, so that controllable production of expected particle size distribution of a crystallization product is realized, and the problem of scaling on the pipe wall is effectively solved.

Description

Technical Field

[0001] The invention belongs to the technical field of industrial crystallization, and in particular relates to a continuous oscillating flow crystallization device with a V-shaped connecting pipe structure. Background Art

[0002] Crystallization is an important process technology in chemical production. It can be divided into separation, purification or crystallization according to the technical objectives. According to the principle of the process method, it is generally divided into cooling (or cooling) crystallization, dissolution crystallization, evaporation crystallization, melt crystallization and reaction crystallization. For chemical intermediates or products with low requirements for impurities, crystal form, particle size and other indicators, the technical goal of industrial crystallization is generally separation. This type of crystallization process generally does not need to pay too much attention to the control of the crystallization process. The process route can be designed according to the capacity requirements, whether it is continuous operation, etc. The process development is relatively easy and the selection of process equipment is relatively wide.

[0003] For products with requirements for purity, crystal form, particle size and other indicators, the technical goal of crystallization is generally purification or crystal transformation. This type of process requires strict control of temperature, concentration, and mass transfer rate during the crystallization process to ensure the expected supersaturation (the driving force for crystal nucleation and growth) and its distribution (mass transfer problem), so as to achieve the purpose of controlling the nucleation and growth process of the crystal, and then achieve controllable key indicators such as purity, crystal form, particle size and distribution. This type of process is the most core process technology for products in the fields of energetic materials, medicines, food additives, electronic chemicals, etc.

[0004] For the crystallization process with purification or crystal conversion as the technical goal, it generally requires multi-step process conditions in the process to achieve the set goal. Therefore, the industry often adopts the batch process with more flexible operation mode. However, with the surge in demand for some products, such as energetic materials related to national defense and APIs related to public health, the existing batch process is often difficult to balance the contradiction between preparation capacity, product quality and process efficiency by further scale-up. Multi-line parallel operation has problems such as large online material volume (significant risk for organic solvent system or recrystallization process of energetic materials) and complex operation, which has become a problem restricting the increase of production capacity.

[0005] The commonly used intermittent mixed suspension mixed discharge crystallizer (MSMPR) has a simple structure and is easy to operate in actual production, but the stirring paddle causes it to have high shear force, which can easily cause crystal breakage; intermittent crystallization production is also prone to uneven mixing, resulting in excessive local supersaturation and uneven particle size distribution; at the same time, in the field of energetic materials and drug production, the consistency of the material residence time at the same position in the device is difficult to control during intermittent production, so the performance and consistency of the discharged product are difficult to guarantee, which leads to the disadvantages of unstable performance and complex tracking of products of different batches. Traditional intermittent crystallizers are generally kettle crystallizers with a relatively small heat exchange area. When a large amount of heat is released by the internal reaction, the heat cannot be removed in time, which can easily cause the material temperature to rise and affect the product quality; the continuous oscillating flow crystallization device has multiple chambers in series, which can greatly increase the heat exchange area and improve the heat exchange efficiency. Therefore, for the crystallization process with purification or crystal conversion as the technical goal, it is urgent to develop process equipment suitable for plug flow, multi-condition series, good solid-liquid mass transfer effect, solids are not easy to settle, and easy to operate continuously.

[0006] Compared with the traditional tubular crystallizer, because the inside of the tubular crystallizer is just an ordinary pipeline structure with a single structure; it is difficult to ensure uniform solid-liquid mixing and high heat exchange efficiency during the flow of materials in the pipeline, and when the tubular crystallizer is used in the continuous cooling crystallization process, the crystals are easily deposited and precipitated on the tube wall, which may even block the tubular crystallizer. When crystal scale forms on the tube wall of the tubular crystallizer, the heat transfer efficiency of the entire crystallization process will be significantly reduced, which will increase the energy consumption of the crystallization process, reduce the efficiency of the crystallization equipment, and extend the crystallization production operation cycle. Therefore, it is of great significance to develop a cooling continuous oscillating flow crystallization device with an optimized structure based on the traditional tubular crystallizer. Summary of the invention

[0007] The present invention aims to overcome the technical defects of scaling of the tube wall and uneven crystal suspension in the existing continuous tube cooling crystallization process, and aims to provide a continuous oscillating flow crystallization device with a V-shaped connecting tube structure.

[0008] To achieve the above-mentioned purpose, the technical solution adopted by the present invention specifically includes a tubular crystallizer assembly with a V-shaped connecting pipe structure, an oscillating flow pump driving mechanism, a feeding mechanism, a discharging mechanism, a circulating cooling mechanism and an intelligent control system; The tubular crystallizer assembly of the V-shaped connecting pipe structure is composed of N-stage tubular crystallizers (1) of the V-shaped connecting pipe structure connected in series via a jacket U-shaped elbow (2); the V-shaped connecting pipe is formed by connecting two round straight pipes, and the V-shaped angle between the axes of the two round straight pipes is θ; the tubular crystallizer (1) of the V-shaped connecting pipe structure is composed of a coaxial sleeve-type shell and a tube pass, the shell inlet and outlet are connected to a circulating cooling mechanism, and the tube pass is composed of repeated units of coaxial cylindrical chambers and V-shaped connecting pipes alternately connected in series, wherein each repeating unit contains two V-shaped connecting pipes and two coaxial cylindrical chambers, one end of the first V-shaped connecting pipe is connected to the bottom of the first cylindrical chamber, and the second V-shaped connecting pipe is connected to the first and second cylindrical chambers respectively. The top of the chamber is connected; the next repeating unit rotates (360 degrees / M) along the axis of the tube side and is then connected in series with the previous repeating unit, wherein M is a positive integer; the inner diameter of the tube side outlet of the tubular crystallizer (1) of the V-shaped connecting pipe structure is preferably equal to the inner diameter of the coaxial cylindrical chamber; the jacket U-shaped elbow (2) is composed of a coaxial sleeve-type shell and a tube side, the shell inlet and outlet are connected to a circulating cooling mechanism, and circular hole baffles are evenly arranged in the tube side, wherein the outer diameter of the circular hole baffles is equal to the inner diameter of the tube side of the jacket U-shaped elbow (2), and the inner diameter of the circular hole baffles is equal to the inner diameter of the V-shaped connecting pipe; a feeding pipe is arranged at the arc top position of the jacket U-shaped elbow (2), and the feeding pipe passes horizontally through the shell side of the jacket U-shaped elbow (2) and then directly passes through its tube side; The oscillating flow pump driving mechanism is composed of an oscillating flow pump (3), a hose assembly (4) and an isolation assembly (5) connected in series, wherein the isolation assembly (5) is composed of an elastic membrane that physically separates the working medium in the oscillating flow pump (3) from the crystallization mother liquid in the tubular crystallizer assembly with a V-shaped connecting pipe structure, thereby preventing the suspended particles and solvent in the crystallization mother liquid in the crystallizer assembly from contacting and corroding the moving parts of the oscillating flow pump (3). The hose assembly (4) can realize a soft connection between the oscillating flow pump (3) and the isolation assembly (5), thereby preventing resonance between the oscillating flow pump (3) and the tubular crystallizer assembly with a V-shaped connecting pipe structure; the isolation assembly (5) is connected to the pipe inlet of the tubular crystallizer assembly with a V-shaped connecting pipe structure; The feeding mechanism is composed of a feeding pump (13), a feeding buffer tank and connecting pipes therebetween; The discharging mechanism is composed of an S-type jacket component (6) and a jacketed stirring kettle (7) connected in series, wherein the S-type jacket component (6) is composed of a coaxial sleeve-type shell layer and a tube side, the shell layer inlet and outlet are connected to a circulating cooling mechanism, the tube side inlet of the S-type jacket component (6) is connected to the tube side outlet of a tubular crystallizer component with a V-shaped connecting pipe structure, and the tube side outlet straight pipe of the S-type jacket component (6) horizontally passes through the jacket of the jacketed stirring kettle (7) and is then inserted into the kettle; the tube side inlet section of the S-type jacket component (6) is evenly provided with circular hole baffles, and the outlet section is not provided with circular hole baffles; the jacket inlet and outlet of the jacketed stirring kettle (7) are connected to the circulating cooling mechanism; The circulating cooling mechanism is composed of (N+1) programmable temperature-controlled external circulating water baths (8), which are respectively connected to the shell inlet and outlet of the tubular crystallizer (1) with N V-shaped connecting pipe structures and the jacketed stirring kettle (7) with stirring, and the temperature and external circulation flow rate of each programmable temperature-controlled external circulating water bath (8) can be individually regulated by the circulating cooling mechanism; The intelligent control system is composed of an online particle size tester probe (9), an online Raman test probe (10), an online temperature measurement probe (11) and an expert system (12). The jacket U-shaped elbows (2) are numbered in sequence from the inlet to the outlet of the tubular crystallizer assembly of the V-shaped connecting pipe structure. The arc top position feeding pipe of the second jacket U-shaped elbow (2) is connected to the feeding pump (13), and the arc top position feeding pipes of the remaining jacket U-shaped elbows (2) with even numbers are alternately connected to the online particle size tester probe (9) and the online Raman test probe (10); the arc top position feeding pipes of the jacket U-shaped elbows (2) with odd numbers are connected to the online temperature measurement probe (11); the online collected Raman data, particle size data and temperature data are input into the expert system (12), and the expert system (12) feedback controls the frequency of the oscillating flow pump (3), the flow rate of the feeding pump (13), and the temperature and flow rate of the program-controlled external circulating water bath (8) of the circulating cooling mechanism; The number of series stages N is a positive integer, preferably N is greater than or equal to 4. According to the connection sequence of the oscillating flow pump (3) to the jacketed stirred kettle (7) with stirring, the second and third tubular crystallizers (1) with V-shaped connecting pipe structures are the crystal nucleation advantage areas, and the fourth and subsequent tubular crystallizers (1) with V-shaped connecting pipe structures are the crystal growth advantage areas. The shell side of the second and third tubular crystallizers (1) with V-shaped connecting pipe structures in the crystal nucleation advantage area suppresses the formation of crystal scale on the inner wall of the tube side and regulates the number of crystal nuclei in the nucleation area through alternating heating and cooling operations.

[0009] The M is preferably 2, 4, 6, 8, 10, 12; the second most preferred is 2, 4; the most preferred is 4.

[0010] 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.

[0011] The number of circular hole baffles arranged in the pipe passage of the jacket U-shaped elbow (2) is preferably not less than 2, less preferably not less than 4, and most preferably not less than 6.

[0012] The inlet and outlet diameters of the tubular crystallizer (1) with the V-shaped connecting pipe structure, the jacket U-shaped elbow (2) and the S-shaped jacket assembly (6) are equal.

[0013] 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.

[0014] The tubular crystallizer (1) of the V-shaped connecting pipe structure, the jacket U-shaped elbow (2), the oscillating flow pump (3), the hose assembly (4), the isolation assembly (5) and the S-shaped jacket assembly (6) are provided with flanges at their pipe ends and are connected in series via the flanges.

[0015] Due to the adoption of the above technical solution, the present invention has the following positive effects compared with the prior art: (1) The continuous oscillating flow crystallization device with a V-shaped connecting pipe structure of the present invention can convert the traditional intermittent cooling crystallization production into a continuous crystallization process, thereby significantly improving the production efficiency. Since the operating conditions of the materials are consistent during the continuous crystallization process, the performance of the crystallized product is stable and consistent, eliminating the stubborn problem of "batch-to-batch differences" in the intermittent crystallization process.

[0016] (2) The continuous oscillating flow crystallization device with a V-shaped connecting pipe structure involved in the present invention adopts a connecting pipe design in a non-axial position. Through the V-shaped connecting pipe structure, and the positions of the connecting front and rear chambers are symmetrically distributed along the axial position, the fluid in the chamber can form a circulation in one oscillation cycle. Compared with the traditional tubular crystallizer, it can significantly enhance the radial mixing intensity, increase the impact force of the fluid on the wall, thin the heat transfer boundary layer and enhance heat transfer. It not only effectively solves the technical bottleneck of uneven crystal suspension at a high solid-liquid ratio, but also can enhance heat transfer and mass transfer, avoid excessive local supersaturation, and improve the quality of crystal products.

[0017] (3) The continuous oscillating flow crystallization device with a V-shaped connecting pipe 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 particle product and the stirring paddle. Therefore, it is particularly suitable for the production of energetic crystals or crystal products with narrow particle size distribution requirements.

[0018] (4) The continuous oscillating flow crystallization device with a V-shaped connecting pipe structure involved in the present invention can efficiently dissolve the crystal scale on the tube wall and the fine crystals in the mother liquor by alternating cooling crystallization and heating dissolution operations in the nucleation advantage area, and regulate the number of crystal nuclei in the crystallization mother liquor, thereby achieving controllable production of the expected particle size distribution of the crystallized product, and effectively solving the scaling problem of the tube wall of the tubular cooling crystallizer. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 It is a structural schematic diagram of the present invention.

[0020] Figure 2 This is a schematic diagram of the repeating unit structure described in Example 1 of the present invention. DETAILED DESCRIPTION

[0021] The present invention is further described below in conjunction with specific implementation modes, but is not intended to limit the protection scope thereof. Example

[0022] A continuous oscillating flow crystallization device with a V-shaped connecting pipe structure, specifically comprising a tubular crystallizer assembly with a V-shaped connecting pipe structure, an oscillating flow pump driving mechanism, a feeding mechanism, a discharging mechanism, a circulating cooling mechanism and an intelligent control system; The tubular crystallizer assembly of the V-shaped connecting pipe structure is composed of a tubular crystallizer (1) of 7-stage V-shaped connecting pipe structure connected in series through a jacket U-shaped elbow (2); the V-shaped connecting pipe is formed by connecting two round straight pipes, and the V-shaped angle between the axes of the two round straight pipes is 120 degrees; the tubular crystallizer (1) of the V-shaped connecting pipe structure is composed of a coaxial sleeve-type shell and a tube pass, the shell inlet and outlet are connected to a circulating cooling mechanism, and the tube pass is composed of repeated units connected in series by coaxial cylindrical chambers and V-shaped connecting pipes alternately connected, wherein each repeating unit contains 2 V-shaped connecting pipes and 2 coaxial cylindrical chambers, one end of the first V-shaped connecting pipe is connected to the bottom of the first cylindrical chamber, and the second V-shaped connecting pipe is connected to the first and second cylindrical chambers respectively. The top of the second cylindrical chamber is connected; the next repeating unit is rotated 90 degrees along the axis of the tube side and then connected in series with the previous repeating unit; the inner diameter of the tube side outlet of the tubular crystallizer (1) of the V-shaped connecting pipe structure is preferably equal to the inner diameter of the coaxial cylindrical chamber; the jacket U-shaped elbow (2) is composed of a coaxial sleeve-type shell and tube side, the shell inlet and outlet are connected to the circulating cooling mechanism, and 6 circular hole baffles are evenly arranged in the tube side, wherein the outer diameter of the circular hole baffle is equal to the inner diameter of the tube side of the jacket U-shaped elbow (2), and the inner diameter of the circular hole baffle is equal to the inner diameter of the V-shaped connecting pipe; a feeding pipe is arranged at the arc top position of the jacket U-shaped elbow (2), and the feeding pipe passes horizontally through the shell side of the jacket U-shaped elbow (2) and then directly passes through its tube side; The oscillating flow pump driving mechanism is composed of an oscillating flow pump (3), a hose assembly (4) and an isolation assembly (5) connected in series, wherein the isolation assembly (5) is composed of an elastic membrane that physically separates the working medium in the oscillating flow pump (3) from the crystallization mother liquid in the tubular crystallizer assembly with a V-shaped connecting pipe structure, thereby preventing the suspended particles and solvent in the crystallization mother liquid in the crystallizer assembly from contacting and corroding the moving parts of the oscillating flow pump (3). The hose assembly (4) can realize a soft connection between the oscillating flow pump (3) and the isolation assembly (5), thereby preventing resonance between the oscillating flow pump (3) and the tubular crystallizer assembly with a V-shaped connecting pipe structure; the isolation assembly (5) is connected to the pipe inlet of the tubular crystallizer assembly with a V-shaped connecting pipe structure; The feeding mechanism is composed of a feeding pump (13), a feeding buffer tank and connecting pipes therebetween; The discharging mechanism is composed of an S-type jacket component (6) and a jacketed stirring kettle (7) connected in series, wherein the S-type jacket component (6) is composed of a coaxial sleeve-type shell layer and a tube side, the shell layer inlet and outlet are connected to a circulating cooling mechanism, the tube side inlet of the S-type jacket component (6) is connected to the tube side outlet of a tubular crystallizer component with a V-shaped connecting pipe structure, and the tube side outlet straight pipe of the S-type jacket component (6) horizontally passes through the jacket of the jacketed stirring kettle (7) and is then inserted into the kettle; the tube side inlet section of the S-type jacket component (6) is evenly provided with circular hole baffles, and the outlet section is not provided with circular hole baffles; the jacket inlet and outlet of the jacketed stirring kettle (7) are connected to the circulating cooling mechanism; The circulating cooling mechanism is composed of 8 programmable temperature-controlled external circulating water baths (8), which are respectively connected to the shell inlet and outlet of the tubular crystallizer (1) with 7 V-shaped connecting pipe structures and the jacketed stirring kettle (7) with stirring, and the temperature and external circulation flow rate of each programmable temperature-controlled external circulating water bath (8) can be individually regulated by the circulating cooling mechanism; The intelligent control system is composed of an online particle size tester probe (9), an online Raman test probe (10), an online temperature measurement probe (11) and an expert system (12). The jacket U-shaped elbows (2) are numbered in sequence from the inlet to the outlet of the tubular crystallizer assembly of the V-shaped connecting pipe structure. The feeding pipe at the arc top position of the second jacket U-shaped elbow (2) is connected to the feeding pump (13), and the feeding pipes at the arc top positions of the fourth and sixth jacket U-shaped elbows (2) are alternately connected to the online particle size tester probe (9) and the online Raman test probe (10); the feeding pipes at the arc top positions of the first, third and fifth jacket U-shaped elbows (2) are connected to the online temperature measurement probe (11); the Raman data, particle size data and temperature data collected online are input into the expert system (12), and the expert system (12) feedback controls the frequency of the oscillating flow pump (3), the flow rate of the feeding pump (13), and the temperature and flow rate of the program-controlled external circulating water bath (8) belonging to the circulating cooling mechanism; According to the connection sequence of the oscillating flow pump (3) to the jacketed stirred kettle (7) with stirring, the tubular crystallizers (1) with the second and third V-shaped connecting pipe structures are the crystal nucleation advantage areas, and the tubular crystallizers (1) with the fourth, fifth, sixth and seventh V-shaped connecting pipe structures are the crystal growth advantage areas. The shell side of the tubular crystallizers (1) with the second and third V-shaped connecting pipe structures in the crystal nucleation advantage areas suppresses the formation of crystal scale on the inner wall of the tube side and regulates the number of crystal nuclei in the nucleation area through alternating heating and cooling operations.

[0023] The inlet and outlet diameters of the tubular crystallizer (1) with the V-shaped connecting pipe structure, the jacket U-shaped elbow (2) and the S-shaped jacket assembly (6) are equal.

[0024] The oscillating flow pump (3) can generate periodic oscillating flow, and its oscillation frequency is set to 3 Hz, and its oscillation frequency is adjustable.

[0025] The tubular crystallizer (1) of the V-shaped connecting pipe structure, the jacket U-shaped elbow (2), the oscillating flow pump (3), the hose assembly (4), the isolation assembly (5) and the S-shaped jacket assembly (6) are provided with flanges at their pipe ends and are connected in series via the flanges.

[0026] The implementation process of the continuous oscillating flow crystallization device with a V-shaped connecting pipe structure of the present invention for continuous oscillating flow cooling crystallization of adipic acid aqueous solution is described as follows in combination with specific process operating conditions: First, the outlet water temperature of the circulating cooling mechanism is set to 60°C, and a 50°C saturated aqueous solution of adipic acid is fed into the tubular crystallizer assembly of the V-shaped connecting pipe structure through the feed pump (13). After the crystallizer assembly is filled with liquid and the exhaust operation is completed, the feed rate of the feed pump (13) is set to 100 mL / min, the shell side inlet temperature of the first tubular crystallizer (1) of the V-shaped connecting pipe structure is 60°C, the shell side inlet temperature of the second tubular crystallizer (1) of the V-shaped connecting pipe structure is 45-50°C, and the shell side inlet temperatures of the third to seventh tubular crystallizers (1) of the V-shaped connecting pipe structure are successively 0-5°C lower than the previous one, and the jacket inlet temperature of the jacket stirred tank (7) is consistent with the shell side inlet temperature of the seventh tubular crystallizer (1) of the V-shaped connecting pipe structure. The online particle size tester probe (9), online Raman test probe (10), online temperature measurement probe (11) and expert system (12) belonging to the intelligent control system are turned on. The number of crystals set by the expert system (12) is 5000-10000. If the measured value of the online particle size tester probe (9) is greater than 10000, the shell inlet temperature and flow rate of the tubular crystallizer (1) with the second V-shaped connecting pipe structure are increased, and the shell inlet temperature and flow rate of the tubular crystallizer (1) with the second V-shaped connecting pipe structure are decreased; if the measured value of the online particle size tester probe (9) is less than 5000, the shell inlet temperature and flow rate of the tubular crystallizer (1) with the second V-shaped connecting pipe structure are decreased, and the shell inlet temperature and flow rate of the tubular crystallizer (1) with the second V-shaped connecting pipe structure are increased. The crystal slurry is continuously filtered, washed, and dried to obtain adipic acid crystal products. The yield of adipic acid continuous crystallization reaches 95-100% of the theoretical yield, wherein the crystal products with 60-80 meshes account for more than 90% of the total crystal mass.

Claims

1. A continuous oscillating flow crystallization device with a V-shaped connecting pipe structure, characterized in that: Specifically, it includes a tubular crystallizer assembly with a V-shaped connecting pipe structure, an oscillating flow pump driving mechanism, a feeding mechanism, a discharging mechanism, a circulating cooling mechanism and an intelligent control system; The tubular crystallizer assembly of the V-shaped connecting pipe structure is composed of N-stage tubular crystallizers (1) of the V-shaped connecting pipe structure connected in series via a jacket U-shaped elbow (2); the V-shaped connecting pipe is formed by connecting two round straight pipes, and the V-shaped angle between the axes of the two round straight pipes is θ; the tubular crystallizer (1) of the V-shaped connecting pipe structure is composed of a coaxial sleeve-type shell and a tube pass, the shell inlet and outlet are connected to a circulating cooling mechanism, and the tube pass is composed of repeated units of coaxial cylindrical chambers and V-shaped connecting pipes alternately connected in series, wherein each repeating unit contains two V-shaped connecting pipes and two coaxial cylindrical chambers, one end of the first V-shaped connecting pipe is connected to the bottom of the first cylindrical chamber, and the second V-shaped connecting pipe is connected to the first and second cylindrical chambers respectively. The top of the chamber is connected; the next repeating unit rotates (360 degrees / M) along the axis of the tube side and is then connected in series with the previous repeating unit, wherein M is a positive integer; the inner diameter of the tube side outlet of the tubular crystallizer (1) of the V-shaped connecting pipe structure is preferably equal to the inner diameter of the coaxial cylindrical chamber; the jacket U-shaped elbow (2) is composed of a coaxial sleeve-type shell and a tube side, the shell inlet and outlet are connected to a circulating cooling mechanism, and circular hole baffles are evenly arranged in the tube side, wherein the outer diameter of the circular hole baffles is equal to the inner diameter of the tube side of the jacket U-shaped elbow (2), and the inner diameter of the circular hole baffles is equal to the inner diameter of the V-shaped connecting pipe; a feeding pipe is arranged at the arc top position of the jacket U-shaped elbow (2), and the feeding pipe passes horizontally through the shell side of the jacket U-shaped elbow (2) and then directly passes through its tube side; The oscillating flow pump driving mechanism is composed of an oscillating flow pump (3), a hose assembly (4) and an isolation assembly (5) connected in series, wherein the isolation assembly (5) is composed of an elastic membrane that physically separates the working medium in the oscillating flow pump (3) from the crystallization mother liquid in the tubular crystallizer assembly with a V-shaped connecting pipe structure, thereby preventing the suspended particles and solvent in the crystallization mother liquid in the crystallizer assembly from contacting and corroding the moving parts of the oscillating flow pump (3). The hose assembly (4) can realize a soft connection between the oscillating flow pump (3) and the isolation assembly (5), thereby preventing resonance between the oscillating flow pump (3) and the tubular crystallizer assembly with a V-shaped connecting pipe structure; the isolation assembly (5) is connected to the pipe inlet of the tubular crystallizer assembly with a V-shaped connecting pipe structure; The feeding mechanism is composed of a feeding pump (13), a feeding buffer tank and connecting pipes therebetween; The discharging mechanism is composed of an S-type jacket component (6) and a jacketed stirring kettle (7) connected in series, wherein the S-type jacket component (6) is composed of a coaxial sleeve-type shell layer and a tube side, the shell layer inlet and outlet are connected to a circulating cooling mechanism, the tube side inlet of the S-type jacket component (6) is connected to the tube side outlet of a tubular crystallizer component with a V-shaped connecting pipe structure, and the tube side outlet straight pipe of the S-type jacket component (6) horizontally passes through the jacket of the jacketed stirring kettle (7) and is then inserted into the kettle; the tube side inlet section of the S-type jacket component (6) is evenly provided with circular hole baffles, and the outlet section is not provided with circular hole baffles; the jacket inlet and outlet of the jacketed stirring kettle (7) are connected to the circulating cooling mechanism; The circulating cooling mechanism is composed of (N+1) programmable temperature-controlled external circulating water baths (8), which are respectively connected to the shell inlet and outlet of the tubular crystallizer (1) with N V-shaped connecting pipe structures and the jacketed stirring kettle (7) with stirring, and the temperature and external circulation flow rate of each programmable temperature-controlled external circulating water bath (8) can be individually regulated by the circulating cooling mechanism; The intelligent control system is composed of an online particle size tester probe (9), an online Raman test probe (10), an online temperature measurement probe (11) and an expert system (12). The jacket U-shaped elbows (2) are numbered in sequence from the inlet to the outlet of the tubular crystallizer assembly of the V-shaped connecting pipe structure. The arc top position feeding pipe of the second jacket U-shaped elbow (2) is connected to the feeding pump (13), and the arc top position feeding pipes of the remaining jacket U-shaped elbows (2) with even numbers are alternately connected to the online particle size tester probe (9) and the online Raman test probe (10); the arc top position feeding pipes of the jacket U-shaped elbows (2) with odd numbers are connected to the online temperature measurement probe (11); the online collected Raman data, particle size data and temperature data are input into the expert system (12), and the expert system (12) feedback controls the frequency of the oscillating flow pump (3), the flow rate of the feeding pump (13), and the temperature and flow rate of the program-controlled external circulating water bath (8) of the circulating cooling mechanism; The number of series stages N is a positive integer, preferably N is greater than or equal to 4. According to the connection sequence of the oscillating flow pump (3) to the jacketed stirred kettle (7) with stirring, the second and third tubular crystallizers (1) with V-shaped connecting pipe structures are the crystal nucleation advantage areas, and the fourth and subsequent tubular crystallizers (1) with V-shaped connecting pipe structures are the crystal growth advantage areas. The shell side of the second and third tubular crystallizers (1) with V-shaped connecting pipe structures in the crystal nucleation advantage area suppresses the formation of crystal scale on the inner wall of the tube side and regulates the number of crystal nuclei in the nucleation area through alternating heating and cooling operations.

2. The continuous oscillating flow crystallization device with a V-shaped connecting pipe structure according to claim 1, characterized in that: The M is preferably 2, 4, 6, 8, 10, 12; the second most preferred is 2, 4; the most preferred is 4.

3. The continuous oscillating flow crystallization device with a V-shaped connecting pipe structure according to claim 1, characterized in that: 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.

4. The continuous oscillating flow crystallization device with a V-shaped connecting pipe structure according to claim 1, characterized in that: The number of circular hole baffles arranged in the pipe passage of the jacket U-shaped elbow (2) is preferably not less than 2, less preferably not less than 4, and most preferably not less than 6.

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

6. The continuous oscillating flow crystallization device with a V-shaped connecting pipe structure according to claim 1, characterized in that: 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.

7. The continuous oscillating flow crystallization device with a V-shaped connecting pipe structure according to claim 1, characterized in that: The tubular crystallizer (1) of the V-shaped connecting pipe structure, the jacket U-shaped elbow (2), the oscillating flow pump (3), the hose assembly (4), the isolation assembly (5) and the S-shaped jacket assembly (6) are provided with flanges at their pipe ends and are connected in series via the flanges.

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