Granulating equipment with drying function for waste plastic recovery and method

Abstract

The invention relates to the technical field of waste plastic regeneration, and discloses a grain cutting device and method for waste plastic recycling and with a drying function.The grain cutting device for waste plastic recycling and with the drying function.The grain cutting device for waste plastic recycling and with the drying function.The grain cutting device comprises a grain cutting box and a plastic extruding machine, the output end of the plastic extruding machine extends into the grain cutting box, and a water cooling box is fixedly connected into the grain cutting box; the output end of the plastic extruding machine is fixedly connected with a forming mold, and the forming mold is fixedly connected to the end of the pelletizing box and communicates with an inner cavity of the pelletizing box. According to the invention, a plurality of groups of symmetrically distributed water-cooling spray pipes are used for carrying out all-dimensional and uniform spray cooling on strip-shaped blanks, so that heat of high-temperature plastic strips can be quickly taken away, the plastic strips are quickly cooled and shaped, the problems of deformation, distortion and the like caused by non-uniform cooling or too low speed are effectively prevented, and the extrusion quality is ensured; and meanwhile, the cooling liquid forms a closed circulating system through the return pipe and the circulating pipe, so that water resources are saved, the production cost is reduced, and high efficiency and energy conservation in the cooling process are realized.

Description

Technical Field

[0001] This invention relates to the field of waste plastic recycling technology, specifically to a pelletizing device and method for recycling waste plastics with a drying function. Background Technology

[0002] With the increasing global awareness of environmental protection and the in-depth promotion of the concept of circular economy, the recycling and reuse of waste plastics has become a key link in solving "white pollution" and achieving sustainable resource utilization. In the plastic recycling process, pelletizing is an important step in processing molten and plasticized waste plastics into standardized pellets. Its processing quality directly affects the quality of recycled materials and their subsequent applications.

[0003] Currently, traditional plastic pelletizing equipment mostly uses simple water-cooling immersion or independent fan drying methods, which have many technical bottlenecks such as low cooling efficiency, incomplete drying, high energy consumption, and unstable pellet forming quality. In addition, in traditional processes, cooling water is mostly directly discharged or simply circulated, resulting in serious waste of water resources and a lack of uniform control over the temperature of the cooling medium. This leads to inconsistent cooling of plastic strips in different batches or in different locations within the same batch. More importantly, existing equipment often separates the cooling, drying, and pelletizing processes, lacking coordination and linkage between the systems. This results in a large overall footprint, low automation, and inconvenient maintenance. Summary of the Invention

[0004] This invention provides a pelletizing device and method for recycling waste plastics with a drying function. It achieves uniform cooling and water-saving circulation through multiple sets of symmetrical sprays; it utilizes the pelletizing power to drive the piston box to generate a cold airflow, which has both drying and secondary cooling functions, preventing sticking to the blade; and it maintains stable water temperature through liquid stirring and airflow heat exchange, achieving high efficiency, energy saving and long-term stable operation. This solves the problems mentioned in the background art, such as low cooling efficiency, incomplete drying, high water and energy consumption, and unstable pellet quality of traditional equipment.

[0005] This invention provides the following technical solution: A pelletizing device with a drying function for waste plastic recycling includes a pelletizing bin and an extruder. The output end of the extruder extends into the pelletizing bin. The device also includes: a water-cooling box fixedly connected to the pelletizing bin; a forming mold fixedly connected to the output end of the extruder, the forming mold fixedly connected to the end of the pelletizing bin and communicating with the inner cavity of the pelletizing bin; a drying section installed inside the pelletizing bin for drying the water-cooled material; and a pelletizing section installed inside the pelletizing bin for pelletizing the dried material.

[0006] As a preferred embodiment of the present invention, the water-cooling section includes a liquid storage tank, and multiple sets of water-cooling chambers are symmetrically arranged inside the water-cooling tank. Each set of water-cooling chambers is fixedly connected to a water-cooling spray pipe, and the output end of each set of water-cooling spray pipes faces the center of the water-cooling tank. The ends of the multiple sets of water-cooling spray pipes are connected to each other through a liquid guide pipe. A liquid supply pipe is fixedly connected to the liquid storage tank, and a cooling water pump is installed on the liquid supply pipe. The input end of the liquid supply pipe extends to the bottom of the inner cavity of the liquid storage tank, and the output end of the liquid supply pipe is connected to the liquid guide pipe.

[0007] As a preferred embodiment of the present invention, each group of water-cooled chambers located at the bottom is fixed and connected to a return pipe, and the bottom ends of each group of return pipes are connected to each other through a circulation pipe, and the output end of the circulation pipe is connected to the upper part of the inner cavity of the liquid storage tank.

[0008] As a preferred embodiment of the present invention, the pelletizing section includes a pelletizing frame, which is fixedly connected to a pelletizing box. A rotating blade is rotatably connected to the upper part of the inner cavity of the pelletizing frame, and a fixed roller is fixedly connected to the lower part of the inner cavity of the pelletizing frame. A traction roller assembly is fixedly connected to the pelletizing box located on the feeding side of the pelletizing frame. The ends of the two sets of traction roller shafts of the traction roller assembly are connected by a gear set for transmission. A pelletizing motor is fixedly connected to the outer wall of the pelletizing box. The output shaft of the pelletizing motor, the rotating shaft of the rotating blade, and the rotating shaft of the traction roller assembly are connected by a pulley set for transmission. A discharge hopper is fixedly connected to the pelletizing box located below the pelletizing frame, and a discharge chute is provided on the side wall of the pelletizing box located at the bottom of the discharge hopper.

[0009] As a preferred embodiment of the present invention, the drying section includes a drying box, which is fixed inside the pelletizing box and located between the water-cooling box and the pelletizing rack. An air guide chamber is fixedly connected to the top of the drying box, and multiple drying holes communicating with the inner cavity of the drying box are opened at the bottom of the air guide chamber. The bottom of the drying box is designed to be inclined, and a guide pipe is fixed and connected to the bottom of the drying box at the lower end of the inclined section. The bottom end of the guide pipe is connected to the bottom of the inner cavity of the liquid storage chamber, and a guide section for conveying airflow into the air guide chamber is provided at the top of the liquid storage chamber. Multiple sets of limiting guide rollers are symmetrically installed inside the liquid storage chamber, inside the drying box, and on both outer walls of the drying box for smoothly conveying the material output from the forming mold.

[0010] In a preferred embodiment of the present invention, the flow guide includes a piston box, which is fixedly connected to the top of the liquid storage chamber. A piston plate is slidably connected inside the piston box, and a push-pull rod is rotatably connected to the side wall of the piston plate. A linkage shaft is rotatably connected to the side wall of the pelletizing box, and a turntable is fixedly connected to the end of the linkage shaft. The other end of the push-pull rod is rotatably connected to the side wall of the turntable. An air inlet pipe is fixedly connected to and communicates with the piston box. The other end of the air inlet pipe is connected to the inner cavity of the air guide chamber, and a one-way valve is provided inside the air inlet pipe. An air suction pipe is fixedly connected inside the liquid storage chamber. The output end of the air suction pipe is connected to the inner cavity of the piston box, and the input end of the air suction pipe extends to the outside of the pelletizing box. A one-way valve is provided inside the air suction pipe.

[0011] As a preferred embodiment of the present invention, a stirring shaft is rotatably connected inside the liquid storage tank located at the lower end of the guide pipe, and stirring blades are fixedly connected to the outer wall of the stirring shaft. The stirring shaft, the linkage shaft, and the rotary blade shaft are connected by a sprocket assembly for transmission.

[0012] As a preferred embodiment of the present invention, the pelletizing box is provided with a heat exchange chamber, the liquid guide pipe, the return pipe and the circulation pipe are all located in the heat exchange chamber, the upper part of the inner cavity of the liquid storage tank is fixed and connected to an exhaust pipe, and the output end of the exhaust pipe extends to one side of the heat exchange chamber.

[0013] As a preferred embodiment of the present invention, a first flip cover is rotatably connected to the side wall of the pelletizing box, a second flip cover is rotatably connected to the side wall of the water-cooling box, and a third flip cover is rotatably connected to the side wall of the air-drying box.

[0014] A pelletizing method for waste plastic recycling with a drying function, comprising the following steps: Step 1: Waste plastic is melted and extruded through an extruder, formed into strips through a molding die, and then cooled in a water-cooling box; Step 2: After cooling, the strips are placed in a drying chamber, where airflow is used to blow away surface moisture and recover any residual liquid on the strips. Step 3: The dried strips are smoothly conveyed to the pelletizing station through multiple sets of limiting guide rollers and traction rollers; Step 4: The strip material is sheared by a rotating blade at the pelletizing station, forming pellets which are then discharged through the discharge hopper.

[0015] Compared with the prior art, the present invention provides a pelletizing device and method with drying function for waste plastic recycling, which has the following beneficial effects: 1. This waste plastic recycling pelletizing equipment with drying function uses multiple symmetrically distributed water-cooled spray pipes to spray and cool the strip-shaped billet in an all-round and uniform manner. This can quickly remove the heat from the high-temperature plastic strip, allowing it to cool and solidify rapidly. This effectively prevents problems such as deformation and twisting caused by uneven cooling or slow cooling speed, ensuring extrusion quality. At the same time, the coolant forms a closed circulation system through the return pipe and circulation pipe, which saves water resources, reduces production costs, and achieves high efficiency and energy saving in the cooling process.

[0016] 2. This waste plastic recycling pelletizing equipment with drying function utilizes the pelletizing power to drive the piston box to reciprocate through the sprocket assembly and linkage shaft, automatically generating airflow that blows onto the strip material through the drying holes, efficiently blowing off surface moisture and ensuring dryness to improve subsequent pelletizing effect; at the same time, the suction pipe is placed in the liquid storage tank, using coolant to water-cool the intake airflow, so that the drying holes output cold airflow, which removes residual heat from the strip material while drying, avoiding sticking to the blade due to incomplete cooling during subsequent pelletizing, and ensuring smooth pelletizing.

[0017] 3. This waste plastic recycling pelletizing equipment with drying function uses a stirring shaft to drive the stirring blades to agitate the water flow in the storage tank, achieving uniform water temperature and avoiding uneven cooling of the strips due to uneven water temperature. At the same time, the airflow and blown-off water in the drying box enter the storage tank through the guide pipe, reducing water flow loss and further improving energy saving. Moreover, the airflow entering the storage tank finally blows the airflow in the heat exchange chamber through the exhaust pipe, accelerating its flow speed. The rapidly flowing airflow exchanges heat with the cooling circulation pipes, effectively reducing the heat absorbed by the circulating water and ensuring the stability of pellet forming quality. Attached Figure Description

[0018] To more clearly illustrate the specific embodiments of the present invention or the technical solutions in the prior art, the accompanying drawings used in the description of the specific embodiments or the prior art will be briefly introduced below. In all the drawings, the elements or parts are not necessarily drawn to actual scale.

[0019] Figure 1 This is a three-dimensional schematic diagram of the entire invention; Figure 2 This is a three-dimensional schematic diagram of the pelletizing box of the present invention; Figure 3 This is a schematic diagram of the internal structure of the pelletizing box of the present invention; Figure 4 This is a schematic cross-sectional view of the water-cooled box of the present invention; Figure 5 For the present invention Figure 4 Enlarged structural diagram of region A in the middle; Figure 6 This is a schematic diagram of the overall half-section structure of the pelletizing box of the present invention; Figure 7 For the present invention Figure 6 Enlarged structural diagram of region B in the middle; Figure 8 For the present invention Figure 6 A magnified structural diagram of region C in the middle.

[0020] In the diagram: 1. Pelletizer; 2. Extruder; 21. Molding die; 3. Water cooling box; 31. Water cooling cavity; 32. Water cooling nozzle; 33. Liquid guide pipe; 4. Liquid storage tank; 41. Liquid supply pipe; 42. Cooling water pump; 43. Return pipe; 44. Circulation pipe; 45. Limiting guide roller; 5. Pelletizer frame; 51. Rotary cutter; 52. Fixed roller; 53. Traction roller assembly; 531. Gear assembly; 54. Pelletizer motor; 55. Pulley assembly; 56. Discharge... 57. Hopper; 6. Discharge chute; 7. Drying box; 8. Air guide chamber; 9. Drying hole; 10. Guide pipe; 11. Piston box; 12. Piston plate; 23. Push-pull rod; 34. Linkage shaft; 45. Turntable; 66. Air inlet pipe; 77. Suction pipe; 88. Stirring shaft; 99. Stirring blades; 100. Sprocket assembly; 11. Heat exchange chamber; 12. Exhaust pipe; 13. First flap; 14. Second flap; 15. Third flap. Detailed Implementation

[0021] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention. Example

[0022] Reference Figures 1-8 A pelletizing device with drying function for waste plastic recycling includes a pelletizing box 1 and an extruder 2. The extruder 2 adopts existing mature technology, and its principle and structure will not be described in detail. The output end of the extruder 2 extends into the pelletizing box 1. The device also includes: a water-cooling box 3, which is fixedly connected to the pelletizing box 1; a forming mold 21, which is fixedly connected to the output end of the extruder 2 and communicates with the inner cavity of the pelletizing box 1; and a multiple strip-shaped forming holes, which can be set according to production needs. The water-cooling box 3 is provided with a water-cooling section for cooling the material output from the forming mold 21; a drying section, which is installed in the pelletizing box 1 for drying the water-cooled material; and a pelletizing section, which is installed in the pelletizing box 1 for pelletizing the dried material.

[0023] Reference Figure 3 , Figure 4 , Figure 6 and Figure 7The water-cooling section includes a liquid storage tank 4. Multiple sets of water-cooling chambers 31 are symmetrically arranged inside the water-cooling box 3. Each set of water-cooling chambers 31 is fixedly connected to a water-cooling nozzle 32, and the output end of each set of water-cooling nozzles 32 faces the center of the water-cooling box 3. The ends of the multiple sets of water-cooling nozzles 32 are connected to each other through a liquid guide pipe 33. A liquid supply pipe 41 is fixedly connected to the liquid storage tank 4. A cooling water pump 42 is installed on the liquid supply pipe 41. The input end of the liquid supply pipe 41 extends to the bottom of the inner cavity of the liquid storage tank 4, and the output end of the liquid supply pipe 41 is connected to the liquid guide pipe 33. The bottom of each set of water-cooling chambers 31 located below is fixed and connected to a return pipe 43. The bottom ends of each set of return pipes 43 are connected to each other through a circulation pipe 44. The output end of the circulation pipe 44 is connected to the upper part of the inner cavity of the liquid storage tank 4.

[0024] With the above-described structure, as the strip-shaped billet passes through the water-cooling box 3, the cooling water pump 42 draws the coolant from the bottom of the storage tank 4 through the supply pipe 41 and delivers it to each water-cooling spray pipe 32 via the guide pipe 33. This sprays the strip-shaped billet in the center of the water-cooling box 3 for cooling. At this time, multiple sets of water-cooling spray pipes 32 are symmetrically distributed inside the water-cooling box 3, ensuring that the strip-shaped billet is sprayed evenly from all angles. This allows for rapid and efficient removal of heat from the high-temperature plastic strip, enabling it to cool and solidify quickly, improving the cooling effect, and effectively preventing deformation and twisting caused by uneven cooling or slow cooling speed, thus ensuring the extrusion quality of the plastic strip. In addition, after absorbing heat, the coolant collects at the bottom of the water-cooling chamber 31 and flows back to the upper part of the storage tank 4 through the return pipe 43 and the circulation pipe 44, forming a closed coolant circulation system. This greatly saves water resources, reduces production costs, and improves the green energy-saving effect.

[0025] Reference Figures 1-4 and Figure 6 The pelletizing section includes a pelletizing frame 5, which is fixedly connected inside the pelletizing box 1. A rotating blade 51 is rotatably connected to the upper part of the inner cavity of the pelletizing frame 5, and a fixed roller 52 is fixedly connected to the lower part of the inner cavity of the pelletizing frame 5. A traction roller group 53 is fixedly connected inside the pelletizing box 1 located on the feeding side of the pelletizing frame 5. The ends of the two sets of traction roller shafts of the traction roller group 53 are connected by a gear group 531. A pelletizing motor 54 is fixedly connected to the outer wall of the pelletizing box 1. The output shaft of the pelletizing motor 54, the rotating shaft of the rotating blade 51, and the rotating shaft of the traction roller group 53 are connected by a belt pulley group 55. The material is pulled and conveyed by the traction roller group 53 to pass between the rotating blade 51 and the fixed roller 52 and is crushed into pellets. A discharge hopper 56 is fixedly connected inside the pelletizing box 1 located below the pelletizing frame 5. A discharge chute 57 is opened on the side wall of the pelletizing box 1 located at the bottom of the discharge hopper 56.

[0026] With the above-described structure, the pelletizing motor 54 is turned on, and the rotating cutter 51 and the traction roller group 53 are driven to rotate through the pulley group 55. The traction roller group 53 continuously feeds the strip-shaped blank to the rotating cutter 51. Finally, the shearing force generated by the rotation of the rotating cutter 51, in conjunction with the fixed roller 52, completes the pelletizing of the strip-shaped blank. The pellets fall onto the discharge hopper 56 under the action of gravity and are discharged from the pelletizing box 1. This achieves automatic and continuous pelletizing, effectively improving pelletizing efficiency.

[0027] Reference Figures 3-6 and Figure 8 The drying section includes a drying chamber 6, which is fixed inside the pelletizing chamber 1 and located between the water-cooling chamber 3 and the pelletizing rack 5. An air guide chamber 61 is fixedly connected to the top of the drying chamber 6. Multiple drying holes 611 communicating with the inner cavity of the drying chamber 6 are opened at the bottom of the air guide chamber 61. The bottom of the drying chamber 6 is designed to be inclined. A guide pipe 62 is fixed and connected to the bottom of the drying chamber 6 at the lower inclined end. The bottom end of the guide pipe 62 is connected to the bottom of the inner cavity of the liquid storage tank 4. The top of the liquid storage tank 4 is provided with a guide section for conveying airflow into the air chamber 61. Multiple sets of limiting guide rollers 45 are symmetrically installed inside the liquid storage tank 4, inside the drying chamber 6, and on the outer walls of both ends of the drying chamber 6 to smoothly convey the material output from the molding die 21. The guide section includes a piston box 63, which is fixedly connected to the top of the liquid storage tank 4. A piston plate 631 is slidably connected inside the piston box 63, and a push-pull rod 632 is rotatably connected to the side wall of the piston plate 631. A linkage shaft 64 is rotatably connected to the side wall of the pelletizing box 1. A turntable 641 is fixedly connected to the end of the linkage shaft 64. The other end of the push-pull rod 632 is rotatably connected to the side wall of the turntable 641. An air filling pipe 65 is fixedly connected to the piston box 63 and communicates with it. The other end of the air filling pipe 65 is connected to the inner cavity of the air guide chamber 61, and a one-way valve is installed inside the air filling pipe 65. An air suction pipe 651 is fixedly connected to the liquid storage chamber 4, and the output end of the air suction pipe 651 is connected to the inner cavity of the piston box 63. The air intake pipe 651 extends to the outside of the pelletizing box 1 and is fixedly connected to a filter cover. The filter cover is used to filter the airflow drawn in from the outside to ensure the cleanliness of the drying airflow. A one-way valve is installed inside the air intake pipe 651. A stirring shaft 66 is rotatably connected inside the liquid storage tank 4 located at the lower end of the guide pipe 62. A stirring blade 661 is fixedly connected to the outer wall of the stirring shaft 66. The stirring shaft 66, the linkage shaft 64 and the rotating shaft of the rotary cutter 51 are connected by a sprocket set 67.

[0028] It should be noted that the one-way valve in the inflation pipe 65 can only allow the airflow in the piston box 63 to enter the air guide chamber 61; the one-way valve in the suction pipe 651 can only allow the external airflow to enter the piston box 63.

[0029] With the above structure, as the strip-shaped blank passes through the drying box 6, the rotation of the rotary cutter 51, in conjunction with the transmission action of the sprocket set 67, will drive the linkage shaft 64 and the stirring shaft 66 to rotate together. When the linkage shaft 64 rotates, the turntable 641 and the push-pull rod 632 drive the piston plate 631 to reciprocate within the piston box 63. When the piston plate 631 slides to the side that compresses the cavity of the piston box 63, it compresses the gas inside the piston box 63 and opens the one-way valve in the air filling pipe 65, allowing the compressed airflow to enter the air guide chamber 61 along the air filling pipe 65 and finally blow it onto the strip material along the multiple sets of air drying holes 611. Subsequently, when the piston plate 631 slides in the opposite direction, it generates a negative pressure suction force in the piston box 63, thereby opening the one-way valve in the air intake pipe 651, allowing external airflow to pass through the air intake pipe 651 and replenish the piston box 63. This process repeats, effectively blowing off the moisture on the surface of the strip material, ensuring the dryness of the strip material surface, and improving the subsequent pelletizing effect. Furthermore, since the suction pipe 651 is located inside the liquid storage chamber 4, the water flow in the liquid storage chamber 4 can be used to cool the airflow in the suction pipe 651, thereby reducing the temperature of the airflow in the suction pipe 651. This results in the downward flow of cold air from the drying hole 611, which, while achieving air drying, further removes residual heat from the strip material, preventing incomplete cooling and sticking to the blades during subsequent pelletizing, ensuring smooth pelletizing. Additionally, the water blown down from the drying box 6 flows along its inclined bottom and into the liquid storage chamber 4 through the guide pipe 62, further minimizing water loss and improving energy efficiency. Meanwhile, the stirring shaft 66 drives the stirring blades 661 to rotate within the liquid storage chamber 4, firstly stirring and mixing the water flow within the chamber, achieving uniform water temperature and preventing uneven cooling of the strip material due to uneven water temperature.

[0030] Reference Figures 1-4 The pelletizing box 1 is equipped with a heat exchange chamber 7. The liquid guide pipe 33, the return pipe 43 and the circulation pipe 44 are all located in the heat exchange chamber 7. The upper part of the inner cavity of the liquid storage tank 4 is fixed and connected to the exhaust pipe 71. The output end of the exhaust pipe 71 extends to one side of the heat exchange chamber 7.

[0031] With the above structure, the airflow in the drying chamber 6 will enter the liquid storage chamber 4 through the guide pipe 62, and finally blow from one side of the heat exchange chamber 7 to the other side along the exhaust pipe 71, thereby accelerating the airflow speed in the heat exchange chamber 7. The rapidly flowing airflow will exchange heat with the guide pipe 33, return pipe 43 and circulation pipe 44, thereby effectively reducing the heat absorbed inside the circulating water flow and achieving long-term stable water cooling and drying effects.

[0032] Reference Figure 2In addition, a first flap 8 is rotatably connected to the side wall of the pelletizing box 1, a second flap 81 is rotatably connected to the side wall of the water cooling box 3, and a third flap 82 is rotatably connected to the side wall of the drying box 6. With the setting of the first flap 8, the second flap 81 and the third flap 82, it is convenient to manually guide the strip material in the early stage of processing to ensure the smooth transmission of the strip material. At the same time, it is convenient to maintain the overall equipment and improve the convenience of maintenance. Example

[0033] Reference Figures 1-8 Similar to Example 1, but based on Example 1, a pelletizing method with drying function for waste plastic recycling is proposed, the steps of which are as follows: Step 1: Waste plastic is melted and extruded through extruder 2, formed into strips through molding die 21, and then cooled in water cooling box 3; Step 2: After cooling, the strip enters the drying chamber 6, where airflow is used to blow away surface moisture and recover any residual liquid on the strip; Step 3: The dried strips are smoothly conveyed to the pelletizing station through multiple sets of limiting guide rollers 45 and traction rollers 53; Step 4: The strip material is sheared by the rotating blade 51 at the pelletizing station, and then discharged through the discharge hopper 56 after forming pellets.

[0034] Reference Figures 1-8 In this invention, during use, the first flap 8, the second flap 81, and the third flap 82 are first opened. Then, the extruder 2 is started, and the cleaned and crushed waste plastic raw material is fed into the extruder 2 for heating and plasticizing. Under the extrusion pressure, the molten plastic is extruded through the forming die 21 to form a continuous strip-shaped billet. The billet is directly conveyed into the water-cooling box 3. At this time, the strip-shaped billet is manually pulled through the water-cooling box 3 and the drying box 6 to reach the traction roller group 53. Simultaneously, the pelletizing motor 54 is turned on. The belt pulley group 55 drives the rotating cutter 51 and the traction roller group 53 to rotate, thereby using the traction roller group 53 to continuously feed the strip-shaped billet to the rotating cutter 51. Finally, the shearing force generated by the rotation of the rotating cutter 51, in conjunction with the fixed roller 52, completes the pelleting of the strip-shaped billet. The pellets will fall onto the discharge hopper 56 under the action of gravity and be discharged from the pelleting box 1. This completes the initial manual intervention traction, avoiding the inability of the relatively soft strip-shaped billet to reach the pelleting station smoothly. Then, the third flap 82, the second flap 81 and the first flap 8 are closed in sequence.

[0035] During the process of the strip-shaped billet passing through the water-cooling box 3, the cooling water pump 42 draws the coolant from the bottom of the liquid storage tank 4 through the supply pipe 41 and delivers it to each water-cooling spray pipe 32 through the guide pipe 33. This sprays the strip-shaped billet in the center of the water-cooling box 3 for cooling. At this time, multiple sets of water-cooling spray pipes 32 are symmetrically distributed in the water-cooling box 3 to ensure that the strip-shaped billet is sprayed in an all-round and uniform manner from all angles. This can quickly and efficiently remove the heat from the high-temperature plastic strip, allowing it to cool and solidify rapidly, improving the cooling effect, and effectively preventing problems such as deformation and twisting of the plastic strip due to uneven cooling or slow cooling speed, thus ensuring the extrusion quality of the plastic strip. In addition, after absorbing heat, the coolant collects at the bottom of the water-cooling chamber 31 and flows back to the upper part of the liquid storage tank 4 through the return pipe 43 and the circulation pipe 44, forming a closed coolant circulation system. This greatly saves water resources, reduces production costs, and improves green energy-saving effects.

[0036] During the process of the strip-shaped material passing through the drying chamber 6, the rotation of the rotary cutter 51, in conjunction with the transmission action of the sprocket assembly 67, drives the linkage shaft 64 and the stirring shaft 66 to rotate together. When the linkage shaft 64 rotates, it drives the piston plate 631 to reciprocate within the piston box 63 via the turntable 641 and the push-pull rod 632. When the piston plate 631 slides to the side that compresses the cavity of the piston box 63, it compresses the gas inside the piston box 63 and opens the one-way valve in the air filling pipe 65, allowing the compressed airflow to enter the air guide chamber 61 along the air filling pipe 65 and finally blown onto the strip material along the multiple sets of drying holes 611. Subsequently, when the piston plate 631 slides in the opposite direction, it generates a negative pressure suction force within the piston box 63, thereby opening the one-way valve in the suction pipe 651, allowing external airflow to pass through the suction pipe 651 and replenish the piston box 63. This reciprocating motion effectively blows off the moisture on the surface of the strip material, ensuring the dryness of the strip material surface and improving the subsequent pelletizing effect. In addition, since the suction pipe 651 is placed inside the liquid storage chamber 4, the water flow in the liquid storage chamber 4 can be used to cool the airflow in the suction pipe 651, thereby reducing the temperature of the airflow in the suction pipe 651. This results in the downward flow of cold air from the drying hole 611, which not only achieves air drying but also removes residual heat from the strip material, preventing incomplete cooling of the strip material during subsequent pelleting and ensuring smooth pelleting. Furthermore, the airflow and blown-off water in the drying box 6 will all flow along its inclined bottom and enter the liquid storage chamber 4 through the guide pipe 62, further avoiding water loss and improving energy efficiency. At this time, the stirring shaft 66 will drive the stirring blades 661 to rotate in the liquid storage chamber 4, which can first stir the water flow in the liquid storage chamber 4 to mix with each other, achieve water temperature uniformity, and avoid uneven cooling of the strip material due to uneven water temperature. The airflow entering the liquid storage chamber 4 will eventually blow from one side of the heat exchange chamber 7 to the other side along the exhaust pipe 71, thereby accelerating the airflow speed in the heat exchange chamber 7. The rapidly flowing airflow will exchange heat with the guide pipe 33, return pipe 43 and circulation pipe 44, thereby effectively reducing the heat absorbed inside the circulating water flow and achieving long-term stable water cooling and drying effect.

[0037] Components not described in detail in this article are existing technologies.

[0038] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, and not to limit them; although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features; and these modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A pelletizing device with drying function for waste plastic recycling, comprising a pelletizing bin (1) and an extruder (2), characterized in that, The output end of the extruder (2) extends into the pelletizing box (1), and also includes: A water-cooled box (3) is fixedly connected inside the pelletizing box (1). A molding die (21) is fixedly connected to the output end of the extruder (2). The molding die (21) is fixedly connected to the end of the pelletizing box (1) and communicates with the inner cavity of the pelletizing box (1). The water-cooled box (3) is equipped with a water-cooling section for cooling the material output from the molding die (21); The drying section is installed inside the pelletizing box (1) and is used to dry the water-cooled material. The pelletizing section is installed inside the pelletizing box (1) and is used to pelletize the dried material.

2. The pelletizing equipment with drying function for waste plastic recycling according to claim 1, characterized in that, The water-cooling section includes a liquid storage tank (4). Multiple sets of water-cooling chambers (31) are symmetrically arranged inside the water-cooling box (3). Each set of water-cooling chambers (31) is fixedly connected to a water-cooling nozzle (32), and the output end of each set of water-cooling nozzles (32) faces the center of the water-cooling box (3). The ends of the multiple sets of water-cooling nozzles (32) are connected to each other through a liquid guide pipe (33). A liquid supply pipe (41) is fixedly connected to the liquid storage tank (4). A cooling water pump (42) is installed on the liquid supply pipe (41). The input end of the liquid supply pipe (41) extends to the bottom of the inner cavity of the liquid storage tank (4), and the output end of the liquid supply pipe (41) is connected to the liquid guide pipe (33).

3. A pelletizing device with drying function for waste plastic recycling according to claim 2, characterized in that, Each group of water-cooled chambers (31) located below is fixed at the bottom and connected to a return pipe (43). The bottom ends of each group of return pipes (43) are connected to each other through a circulation pipe (44). The output end of the circulation pipe (44) is connected to the upper part of the inner cavity of the liquid storage tank (4).

4. A pelletizing device with drying function for waste plastic recycling according to claim 2, characterized in that, The pelletizing section includes a pelletizing frame (5), which is fixedly connected inside the pelletizing box (1). A rotating blade (51) is rotatably connected to the upper part of the inner cavity of the pelletizing frame (5), and a fixed roller (52) is fixedly connected to the lower part of the inner cavity of the pelletizing frame (5). A traction roller group (53) is fixedly connected inside the pelletizing box (1) on the feeding side of the pelletizing frame (5). The ends of the two sets of traction roller shafts of the traction roller group (53) are connected by a gear group (531). A pelletizing motor (54) is fixedly connected to the outer wall of the pelletizing box (1). The output shaft of the pelletizing motor (54), the rotating shaft of the rotating blade (51), and the rotating shaft of the traction roller group (53) are connected by a belt pulley group (55). Among them, a discharge hopper (56) is fixedly connected inside the pelletizing box (1) located below the pelletizing frame (5), and a discharge chute (57) is provided on the side wall of the pelletizing box (1) located at the bottom of the discharge hopper (56).

5. A pelletizing device with drying function for waste plastic recycling according to claim 4, characterized in that, The drying section includes a drying box (6), which is fixed inside the pelletizing box (1) and located between the water-cooled box (3) and the pelletizing rack (5). A guide chamber (61) is fixedly connected to the top of the drying box (6). The bottom of the guide chamber (61) has multiple drying holes (611) that communicate with the inner cavity of the drying box (6). The bottom of the drying box (6) is designed to be inclined. The bottom of the drying box (6) at the lower end of the inclined section is fixed and connected to a guide pipe (62). The bottom end of the guide pipe (62) is connected to the bottom of the inner cavity of the liquid storage tank (4). The top of the liquid storage tank (4) is provided with a guide section for conveying airflow into the guide chamber (61). Multiple sets of limiting guide rollers (45) are symmetrically installed inside the liquid storage tank (4), inside the drying box (6), and on the outer walls of both ends of the drying box (6) for smooth conveying of the material output from the molding die (21).

6. A pelletizing device with drying function for waste plastic recycling according to claim 5, characterized in that, The flow guide includes a piston box (63), which is fixedly connected to the top of the liquid storage tank (4). A piston plate (631) is slidably connected inside the piston box (63). A push-pull rod (632) is rotatably connected to the side wall of the piston plate (631). A linkage shaft (64) is rotatably connected to the side wall of the pelletizing box (1). A turntable (641) is fixedly connected to the end of the linkage shaft (64). The other end of the push-pull rod (632) is rotatably connected to the side wall of the turntable (641). An air filling pipe (65) is fixedly connected to the piston box (63) and communicates with it. The other end of the air filling pipe (65) is connected to the inner cavity of the air guide chamber (61). A one-way valve is provided inside the air filling pipe (65). The storage tank (4) is fixedly connected with a suction pipe (651). The output end of the suction pipe (651) is connected to the inner cavity of the piston box (63). The input end of the suction pipe (651) extends to the outside of the pelletizing box (1). A one-way valve is provided inside the suction pipe (651).

7. A pelletizing device with drying function for waste plastic recycling according to claim 6, characterized in that, A stirring shaft (66) is rotatably connected inside the liquid storage tank (4) located at the lower end of the guide pipe (62). A stirring blade (661) is fixedly connected to the outer wall of the stirring shaft (66). The stirring shaft (66), the linkage shaft (64), and the rotating shaft of the rotary cutter (51) are connected by a sprocket set (67).

8. A pelletizing device with drying function for waste plastic recycling according to claim 3, characterized in that, The pelletizing box (1) is provided with a heat exchange chamber (7). The liquid guide pipe (33), return pipe (43) and circulation pipe (44) are all located in the heat exchange chamber (7). The upper part of the inner cavity of the liquid storage tank (4) is fixed and connected to an exhaust pipe (71). The output end of the exhaust pipe (71) extends to one side of the heat exchange chamber (7).

9. A pelletizing device with drying function for waste plastic recycling according to claim 5, characterized in that, The pelletizing box (1) is rotatably connected to a first flip cover (8), the water-cooling box (3) is rotatably connected to a second flip cover (81), and the air-drying box (6) is rotatably connected to a third flip cover (82).

10. A pelletizing method for waste plastic recycling with a drying function, comprising using a pelletizing device for waste plastic recycling with a drying function as described in any one of claims 1-9, characterized in that, The steps are as follows: Step 1: Waste plastic is melted and extruded through an extruder (2), formed into strips through a molding die (21), and then cooled in a water-cooling box (3); Step 2: After cooling, the strip enters the drying box (6), where airflow is used to blow away the surface moisture and recover the residual liquid on the strip; Step 3: The dried strips are smoothly conveyed to the pelletizing station through multiple sets of limiting guide rollers (45) and traction rollers (53); Step 4: The strip material is sheared by a rotating cutter (51) at the pelletizing station, and then discharged through the discharge hopper (56) after forming pellets.

Images