Environmentally friendly crack-resistant recycled asphalt concrete and its production method

Abstract

This application relates to environmentally friendly crack-resistant recycled asphalt concrete, comprising the following raw material components: recycled asphalt pavement material, new aggregate, new base asphalt, recycling agent, and crack-resistant agent components. The crack-resistant agent components include limestone powder, PET fiber, and warm mix agent in a weight ratio of 15:1:1. The application also relates to a production method for environmentally friendly crack-resistant recycled asphalt concrete. The raw material components are mixed in a mixing tank. The mixing tank is equipped with a premixing section including a premixing tank body and longitudinal mixing rollers. The premixing tank body includes a cover and a bottom plate. The cover body can be raised and lowered relative to the bottom plate. The longitudinal mixing rollers are installed inside the cover body and fixed to the bottom plate. In this application, the recycled asphalt pavement material and recycling agent are premixed in the premixing tank to restore flexibility and adhesion. After the cover body rises relative to the bottom plate, the centrifugal force generated by the rotation of the longitudinal mixing rollers throws the activated recycled asphalt pavement material into the mixing tank for further mixing, ensuring the final quality of the recycled asphalt concrete.

Description

Technical Field

[0001] This application relates to the technical field of recycled asphalt concrete production, and in particular to environmentally friendly crack-resistant recycled asphalt concrete and its production method. Background Technology

[0002] After long-term service, asphalt pavements generate a large amount of milled material. How to efficiently and effectively utilize this waste material has become a key issue for the sustainable development of the industry. Recycled asphalt concrete technology restores the activity of old asphalt by introducing recycling agents, realizing the resource utilization of waste material and demonstrating significant environmental and economic benefits.

[0003] However, existing recycled asphalt mixtures generally have performance shortcomings, especially in terms of crack resistance, which is difficult to meet the requirements of high-grade pavements, so there is still room for improvement. Summary of the Invention

[0004] To improve the crack resistance of recycled asphalt concrete, this application provides environmentally friendly crack-resistant recycled asphalt concrete and its production method.

[0005] The environmentally friendly, crack-resistant recycled asphalt concrete provided in this application adopts the following technical solution: Environmentally friendly crack-resistant recycled asphalt concrete, by weight percentage, includes the following raw material components: 42-44% recycled old asphalt pavement material, 39-41% new aggregate, 5.5-10.5% new base asphalt, 0.1-0.3% recycling agent, and 4.2-4.5% crack-resistant agent component. The crack-resistant agent component includes limestone powder, PET fiber, and warm mix agent in a weight ratio of 15:1:1.

[0006] By adopting the above technical solution and introducing a specific weight ratio of 15:1:1 for the anti-cracking agent components, a highly efficient anti-cracking network is constructed. Among them, PET fiber plays a reinforcing role in the mixture, effectively bridging micro-cracks and inhibiting crack propagation; limestone powder and asphalt form a high-strength binder, enhancing the adhesion between aggregates; warm mix agent improves workability and ensures uniform mixing of the mixture; the synergistic effect of the three significantly improves the flexibility and deformation resistance of asphalt pavement and enhances the crack resistance of recycled asphalt concrete.

[0007] Preferably, the new aggregate comprises 10-20mm crushed stone, 5-10mm crushed stone and 5mm manufactured sand in a weight ratio of 11:6:4.

[0008] Preferably, the recycling agent is asphalt recycling agent 111-87-5; the warm mix agent is ZZ-W2 warm mix agent.

[0009] This application also provides a method for producing environmentally friendly crack-resistant recycled asphalt concrete, employing the following technical solution: the raw material components are mixed in a mixing tank supported by a frame. The mixing tank is equipped with a premixing section, which includes a premixing tank body disposed within the mixing tank and having a premix material inlet, and a longitudinal stirring roller installed within the premixing tank. The longitudinal stirring roller is driven by a fixed motor fixed to the mixing tank. Recycled old asphalt pavement material and 80% of the total amount of recycling agent are placed in the premixing tank. Spiral stirring blades are crisscrossed around the longitudinal stirring roller. The premixing tank body includes a cover and a bottom plate. The bottom plate is fixed to the bottom of the longitudinal stirring roller. The cover moves on the mixing tank via a lifting structure and can be raised and lowered relative to the bottom plate. The longitudinal stirring roller can be raised and lowered along the cover.

[0010] By adopting the above technical solution, the recycled asphalt pavement material and recycling agent are pre-mixed and allowed to stand in the premix tank before entering the mixing tank, which quickly restores the flexibility and adhesion, avoiding the decline in the performance of the mixture due to incomplete activation of the recycled asphalt pavement material. After activation is completed, the cover of the premix tank rises relative to the bottom plate, and with the rotation of the longitudinal mixing rollers, the activated recycled asphalt pavement material in the premix tank is thrown into the mixing tank by centrifugal force for further mixing. The activated recycled asphalt pavement material has a higher compatibility with other raw material components, which helps to ensure the final quality of recycled asphalt concrete.

[0011] Preferably, the lifting structure includes a lifting cylinder and a lifting ring. The lifting ring is fixed to the outer wall of the cover. One side of the lifting ring is fixed with an opposing extension rod, and a connecting rod is fixed between the opposing extension rods. The lifting cylinder is installed on the outside of the side wall of the mixing tank, and the piston rod of the lifting cylinder is fixed to the connecting rod.

[0012] By adopting the above technical solution, the lifting ring located outside the cover can improve the stability of the lifting cylinder's lifting drive for the entire cover, and the lifting cylinder can be used to drive the lifting of the cover, making it more convenient to use.

[0013] Preferably, the stirring blade includes a first shear blade and a second shear blade, the radial width of the second shear blade is greater than the radial width of the first shear blade, and the second shear blade is in a spiral shape opposite to that of the first shear blade.

[0014] By adopting the above technical solution, the first and second shear blades are used to improve the uniform mixing effect of recycled old asphalt pavement material and recycling agent, thereby achieving full regeneration and activation of recycled old asphalt pavement material.

[0015] Preferably, the mixing tank is further provided with a blending section; the blending section includes a blending chamber located in the mixing tank for placing the remaining raw material components and a transverse stirring roller driven by a drive motor disposed in the blending chamber, the transverse stirring roller is provided with spiral blades, and the lower part of the mixing tank forms an inverted cone shape; a main feed inlet that can be opened and closed is provided on the side wall of the mixing tank at a position offset from the transverse stirring roller; and a discharge port that can be opened and closed is provided at the bottom of the mixing tank.

[0016] By adopting the above technical solution, the premixed materials of old asphalt pavement recycling material and recycling agent are uniformly mixed with other raw material components through the mixing section; the lower part of the mixing tank is formed into an inverted cone shape, which cooperates with the spiral blades on the transverse mixing roller to reduce the mixing dead zone; the main feed inlet is set on the side wall of the mixing tank to avoid structural interference with the premix tank body.

[0017] Preferably, a relief groove is provided on the outer periphery of the base plate, the bottom of the cover extends and is positioned in the relief groove, and an inner sealing ring is fixed on the inner side wall of the cover, which is inserted into the relief groove and abuts against the inner side of the base plate; the upper surface of the base plate forms a conical surface.

[0018] By adopting the above technical solution, a sealing ring is set on the inner side wall of the hood and accommodated in the clearance groove on the outer periphery of the bottom plate, so that the hood and the bottom plate are relatively positioned to maintain a seal and avoid leakage of premixed materials. When the hood rises relative to the bottom plate and is fed by the rotation of the longitudinal stirring roller, the sealing ring will not obstruct the feeding process. The conical surface on the bottom plate is used to assist in feeding.

[0019] Preferably, the mixing tank is fixed with cross-arranged support rods, which abut against the bottom of the base plate.

[0020] Preferably, a lifting plate is fixed on the mixing tank, a fixed motor is fixed on the lifting plate, and a through hole is opened on the mixing tank for the lifting of the cover. The two ends of the lifting plate are respectively located on the outside of the through hole. An outer circumferential sealing ring is fixed on the side wall of the through hole and abuts against the outside of the side wall of the cover. A through hole is opened on the cover for the movement of the longitudinal stirring roller, and a matching sealing ring is fixed on the side wall of the through hole and sleeved on the longitudinal stirring roller. The premixed material inlet extends obliquely outward from the mixing tank and is offset from the fixed motor.

[0021] In summary, this application includes at least one of the following beneficial technical effects: A crack-resistant agent component with a specific weight ratio of 15:1:1 was introduced into the raw material composition to construct a highly efficient crack-resistant network. Among them, PET fiber acts as a reinforcement in the mixture, effectively bridging micro-cracks and inhibiting crack propagation; limestone powder and asphalt form a high-strength binder, enhancing the adhesion between aggregates; warm mix agent improves workability and ensures uniform mixing of the mixture; the synergistic effect of these three components significantly improves the flexibility and deformation resistance of asphalt pavement, and enhances the crack resistance of recycled asphalt concrete. The recycled asphalt pavement material and recycling agent are pre-mixed and allowed to stand in the premix tank before entering the mixing tank. This process quickly restores the material's flexibility and adhesion, preventing a decline in the mixture's performance due to incomplete activation of the recycled asphalt pavement material. Once activation is complete, the premix tank's cover rises relative to the bottom plate. As the longitudinal mixing rollers rotate, centrifugal force is used to throw the activated recycled asphalt pavement material from the premix tank into the mixing tank for further mixing. The activated recycled asphalt pavement material has a higher compatibility with other raw material components, which helps ensure the final quality of the recycled asphalt concrete. A sealing ring is installed on the inner wall of the hood and accommodated in the clearance groove on the outer periphery of the base plate. This ensures that the hood and the base plate remain sealed when they are positioned relative to each other, preventing leakage of premixed materials. When the hood rises relative to the base plate and is fed by the rotation of the longitudinal stirring roller, the sealing ring will not obstruct the feeding process. The conical surface on the base plate is used to assist in feeding. Attached Figure Description

[0022] Figure 1 This is a structural schematic diagram of an embodiment of this application; Figure 2 This is a partial cross-sectional structural diagram highlighting the interior of the premix tank and the blending section of an embodiment of this application; Figure 3 This is a partial structural diagram highlighting the interconnection of the longitudinal stirring roller, the cover, and the mixing tank in an embodiment of this application. Figure 4 yes Figure 2 A magnified structural diagram of part A in the middle; Figure 5 This is a schematic diagram of the structure of the first and second shear blades in an embodiment of this application.

[0023] Explanation of reference numerals in the attached drawings: 1. Frame; 2. Mixing tank; 21. Through hole; 22. Support rod; 23. Lifting plate; 24. Main feed inlet; 25. Discharge outlet; 3. Premixing section; 31. Premixing tank body; 311. Cover; 312. Bottom plate; 32. Longitudinal stirring roller; 321. First shearing blade; 322. Second shearing blade; 4. Blending section; 41. Blending chamber; 42. Transverse stirring roller; 421. Spiral blade; 5. Premixed material feed inlet; 6. Outer circumferential sealing ring; 7. Relief groove; 8. Inner sealing ring; 9. Fixed motor; 10. Through hole; 101. Matching sealing ring; 11. Lifting structure; 111. Lifting cylinder; 112. Lifting ring; 12. Extension rod; 13. Connecting rod; 14. Conical surface; 15. Drive motor. Detailed Implementation

[0024] The present application will be further described in detail below with reference to the accompanying drawings.

[0025] This application discloses an environmentally friendly, crack-resistant recycled asphalt concrete, which, by weight percentage, comprises the following raw material components: 42-44% recycled asphalt pavement material, 39-41% new aggregate, 5.5-10.5% new base asphalt, 0.1-0.3% recycling agent, and 4.2-4.5% crack-resistant agent component. The crack-resistant agent component includes limestone powder, PET fiber, and warm mix agent in a weight ratio of 15:1:1. The introduction of the specific weight ratio of crack-resistant agent component of 15:1:1 constructs a highly efficient crack-resistant network. Among them, PET fiber plays a reinforcing role in the mixture, effectively bridging micro-cracks and inhibiting crack propagation; limestone powder and asphalt form a high-strength binder, enhancing the adhesion between aggregates; warm mix agent improves workability and ensures uniform mixing of the mixture; the synergistic effect of the three components significantly improves the flexibility and deformation resistance of the asphalt pavement, and enhances the crack resistance of the recycled asphalt concrete.

[0026] The new aggregates consist of 10-20mm crushed stone, 5-10mm crushed stone, and 5mm manufactured sand in a weight ratio of 11:6:4. The fineness modulus of the manufactured sand is 2.6-3.0, and the parent rock is basalt. The recycling agent is asphalt recycling agent 111-87-5. The warm mix agent is ZZ-W2 warm mix agent. The limestone mineral powder has a particle size of less than 0.075mm. The PET fiber has a length of 3-6mm and a diameter of 10-20μm.

[0027] This application also discloses a method for producing environmentally friendly, crack-resistant recycled asphalt concrete.

[0028] Reference Figure 1 , 2 The raw material components are mixed in a mixing tank 2 supported by a frame 1. The mixing tank 2 is equipped with a premixing section 3 and a blending section 4. First, the recycled old asphalt pavement material is crushed and screened to a particle size ≤26.5mm. Then, the recycled old asphalt pavement material and 80% of the total amount of recycling agent are premixed in the premixing section 3 for 3-5 minutes and allowed to stand for 10-20 minutes to form a premixed material, which quickly restores flexibility and adhesion. Other raw material components are mixed in the blending section 4 of the mixing tank 2, and finally the premixed material enters the blending section 4 to be uniformly mixed with other raw material components.

[0029] Reference Figure 1 , 2 The premixing section 3 includes a premixing tank 31 disposed inside the mixing tank 2 and having a premixed material inlet 5. The premixing tank 31 includes a cover 311 and a bottom plate 312 located at the bottom of the cover 311. A premixed material inlet 5 is provided on one side above the cover 311. It should be noted that the cover 311 has an interlayer, and heat transfer oil can be placed in the interlayer to maintain the temperature inside the cover 311 at 110°C, ensuring that the recycling agent fully penetrates the recycled old asphalt pavement material and restores its flexibility.

[0030] Reference Figure 2 , 3 The mixing tank 2 has a through hole 21 in the middle. The cover 311 can be raised and lowered relative to the bottom plate 312 at the through hole 21. A high-temperature resistant outer peripheral sealing ring 6 is fixed on the side wall of the through hole 21 and abuts against the outside of the side wall of the cover 311. The outer peripheral sealing ring 6 does not affect the raising and lowering of the cover 311.

[0031] Reference Figure 2 Inside the mixing tank 2, there are cylindrical support rods 22 arranged in a cross pattern. The support rods 22 are supported on the bottom of the base plate 312. The bottom contact surface of the base plate 312 is polished and coated with high-temperature resistant grease to reduce the contact friction between the base plate 312 and the support rods 22 when the base plate 312 rotates. The cylindrical support rods 22 will not affect the feeding process of the premixed material. In addition, the outer end of the support rods 22 away from the base plate 312 can be reduced in diameter to reduce the contact area with the base plate 312 and reduce friction.

[0032] Reference Figure 2 , 4 The bottom plate 312 has a relief groove 7 on its outer periphery. The bottom of the cover 311 extends and is positioned in the relief groove 7. A high-temperature resistant inner sealing ring 8 is fixed on the inner wall of the cover 311, which is inserted into the relief groove 7 and abuts against the bottom plate 312. This keeps the cover 311 and the bottom plate 312 sealed when they are positioned relative to each other, thus preventing leakage of premixed materials.

[0033] Reference Figure 2 , 5 The premixing section 3 also includes a longitudinal stirring roller 32 installed inside the premixing tank. The longitudinal stirring roller 32 is provided with spiral stirring blades that are crisscrossed. The upper end of the longitudinal stirring roller 32 passes through the cover 311 and the lower end is fixed to the bottom plate 312. As the longitudinal stirring roller 32 rotates, the cover 311 rises, and a feeding gap is formed between the cover 311 and the bottom plate 312. Under the centrifugal force of the rotation of the longitudinal stirring roller 32, the premixed material can be evenly thrown into the mixing section. The upper surface of the bottom plate 312 forms a conical surface 14, which plays an auxiliary role in feeding.

[0034] Reference Figure 5 The mixing blades include a first shear blade 321 and a second shear blade 322. The radial width of the second shear blade 322 is greater than the radial width of the first shear blade 321, and the second shear blade 322 is spiral in the opposite direction to the first shear blade 321. The first shear blade 321 and the second shear blade 322 are used to improve the uniform mixing effect of the recycled old asphalt pavement material and the recycling agent, so as to achieve full regeneration and activation of the recycled old asphalt pavement material.

[0035] Reference Figure 2 , 3A lifting plate 23 of a certain height is fixed above the mixing tank 2. A fixed motor 9 is fixed on the lifting plate 23. The longitudinal mixing roller 32 is driven by the fixed motor 9. The two ends of the lifting plate 23 are located on the outside of the through hole 21. The lifting plate 23 provides space for the lifting of the cover 311. After the cover 311 rises relative to the bottom plate 312, the centrifugal force of the longitudinal mixing roller 32 is used to throw the old asphalt pavement recycled material activated by the recycling agent in the cover 311 into the mixing part 4 in the mixing tank 2 for further mixing.

[0036] Reference Figure 3 A through hole 10 is provided in the upper middle part of the cover 311 for the upper end of the longitudinal stirring roller 32 to move. A high-temperature resistant mating sealing ring 101 is fixed on the side wall of the through hole 10 and sleeved on the longitudinal stirring roller 32. The mating sealing ring 101 does not interfere with the lifting and lowering of the cover 311. The through hole 10 provides room for the lifting and lowering of the cover 311 relative to the longitudinal stirring roller 32. The premixed material inlet 5 extends obliquely outward from the mixing tank 2 and is offset from the fixed motor 9 so that the fixed motor 9 will not interfere with the premixed material inlet 5 during the lifting and lowering of the cover 311.

[0037] Reference Figure 1 The lifting and lowering of the cover 311 is driven by the lifting structure 11. The lifting structure 11 includes a lifting cylinder 111 and a lifting ring 112. The lifting ring 112 is fixed to the outer wall of the cover 311. An opposite extension rod 12 is fixed to one side of the lifting ring 112. A connecting rod 13 is fixed between the opposite extension rods 12 at intervals. The lifting cylinder 111 is installed on the outside of the side wall of the mixing tank 2, and the piston rod of the lifting cylinder 111 is fixed to the connecting rod 13 near the outer end of the extension rod 12. The lifting ring 112 can improve the stability of the lifting cylinder 111 in driving the lifting and lowering of the entire cover 311. The lifting cylinder 111 is used to drive the lifting and lowering of the cover 311, making it more convenient to use. It should be noted that the lifting cylinder 111 can also be symmetrically arranged on both sides of the mixing tank 2 and synchronized by a pneumatic synchronization valve to synchronously lift the lifting ring 112 and both sides of the cover 311.

[0038] Reference Figure 1 , 2 The mixing section 4 includes a mixing chamber 41 located inside the mixing tank 2 for placing the remaining raw material components and a transverse stirring roller 42 disposed inside the mixing chamber 41. The transverse stirring roller 42 is driven by a drive motor 15 fixed to the side wall of the mixing tank 2, and the transverse stirring roller 42 is provided with a spiral blade 421. The lower part of the mixing tank 2 is formed into an inverted cone shape so that the spiral blade 421 can cover the mixing chamber 41 as much as possible and reduce the mixing dead zone.

[0039] Reference Figure 1 , 2The mixing tank 2 has an openable and closable main feed inlet 24 located on its side wall at a position offset from the transverse mixing roller 42. The main feed inlet 24 is located on the side wall of the mixing tank 2 to avoid obstructing the lifting and lowering of the cover 311. The bottom of the mixing tank 2 has an openable and closable discharge outlet 25, from which the evenly mixed recycled asphalt concrete is discharged. The premixed material feed inlet 5, the main feed inlet 24, and the discharge outlet 25 are all sealed with bolted cover plates. It should be noted that during the blending process, the new aggregate is heated to 175°C in the drying drum before being fed into the main feed inlet 24. This allows the temperature of the overall mixture to be balanced and maintained at around 150°C through heat transfer when the raw material components are blended with the premixed material, thus meeting the temperature requirements for the production of recycled asphalt concrete.

[0040] 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. Environmentally friendly, crack-resistant recycled asphalt concrete, characterized by: By weight percentage, it includes the following raw material components: 42-44% recycled old asphalt pavement material, 39-41% new aggregate, 5.5-10.5% new base asphalt, 0.1-0.3% recycling agent, and 4.2-4.5% crack-resistant agent component, wherein the crack-resistant agent component includes limestone mineral powder, PET fiber and warm mix agent in a weight ratio of 15:1:

1.

2. The environmentally friendly crack-resistant recycled asphalt concrete according to claim 1, characterized in that: The new aggregate comprises 10-20mm crushed stone, 5-10mm crushed stone, and 5mm manufactured sand in a weight ratio of 11:6:

4.

3. The environmentally friendly crack-resistant recycled asphalt concrete according to claim 2, characterized in that: The recycling agent is asphalt recycling agent 111-87-5; the warm mix agent is ZZ-W2 warm mix agent.

4. The method for producing environmentally friendly crack-resistant recycled asphalt concrete according to claim 3, characterized in that: The raw material components are mixed in a mixing tank (2) supported by a frame (1). The mixing tank (2) is provided with a premixing section (3). The premixing section (3) includes a premixing tank body (31) set in the mixing tank (2) and a premix material inlet (5) and a longitudinal stirring roller (32) installed in the premixing tank. The longitudinal stirring roller (32) is driven by a fixed motor (9) fixed on the mixing tank (2). Old asphalt pavement recycled material and 80% of the total amount of recycling agent are placed in the premixing tank. Spiral stirring blades are crisscrossed on the longitudinal stirring roller (32). The premixing tank body (31) includes a cover (311) and a bottom plate (312). The bottom plate (312) is fixed to the bottom of the longitudinal stirring roller (32). The cover (311) moves on the mixing tank (2) through a lifting structure (11) and can be raised and lowered relative to the bottom plate (312). The longitudinal stirring roller (32) can be raised and lowered along the cover (311).

5. The method for producing environmentally friendly crack-resistant recycled asphalt concrete according to claim 4, characterized in that: The lifting structure (11) includes a lifting cylinder (111) and a lifting ring (112). The lifting ring (112) is fixed to the outer wall of the cover (311). One side of the lifting ring (112) is fixed with an opposite extension rod (12). A connecting rod (13) is fixed between the opposite extension rods (12). The lifting cylinder (111) is installed on the outside of the side wall of the mixing tank (2), and the piston rod of the lifting cylinder (111) is fixed to the connecting rod (13).

6. The method for producing environmentally friendly crack-resistant recycled asphalt concrete according to claim 4, characterized in that: The stirring blades include a first shear blade (321) and a second shear blade (322). The radial width of the second shear blade (322) is greater than the radial width of the first shear blade (321), and the second shear blade (322) is spiral-shaped opposite to that of the first shear blade (321).

7. The method for producing environmentally friendly crack-resistant recycled asphalt concrete according to claim 4, characterized in that: The mixing tank (2) is also provided with a blending section (4); the blending section (4) includes a blending chamber (41) located in the mixing tank (2) for placing the remaining raw material components and a transverse stirring roller (42) driven by a drive motor (15) located in the blending chamber (41). The transverse stirring roller (42) is provided with a spiral blade (421), and the lower part of the mixing tank (2) forms an inverted cone shape; a main feed inlet (24) that can be opened and closed is provided on the side wall of the mixing tank (2) at the offset position from the transverse stirring roller (42); and a discharge outlet (25) that can be opened and closed is provided at the bottom of the mixing tank (2).

8. The method for producing environmentally friendly crack-resistant recycled asphalt concrete according to claim 4, characterized in that: The base plate (312) has a relief groove (7) on its outer periphery. The bottom of the cover (311) extends and is positioned in the relief groove (7). An inner sealing ring (8) is fixed on the inner wall of the cover (311), which is inserted into the relief groove (7) and abuts against the base plate (312). The upper surface of the base plate (312) forms a conical surface (14).

9. The method for producing environmentally friendly crack-resistant recycled asphalt concrete according to claim 4, characterized in that: The mixing tank (2) is fixed with cross-arranged support rods (22), which abut against the bottom of the base plate (312).

10. The method for producing environmentally friendly crack-resistant recycled asphalt concrete according to claim 4, characterized in that: A lifting plate (23) is fixed on the mixing tank (2), and a fixed motor (9) is fixed on the lifting plate (23). A through hole (21) for the lifting of the cover (311) is provided on the mixing tank (2). The two ends of the lifting plate (23) are located on the outside of the through hole (21). An outer circumferential sealing ring (6) is fixed on the side wall of the through hole (21) and abuts against the side wall of the cover (311). A through hole (10) for the longitudinal stirring roller (32) to move is provided on the cover (311). A matching sealing ring (101) is fixed on the side wall of the through hole (10) and sleeved on the longitudinal stirring roller (32). The premixed material inlet (5) extends obliquely outward from the mixing tank (2) and is offset from the fixed motor (9).

Images