Double shaft mixing device with a screening circulation structure

Abstract

The application relates to a double-shaft stirring device with a screening circulation structure, belongs to the technical field of mechanical equipment, and comprises a first driving motor, a second driving motor, a first stirring shaft and a second stirring shaft, the second stirring shaft is provided with stirring rods, the stirring rods are provided with paddle plates, the first stirring shaft is provided with stirring blades, the stirring blades are inserted between two adjacent upper and lower paddle plates, a screening container is arranged at the bottom of a reaction kettle, the first stirring shaft extends into the screening container, a circular table screen is arranged in the screening container, the circular table screen is connected to the first stirring shaft through a speed increasing and changing mechanism, the circular table screen adopts a screen with mesh size meeting the fineness requirement of discharging, a recycling material table is arranged in the screening container, the recycling material table is provided with a discharging port, the discharging port of the recycling material table is connected with a communication pipeline, the communication pipeline is communicated with a feeding port of the reaction kettle, and a fluid pump is arranged on the communication pipeline. The application realizes material screening circulation, reduces the working load of subsequent processing equipment and reduces the maintenance cost of the subsequent processing equipment.

Description

Technical Field

[0001] This application relates to the technical field of mechanical equipment, and in particular to mixing devices. Background Technology

[0002] Emulsification equipment is used in the fields of daily chemicals, pharmaceuticals, food and fine chemicals for material emulsification. Through stirring, grinding and other actions, it mixes and refines various immiscible or difficult-to-mix materials to form a uniform and stable emulsion state, thereby meeting the requirements for material morphology and uniformity in the production and process development of related products.

[0003] Existing emulsification equipment typically includes a reaction vessel for holding materials, a stirring device mounted on the reaction vessel, and a homogenizer connected to the reaction vessel. To ensure more uniform mixing of materials in the reaction vessel, a twin-shaft stirring device is usually used. A twin-shaft stirring device generally consists of a first stirring shaft, a second stirring shaft, and drive motors that drive the two shafts to rotate. The first stirring shaft has blades directly mounted on it, while the second stirring shaft has stirring rods extending along the inner wall of the reaction vessel. The stirring rods also have blades mounted on them, and the blades on the first stirring shaft and the stirring rods are distributed in an alternating pattern. In actual operation, the staff first put the materials to be processed into the reactor, start the drive motor to drive the two stirring shafts to rotate in opposite directions, so that the two sets of blades rotate synchronously with the shafts. Through the interlacing and reverse movement of the blades, the convection stirring of the materials in the reactor is realized, breaking the initial agglomeration of the materials and realizing the mixing of the materials. After the initial stirring is completed, the materials in the reactor are transported to the homogenizer. The high-frequency shearing or grinding action of the homogenizer is used to further refine the materials. After being processed by the homogenizer, the materials are discharged through the discharge pipe, completing the entire emulsification process.

[0004] Regarding the aforementioned technologies, while existing twin-shaft mixing devices can achieve material mixing through the interlocking of two sets of blades, the particle size of the mixed material is not fine enough. Some large particles will flow directly into the homogenizer from the bottom outlet of the reactor along with the overall material. Although these large particles can be ground to the required small particle size by the homogenizer, long-term operation will significantly increase the workload of the homogenizer, leading to accelerated wear and shortening its service life. This also increases equipment maintenance costs and indirectly raises the production cost of material emulsification. Utility Model Content

[0005] In view of the shortcomings of the existing technology, one of the purposes of this utility model is to provide a twin-shaft stirring device with a screening and circulation structure.

[0006] The twin-shaft stirring device with a screening and circulation structure provided in this application adopts the following technical solution:

[0007] A dual-shaft stirring device with a screening and circulation structure includes a first drive motor and a second drive motor mounted above a reactor. The first drive motor is driven by a first stirring shaft, and the second drive motor is driven by a second stirring shaft. Both the first and second stirring shafts extend into the reactor. The second stirring shaft is a hollow shaft structure and is rotatably mounted on the first stirring shaft, with the first and second stirring shafts rotating in opposite directions. One end of the second stirring shaft extending into the reactor is provided with a stirring rod extending along the inner wall of the reactor. The stirring rod is provided with uniformly arranged blades. One end of the first stirring shaft extending into the reactor is provided with a cylindrical structure arranged from top to bottom. The outer wall of the cylindrical structure is provided with blades uniformly arranged circumferentially, called agitation blades, which are inserted between two adjacent blades.

[0008] A container called a screening container is installed at the bottom of the reactor. The screening container is connected to the discharge port of the reactor, and a solenoid valve is installed at the connection between the screening container and the discharge port of the reactor. The end of the first stirring shaft away from the first drive motor extends into the screening container.

[0009] The screening container is equipped with an inverted frustum-shaped screen, called a frustum screen. The diameter of the upper end of the frustum screen is larger than the diameter of the discharge port of the reactor. An ultrasonic level switch is installed at the top of the screening container corresponding to the frustum screen. The ultrasonic level switch is electrically connected to a solenoid valve.

[0010] The frustum screen is connected to the first stirring shaft through a speed-increasing mechanism, and the frustum screen is a screen with a mesh size that meets the fineness requirements of the output.

[0011] The screening container is provided with an annular groove container surrounding the outer periphery of the frustum screen, which is called the recycling platform. The height of the inner sidewall of the recycling platform is between three-fifths and four-fifths of the height of the frustum screen.

[0012] The bottom of the recycling platform is connected to the cavity wall of the screening container, with the cavity wall of the screening container serving as the outer wall of the recycling platform. The height of the outer wall of the recycling platform is higher than that of the frustum screen.

[0013] The recycling platform has an opening at the bottom as its outlet. The outlet of the recycling platform is connected to a connecting pipe, and the outlet end of the connecting pipe is connected to the feed port of the reactor. A fluid pump is installed on the connecting pipe to form a recycling and feeding system from the recycling platform to the reactor.

[0014] By adopting the above technical solution, the impeller plates on the first stirring shaft are replaced with agitator blades, and the agitator blades are inserted between two adjacent impeller plates. While retaining the convective mixing advantage formed by the interlocking of the impeller plates on the first and second stirring shafts, the agitator blades can directly shear the material flowing from top to bottom when the first and second stirring shafts rotate in opposite directions. This ensures that the material is mixed evenly in the convective mixing and also performs preliminary shearing and refining of the material, laying the foundation for the subsequent screening process.

[0015] Meanwhile, the inverted frustum screen in the screening container at the bottom of the reactor has an upper diameter larger than the reactor outlet diameter, which can completely receive the material discharged from the reactor. An ultrasonic level switch detects the material height in the frustum screen and controls the opening and closing of the solenoid valve at the connection between the screening container and the reactor outlet based on the material height, thus controlling the flow rate of material from the reactor into the frustum screen and preventing spillage. The frustum screen, in conjunction with the speed-increasing mechanism connected to the first stirring shaft, allows the frustum screen to rotate at a higher speed than the first stirring shaft. Centrifugal force is used to ensure that material with the required particle size for discharge passes smoothly through the screen. This process is equivalent to pre-screening the material, making the screened material more refined. When the material enters the next grinding stage (such as homogenization), the homogenizer does not need to perform additional grinding on a large amount of material, effectively reducing the workload of the homogenizer, extending its service life, and reducing its maintenance costs, which indirectly reduces the production cost of material emulsification. Meanwhile, materials whose particle size does not meet the requirements will be thrown to the outer periphery of the frustum screen under centrifugal force. Because the recovery platform is set around the frustum screen and the height of its inner wall is three-fifths to four-fifths of the height of the frustum screen, materials whose particle size does not meet the requirements can fall accurately into the recovery platform. Furthermore, because the solenoid valve controls the flow rate of the material from the reactor into the frustum screen, it can prevent the material from overflowing into the recovery platform, thus achieving effective separation of qualified and unqualified materials.

[0016] The recycling platform is connected to a connecting pipe through a bottom outlet, and a fluid pump on the connecting pipe forms a recycling feeding system. This system can transport materials that do not meet the particle size requirements that fall into the recycling platform back to the feed port of the reactor, allowing the materials that do not meet the particle size requirements to re-enter the reactor. Under the synergistic action of the stirring blades and the impeller plates, the materials undergo secondary stirring and shearing, and then re-enter the screening container for screening. This forms a closed-loop processing flow of stirring, shearing, screening, recycling, and re-stirring, which improves the fineness of the final output and reduces the material processing cost.

[0017] Preferably, the stirring blade is inclined at an angle of 30 to 60 degrees to the axis of the cylindrical structure, and the blade direction of the stirring blade is consistent with the rotation direction of the first stirring shaft.

[0018] By adopting the above technical solution, the inclined stirring blades can shear the material when rotating with the first stirring shaft. At the same time, the inclined blade surface can guide the material flowing from top to bottom in the reactor, so that the material flows along the inclined direction of the blades, ensuring that the material is evenly distributed in the stirring area. Meanwhile, the blade direction of the stirring blades is consistent with the rotation direction of the first stirring shaft, so that the cutting surface of the blades can directly act on the material movement direction. When the material comes into contact with the blades, the blades can shear the material in a forward cutting manner, improving the shearing efficiency.

[0019] Preferably, the inner wall of the frustum screen is provided with spiral ribs arranged from top to bottom, called guide ribs, and the spiral direction of the guide ribs is opposite to the rotation direction of the frustum screen.

[0020] By adopting the above technical solution, when the frustum screen rotates at high speed driven by the speed-increasing mechanism, the material will slide along the inner wall of the screen under the action of its own gravity and centrifugal force. If there is no guiding structure, the material will easily slide over the screen surface quickly, resulting in too short a contact time between the material and the screen. Some fine materials will be thrown out with the coarse materials because they do not fully contact the screen, affecting the screening effect. The spiral guide strip can block and guide the sliding material, allowing the material to slide along the spiral path of the guide strip. Since the spiral direction of the guide strip is opposite to the rotation direction of the frustum screen, the contact time between the material and the frustum screen is greatly extended, allowing fine materials more time to pass through the screen. At the same time, it can ensure that the fine materials attached to the surface of the coarse materials are fully screened out during the continuous contact with the screen, thereby improving the screening accuracy.

[0021] Preferably, the stirring rod is provided with uniformly arranged scraper plates on the side close to the inner wall of the reactor.

[0022] By adopting the above technical solution, the scraper rotates synchronously with the stirring rod, and the end of the scraper away from the stirring rod is in contact with the inner wall of the reactor. When the stirring rod rotates along the inner wall of the reactor, the scraper can continuously slide along the inner wall to scrape off the material adhering to the inner wall of the reactor in time. The scraped material falls back into the stirring area inside the reactor and mixes evenly with other materials, thus avoiding material waste.

[0023] Preferably, a one-way valve is provided on the connecting pipe, and the one-way valve is directed from the recovery platform to the reaction vessel.

[0024] By adopting the above technical solution, the one-way valve can strictly limit the flow direction of materials, allowing only the materials in the recycling platform to be transported to the reactor through the connecting pipe, preventing the materials in the reactor from flowing backward, and ensuring that the recycling feeding system always maintains a one-way and orderly conveying state.

[0025] Preferably, the blade plate has several through holes, called turbulence holes, which are arranged in a staggered manner.

[0026] By adopting the above technical solution, the turbulence holes on the impeller plate allow some material to pass through them during flow, forming local turbulence and making the material mixing more uniform. Furthermore, the staggered arrangement of the turbulence holes further enhances the turbulence effect. Combined with the opposite rotation of the first and second stirring shafts, the material can be mixed more finely through convection stirring and shearing, thanks to the effect of the turbulence holes. This is particularly suitable for material processing scenarios requiring high mixing precision.

[0027] In summary, this application includes at least one of the following beneficial technical effects:

[0028] 1. Replace the impeller blades on the first stirring shaft with agitator blades, and insert the agitator blades between two adjacent impeller blades. While retaining the convective mixing advantage formed by the interlocking impeller blades on the first and second stirring shafts, the agitator blades can directly shear the material flowing from top to bottom when the first and second stirring shafts rotate in opposite directions. This ensures that the material is mixed evenly in the convective mixing and also performs preliminary shearing and refining of the material, laying the foundation for the subsequent screening process.

[0029] Meanwhile, the inverted frustum screen inside the screening container at the bottom of the reactor, with an upper diameter larger than the reactor outlet diameter, can completely catch the material discharged from the reactor, preventing spillage. The frustum screen, in conjunction with the speed-increasing mechanism connected to the first stirring shaft, allows it to rotate at a higher speed than the first stirring shaft. Centrifugal force ensures that materials meeting the discharge fineness requirements pass smoothly through the screen. This process is equivalent to pre-screening the material, allowing it to proceed smoothly into the next grinding stage (such as homogenization). This eliminates the need for a homogenizer to grind large quantities of materials, effectively reducing the homogenizer's workload, extending its service life, and lowering its maintenance costs, thus indirectly reducing the production cost of material emulsification. Materials with particle sizes that do not meet the requirements will be thrown towards the outer periphery of the frustum screen under centrifugal force. Because the recovery platform surrounds the frustum screen and its inner wall height is three-fifths to four-fifths of the screen's height, materials with particle sizes that do not meet the requirements can accurately fall into the recovery platform, achieving effective separation of qualified and unqualified materials.

[0030] The recycling platform is connected to a connecting pipe through a bottom outlet, and a fluid pump on the connecting pipe forms a recycling feeding system. This system can transport materials that do not meet the particle size requirements that fall into the recycling platform back to the feed port of the reactor, allowing the materials that do not meet the particle size requirements to re-enter the reactor. Under the synergistic action of the stirring blades and the impeller plates, the materials undergo secondary stirring and shearing, and then re-enter the screening container for screening. This forms a closed-loop processing flow of stirring, shearing, screening, recycling, and re-stirring, which improves the fineness of the final output and reduces the material processing cost.

[0031] 2. The inclined stirring blades, when rotating with the first stirring shaft, can shear the material. At the same time, the inclined blades can guide the material flowing from top to bottom in the reactor, ensuring that the material flows along the inclined direction of the blades and is evenly distributed in the stirring area. Meanwhile, the blades are oriented in the same direction as the rotation of the first stirring shaft, allowing the cutting surface of the blades to act directly on the direction of material movement. When the material comes into contact with the blades, the blades can shear the material in a forward cutting manner, improving the shearing efficiency.

[0032] 3. When the frustum screen rotates at high speed driven by the speed-increasing mechanism, the material slides along the inner wall of the screen under its own gravity and centrifugal force. If there is no guiding structure, the material can easily slide quickly across the screen surface, resulting in too short a contact time between the material and the screen. Some fine materials are thrown out with the coarse materials because they do not make sufficient contact with the screen, affecting the screening effect. The spiral guide strip can block and guide the sliding material, causing the material to slide along the spiral path of the guide strip. Since the spiral direction of the guide strip is opposite to the rotation direction of the frustum screen, the contact time between the material and the frustum screen is greatly extended, allowing fine materials more time to pass through the screen. At the same time, it ensures that the fine materials attached to the surface of the coarse materials are fully screened out during continuous contact with the screen, thereby improving the screening accuracy. Attached Figure Description

[0033] Figure 1 This is a schematic diagram of the overall structure of a twin-shaft stirring device with a screening and circulation structure, as shown in the embodiments of this application.

[0034] Figure 2 This is a three-dimensional structural diagram of a frustum screen and a guide bar, as shown in this embodiment of the application.

[0035] Reference numerals in the attached drawings: 1. Reactor; 2. First drive motor; 3. Second drive motor; 4. First stirring shaft; 5. Second stirring shaft; 6. Stirring rod; 7. Paddle plate; 8. Agitator blade; 9. Screening container; 10. Solenoid valve; 11. Frustum screen; 12. Ultrasonic level switch; 13. Speed ​​increase mechanism; 14. Recovery platform; 15. Connecting pipe; 16. Fluid pump; 17. Guide bar; 18. Scraper; 19. Check valve; 20. Turbulence hole. Detailed Implementation

[0036] The following is in conjunction with the appendix Figure 1 -Appendix Figure 2 This application will be described in further detail.

[0037] This application discloses a biaxial stirring device with a screening and circulation structure.

[0038] Reference Figure 1 The dual-shaft stirring device with a screening and circulation structure includes a first drive motor 2 and a second drive motor 3. A motor bracket is fixedly installed on the top of the reactor 1. Both the first drive motor 2 and the second drive motor 3 are fixed on the motor bracket, with the first drive motor 2 located directly above the second drive motor 3. The output shafts of both are vertically downward. The output shaft of the first drive motor 2 is driven by a first stirring shaft 4, and the output shaft of the second drive motor 3 is driven by a second stirring shaft 5. The first stirring shaft 4 and the second stirring shaft 5 rotate in opposite directions. The second stirring shaft 5 is a hollow shaft structure, with its inner diameter slightly larger than the outer diameter of the first stirring shaft 4. The first stirring shaft 4 is coaxially inserted into the hollow shaft body of the second stirring shaft 5, realizing the rotational sleeve of the second stirring shaft 5 on the first stirring shaft 4.

[0039] The second stirring shaft 5 extends into the outer wall of the reactor 1, and a stirring rod 6 extending along the inner wall of the reactor 1 is fixed thereon. The stirring rod 6 has blades 7 evenly arranged along the length of the second stirring shaft 5 to ensure that the material near the inner wall of the reactor 1 is fully stirred. Several through holes, called turbulence holes 20, are opened on the blades 7. The turbulence holes 20 on the blades 7 are staggered. When the blades 7 rotate with the stirring rod 6, the material can pass through the turbulence holes 20 to form local turbulence, which further makes the material uniformly mixed. At the same time, a scraper 18 is evenly arranged on the side of the stirring rod 6 close to the inner wall of the reactor 1. The end of the scraper 18 away from the stirring rod 6 is in contact with the inner wall of the reactor 1 with a contact gap greater than 1 mm and less than 3 mm. When the stirring rod 6 rotates, the scraper 18 can slide along the inner wall of the reactor 1 to scrape off the material attached to the inner wall of the reactor 1.

[0040] The first stirring shaft 4 extends into the outer wall of the reactor 1. A cylindrical structure is arranged from top to bottom, with its axis coinciding with the axis of the first stirring shaft 4. Each cylindrical structure has blades evenly distributed along its circumference, called stirring blades 8, which are inserted between two adjacent impeller plates 7. The stirring blades 8 are inclined at an angle of 30-60 degrees to the axis of the cylindrical structure, and their direction is consistent with the rotation direction of the first stirring shaft 4. When the first stirring shaft 4 rotates, the inclined stirring blades 8 not only generate lateral shearing force on the material but also push the material downwards along the axial direction of the first stirring shaft 4. Combined with the reverse rotation of the second stirring shaft 5, this creates a combined stirring effect of lateral shearing and axial pushing, improving the mixing degree of the material while performing shearing pretreatment.

[0041] Reference Figure 1 and Figure 2 A container called screening container 9 is provided at the bottom of the reactor 1. The screening container 9 is connected to the discharge port of the reactor 1, and a solenoid valve 10 is provided at the connection between the screening container 9 and the discharge port of the reactor 1. The end of the first stirring shaft 4 away from the first drive motor 2 passes through the reactor 1 and extends into the interior of the screening container 9.

[0042] The screening container 9 has an inverted frustum-shaped screen, called frustum screen 11, coaxially arranged inside. The diameter of the upper end of the frustum screen 11 is larger than the diameter of the outlet of the reactor 1. An ultrasonic level switch 12 is installed at the top of the screening container 9 corresponding to the frustum screen 11. The ultrasonic level switch 12 is electrically connected to the solenoid valve 10. The ultrasonic level switch 12 detects the material height in the frustum screen 11. Based on the material height in the frustum screen 11, it controls the opening and closing amplitude of the solenoid valve 10 at the connection between the screening container 9 and the discharge port of the reactor 1, thereby controlling the flow rate of material from the reactor 1 into the frustum screen 11. The diameter of the upper end of the frustum screen 11 is larger than the diameter of the discharge port of the reactor 1, ensuring that the material discharged from the discharge port of the reactor 1 completely falls into the frustum screen 11. The frustum screen 11 is connected to the first stirring shaft 4 via a speed-increasing mechanism 13. The frustum screen 11 uses a mesh size that meets the fineness requirements of the discharge. Through the centrifugal force generated by the high-speed rotation of the frustum screen 11, material with a particle size that meets the fineness requirements of the discharge is screened out through the mesh of the frustum screen 11, while material with a particle size that does not meet the fineness requirements is thrown out of the frustum screen 11 under the action of centrifugal force.

[0043] Preferably, the inner wall of the frustum screen 11 is provided with spiral ribs arranged from top to bottom, called guide strips 17. The guide strips 17 are integrally formed with the frustum screen 11. The spiral direction of the guide strips 17 is opposite to the rotation direction of the frustum screen 11. When the frustum screen 11 rotates, the guide strips 17 can slow down the speed at which the material slides down the inner wall of the screen, prolong the contact time between the material and the screen, and improve the screening efficiency.

[0044] The screening container 9 also has an annular groove container surrounding the outer periphery of the frustum screen 11, called the recovery platform 14. The height of the recovery platform 14 is between three-fifths and four-fifths of the height of the frustum screen 11, ensuring that the material thrown out by the frustum screen 11 can fall smoothly into the recovery platform 14. And because the solenoid valve 10 controls the flow rate of the material from the reactor 1 into the frustum screen 11, it can prevent the material from overflowing into the recovery platform 14. The bottom of the recovery platform 14 is integrally formed with the cavity wall of the screening container 9, forming the cavity wall of the screening container 9 as the outer wall of the recovery platform 14. The height of the outer wall of the recovery platform 14 is higher than the height of the frustum screen 11. The recovery platform 14 is provided with an opening at the bottom as the discharge port of the recovery platform 14. The discharge port of the recovery platform 14 is connected to a connecting pipe 15.

[0045] One end of the connecting pipe 15 away from the discharge port of the recovery platform 14 is connected to the feed port of the reactor 1, ensuring that the recovered material can directly enter the shearing zone of the dual-shaft stirring. A one-way valve 19 and a fluid pump 16 are sequentially installed on the connecting pipe 15 along the material flow direction. The fluid pump 16 is used to provide power for the conveying of the recovered material. The one-way valve 19 is in the direction of conduction from the recovery platform 14 to the reactor 1, preventing the material in the reactor 1 from flowing back into the recovery platform 14 through the connecting pipe 15, ensuring the one-way conveying function of the recovery feeding system, and forming a recovery feeding system from the recovery platform 14 to the reactor 1.

[0046] The implementation principle of this application embodiment is as follows:

[0047] When using a twin-shaft stirring device with a screening and circulation structure, the first drive motor 2 and the second drive motor 3 are started first. The first drive motor 2 and the second drive motor 3 will drive the first stirring shaft 4 and the second stirring shaft 5 to rotate in opposite directions, respectively. As the second stirring shaft 5 rotates, the stirring rod 6, which is fixed to the outer wall of the reactor 1 and extends along the inner wall of the reactor 1, rotates synchronously. The impeller 7 on the stirring rod 6 stirs the material near the inner wall of the reactor 1. The turbulence holes 20 on the impeller 7 allow the material to pass through the turbulence holes 20 as the impeller 7 rotates, forming local turbulence and further improving the uniformity of material mixing. At the same time, the scraper 18 on the side of the stirring rod 6 close to the inner wall of the reactor 1 scrapes off the material adhering to the inner wall of the reactor 1 and reintegrates it into the stirring area.

[0048] The stirring blade 8 on the first stirring shaft 4 rotates with the first stirring shaft 4. Because the stirring blade 8 is inclined to the axis of the cylindrical structure and the blade direction is consistent with the rotation direction of the first stirring shaft 4, it not only generates shearing force on the material when rotating, but also pushes the material to flow downward along the axis of the first stirring shaft 4. Combined with the reverse rotation of the second stirring shaft 5, it forms a compound stirring effect of shearing and axial pushing, which improves the mixing degree of the material and completes the shearing pretreatment of the material.

[0049] The pre-treated material flows from the outlet of the reactor 1 into the connected screening container 9. The speed-increasing mechanism 13 within the screening container 9 drives the coaxially arranged inverted frustum screen 11 to rotate at high speed. The upper diameter of the frustum screen 11 is larger than the outlet diameter of the reactor 1. An ultrasonic level switch 12 detects the material height within the frustum screen 11 and controls the material flow rate via a solenoid valve 10, ensuring that the material discharged from the outlet completely falls into the frustum screen 11. Under centrifugal force, material with a particle size meeting the discharge fineness requirements is screened out through the mesh of the frustum screen 11, while material with a smaller particle size is thrown towards the outer periphery of the frustum screen 11. Spiral guide strips 17 are arranged on the inner wall of the frustum screen 11, which slow down the sliding speed of the material along the inner wall of the frustum screen 11. Extending the contact time between the material and the frustum screen 11 improves screening efficiency. The material thrown towards the outer periphery of the frustum screen 11 falls into the screening container 9 and is surrounded by the recovery platform 14. Subsequently, the material that does not meet the particle size requirements enters the connecting pipe 15 from the outlet of the recovery platform 14, and is transported to the feed port of the reactor 1 by the fluid pump 16 on the connecting pipe 15. At the same time, the one-way valve 19 on the connecting pipe 15 prevents the material in the reactor 1 from flowing back into the recovery platform 14, so that the material that does not meet the particle size requirements re-enters the shearing zone of the twin-shaft agitator and undergoes the agitation, shearing, and screening process again, forming a continuous closed-loop process until the material meets the discharge fineness requirements and is finally discharged from the screening container 9 and enters the homogenizer for grinding.

[0050] The above are all preferred embodiments of this application, and are not intended to limit the scope of protection of this application. Therefore, all equivalent changes made in accordance with the structure, shape and principle of this application should be covered within the scope of protection of this application.

Claims

1. A dual-shaft stirring device with a screening circulation structure, comprising a first drive motor (2) and a second drive motor (3) disposed above a reactor (1), wherein the first drive motor (2) is drivenly connected to a first stirring shaft (4), and the second drive motor (3) is drivenly connected to a second stirring shaft (5); both the first stirring shaft (4) and the second stirring shaft (5) extend into the reactor (1), the second stirring shaft (5) is a hollow shaft structure, the second stirring shaft (5) is rotatably sleeved on the first stirring shaft (4), and the rotation directions of the first stirring shaft (4) and the second stirring shaft (5) are opposite; one end of the second stirring shaft (5) extending into the reactor (1) is provided with a stirring rod (6) extending along the inner wall of the reactor (1), wherein the stirring rod (6) is provided with uniformly arranged blades (7), characterized in that, The first stirring shaft (4) extends into the reactor (1) and is provided with a cylindrical structure arranged from top to bottom. The outer wall of the cylindrical structure is provided with blades evenly arranged in the circumferential direction, which are called stirring blades (8). The stirring blades (8) are inserted between two adjacent blade plates (7). A container called a screening container (9) is provided at the bottom of the reactor (1). The screening container (9) is connected to the outlet of the reactor (1), and a solenoid valve (10) is provided at the connection between the screening container (9) and the outlet of the reactor (1). The end of the first stirring shaft (4) away from the first drive motor (2) extends into the screening container (9). The screening container (9) is provided with an inverted frustum-shaped screen, called frustum screen (11). The diameter of the upper end of the frustum screen (11) is larger than the diameter of the outlet of the reactor (1). An ultrasonic level switch (12) is provided at the top of the screening container (9) corresponding to the frustum screen (11). The ultrasonic level switch (12) is electrically connected to the solenoid valve (10). The frustum screen (11) is connected to the first stirring shaft (4) through a speed-increasing mechanism (13). The frustum screen (11) is a screen with a mesh size that meets the fineness requirements of the output. The screening container (9) is provided with an annular groove container surrounding the outer periphery of the frustum screen (11), which is called the recycling platform (14). The height of the inner side wall of the recycling platform (14) is between three-fifths and four-fifths of the height of the frustum screen (11). The bottom of the recycling platform (14) is connected to the cavity wall of the screening container (9), and the cavity wall of the screening container (9) is used as the outer wall of the recycling platform (14). The height of the outer wall of the recycling platform (14) is higher than that of the frustum screen (11). The recycling platform (14) is provided with an opening at the bottom as the outlet of the recycling platform (14). The outlet of the recycling platform (14) is connected to a connecting pipe (15). The outlet end of the connecting pipe (15) is connected to the feed port of the reactor (1). A fluid pump (16) is provided on the connecting pipe (15) to form a recycling feeding system from the recycling platform (14) to the reactor (1).

2. The twin-shaft stirring device with a screening and circulation structure according to claim 1, characterized in that, The stirring blade (8) is inclined at an angle of 30 to 60 degrees to the axis of the cylindrical structure, and the blade direction of the stirring blade (8) is consistent with the rotation direction of the first stirring shaft (4).

3. The twin-shaft stirring device with a screening and circulation structure according to claim 1, characterized in that, The inner wall of the frustum screen (11) is provided with spiral ridges arranged from top to bottom, which are called guide strips (17). The spiral direction of the guide strips (17) is opposite to the rotation direction of the frustum screen (11).

4. The twin-shaft stirring device with a screening and circulation structure according to claim 1, characterized in that, The stirring rod (6) is provided with uniformly arranged scraper plates (18) on the side close to the inner wall of the reactor (1).

5. The twin-shaft stirring device with a screening and circulation structure according to claim 1, characterized in that, A one-way valve (19) is provided on the connecting pipe (15), and the one-way valve (19) is directed from the recovery platform (14) to the reactor (1).

6. The twin-shaft stirring device with a screening and circulation structure according to claim 1, characterized in that, The blade plate (7) has several through holes, called turbulence holes (20), and the turbulence holes (20) on the blade plate (7) are arranged in a staggered manner.

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