Mixing extrusion mechanism of three-cone screw extrusion tablet press
The mixing and extrusion mechanism of the three-cone screw extruder tablet press solves the problem of insufficient mixing and dispersion effect of traditional screw extruders, and realizes efficient mixing and low energy consumption material processing, which is suitable for the production of high-performance materials.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- NANJING GREEN ELEPHANT MACHINERY IND TECHNOLOGY CO LTD
- Filing Date
- 2025-04-21
- Publication Date
- 2026-04-17
AI Technical Summary
Traditional single-screw and twin-screw extruders have limited mixing and dispersion effects, making it difficult to meet the needs of high-performance material preparation. Furthermore, the shear force is not easily adjusted when processing heat-sensitive materials, resulting in significant energy consumption and waste emissions.
The mixing and extrusion mechanism of the three-cone screw extruder tablet press uses the arrangement of three conical screws to achieve thorough and repeated kneading and crushing of materials, enhancing the mixing uniformity and mixing efficiency. Combined with a permanent magnet variable frequency motor and a transmission gearbox, it realizes the coordinated work between the screws.
It improves the uniformity of material mixing and output, reduces energy consumption, is suitable for processing special materials, enhances product quality and production efficiency, and expands the scope of application.
Smart Images
Figure CN224130421U_ABST
Abstract
Description
Technical Field
[0001] This utility model specifically relates to the screw extrusion mechanism of a screw extrusion tablet press. Background Technology
[0002] As the requirements for material performance continue to increase, there is a need to develop more advanced extrusion technologies to meet these demands. For example, in the field of polymer materials, more efficient mixing and plasticizing equipment is required to prepare high-performance polymer composites and alloys.
[0003] The rapid development of polymer multiphase alloy systems and their nanocomposites has placed new demands on compounding processes and equipment. Traditional single-screw and twin-screw extruders have limited compounding and dispersion effects when dealing with complex blending systems, making it difficult to meet the needs of high-performance material preparation.
[0004] Single-screw extruders have a simple structure, but their mixing capacity is relatively weak, and the material flow within the barrel is relatively uniform, resulting in insufficient plasticizing effect and mixing uniformity. While twin-screw extruders are superior to single-screw extruders in terms of mixing and conveying capacity, they still have certain limitations for processing some complex blending systems or materials with special performance requirements. For example, it is difficult to achieve precise dispersion control of materials, and the shearing action may not be easy to adjust precisely when processing heat-sensitive materials.
[0005] With increasingly stringent environmental policies, higher requirements are being placed on energy consumption and waste emissions during the extrusion process. As demands for material performance continue to rise, more advanced extrusion technologies need to be developed to meet these needs. For example, in the field of polymer materials, reducing resource waste is crucial for preparing high-performance polymer composites and alloys. Summary of the Invention
[0006] Purpose of the invention: In view of the defects and technical problems existing in the background technology, this utility model provides a mixing extrusion mechanism for a three-cone screw extruder tablet press. By changing the gap between the screws and between the screws and the hopper components through the arrangement of the three conical screws, the material in the hopper can be fully and repeatedly kneaded and crushed, which can improve the mixing uniformity of the material and enhance the mixing efficiency.
[0007] Technical Solution: To achieve the above-mentioned objectives, this utility model adopts the following technical solution: a compounding extrusion mechanism for a three-cone screw extruder tablet press, comprising a base, a transmission gearbox and a screw hopper mounted on the base, wherein:
[0008] The screw hopper includes a hopper and a screw assembly disposed within the hopper. The screw assembly includes a central screw, a left screw and a right screw horizontally disposed on both sides of the central screw. The central screw, the left screw and the right screw are all tapered screws. The diameter of the screw from the tail end to the front end includes a feeding section, a compression section and a metering section. The thread diameter of the feeding section, the compression section and the metering section gradually decreases.
[0009] The transmission gearbox includes a transmission housing, and an intermediate gear, a left gear, and a right gear disposed within the transmission housing, which are respectively sleeved with the tail ends of the intermediate screw, the left screw, and the right screw. The intermediate gear meshes and drives the left gear and the right gear respectively, and the left screw and the right screw can rotate in opposite directions with the intermediate screw under the drive of the intermediate screw.
[0010] Preferably, the hopper is provided with a conical space that matches the shape of the screw assembly.
[0011] Preferably, the length of the feed section, compression section and metering section of the screw is 1-2 screw pitches.
[0012] Preferably, the system also includes a permanent magnet variable frequency motor, which is connected to the intermediate screw drive.
[0013] Preferably, the middle screw, left screw and right screw are respectively provided with heat transfer channels for the flow of heat exchange medium, and a connection end for the heat exchange medium is provided at the tail end of the screw.
[0014] Preferably, the transmission gearbox further includes a front bearing assembly and a rear bearing assembly respectively fitted onto the tail ends of all screws and located on both sides of the gear;
[0015] The rear bearing assembly includes an intermediate bearing and a rear bearing that are sequentially sleeved on the screw along the axial direction. The tail end of the screw is also provided with a rear spacer, and a rear seal is provided between the rear spacer and the gearbox.
[0016] The front bearing assembly includes a front bearing fitted on a screw, a middle spacer and a front spacer provided on both sides of the front bearing, and a front bearing seat cover that seals the front bearing.
[0017] Preferably, the intermediate bearing is further provided with a front nut, and the tail end of the screw is further provided with a rear nut.
[0018] Preferably, the tail end of the hopper is also provided with a front bearing seat cover.
[0019] Preferably, a rear seal is provided on the outer side of the rear bearing; and a rear bearing is provided on the outer side of the front bearing.
[0020] Preferably, the screw is also provided with a feed tray.
[0021] Beneficial Effects: Compared with existing technologies, this utility model has the following advantages: The mixing and extrusion mechanism of the three-cone screw extruder tablet press of this utility model, by increasing the number of screws and optimizing the screw structure, enables the material to be more fully stirred, compressed, and mixed, effectively solving the mixing and feeding problems existing in twin-screw extruder tablet presses, and improving the tablet quality. Because the three screws work in tandem, more material can be conveyed and processed in the same amount of time, significantly increasing the output compared to two-cone screw extruder tablet presses. This new model has better dispersion effect, venting performance, and shorter material residence time, making it more suitable for processing such special materials, thereby expanding the application range of extruder tablet presses. Specifically:
[0022] It exhibits excellent mixing and plasticizing effects. Because the three-screw extruder has three screws, it forms multiple meshing zones, subjecting the material to intense shearing, kneading, and stretching during extrusion. Its larger compaction area and stronger kneading action enable more thorough plasticization and more uniform dispersion of the material, making it particularly suitable for processing materials with high pigment and filler content.
[0023] High output: Due to the coordinated operation of the three screws, more material can be conveyed and processed in the same amount of time, resulting in a significantly higher output compared to a two-cone screw extruder. In the production of carbon black masterbatch, the three-cone screw extruder can achieve an output of 180 kg / hour, while the two-cone screw extruder only reaches 80 kg / hour.
[0024] Superior Product Quality: Due to the thorough plasticization and uniform component dispersion achieved by the three-cone screw extruder, the produced products exhibit more stable performance and higher quality. For example, PP flame-retardant cable material produced using a three-cone screw extruder demonstrates superior strength and elongation compared to products manufactured using a two-cone screw extruder.
[0025] Excellent energy efficiency: Due to the high efficiency of the three-cone screw extruder, its energy consumption is relatively low when producing the same output of products. Taking the production of 50% concentration carbon black masterbatch as an example, the specific power of the three-cone screw extruder is only 0.2-0.25kw / kg. Attached Figure Description
[0026] Figure 1 This is a schematic diagram of the mixing and extrusion mechanism of the three-cone screw extruder tablet press of this utility model.
[0027] Figure 2 for Figure 1 A cross-sectional view along the AA direction.
[0028] Among them, 1. Transmission box 2. Feed hopper 3. Screw hopper 4. Permanent magnet variable frequency motor (1) 5. Flat key 6. Intermediate gear 7. Right gear 8. Middle partition sleeve 9. Front partition sleeve 10. Front bearing seat cover 11. Right screw 12. Intermediate screw 13. Left screw 14. Baffle plate 15. Front seal 16. Front bearing 17. Left gear 18. Front nut 19. Intermediate bearing 20. Rear bearing 21. Rear partition sleeve 22. Rear seal 23. Rear nut 24. Base 25. Rotary joint 26. Reduction gearbox. Detailed Implementation
[0029] The present invention will be further illustrated below with reference to the accompanying drawings and specific embodiments. It should be understood that these embodiments are for illustrative purposes only and are not intended to limit the scope of the present invention. After reading the present invention, any modifications of the present invention in various equivalent forms by those skilled in the art will fall within the scope defined by the appended claims.
[0030] The compounding extrusion mechanism of this utility model three-cone screw extruder combines the advantages of twin-screw extruders, conical extruders, and differential kneaders. The increased screw tail diameter improves feeding capacity and load-bearing capacity, facilitating the arrangement of thrust bearings and gears. The large screw channel volume in the feeding section facilitates the addition of loose powders and also promotes heat conduction. The small screw diameter in the discharge section results in a low circumferential speed, reducing shear and frictional heat, which is beneficial for processing heat-sensitive materials. The three screws mesh to form two meshing zones, providing multiple functions such as shearing and stretching, significantly enhancing mixing and plasticizing effects, and also possessing self-cleaning capabilities.
[0031] In a conical screw extruder tablet press, three screws rotate in coordination to draw material from the hopper into the barrel. Due to the special shape and rotation of the screws, the material moves axially under the action of the screws, and is also subjected to squeezing, shearing, and tensile forces from the screws.
[0032] The three screws form multiple meshing points and meshing zones, where the material is subjected to intense shearing. This is similar to using multiple mixers to simultaneously agitate the material, allowing the various components to mix, particles of different sizes to be evenly distributed, and the additives to fully contact the matrix material.
[0033] The arrangement of the three-cone screws further kneads and crushes the material within the barrel. The varying gaps between the screws and between the screws and the barrel wall cause the material to be repeatedly squeezed and kneaded as it passes through, much like repeatedly pressing dough between two boards. This further improves the uniformity of the mixture and enhances the mixing efficiency.
[0034] After thorough mixing and plasticizing, the material is extruded through the die head and mold by the continued push of the screw. The die head and mold have specific shapes and sizes. When the material passes through the mold, it is extruded and shaped according to the shape of the mold to form the desired product shape, such as pipes, sheets, profiles, etc.
[0035] like Figure 1 and 2 As shown, the mixing and extrusion mechanism of the three-cone screw extruder tablet press of this utility model mainly includes a base, a transmission gearbox and a screw hopper disposed on the base, wherein:
[0036] The screw hopper includes a hopper, a feed hopper located above the hopper, and a screw assembly located inside the hopper. The hopper has a conical space that matches the shape of the screw assembly. The screw assembly includes a central screw, and left and right screws horizontally located on either side of the central screw. All three screws are conical, and their diameters gradually decrease from the tail end to the front end, comprising a feeding section, a compression section, and a metering section. Typically, the feeding and compression sections are two screw pitches long, while the metering section is one screw pitch long.
[0037] The transmission gearbox includes a transmission housing, and an intermediate gear, a left gear, and a right gear disposed within the transmission housing, which are respectively sleeved onto the tail ends of the intermediate screw, left screw, and right screw. The intermediate gear meshes and drives the left and right gears, respectively. The left and right screws can rotate in opposite directions to the intermediate screw under its drive. The tail end of the intermediate screw is driven by a permanent magnet variable frequency motor.
[0038] Furthermore, the transmission gearbox also includes a front bearing assembly and a rear bearing assembly, respectively fitted onto the tail ends of all screws and located on both sides of the gear; the rear bearing assembly includes an intermediate bearing and a rear bearing sequentially fitted onto the screws along the axial direction, and a rear spacer is also provided at the tail end of the screws, with a rear seal between the rear spacer and the gearbox; the front bearing assembly includes a front bearing fitted onto the screws, an intermediate spacer and a front spacer provided on both sides of the front bearing, and a front bearing seat cover sealing the front bearing. The intermediate bearing also has a front nut, and the tail end of the screw also has a rear nut.
[0039] As a preferred embodiment, the middle screw, left screw and right screw are respectively provided with heat transfer channels for the flow of heat exchange medium, and a connection end for the heat exchange medium is provided at the tail end of the screw.
[0040] The mixing and extrusion mechanism of this utility model's three-cone screw extruder combines the advantages of twin-screw extruders, conical extruders, and differential kneaders. The increased screw tail diameter improves the feeding capacity and load-bearing capacity, facilitating the arrangement of thrust bearings and gears. The large screw channel volume in the feeding section facilitates the addition of loose powders and also promotes heat conduction. The small screw diameter in the discharge section results in a low circumferential speed, reducing shear and frictional heat, which is beneficial for processing heat-sensitive materials. The three screws mesh to form two meshing zones, providing multiple functions such as shearing and stretching, significantly enhancing mixing and plasticizing effects, and also possessing self-cleaning capabilities.
[0041] In a conical screw extruder tablet press, three screws rotate in coordination to draw material from the hopper into the barrel. Due to the special shape and rotation of the screws, the material moves axially under the action of the screws, and is also subjected to squeezing, shearing, and tensile forces from the screws.
[0042] The three screws form multiple meshing points and meshing zones, where the material is subjected to intense shearing. This is similar to using multiple mixers to simultaneously agitate the material, allowing the various components to mix, particles of different sizes to be evenly distributed, and the additives to fully contact the matrix material.
[0043] The arrangement of the three-cone screws further kneads and crushes the material within the barrel. The varying gaps between the screws and between the screws and the barrel wall cause the material to be repeatedly squeezed and kneaded as it passes through, much like repeatedly pressing dough between two boards. This further improves the uniformity of the mixture and enhances the mixing efficiency.
[0044] After thorough mixing and plasticizing, the material is extruded through the die head and mold by the continued push of the screw. The die head and mold have specific shapes and sizes. When the material passes through the mold, it is extruded and shaped according to the shape of the mold to form the desired product shape, such as pipes, sheets, profiles, etc.
[0045] The above embodiments are merely illustrative of the principles and effects of this application and are not intended to limit this application. Any person skilled in the art can modify or alter the above embodiments without departing from the spirit and scope of this application. Therefore, all equivalent modifications or alterations made by those skilled in the art without departing from the spirit and technical concept disclosed in this application should still be covered by the claims of this application.
Claims
1. A mixing and extruding mechanism of a triple-tapered screw type extrusion tablet press, characterized by: Includes a base, a transmission gearbox mounted on the base, and a screw hopper, wherein: The screw hopper includes a hopper and a screw assembly disposed within the hopper. The screw assembly includes a central screw, a left screw and a right screw horizontally disposed on both sides of the central screw. The central screw, the left screw and the right screw are all tapered screws. The diameter of the screw from the tail end to the front end includes a feeding section, a compression section and a metering section. The thread diameter of the feeding section, the compression section and the metering section gradually decreases. The transmission gearbox includes a transmission housing, and an intermediate gear, a left gear, and a right gear disposed within the transmission housing, which are respectively sleeved with the tail ends of the intermediate screw, the left screw, and the right screw. The intermediate gear meshes and drives the left gear and the right gear respectively, and the left screw and the right screw can rotate in opposite directions with the intermediate screw under the drive of the intermediate screw.
2. The mixing and extruding mechanism of the triple-tapered screw type extrusion and tablet press according to claim 1, wherein: The hopper is provided with a conical space that matches the shape of the screw assembly.
3. The mixing and extruding mechanism of the triple-tapered screw type extrusion and tablet press according to claim 1, wherein: The length of the feed section, compression section, and metering section of the screw is 1-2 screw pitches.
4. The mixing and extruding mechanism of the triple-tapered screw type extrusion and tablet press according to claim 1, wherein: It also includes a permanent magnet variable frequency motor, which is connected to the intermediate screw drive.
5. The mixing and extruding mechanism of the triple-tapered screw type extrusion and tablet press according to claim 1, wherein: The middle screw, left screw, and right screw are each provided with a heat transfer channel for the heat exchange medium to flow through, and a connection end for the heat exchange medium is provided at the tail end of the screw.
6. The mixing and extrusion mechanism of the three-cone screw extruder tablet press according to claim 1, characterized in that: The transmission gearbox also includes a front bearing assembly and a rear bearing assembly respectively fitted onto the tail ends of all screws and located on both sides of the gear; The rear bearing assembly includes an intermediate bearing and a rear bearing that are sequentially sleeved on the screw along the axial direction. The tail end of the screw is also provided with a rear spacer, and a rear seal is provided between the rear spacer and the gearbox. The front bearing assembly includes a front bearing fitted on a screw, a middle spacer and a front spacer provided on both sides of the front bearing, and a front bearing seat cover that seals the front bearing.
7. The mixing and extruding mechanism of the triple-tapered screw type extrusion and tablet press according to claim 6, wherein: The intermediate bearing is also provided with a front nut, and the tail end of the screw is also provided with a rear nut.
8. The mixing and extruding mechanism of the triple-tapered screw type extrusion and tablet press according to claim 6, wherein: The tail end of the hopper is also equipped with a front bearing seat cover.
9. The mixing and extruding mechanism of the triple-tapered screw type extrusion and tablet press according to claim 6, wherein: The rear bearing is further provided with a rear seal on its outer side; the front bearing is further provided with a rear bearing on its outer side.
10. The mixing and extruding mechanism of the triple-tapered screw type extrusion and tablet press according to claim 6, wherein: The screw is also equipped with a feed pan.