A vertical internal-meshing stirring device, a preparation method of a high-viscosity fluid solution and applications

Abstract

The present application relates to a kind of vertical internal engagement stirring device, the preparation method and application of high viscosity solution, mainly solve the problems such as low mixing kneading efficiency, poor self-cleaning effect, narrow raw material application range in prior art.The present application is by a kind of vertical internal engagement stirring device, it mainly includes wall surface paddle, internal engagement paddle and center paddle, by the intensive stirring kneading effect between paddle, promote the heat transfer and mass transfer of material and surface renewal rate, realize the rapid and uniform mixing of raw material.The stirring device improves the mixing efficiency and self-cleaning rate in the mixing process of high viscosity polymer solution and solvent, is beneficial to the uniform discharge of mixed solution, provides high quality, stable and reliable polymer solution for downstream process.The vertical internal engagement stirring device and the technical scheme for preparing high viscosity solution provided by the present application better solve the technical problems in prior art, and can be used for the preparation of various material solutions.

Description

Technical Field

[0001] This invention belongs to the field of stirring device technology, specifically relating to a vertical internal meshing stirring device, a method for preparing high-viscosity fluid solutions and their applications. This vertical internal meshing stirring device is mainly used for material mixing, dissolution and polymerization reaction processes of polymer materials. Background Technology

[0002] With the rapid development and widespread application of polymer materials, they have become indispensable materials in various industries such as automotive, electronics, construction, medical and health, textiles, and rail transportation. However, polymer materials are characterized by high viscosity, tendency to become viscous, or coking, and possess complex rheological and phase change properties. This undoubtedly increases the difficulty of mixing, heat transfer, and mass transfer between systems. Furthermore, as viscosity increases further, materials easily adhere to the inner wall, impeller blades, and stirring shaft, causing problems such as difficult material flow, reduced mixing effect, and excessively high local temperatures, seriously affecting product quality and normal operation. To solve these problems, some high-viscosity fluid stirring devices with self-cleaning functions, as well as all-phase stirring devices capable of handling both viscous liquids and powders, have been proposed.

[0003] Commonly used self-cleaning equipment for high-viscosity fluids includes planetary mixers, twin-screw extruders, and horizontal self-cleaning mixers. Planetary mixers utilize rotating and self-rotating impellers to create complex movements within the reactor, subjecting the material to shearing, compression, and friction. They also feature wall and bottom scraping functions, eliminating dead zones and residues, thus achieving highly efficient mixing and kneading. However, they suffer from weaker kneading and self-cleaning effects between the impeller blades and difficulties in discharging the material. Horizontal self-cleaning reactors, on the other hand, achieve strong kneading and self-cleaning effects through the mutual kneading and scraping between the mixing shaft and the cleaning shaft / bar, preventing adhesion to the mixing shaft and walls and promoting efficient mixing of materials. The development and optimization of horizontal self-cleaning reactors have largely solved the problems of difficult mixing of high-viscosity fluids and material adhesion to impeller blades and walls.

[0004] However, most currently proposed self-cleaning reactors are horizontal, externally meshing types. This structure has a low material loading coefficient, requires a large gas phase space, and as the reactor diameter increases, the mixing and kneading efficiency decreases. The kneading frequency and kneading area of ​​the stirring blades also gradually weaken with reactor enlargement, leading to a sharp increase in stirring power consumption during normal operation. Therefore, there is an urgent need to develop a new type of stirring equipment with high mixing and kneading density, good self-cleaning effect, and a wide range of applicable raw materials. This equipment should effectively address the adverse effects of reactor enlargement and increased blade diameter, meeting the requirements for mixing, heat and mass transfer of raw materials with different properties and characteristics, and finding applications in material mixing, dissolution, and polymerization reactions. Summary of the Invention

[0005] One of the main technical problems addressed by this invention is the low mixing and kneading efficiency, poor self-cleaning effect, and narrow applicability of raw materials in existing technologies. The challenge lies in increasing the stirring and kneading frequency to achieve comprehensive self-cleaning and prevent materials from adhering to the walls and stirring shaft. This invention achieves rapid and uniform mixing, dissolution, or polymerization of raw materials through the intense and intensive stirring, kneading, and self-cleaning action between the blades.

[0006] The second technical problem to be solved by the present invention is to provide a method for mixing a high-viscosity polymer solution and a solvent using the apparatus for solving one of the technical problems.

[0007] The first aspect of the present invention is to provide a vertical internal meshing stirring device, including a transmission unit, a stirring paddle assembly and a vessel body, wherein the stirring paddle assembly is disposed in the vessel body and one end is connected to the transmission unit, and the stirring paddle assembly includes a multi-axis blade assembly and a propulsion blade assembly connected sequentially from top to bottom.

[0008] According to the present invention, in the vertical internal meshing stirring device:

[0009] The distance between the outer edge of the multi-axis blade group, the outer edge of the propulsion blade group and the corresponding inner wall of the vessel body is 1 to 10 mm.

[0010] The vessel body includes a lid, a cylindrical body, and a tapered cylindrical body at the bottom that narrows from top to bottom; preferably, the tapered cylindrical body is an inverted conical body or a semi-elliptical body; the diameter of the upper end of the tapered cylindrical body is the same as the diameter of the cylindrical body; the multi-axis blade assembly is located inside the cylindrical body of the vessel body; the propulsion blade assembly is located inside the tapered cylindrical body of the vessel body.

[0011] According to the present invention, the propulsion blade assembly includes a propulsion and stirring shaft and blades disposed thereon; preferably, the blades are stirring blades with axial downward propulsion, more preferably ribbon blades, double ribbon blades, anchor blades, frame blades, or bottom-sweeping blades; the propulsion and stirring shaft is provided with blade reinforcing crossbars at intervals from the top, and the two ends of the blade reinforcing crossbars are connected to the blades corresponding to their horizontal positions; more preferably, the blade reinforcing crossbars are parallel to each other or have an angle between them; the blade reinforcing crossbars are evenly or unevenly distributed on the propulsion and stirring shaft; even more preferably, the blade reinforcing crossbars have an angle between them, and the angle is the circumferential angle of the blade reinforcing crossbars; the blade reinforcing crossbars are evenly distributed on the propulsion and stirring shaft.

[0012] According to the present invention, the multi-shaft impeller assembly includes a central stirring shaft, multiple internal meshing stirring shafts, multiple wall-mounted stirring shafts, and scrapers disposed on each stirring shaft; the multiple internal meshing stirring shafts are arranged along a circumference centered on the central stirring shaft, forming the inner circumference of the multi-shaft impeller assembly; the multiple wall-mounted stirring shafts are arranged along a circumference centered on the central stirring shaft, forming the outer circumference of the multi-shaft impeller assembly, with the outer circumference close to the vessel wall; a horizontal bottom support is disposed at the bottom end of the central stirring shaft, and the bottom ends of each wall-mounted stirring shaft are vertically connected to the bottom support;

[0013] Preferably, the bottom support is a star-shaped support radiating outward from the bottom end of the central stirring shaft; more preferably, the number of bottom supports is the same as the number of wall-mounted stirring shafts; the central stirring shaft and the inner meshing stirring shaft are cylindrical; the cross-section of the wall-mounted stirring shaft is a trapezoid with an arc base, one side of which is close to the vessel wall; more preferably, the scraping angle between the wall-mounted stirring shaft and the vessel wall is an obtuse angle; the number of wall-mounted stirring shafts is 2 to 24; more preferably, the wall-mounted stirring shafts are evenly distributed at angles on the outer circumference of the multi-shaft impeller assembly; the number of inner meshing stirring shafts is less than the number of wall-mounted stirring shafts; more preferably, the number of inner meshing stirring shafts is... The number of internal stirring shafts does not exceed 1 / 2 of the number of wall-mounted stirring shafts; the internally meshing stirring shafts are evenly distributed at angles on the inner circumference of the multi-shaft impeller assembly; the radius of the inner circumference where the internally meshing stirring shafts are located is half the radius of the outer circumference where the wall-mounted stirring shafts are located; the central stirring shaft and the internally meshing stirring shafts are connected to the gearbox output shaft; the wall-mounted stirring shafts move in a circular motion along the inner wall of the vessel under the rotation of the central stirring shaft; the bottom end of the internally meshing stirring shaft is higher than the bottom support; the stirring direction and stirring speed of the internally meshing stirring shafts are not particularly limited; the rotation direction of the internally meshing stirring shafts may be the same as or different from that of the central stirring shaft.

[0014] According to the present invention, in the vertical internal meshing stirring device:

[0015] The scraper can adopt the scraper shape and structure commonly used in the prior art, preferably at least one of double E type, double T type, double F type, double U type, and double C type, with its individual straight rod vertically connected to the stirring shaft; the scrapers on the central stirring shaft, the internal meshing stirring shaft, and the wall stirring shaft are preferably scrapers of the same model;

[0016] At least two rows of scraper sets are arranged axially on the central stirring shaft and / or the internal meshing stirring shaft; preferably, the scrapers on the central stirring shaft and / or the internal meshing stirring shaft are arranged at equal angles around the shaft, and each row of scraper sets has at least two scrapers arranged vertically along the axial direction; more preferably, on the central stirring shaft and / or the internal meshing stirring shaft, the edge of each scraper forms an angle of 0 to 10° with the axis of the stirring shaft, most preferably, all angles are the same; the upper and lower adjacent scrapers form an angle of 0 to 10°, most preferably, all angles are the same; even more preferably, the angle between the line connecting the edges of each row of scrapers and the axis is 0 to 10° (i.e., the angle between the edges of each row of scrapers on the central stirring shaft and / or the internal meshing stirring shaft is 0 to 10°). The wall-mounted stirring shaft has at least one row of scraper groups along its axial direction. More preferably, the scrapers on the wall-mounted stirring shaft are located on the inner side of the wall-mounted stirring shaft. The edge of each scraper forms an angle of 0-10° with the axis of the stirring shaft. Most preferably, all scrapers have the same angle. The upper and lower adjacent scrapers form an angle of 0-10° with each other. Most preferably, all scrapers have the same angle. Further preferably, the angle between the line connecting the edges of each row of scraper groups on the wall-mounted stirring shaft and the central axis is 0-10° (i.e., the line connecting the edges of each row of scraper groups on the wall-mounted stirring shaft has a spiral angle of 0-10°). The total height of each row of scraper groups on the wall-mounted stirring shaft is 0.5-0.8 times the height of the reactor cylinder. The above-mentioned design with a spiral angle allows the central stirring shaft scraper and the inner meshing stirring shaft scraper to press down the material during rotation, while the wall-mounted stirring shaft scraper lifts the material, enabling the material to circulate within the reactor.

[0017] According to the present invention, in the vertical internal meshing stirring device:

[0018] The number of scrapers in each column on the wall-mounted stirring shaft is less than the number of scrapers in each column on the central stirring shaft. The difference is not particularly limited, but it must be at least one, for example, 1 to 10. Preferably, the vertical positions of the scrapers on the wall-mounted stirring shaft from bottom to top correspond one-to-one with the vertical positions of the scrapers on the central stirring shaft, and the extra scrapers on the central stirring shaft are located at the upper end of the central stirring shaft.

[0019] The number of scrapers in each row of the wall-mounted stirring shaft is the same as the number of scrapers in each row of the internal meshing stirring shaft.

[0020] The scrapers on the internal meshing stirring shaft and the scrapers on the wall stirring shaft are arranged alternately. Preferably, the shortest distance between the edge of the scraper on the internal meshing stirring shaft and the wall stirring shaft, between the edge of the scraper on the wall stirring shaft and the internal meshing stirring shaft, and between the edge of the scraper on the internal meshing stirring shaft and the edge of the scraper on the wall stirring shaft are each 1 to 10 mm independently.

[0021] The scrapers on the inner meshing stirring shaft and the scrapers on the central stirring shaft are arranged alternately. Preferably, the shortest distance between the edge of the scraper on the inner meshing stirring shaft and the central stirring shaft, and between the edge of the scraper on the central stirring shaft and the inner meshing stirring shaft, are each 1 to 10 mm independently.

[0022] The shortest distance between the stirring shaft on the wall and the inner wall of the cylindrical vessel is 1 to 10 mm.

[0023] According to the present invention, in the vertical internal meshing stirring device:

[0024] The transmission unit includes a motor, a reducer, and a gearbox connected in sequence. The reducer is connected to the input shaft of the gearbox via a coupling. The gearbox has a multi-axis output. Preferably, the transmission unit is located on the upper part of the vessel body, and the output shaft of the gearbox passes through the vessel cover and is connected to the central stirring shaft and the internal meshing stirring shaft via flanges.

[0025] The outer periphery of the vessel body is provided with a jacket, the jacket inlet is located at the lower end cap, and the jacket outlet is located at the upper end of the vessel body cylindrical cylinder.

[0026] The vessel lid is provided with a material inlet, a vacuum extraction port, a solvent replenishment port, and a gas outlet. Preferably, the material inlet is connected to an internally extended straight pipe, the length of which extends into the vessel body is 0.1 to 0.5 times the height of the upper end cap. The solvent replenishment port is connected to an internally extended ring pipe or an internally extended manifold pipe, located near the top of the inner wall of the vessel lid, the length of which is 1 to 3 times the inner diameter of the cylindrical structure of the vessel body, and a small hole is provided at the bottom of the solvent inlet pipe. More preferably, at least 10 small holes with a diameter of 0.5 to 5 mm are provided at the bottom of the solvent inlet pipe. Even more preferably, 10 to 100 small holes are provided at the bottom of the solvent inlet pipe.

[0027] A material outlet is provided at the bottom of the reactor body;

[0028] The central stirring shaft of the multi-axis blade assembly is connected to the propulsion stirring shaft of the propulsion blade assembly.

[0029] A second aspect of the present invention is to provide a method for preparing a high-viscosity fluid solution, which is performed in the above-mentioned vertical internal meshing stirring device, preferably including the step of mixing the high-viscosity fluid and the solvent in the vertical internal meshing stirring device.

[0030] According to the present invention, the preparation method includes: introducing a preheated high-viscosity fluid into a vertical internal meshing stirring device through a material inlet; injecting a preheated solvent into the vertical internal meshing stirring device through a solvent replenishment port; and introducing a heat transfer medium into the jacket. The high-viscosity fluid and solvent are stirred and mixed uniformly under the stirring and kneading action of the central stirring shaft scraper, the wall stirring shaft scraper, and the internal meshing stirring shaft scraper. Then, under the stirring action of the bottom propeller blades, the mixture flows out from the material outlet at the bottom of the vessel. The viscosity of the high-viscosity fluid described in this invention is not particularly limited, for example, it is 10–500 Pa·s.

[0031] According to a preferred embodiment of the present invention, the preparation method of the high-viscosity fluid solution can adopt the following technical solution: Preheated high-viscosity fluid flows into a vertical internal meshing stirring device through an inner straight pipe from the material inlet; preheated solvent is sprayed into the vertical internal meshing stirring device through an inner coil from the solvent replenishment port; and the heat transfer medium enters from the jacket inlet and flows out from the jacket outlet. Under the stirring and kneading action of the central stirring shaft scraper, the wall stirring shaft scraper, and the internal meshing stirring shaft scraper, the high-viscosity fluid and solvent are subjected to sufficient compression, shearing, and stretching. Simultaneously, the helical angle of the central stirring shaft, the wall stirring shaft, and the internal meshing stirring shaft achieves axial propulsion of the solution, forming a downward axial propulsion force in the middle and an upward axial propulsion force near the wall, resulting in good mixing of the high-viscosity fluid and solvent in both radial and axial positions. During continuous stirring and kneading, the high-viscosity fluid and low-viscosity solvent are uniformly mixed. Under the stirring action of the bottom stirring blades at the lower end cap, the uniformly mixed solution flows out from the lower material outlet.

[0032] The temperature of the preheated high-viscosity fluid is 30–120°C, preferably 45–75°C;

[0033] The temperature of the preheated solvent is 35–150°C, preferably 50–80°C;

[0034] The feed ratio of the high-viscosity fluid to the solvent is 1:(0.001~100), preferably 1:(0.01~10);

[0035] The heat transfer medium is hot water or heat transfer oil;

[0036] The temperature of the heat transfer medium is 30–150°C, preferably 60–80°C;

[0037] The filling coefficient of the material in the vessel of the stirring device is 0.1 to 0.9, preferably 0.25 to 0.75;

[0038] The operating pressure inside the vessel of the stirring device is -100 to 300 kPa, preferably -50 to 20 kPa;

[0039] The residence time of the material in the vessel of the stirring device is 1 to 120 minutes, preferably 10 to 30 minutes;

[0040] In the stirring device, the rotational speed of the central stirring shaft is 0 to 240 rpm, preferably 10 to 120 rpm;

[0041] In the stirring device, the ratio of the rotational speeds of the central stirring shaft and the inner meshing stirring shaft is (0.01-10):1, preferably (0.1-5):1.

[0042] A third aspect of the present invention is to provide the application of the above-described vertical internal meshing stirring device or the above-described method for preparing high-viscosity fluid solutions in the preparation of mixtures and polymer polymerization reactions.

[0043] The beneficial effects of this invention are:

[0044] 1) This invention proposes a novel vertical internal meshing stirring device, in which the central stirring shaft scraper, the wall stirring shaft scraper, and the internal meshing stirring shaft scraper have high kneading density and high kneading strength, which is beneficial to the rapid mixing of raw materials and the transfer of heat and mass.

[0045] 2) The wall-mounted stirring shaft adopts a round-bottomed trapezoidal shape. When scraping the wall surface, the wall-mounted stirring shaft can form a product side angle greater than 90° with the wall surface. This is beneficial for mixing and stirring materials containing solids and high viscosity, and avoids the material retention and jamming of the stirring shaft caused by the compaction and compression of solid particles and high viscosity materials between the wall surface and the scraper.

[0046] 3) The scraper of the vertical internal meshing stirring device adopts double-layer blades, which improves the meshing density and scraping frequency of the blades. The gaps between the blades, the stirring shaft, and the wall are small. During rotation, the material adhering to the blades and the wall will be scraped off quickly, avoiding coking or skinning caused by uneven heating. It also has a fast mixing efficiency, which greatly shortens the time of mixing, reaction, and dissolving processes and greatly improves efficiency.

[0047] 4) The central stirring shaft scraper, wall-mounted stirring shaft scraper, and internal meshing stirring shaft scraper are equipped with helical angles, creating a downward axial thrust in the central region of the reactor and an upward axial thrust near the wall, promoting uniform mixing of highly viscous materials in both radial and axial directions. The bottom impellers have a downward axial thrust, facilitating the smooth discharge of highly viscous materials.

[0048] This invention achieves uniform mixing of materials through the design of a central stirring shaft impeller, internal meshing stirring shaft impeller, bottom propulsion impeller, material inlet, material outlet, solvent replenishment port, jacket inlet, and jacket outlet. This promotes radial and axial heat and mass transfer, increases kneading frequency, and improves self-cleaning rate. The vertical internal meshing stirring device provided by this invention can achieve a solid content (CV) value of less than 0.1% at the outlet when used for mixing high-viscosity fluids with solvents. It also features low power consumption, compact structure, and high stability, significantly reducing equipment investment and production costs, and has promising application prospects. Attached Figure Description

[0049] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with the embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0050] Figure 1 This is a schematic diagram of the vertical internal meshing stirring device of the present invention, wherein 1 is a motor, 2 is a reducer, 3 is a coupling, 4 is a gearbox, 5 is a vessel body, 6 is a central impeller, 7 is an internal meshing impeller, 8 is a bottom impeller, 9 is a material inlet, 10 is a material outlet, 11 is a vacuum port, 12 is a gas inlet, 13 is a solvent replenishment port, 14 is a central stirring shaft port, 15 is an internal meshing stirring shaft port, 16 is a jacket inlet, and 17 is a jacket outlet.

[0051] Figures 2-1 to 2-6 This is a schematic diagram of the components of the agitator assembly, specifically... Figure 2-1 This is a front view of the agitator assembly. Figure 2-2 This is a schematic diagram of the central stirring shaft, the wall-mounted stirring shaft, and the bottom support. Figure 2-3 This is a schematic diagram of the central stirring shaft, the wall-mounted stirring shaft, and the scraper on it. Figure 2-4 This is a schematic diagram of an internally meshing stirring shaft and its scraper. Figure 2-5 A schematic diagram of the propulsion blades. Figure 2-6 This is a schematic diagram of the staggered arrangement of scrapers in a multi-shaft impeller assembly. In the diagram, 6 is the center impeller, 7 is the inner meshing impeller, 8 is the bottom impeller, 61 is the center stirring shaft, 62 is the wall stirring shaft, 63 is the bottom connecting shaft, 64 is the center stirring shaft scraper, 65 is the wall stirring shaft scraper, 71 is the inner meshing stirring shaft, 72 is the inner meshing stirring shaft scraper, 81 is the bottom stirring shaft, 82 is the bottom stirring shaft impeller, and 83 is the impeller reinforcing crossbar.

[0052] Figures 3-1 to 3-2 This is a schematic diagram of a mixing impeller assembly with rotating blades. Specifically, Figure 3-1 This is a schematic diagram of the agitator assembly. Figure 3-2 This is a top view of a multi-axis blade assembly with a rotation angle.

[0053] Figures 4-1 to 4-5 For scrapers of different structural types, specifically, Figures 4-1 to 4-5 The blades are, in order, double E-type, double T-type, F-type, double U-type, and double C-type.

[0054] Figure 5 The diagram shows the ports on the vessel lid. 9 is the material inlet, 11 is the vacuum port, 12 is the gas inlet, 13 is the solvent replenishment port, 14 is the central stirring shaft port, and 15 is the internal meshing stirring shaft port.

[0055] Figures 6-1 to 6-3 This is a schematic diagram of the components on the lid of the vessel, specifically... Figure 6-1 This is a schematic diagram of the inner straight pipe for material inlet. Figure 6-2 This is a schematic diagram of the solvent inlet and the inner extension tube. Figure 6-3 This is a schematic diagram of the inside of the kettle lid.

[0056] Figure 7 This is a schematic diagram of the vertical double-ribbon impeller stirred tank used in Comparative Example 1. Detailed Implementation

[0057] The present invention will now be described in detail with reference to specific embodiments and accompanying drawings. It should be noted that the following embodiments are only used to further illustrate the present invention and should not be construed as limiting the scope of protection of the present invention. Some non-essential improvements and adjustments made by those skilled in the art based on the content of the present invention are still within the scope of protection of the present invention.

[0058] like Figure 1 As shown in Figure 6, the vertical internal meshing stirring device provided by the present invention includes a transmission unit, a stirring paddle assembly, and a vessel body. The stirring paddle assembly is disposed within the vessel body and connected at one end to the transmission unit. The stirring paddle assembly comprises a multi-axis blade assembly and a propulsion blade assembly connected sequentially from top to bottom. The vessel body includes a vessel lid, a cylindrical body, and a tapered cylindrical body at the bottom that narrows from top to bottom. Preferably, the tapered cylindrical body is an inverted conical cylinder or a semi-elliptical cylinder. The diameter of the upper end of the tapered cylindrical body is the same as the diameter of the cylindrical body. The multi-axis blade assembly is located within the cylindrical body of the vessel body. The propulsion blade assembly is located within the tapered cylindrical body of the vessel body.

[0059] The transmission unit includes a motor 1, a reducer 2, and a gearbox 4 connected in sequence. The reducer 2 is connected to the input shaft of the gearbox 4 via a coupling 3. The gearbox 4 has a multi-axis output. Preferably, the transmission unit is located on the upper part of the vessel body 5. The output shaft of the gearbox 4 passes through the vessel cover of the vessel body 5 and is connected to the central stirring shaft 61 of the central impeller 6 and the internal stirring shaft 71 of the internal meshing impeller 7 via flanges. The central stirring shaft 61 of the central impeller 6 is connected to the propulsion stirring shaft 81 of the propulsion impeller group 8.

[0060] The outer periphery of the vessel body 5 is provided with a jacket, the jacket inlet 16 is located at the lower end cap, and the jacket outlet 17 is located at the upper end of the cylindrical body of the vessel body 5; a material outlet 10 is provided at the bottom of the vessel body 5.

[0061] The vessel lid is provided with a material inlet 9, a vacuum extraction port 11, a solvent replenishment port 13, and a gas outlet 12. Preferably, the material pipe connected to the material inlet 9 is an internally extended straight pipe, and the length of the material pipe extending into the vessel body 5 is 0.1 to 0.5 times the height of the upper end cap. The solvent inlet pipe connected to the solvent replenishment port 13 is an internally extended ring pipe or an internally extended manifold pipe, located near the top of the inner wall of the vessel lid. The length of the solvent inlet pipe is 1 to 3 times the inner diameter of the cylindrical structure of the vessel body 5. The bottom of the solvent inlet pipe is provided with small holes, preferably at least 10 small holes. More preferably, the bottom of the solvent inlet pipe is provided with at least 10 to 100 small holes, and the diameter of the small holes is 0.5 to 5 mm.

[0062] The propulsion blade assembly 8 includes a propulsion and stirring shaft 81 and blades 82 disposed thereon; preferably, the blades 82 are stirring blades with axial downward propulsion, more preferably they are ribbon blades, double ribbon blades, anchor blades, frame blades, or bottom-sweeping blades; the propulsion and stirring shaft 81 is provided with blade reinforcing crossbars 83 at intervals from the top, and the two ends of the blade reinforcing crossbars 83 are connected to the blades corresponding to their horizontal positions; more preferably, the blade reinforcing crossbars 83 are parallel to each other or have an angle between them; the blade reinforcing crossbars 83 are evenly or unevenly distributed on the propulsion and stirring shaft; even more preferably, the blade reinforcing crossbars 83 have an angle between them, and the angle is the circumferential angle of the blade reinforcing crossbars; the blade reinforcing crossbars 83 are evenly distributed on the propulsion and stirring shaft.

[0063] The multi-shaft impeller assembly includes a central stirring shaft 61, multiple internally meshing stirring shafts 71, multiple wall-mounted stirring shafts 62, and scrapers mounted on each stirring shaft. The multiple internally meshing stirring shafts 71 are arranged around the central stirring shaft 61, forming the inner circumference of the multi-shaft impeller assembly. The multiple wall-mounted stirring shafts 62 are arranged around the central stirring shaft 61, forming the outer circumference of the multi-shaft impeller assembly, with the outer circumference close to the vessel wall. A horizontal bottom support 63 is provided at the bottom end of the central stirring shaft 61, and the bottom ends of the wall-mounted stirring shafts 62 are all vertically connected to the bottom support 63.

[0064] Preferably, the bottom support 63 is a star-shaped support radiating outward from the bottom end of the central stirring shaft 61; more preferably, the number of bottom supports 63 is the same as the number of wall-mounted stirring shafts 62; the central stirring shaft 61 and the inner meshing stirring shaft 71 are cylindrical; the cross-section of the wall-mounted stirring shaft 62 is a trapezoid with a circular arc at the bottom, with one side of the circular arc close to the vessel wall; more preferably, the scraping angle between the wall-mounted stirring shaft 62 and the vessel wall is an obtuse angle; the number of wall-mounted stirring shafts 62 is 2 to 24; more preferably, the wall-mounted stirring shafts 62 are evenly distributed at angles on the outer circumference of the multi-shaft impeller assembly; the number of the inner meshing stirring shafts 71 is... The number of internal stirring shafts 71 is less than the number of wall-mounted stirring shafts 62. More preferably, the number of internal stirring shafts 71 does not exceed 1 / 2 of the number of wall-mounted stirring shafts 62. The internal stirring shafts 71 are evenly distributed at angles on the inner circumference of the multi-shaft impeller assembly. The radius of the inner circumference where the internal stirring shafts 71 are located is half the radius of the outer circumference where the wall-mounted stirring shafts 62 are located. The central stirring shaft 61 and the internal stirring shafts 71 are connected by the output shaft of the gearbox 4. The wall-mounted stirring shafts 62 move in a circular motion along the inner wall of the vessel under the rotation of the central stirring shaft 61. The rotation direction of the internal stirring shafts 71 is the same as or different from that of the central stirring shaft 61.

[0065] At least two rows of scraper sets are arranged axially on the central stirring shaft 61 and / or the internal meshing stirring shaft 71; preferably, the scrapers on the central stirring shaft and / or the internal meshing stirring shaft are arranged at equal angles around the shaft, and each row of scraper sets has at least two scrapers arranged vertically along the axial direction; more preferably, the angle between the line connecting the edges of each row of scraper sets on the central stirring shaft 61 and / or the internal meshing stirring shaft 71 and the axis is 0 to 10° (i.e., the angle between the edges of each row of scraper sets on the central stirring shaft and / or the internal meshing stirring shaft). The wall-mounted stirring shaft 62 has at least one row of scraper groups along its axial direction. More preferably, the scrapers on the wall-mounted stirring shaft 62 are located on the inner side of the wall-mounted stirring shaft 62. The angle between the edge connecting line of each row of scraper groups on the wall-mounted stirring shaft 62 and the central axis is 0-10° (i.e., the edge connecting line of each row of scraper groups on the wall-mounted stirring shaft has a spiral angle of 0-10°). The total height of each row of scraper groups on the wall-mounted stirring shaft 62 is 0.5-0.8 times the height of the reactor cylinder. The above-mentioned design with a spiral angle allows the central stirring shaft scraper and the inner meshing stirring shaft scraper to press down the material during rotation, while the wall-mounted stirring shaft scraper lifts the material, enabling the material to circulate within the reactor.

[0066] The number of scrapers in each row on the wall-mounted stirring shaft 62 is less than the number of scrapers in each row on the central stirring shaft 61. The difference is not particularly limited, but it must be at least one. Preferably, the vertical positions of the scrapers on the wall-mounted stirring shaft 62 from bottom to top correspond one-to-one with the vertical positions of the scrapers on the central stirring shaft 61. The extra scrapers on the central stirring shaft 61 are located at the upper end of the central stirring shaft 61. The number of scrapers in each row on the wall-mounted stirring shaft 62 is the same as the number of scrapers in each row on the inner meshing stirring shaft 71. The scrapers on the inner meshing stirring shaft 71 and the scrapers on the wall-mounted stirring shaft 62 are arranged alternately.

[0067]

Example 1

[0068] use Figure 1 The vertical internal meshing agitator shown has a reactor inner diameter of 1.0m and a length of 2m. It features one central agitator shaft with four rows of 21 scrapers per row, eight wall agitator shafts with one row of 20 scrapers per row, and four internal meshing agitator shafts with four rows of 20 scrapers per row. The central, wall, and internal meshing agitator shaft scrapers all use double-E-shaped blades with a helical angle of 5°. The distances between the wall agitator shaft and the reactor wall, between the wall agitator shaft scrapers and the internal meshing agitator shafts, and between the internal meshing agitator shaft scrapers and the central agitator shaft are all 5mm. The bottom agitator blades use a double-conical spiral design, with a 5mm distance between the blades and the lower head wall.

[0069] Under a negative pressure of -15 kPa, a high-viscosity polyacrylonitrile solution preheated to 60°C (viscosity 80 Pa·s) is introduced into the reactor at a flow rate of 3000 kg / h from the material inlet. Dimethyl sulfoxide preheated to 65°C is introduced into the reactor at a flow rate of 150 kg / h from the solvent inlet. The polymerization solution and solvent fall above the liquid surface. The rotation of the central impeller, wall impellers, and internal meshing impellers causes stirring and kneading between the impellers, subjecting the solution and solvent units to compression, shearing, and stretching. The internal meshing stirring shaft rotates at 80 rpm, and the central stirring shaft rotates at 40 rpm. Simultaneously, under the rotation of the central impeller and the internal meshing impellers, the solution mixes well in both radial and axial directions. The helix angle allows the solution to propel downwards at the center and upwards near the wall. The material loading coefficient in the vertical internal meshing stirring device is 0.7, and the residence time in the device is 20 min. During continuous stirring and kneading, the polymerization solution and solvent are mixed evenly, and the solid content decreases from the original 20.00% to 19.05%. According to the coefficient of variation (CV) = (standard deviation / mean) × 100%, the CV value of the solid content is calculated to be <0.1%. The uniformly mixed polymer solution flows out from the material outlet below, and the discharged raw liquid does not contain air bubbles.

[0070]

Examples 2-8

[0071] The vertical internal meshing stirring device and the mixing method of high viscosity fluid and solvent in Example 1 were used, but with different numbers of wall stirring shafts, number of wall stirring shaft scrapers, number of internal meshing stirring shafts, blade clearance distance, internal meshing stirring shaft speed, filling coefficient and material residence time. The specific parameters and test results are shown in Table 1.

[0072] Comparative Example 1

[0073] Traditional vertical double-ribbon impeller agitator (such as...) Figure 7 (As shown) A high-viscosity polymerization solution was mixed with a solvent, and the CV value of the solid content reached 0.65%.

[0074] Table 1 Comparison of parameters in the embodiments

[0075]

[0076] As can be seen from the results in Table 1, compared with Comparative Example 1, Examples 1 to 8 can better improve the uniform mixing of high-viscosity materials and reduce the solid content.

[0077] It should be noted that the embodiments described above are only for explaining the present invention and do not constitute any limitation on the present invention. The present invention has been described with reference to typical embodiments, but it should be understood that the words used therein are descriptive and explanatory terms, not limiting terms. Modifications can be made to the present invention within the scope of the claims, and revisions can be made to the present invention without departing from the scope and spirit of the present invention. Although the present invention described herein relates to specific methods, materials, and embodiments, it does not mean that the present invention is limited to the specific examples disclosed herein; on the contrary, the present invention can be extended to all other methods and applications with the same function.

Claims

1. A vertical internal meshing stirring device, comprising a transmission unit, a stirring paddle assembly, and a vessel body, wherein the stirring paddle assembly is disposed within the vessel body and one end is connected to the transmission unit, and the stirring paddle assembly comprises a multi-axis blade assembly and a propulsion blade assembly connected sequentially from top to bottom.

2. The vertical internal meshing stirring device according to claim 1, characterized in that, The distances between the outer edge of the multi-axis blade assembly, the outer edge of the propulsion blade assembly, and the corresponding inner wall of the vessel body are independently 1–10 mm; and / or, The vessel body includes a lid, a cylindrical body, and a tapered cylindrical body at the bottom that narrows from top to bottom; preferably, the tapered cylindrical body is an inverted conical body or a semi-elliptical body; and / or, the diameter of the upper end of the tapered cylindrical body is the same as the diameter of the cylindrical body; and / or, the multi-axis blade assembly is located inside the cylindrical body of the vessel body; and / or, the propulsion blade assembly is located inside the tapered cylindrical body of the vessel body.

3. The vertical internal meshing stirring device according to claim 1 or 2, characterized in that, The propulsion blade assembly includes a propulsion and stirring shaft and blades disposed thereon; preferably, The impeller is an agitator impeller with an axially downward propulsive force, more preferably a ribbon impeller, a double ribbon impeller, an anchor impeller, a frame impeller, or a bottom-sweeping impeller; and / or, The propulsion and stirring shaft is provided with blade reinforcement crossbars spaced apart from the top, and the two ends of the blade reinforcement crossbars are connected to the blades corresponding to their horizontal positions; more preferably, the blade reinforcement crossbars are parallel to each other or have an angle between them; and / or, the blade reinforcement crossbars are evenly or unevenly distributed on the propulsion and stirring shaft; even more preferably, the blade reinforcement crossbars have an angle between them, and the angle is the circumferential angle of the blade reinforcement crossbars; and / or, the blade reinforcement crossbars are evenly distributed on the propulsion and stirring shaft.

4. The vertical internal meshing stirring device according to claim 1 or 2, characterized in that, The multi-shaft impeller assembly includes a central stirring shaft, multiple internal meshing stirring shafts, multiple wall-mounted stirring shafts, and scrapers mounted on each stirring shaft. The multiple internal meshing stirring shafts are arranged circumferentially around the central stirring shaft, forming the inner circumference of the multi-shaft impeller assembly. The multiple wall-mounted stirring shafts are also arranged circumferentially around the central stirring shaft, forming the outer circumference of the multi-shaft impeller assembly, with the outer circumference close to the vessel wall. A horizontal bottom support is provided at the bottom end of the central stirring shaft, and the bottom ends of each wall-mounted stirring shaft are vertically connected to the bottom support. Preferably... The bottom support is a star-shaped support radiating outwards from the bottom end of the central stirring shaft; more preferably, the number of bottom supports is the same as the number of wall-mounted stirring shafts; and / or, The central stirring shaft and the internal meshing stirring shaft are cylindrical; and / or, The cross-section of the wall-mounted stirring shaft is a trapezoid with a circular arc base, one side of which is close to the vessel wall; more preferably, the scraping angle between the wall-mounted stirring shaft and the vessel wall is an obtuse angle; and / or, The number of wall-mounted stirring shafts is 2 to 24; more preferably, the wall-mounted stirring shafts are distributed at equal angles on the outer circumference of the multi-shaft impeller assembly; and / or, The number of internally meshing stirring shafts is less than the number of wall-mounted stirring shafts; more preferably, the number of internally meshing stirring shafts does not exceed 1 / 2 of the number of wall-mounted stirring shafts; and / or, the internally meshing stirring shafts are distributed at equal angles on the inner circumference of the multi-shaft impeller assembly; and / or The radius of the inner circumference of the internal meshing stirring shaft is half the radius of the outer circumference of the wall-mounted stirring shaft; and / or, The central stirring shaft and the internal meshing stirring shaft are connected to the gearbox output shaft; and / or, The wall-mounted stirring shaft moves in a circular motion along the inner wall of the vessel under the rotation of the central stirring shaft; and / or, The internal meshing stirring shaft may rotate in the same or different directions as the central stirring shaft.

5. The vertical internal meshing stirring device according to claim 4, characterized in that, The scraper is at least one of the following types: double E-type, double T-type, double F-type, double U-type, and double C-type, with a single straight rod of its shape vertically connected to the stirring shaft; and / or, At least two rows of scraper sets are arranged axially on the central stirring shaft and / or the internal meshing stirring shaft. Preferably, the scrapers on the central stirring shaft and / or the inner meshing stirring shaft are arranged at equal angles around the shaft; and / or, each row of scrapers has at least two scrapers arranged vertically along the axial direction; more preferably, on the central stirring shaft and / or the inner meshing stirring shaft, the edge of each scraper forms an angle of 0 to 10° with the axis of the stirring shaft, and / or, the angle between two adjacent scrapers is 0 to 10°; most preferably, the angle between the line connecting the edges of each row of scrapers and the axis is 0 to 10°; and / or, Preferably, the wall-mounted stirring shaft is provided with at least one row of scraper groups along the axial direction; more preferably, the scrapers on the wall-mounted stirring shaft are arranged on the inner side of the wall-mounted stirring shaft, and / or, the total height of each row of scraper groups on the wall-mounted stirring shaft is 0.5 to 0.8 times the height of the reactor cylinder, and / or, the edge of each scraper forms an angle of 0 to 10° with the axis of the stirring shaft, and / or, the upper and lower adjacent scrapers form an angle of 0 to 10°; most preferably, the angle between the line connecting the edges of each row of scraper groups on the wall-mounted stirring shaft and the central axis is 0 to 10°.

6. The vertical internal meshing stirring device according to claim 5, characterized in that, The number of scrapers in each row on the wall-mounted stirring shaft is less than the number of scrapers in each row on the central stirring shaft. Preferably, the vertical positions of the scrapers on the wall-mounted stirring shaft from bottom to top correspond one-to-one with the vertical positions of the scrapers on the central stirring shaft, and the extra scrapers on the central stirring shaft are located at the upper end of the central stirring shaft; and / or, The number of scrapers in each row of the wall-mounted stirring shaft is the same as the number of scrapers in each row of the internal meshing stirring shaft; and / or, The scrapers on the internal meshing stirring shaft and the scrapers on the wall stirring shaft are arranged alternately, one above the other; preferably, the shortest distance between the edge of the scraper on the internal meshing stirring shaft and the wall stirring shaft, the edge of the scraper on the wall stirring shaft and the internal meshing stirring shaft, and the edge of the scraper on the internal meshing stirring shaft and the edge of the scraper on the wall stirring shaft are each independently 1 to 10 mm; and / or, The scrapers on the inner meshing stirring shaft and the scrapers on the central stirring shaft are arranged alternately, preferably with the shortest distance between the edge of the scraper on the inner meshing stirring shaft and the central stirring shaft, and the shortest distance between the edge of the scraper on the central stirring shaft and the inner meshing stirring shaft, each independently being 1-10 mm; and / or, The shortest distance between the stirring shaft on the wall and the inner wall of the cylindrical vessel is 1 to 10 mm.

7. The vertical internal meshing stirring device according to claim 1, characterized in that, The transmission unit includes a motor, a reducer, and a gearbox connected in sequence. The reducer is connected to the input shaft of the gearbox via a coupling. The gearbox has multi-axis output. Preferably, the transmission unit is located on the upper part of the vessel body, and the output shaft of the gearbox passes through the vessel cover and is connected to the central stirring shaft and the internal meshing stirring shaft via flanges. And / or, The outer periphery of the vessel body is provided with a jacket, the jacket inlet being located at the lower end cap, and the jacket outlet being located at the upper end of the cylindrical vessel body; and / or, The vessel lid is provided with a material inlet, a vacuum extraction port, a solvent replenishment port, and a gas outlet; preferably, the material inlet is connected to an internally extended straight pipe, the length of which extends into the vessel body is 0.1 to 0.5 times the height of the upper end cap; and / or, the solvent replenishment port is connected to an internally extended ring pipe or an internally extended manifold pipe, located near the top of the inner wall of the vessel lid, the length of which is 1 to 3 times the inner diameter of the cylindrical structure of the vessel body, and a small hole is provided at the bottom of the solvent inlet pipe; more preferably, the bottom of the solvent inlet pipe is provided with at least 10 small holes, the diameter of which is 0.5 to 5 mm; and / or, A material outlet is provided at the bottom of the vessel; and / or, The central stirring shaft of the multi-axis blade assembly is connected to the propulsion stirring shaft of the propulsion blade assembly.

8. A method for preparing a high-viscosity fluid solution, performed using the vertical internal meshing stirring apparatus according to any one of claims 1 to 7, preferably comprising the step of mixing the high-viscosity fluid and a solvent in the vertical internal meshing stirring apparatus.

9. The preparation method according to claim 8, characterized in that, The preparation method includes: a preheated high-viscosity fluid flowing into a vertical internal meshing stirring device from a material inlet; a preheated solvent being sprayed into the vertical internal meshing stirring device from a solvent replenishment port; and a heat transfer medium being introduced into the jacket. The high-viscosity fluid and solvent are stirred and mixed evenly under the stirring and kneading action of the central stirring shaft scraper, the wall stirring shaft scraper, and the internal meshing stirring shaft scraper. Then, under the stirring action of the bottom propeller blades, the mixture flows out from the material outlet at the bottom of the vessel.

10. The preparation method according to claim 9, characterized in that, The temperature of the preheated high-viscosity fluid is 30–120°C, preferably 45–75°C; and / or, The temperature of the preheated solvent is 35–150°C, preferably 50–80°C; and / or, The feed ratio of the high-viscosity fluid to the solvent is 1:(0.001–100), preferably 1:(0.01–10); and / or, The heat transfer medium is hot water or thermal oil; and / or, The temperature of the heat transfer medium is 30–150°C, preferably 60–80°C; and / or, The filling coefficient of the material inside the stirring device is 0.1 to 0.9, preferably 0.25 to 0.75; and / or, The operating pressure inside the vessel of the stirring device is -100 to 300 kPa, preferably -50 to 20 kPa; and / or, The residence time of the material in the vessel of the stirring device is 1–120 min, preferably 10–30 min; and / or, In the stirring device, the rotational speed of the central stirring shaft is 0–240 rpm, preferably 10–120 rpm; and / or, In the stirring device, the ratio of the rotational speeds of the central stirring shaft and the inner meshing stirring shaft is (0.01-10):1, preferably (0.1-5):

1.

11. The vertical internal meshing stirring device according to any one of claims 1 to 7 or the method for preparing a high-viscosity fluid solution according to any one of claims 8 to 10, and its application in the preparation of mixtures and polymer polymerization reactions.

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