Constant-flow type granulation extruder and method for recycling waste plastics

Abstract

The invention relates to the technical field of plastic extruding machines, and particularly discloses a constant-flow type granulation extruding machine and method for recycling waste plastics, the constant-flow type granulation extruding machine comprises an extruding barrel, a cooling box filled with heat conduction liquid is arranged at the discharging end of the extruding barrel, a die head is arranged between the cooling box and the extruding barrel, and the die head is fixedly connected to the discharging end of the extruding barrel; a plurality of extrusion holes are formed in the periphery of the die head, and a cooling sleeve is arranged in the cooling box. Through linkage control of rotation of the gas sleeve and the telescopic rod, precise cutting and channel switching of extruded raw materials are achieved, the gas sleeve and the die head are kept in a concentric channel in the cooling and curing stage, the raw materials are automatically deflected and cut off after preliminary cooling is completed, uneven fractures caused by manual intervention are avoided, gas channels are synchronously switched in the cutting process, and the production efficiency is improved. According to the technical scheme, preparation is provided for follow-up pneumatic discharging, automatic connection of the production process is achieved, final cooling is completed after grain cutting is conducted, the cooling mode is conducted through air cooling, and therefore compared with a water cooling mode in the prior art, occupied space is small.

Description

Technical Field

[0001] The invention relates to the technical field of extruders, in particular to a constant-flow granulating extruder and a method for recycling waste plastics. Background Art

[0002] After extrusion, the extruded strip material needs to be cooled and solidified before being cut into pellets. Rapid cooling causes residual stress in crystalline materials (such as PE and PP), which may lead to cracking in the product. Therefore, the existing cooling methods mainly use water cooling and air cooling for gradual cooling. Water cooling is a staged cooling method (hot water → warm water → cold water), which is suitable for crystalline materials such as PE / PP and can effectively eliminate internal stress. Air cooling uses forced air cooling with a fan and is suitable for small and medium-sized extruders. Its advantages are uniformity and cleanliness, but it takes up a lot of space. For example, the prior art publication number CN112454860A discloses a waste plastic recycling and granulation production equipment, which includes an extruder, a hopper, a melting screw and an extrusion screw. The extruder is provided with two sets of chutes and slideways corresponding to the position above the hopper, and the slideways are movably connected to the cylinder through a slider. In this waste plastic recycling and granulation production equipment, when the molten plastic moves with the rotation of the extrusion screw, two filter materials are inserted into the groove of the extrusion screw in turn to filter out the plastic or impurities that are not completely melted, increase the purity of the melt, and improve the quality of the recycled plastic. Secondly, the airflow generated by the movement of the cylinder is used to squeeze the plastic on the inner wall of the hopper, so that one side of the plastic that has bridged is suspended in the air, thereby assisting the movement of the plastic fragments in the hopper. Secondly, the rapid pulsed airflow will also increase the disturbance of the plastic fragments, further reducing the probability of bridge formation and increasing the conveying speed of the broken fragments to make them compatible with the processing speed of the granulator. The defects of the existing technology are: after gradual cooling by water cooling, the cold water will cause residual moisture on the surface of the particles to form a water film on the surface of the plastic particles, and the water film needs to be air-dried separately. The cooling time of the existing technology through water cooling is relatively long, so the length of the water cooling pool is also very long, and the site occupancy rate is very high. Summary of the Invention

[0003] The purpose of this section is to summarize some aspects of the embodiments of the present invention and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of this application to avoid obscuring the purpose of this section, the abstract and the title of the invention, and such simplifications or omissions should not be used to limit the scope of the present invention.

[0004] The present invention provides a constant flow type granulation extruder and method for recycling waste plastics, which can solve the problem of high site occupancy rate during cooling in the prior art. The specific solution is as follows: On the one hand, the present invention provides a constant flow type granulating extruder for recycling waste plastics, comprising an extrusion barrel, a cooling box filled with heat transfer liquid is provided at the discharge end of the extrusion barrel, a die head is provided between the cooling box and the extrusion barrel, the die head is fixedly connected to the discharge end of the extrusion barrel, a plurality of extrusion holes are provided around the die head, a cooling jacket is provided inside the cooling box, a plurality of cooling holes are provided around the cooling jacket, a cooling cylinder is connected to the end of the cooling jacket away from the die head, the number and inner diameter of the cooling cylinder correspond to the plurality of cooling holes, a plurality of through holes are provided on the outer wall of the cooling cylinder, the plastic raw material enters the cooling hole and the cooling cylinder after being extruded from the extrusion hole, a granulating box is provided at the other end of the cooling cylinder, a granulating cavity is provided in the granulating box, and a granulating cavity is provided in the granulating cavity. It has a blade, which blows the strip raw materials in the cooling hole and the cooling tube into the granulation chamber through gas, and the blade cuts the strip raw materials into granular raw materials to complete granulation; the precise cutting and channel switching of the extruded raw materials are achieved through the linkage control of the air sleeve rotation and the telescopic rod. During the cooling and solidification stage, the air sleeve and the die head maintain a concentric channel, and automatically deflect and cut the raw materials after the initial cooling is completed, avoiding uneven fracture caused by manual intervention. The gas channel is switched synchronously during the cutting process to prepare for subsequent pneumatic discharge, realize the automatic connection of the production process, and complete the final cooling after pelletizing. Moreover, the cooling method is through partial cooling, so it occupies less space than the water cooling method of the existing technology.

[0005] Preferably, one side of the cooling box is connected to a liquid inlet pipe and a liquid outlet pipe, which are respectively fixed at the upper and lower ends of one side of the cooling box, and can respectively realize liquid inlet and liquid outlet. The other ends of the liquid inlet pipe and the liquid outlet pipe pass through the rear of the cooling box and are connected to the heat dissipation water tank behind the cooling box. The interior of the liquid inlet pipe and the liquid outlet pipe are connected to the interior of the heat dissipation water tank, and the outer wall of the heat dissipation water tank is connected to the heat dissipation fins.

[0006] Preferably, an air jacket is provided between the die head and the cooling jacket, and the air jacket is rotatably mounted on one end of the die head close to the cooling jacket through a bearing, the end of the die head close to the air jacket is fixedly connected to a first support block, the outer wall of the air jacket is fixedly connected to a second support block, the first support block and the second support block are arranged on the same plumb line, the bottom of the first support block is fixedly connected to a telescopic rod, and the telescopic end of the bottom of the telescopic rod is against the top of the second support block; the outer wall of the air jacket is also connected to a third support block, and the outer wall of the die head is connected to a fourth support block.

[0007] Preferably, a spring is connected between the fourth support block and the third support block. The spring is in a contracted state by default. When the telescopic rod is extended quantitatively, the bottom end of the telescopic rod can exert pressure on the second support block, thereby driving the second support block and the air sleeve to rotate.

[0008] Preferably, a plurality of through holes are provided around the air jacket, the positions and numbers of the through holes correspond to the extrusion holes, a countersunk hole is provided between every two adjacent through holes, one end of the countersunk hole is closed, and the open end of the countersunk hole faces the cooling jacket.

[0009] Preferably, an annular groove is provided around the air sleeve, and a plurality of countersunk holes are connected to the annular groove. The top of the air sleeve is fixedly connected to an air inlet pipe, which is a hose, and the top of the air inlet pipe is connected to the air pump.

[0010] Preferably, a rotating shaft is installed rotatably through the middle of the granulation box, and a plurality of feed holes are opened at one end of the granulation chamber close to the cooling tube. The number and position of the feed holes correspond to the cooling tube. The blade is fixed on the rotating shaft and rotates synchronously with it. The outer wall of the rotating shaft is connected to a plurality of spoilers, and the spoilers correspond to the positions of the through holes on the cooling tube.

[0011] Preferably, a stirring blade is further provided inside the granulation chamber, the width of the stirring blade matches the width of the granulation chamber, there are several stirring blades, and the stirring blades are fixedly connected to the outer wall of the rotating shaft, and the stirring blades fully stir the granulated raw materials.

[0012] Preferably, a blowing cavity is further provided inside the granulation box, and two fans are arranged inside the blowing cavity. The two fans rotate under the drive of the driving device to generate wind force, and the wind force is converted into cold air through the cooling pipe and blown into the interior of the granulation cavity, thereby finally cooling the granules after granulation, and ensuring that the cut parts of the granules are completely cooled and solidified.

[0013] In another aspect, the present invention provides a constant flow granulation extrusion method for recycling waste plastics, comprising the following steps: S1, extrude the molten plastic through the die head at the discharge end of the extrusion barrel, so that the plastic raw material is formed into strips from multiple extrusion holes distributed circumferentially of the die head; S2. The strip material is introduced into a cooling jacket in a cooling box. The cooling jacket is provided with a plurality of cooling holes corresponding to the extrusion holes, and a cooling pipe with a through hole is connected to the end of the cooling jacket away from the die head. The strip material is cooled and solidified through the cooling holes and the cooling pipe; S3, introducing gas into the through hole of the cooling tube to blow the solidified strip raw material into the granulation cavity of the granulation box; S4. The strip-shaped raw material is cut by driving the rotating blade in the granulation chamber to form granular plastic raw materials to complete granulation.

[0014] Compared with the prior art, the present invention can achieve at least one of the following beneficial effects: 1. The present invention realizes precise cutting and channel switching of extruded raw materials through the linkage control of the air sleeve rotation and the telescopic rod. During the cooling and solidification stage, the air sleeve and the die head maintain a concentric channel. After the initial cooling is completed, the raw material is automatically deflected and cut off to avoid uneven fracture caused by manual intervention. The gas channel is switched synchronously during the cutting process to prepare for subsequent pneumatic discharge and realize automatic connection of the production process. The final cooling is completed after pelletizing. In addition, the cooling method is through air cooling, so it occupies less space than the water cooling method of the existing technology.

[0015] 2. The present invention utilizes a dual cooling mechanism combining indirect cooling with contact cooling. Initially, the raw material solidifies through indirect heat exchange via the cooling jacket, and then solidifies through direct contact with the thermal fluid via the cooling cylinder. This phased cooling method prevents internal stress cracking in the plastic caused by sudden cooling while ensuring cooling efficiency and effectively maintaining the physical stability of the plastic product.

[0016] 3. The present invention adopts a linkage design of compressed gas pushing and mechanical cutting. The cut strip raw materials enter the granulation chamber under the push of high-pressure airflow, and cooperate with the rotating blade to complete precise cutting. Pneumatic pushing not only avoids material deformation caused by mechanical transportation, but also promotes the circulation of heat transfer fluid through airflow disturbance, improves heat exchange efficiency, and achieves dual protection of production continuity and product quality.

[0017] 4. The present invention integrates semiconductor refrigeration plates with air cooling systems, uses a multi-stage temperature control module to accurately adjust the granulation environment temperature, and sets independent temperature control units for the cooling tube and the granulation chamber. The cooling intensity can be adjusted according to the characteristics of different plastics. This design can prevent the particles from sticking together and ensure that the cut surface is fully solidified, thus solving the technical problem of secondary heating deformation of traditional granulators.

[0018] 5. The present invention adopts an energized spring to control the arc plate, and realizes automatic opening and closing of the discharge port by circuit on and off. It remains closed under normal conditions to ensure sufficient cooling, and opens quickly after power is turned on to realize batch discharge. The inclined discharge port is combined with the arc guide plate design to ensure smooth discharge of particles and to observe the discharge status in real time, effectively preventing equipment blockage caused by particle accumulation.

[0019] Other features and advantages of the present invention will be described in the following description, and part of them will become obvious from the description, or will be understood by practicing the present invention. The purpose and other advantages of the present invention can be realized and obtained by the structures particularly pointed out in the written description and the accompanying drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to more clearly illustrate the technical solutions of the embodiments of the present invention, the following briefly introduces the drawings required for describing the embodiments. Obviously, the drawings described below are only some embodiments of the present invention. Those skilled in the art can also derive other drawings based on these drawings without inventive effort. Among them: Figure 1 It is an overall three-dimensional diagram of the present invention; Figure 2 A state diagram showing the removal of the extrusion barrel of the present invention; Figure 3 A perspective view of one side of the cooling box of the present invention; Figure 4 This is a perspective view of the other side of the cooling box of the present invention; Figure 5 Exploded perspective view of the cooling box, die head and granulation box of the present invention Figure 6 A perspective view of the air jacket and cooling box of the present invention; Figure 7 It is a partial cross-sectional view of the air sleeve of the present invention; Figure 8 It is a sectional view of the entire part of the present invention; Figure 9 A three-dimensional diagram of the stirring sheet and blade of the present invention; Figure 10 It is a top sectional view of the granulation box of the present invention; Figure 11 A perspective view of the rotating shaft and fan of the present invention; Figure 12 It is a side sectional view of the granulation box of the present invention.

[0021] The accompanying drawings are numerals as follows: 1. Feed box; 2. Drive motor; 3. Extrusion barrel; 4. Screw; 5. Cooling box; 6. Liquid inlet pipe; 7. Liquid outlet pipe; 8. Heat dissipation tank; 9. Cooling jacket; 10. Die head; 11. Extrusion hole; 12. Cooling hole; 13. Air jacket; 14. First support block; 15. Second support block; 16. Telescopic rod; 17. Third support block; 18. Fourth support block; 19. Spring; 20. Inlet pipe; 21. Through hole; 22. Countersunk hole; 2 3. Annular groove; 24. Cooling cylinder; 25. Granulating box; 26. Rotating shaft; 27. Spoiler; 28. Granulating chamber; 29. Feeding hole; 30. Blade; 31. Stirring blade; 32. Blowing chamber; 33. Fan; 34. Cooling pipe; 35. Semiconductor refrigerator; 36. Semiconductor cooling plate; 37. Driven gear; 39. Driving gear; 40. Transmission wheel; 41. Transmission belt; 42. Discharge port; 43. Curved plate; 44. Energized spring. DETAILED DESCRIPTION

[0022] The preferred embodiments of the present invention will be described in detail below with reference to the accompanying drawings, wherein the accompanying drawings constitute a part of the present invention and are used to explain the principles of the present invention together with the embodiments of the present invention.

[0023] Example 1: Figure 1 、 Figure 2 As shown, this embodiment provides a constant flow granulation extruder for recycling waste plastics, including a feed box 1, which can be fixed to the ground by bolts and a base. A drive motor 2 is provided on one side of the feed box 1, and an extrusion barrel 3 is provided on the other side of the feed box 1. A screw 4 is provided inside the extrusion barrel 3, and the output shaft of the drive motor 2 is connected to one end of the screw 4 through a transmission (not shown in the figure), so that the drive motor 2 can drive the screw 4 to rotate.

[0024] like Figure 3 、 Figure 4 As shown, a cooling box 5 is provided at the discharge end of the extrusion barrel 3. One end of the cooling box 5 is fixedly connected to the discharge end of the extrusion barrel 3. The interior of the cooling box 5 is filled with a heat-conducting liquid, which can be water or heat-conducting oil; a liquid inlet pipe 6 and a liquid outlet pipe 7 are connected to one side of the cooling box 5. The liquid inlet pipe 6 and the liquid outlet pipe 7 are respectively fixed at the upper and lower ends of one side of the cooling box 5, and can respectively realize liquid inlet and liquid outlet. The other ends of the liquid inlet pipe 6 and the liquid outlet pipe 7 pass through the rear of the cooling box 5 and are connected to the heat dissipation water tank 8 behind the cooling box 5. The interior of the liquid inlet pipe 6 and the liquid outlet pipe 7 are connected to the interior of the heat dissipation water tank 8. The outer wall of the heat dissipation water tank 8 is connected with a heat dissipation fin. A circulating pump (not shown in the figure) is provided on the liquid inlet pipe 6 or the liquid outlet pipe 7. The heat-conducting liquid inside the cooling box 5 can be circulated by the circulating pump, so that the hot water inside the cooling box 5 is injected into the interior of the heat dissipation water tank 8, and then the external cold air is heat-exchanged with the heat in the heat dissipation water tank 8 through the heat dissipation fins, thereby achieving the purpose of heat dissipation of the heat-conducting liquid.

[0025] It should be noted that, in the above solution, the internal structure of the heat dissipation water tank 8 is a multi-layer plate structure, which can make the running track of the heat transfer liquid be "S" shaped.

[0026] like Figure 5 、 Figure 6 、 Figure 7 、 Figure 8As shown, a cooling jacket 9 is provided inside the cooling box 5, and a plurality of cooling holes 12 are provided around the cooling jacket 9. A die head 10 is provided between the cooling box 5 and the extrusion barrel 3. The die head 10 is fixedly connected to the discharge end of the extrusion barrel 3. A plurality of extrusion holes 11 are opened around the die head 10, and the number and position of the extrusion holes 11 correspond to the cooling holes 12; an air jacket 13 is provided between the die head 10 and the cooling jacket 9, and the air jacket 13 is rotatably mounted on the end of the die head 10 close to the cooling jacket 9 through a bearing, and the end of the die head 10 close to the air jacket 13 is fixedly connected to a first support block 14, and the outer wall of the air jacket 13 is fixedly connected to a second support block 15, and the first support block 14 and the second support block 15 are arranged on the same plumb line, and the bottom of the first support block 14 is fixedly connected to a telescopic rod 16, and the telescopic end of the bottom of the telescopic rod 16 is against the top of the second support block 15; the outer wall of the air jacket 13 is also connected to a third support block 17, and the outer wall of the die head 10 is connected to a fourth support block 18.

[0027] like Figure 6 As shown, a spring 19 is connected between the fourth support block 18 and the third support block 17. The spring 19 is in a contracted state by default. In this state, the spring 19 can keep the air sleeve 13 as shown. Figure 6 In the state shown, when the telescopic rod 16 is quantitatively extended, the bottom end of the telescopic rod 16 can exert pressure on the second support block 15, thereby driving the second support block 15 and the air sleeve 13 to rotate at a small angle.

[0028] like Figure 7 As shown, a plurality of through holes 21 are provided around the air jacket 13, and the positions and numbers of the through holes 21 correspond to the extrusion holes 11. A countersunk hole 22 is provided between every two adjacent through holes 21, and one end of the countersunk hole 22 is closed, and the open end of the countersunk hole 22 faces the cooling jacket 9; in the above scheme, when the air jacket 13 and the spring 19 are in the default state, the plurality of through holes 21 are concentric with the extrusion hole 11 and the cooling hole 12, and when the telescopic rod 16 drives the second support block 15 and the air jacket 13 to rotate to the set maximum angle, the countersunk hole 22 is concentric with the extrusion hole 11 and the cooling hole 12; an annular groove 23 is provided around the air jacket 13, and a plurality of countersunk holes 22 are connected to the annular groove 23, and an air inlet pipe 20 is fixedly connected to the top of the air jacket 13, and the air inlet pipe 20 is a hose, and the top of the air inlet pipe 20 is connected to the air pump (not shown in the figure).

[0029] like Figure 8 As shown, the end of the cooling sleeve 9 away from the die head 10 is connected to a cooling cylinder 24. The number and inner diameter of the cooling cylinder 24 correspond to the plurality of cooling holes 12. The outer wall of the cooling cylinder 24 is provided with a plurality of through holes, which are used to allow the heat transfer liquid to directly enter the cooling cylinder 24.

[0030] In the above scheme, in the default state, the screw 4 in the extrusion barrel 3 is continuously driven by the driving motor 2 to continuously extrude the plastic raw material from the extrusion hole 11 on the die head 10 to form a strip of plastic raw material. When the strip of raw material fills the cooling hole 12 and the cooling cylinder 24, the telescopic rod 16 extends downward so that the bottom end of the telescopic rod 16 abuts against the second support block 15, thereby driving the air sleeve 13 to rotate to the set maximum angle. At this time, the through hole 21 on the air sleeve 13 and the cooling hole 12 on the cooling sleeve 9 are staggered, so that the countersunk hole 22 and the cooling hole 12 are in a concentric state, and in the process of rotation of the air sleeve 13, the part of the raw material extruded is just cut off. At this time, the screw 4 also stops rotating, and since both the cooling jacket 9 and the cooling cylinder 24 are immersed in the heat transfer fluid, the raw material is first cooled initially by the heat transfer fluid when passing through the cooling hole 12 on the cooling jacket 9, so that the paste-like raw material is initially solidified, and then when passing through the cooling cylinder 24, the strip-shaped raw material directly contacts the heat transfer fluid and directly exchanges heat to further cool the raw material. In this scheme, since the cooling jacket 9 is indirectly cooled, the raw material will not shrink rapidly (thermal expansion and contraction), but will gradually cool down. Although the cooling cylinder 24 is directly cooled, the temperature of the heat transfer fluid is controllable, so it will not cool down suddenly, thereby ensuring the physical properties of the plastic raw material.

[0031] After completing the above operations, start the air pump, which will push the compressed gas into the cooling hole 12 from the air inlet pipe 20, the annular groove 23 and the countersunk hole 22 in sequence. Under the blowing of the gas, the plastic strip raw materials in the cooling hole 12 and the cooling cylinder 24 are blown into the next process.

[0032] Example 2: This example differs from Example 1 in that the following steps are described for the plastic strip material after preliminary cooling: like Figure 8 、 Figure 9As shown, the cooling box 5 is fixedly connected to a granulation box 25 at one end away from the extrusion barrel 3, and a rotating shaft 26 is rotatably installed in the middle of the granulation box 25. The other end of the rotating shaft 26 is rotatably installed in the middle of the die head 10. A granulation cavity 28 is opened inside the granulation box 25, and a plurality of feed holes 29 are opened at one end of the granulation cavity 28 close to the cooling cylinder 24. The number and position of the feed holes 29 correspond to those of the cooling cylinder 24, and the inner diameter of the feed hole 29 is larger than the inner diameter of the cooling cylinder 24, so as to facilitate the entry of the strip raw material into the granulation cavity 28. The outer wall of the rotating shaft 26 is connected to a plurality of spoilers 27. The spoiler 27 is used to The purpose is to disturb the heat transfer liquid when the rotating shaft 26 rotates, so that the heat transfer liquid can flow fully, thereby avoiding heat accumulation inside the cooling cylinder 24 and improving the heat exchange efficiency between the raw material and the heat transfer liquid. A blade 30 is provided inside the granulation chamber 28. The blade 30 is provided on one side of a plurality of feed holes 29. The plurality of blades 30 are fixedly connected to the outer wall of the rotating shaft 26. As the raw material is pushed in by the gas, the rotating shaft rotates under the drive source, so that the blade 30 rotates, cutting the hardened strip raw material, and cutting the strip raw material into particles of uniform size, thereby achieving the granulation effect.

[0033] like Figure 9 、 Figure 10 As shown, a stirring blade 31 is also provided inside the granulation chamber 28. The width of the stirring blade 31 matches the width of the granulation chamber 28. There are several stirring blades 31, and several stirring blades 31 are fixedly connected to the outer wall of the rotating shaft 26. The stirring blades 31 fully stir the granulated raw materials to prevent them from sticking to each other.

[0034] like Figure 10 As shown, a blowing chamber 32 is further provided inside the granulation box 25, and two fans 33 are provided inside the blowing chamber 32. The two fans 33 rotate under the drive of the driving device to generate wind force, and the wind force is converted into cold air through the cooling pipe 34 and blown into the inside of the granulation chamber 28, so as to finally cool the granules after granulation, and ensure that the cut parts of the granules are completely cooled and solidified. The specific working mechanism of the cooling pipe 34 is: a compressor refrigerator is set outside to generate cold air and transmit it to the cooling pipe 34.

[0035] like Figure 8 、 Figure 10 As shown, when the cold air passes through the cooling pipe 34, it can also pass through the semiconductor refrigeration plate 36, and the semiconductor refrigeration plate 36 is connected to the bottom of the semiconductor refrigerator 35, thereby further cooling.

[0036] like Figure 11As shown, as a way to drive the fans 33 to rotate, a driven gear 37 is connected to the shaft of one of the fans 33, and a driving gear 39 is fixedly connected to the rotating shaft 26. The driving gear 39 is engaged with the driven gear 37, so that when the rotating shaft 26 rotates, it can drive one of the fans 33 to rotate. A transmission wheel 40 is connected to the shafts of the two fans 33, and the two transmission wheels 40 are connected by a transmission belt 41. The transmission wheel 40 can be specifically a pulley or a sprocket, and the transmission belt 41 can be specifically a belt or a chain, so that the two fans 33 can rotate synchronously, and blow air into the blowing chamber 32 from the person.

[0037] like Figure 12 As shown, after the plastic particles are fully cooled in the granulation chamber 28, they can be discharged from the discharge port 42, wherein the discharge port 42 is tilted at the bottom of the granulation chamber 28, so that the plastic particles can roll and discharge, and an arc-shaped plate 43 is provided at one end of the discharge port 42 closer to the granulation chamber 28. The arc-shaped plate 43 can just match the curvature of the granulation chamber 28, so that a complete circular cavity is formed inside the granulation chamber 28. The arc-shaped plate 43 is hingedly installed at the bottom of the granulation chamber 28, and an energized spring 44 is connected between the bottom of the arc-shaped plate 43 and the bottom of the discharge port 42. In the default state, the energized plate 43 can be kept closed. When the energized spring 44 is energized and contracted, the arc-shaped plate 43 can be opened to allow the material to be discharged.

[0038] Example 3: This example differs from Example 1 and Example 2 in that it provides a constant-flow granulation extrusion method for recycling waste plastics, comprising the following steps: S1. When the pelletizer is in operation, the drive motor 2 rotates the screw 4 through the transmission, conveying the waste plastic raw material from the feed box 1 to the extrusion barrel 3. Under the extrusion of the screw 4, the molten plastic passes through the extrusion hole 11 of the die head 10 to form a strip of material, and then enters the cooling jacket 9 of the cooling box 5. At this time, the air jacket 13 is in the default position, and its through hole 21 maintains a concentric channel with the extrusion hole 11 and cooling hole 12 of the die head 10; The strip material passes through the cooling holes 12 of the cooling jacket 9 and the extended cooling cylinder 24 in sequence, and undergoes two cooling stages during this process: Indirect slow cooling stage: Indirect heat exchange is carried out at the cooling jacket 9 through the heat transfer liquid. The coolant circulates between the heat dissipation water tank 8 and the cooling box 5 through the liquid inlet pipe 6 and the liquid outlet pipe 7 to initially solidify the surface of the material; Direct shaping stage: the material is in direct contact with the circulating coolant in the cooling cylinder 24, and the through holes on the outer wall of the cooling cylinder 24 accelerate heat exchange to complete the shaping of the material; S2. When the material fills the cooling channel, telescopic rod 16 pushes down, rotating air jacket 13 and stretching spring 19. Now, countersunk hole 22 of air jacket 13 aligns with cooling hole 12, and through hole 21 is misaligned with extrusion hole 11. The rotation of air jacket 13 severs the strips of material. Once the strips are severed, the air pump activates, injecting compressed air through inlet pipe 20, annular groove 23, and countersunk hole 22 into cooling hole 12, blowing the solidified plastic strips into feed hole 29 of pelletizing box 25. In the granulation chamber 28: The rotating shaft 26 drives the blade 30 to rotate and cut the strip material, and the stirring blade 31 prevents the particles from sticking together; The semiconductor cooling plate 36 deeply cools the air flow in the blowing cavity 32 through the cooling pipe 34, and the two fans 33 rotate synchronously via the transmission belt 41 to enhance the cooling effect; S3. The granules after granulation are accumulated at the bottom of the granulation chamber 28. When the set output is reached, the energized spring 44 contracts to open the arc plate 43, and the granules roll out along the inclined discharge port 42. The whole process realizes continuous production through pneumatic cutting, graded cooling and linked granulation.

[0039] Throughout this specification, references to terms such as "one embodiment," "example," or "specific example" indicate that the specific features, structures, materials, or characteristics described in conjunction with that embodiment or example are included in at least one embodiment or example of the present invention. In this specification, schematic representations of these terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in any one or more embodiments or examples.

[0040] The terms "first", "second", "third", "fourth", etc. (if any) in the specification and claims of the embodiments of the present application and the above-mentioned drawings are used to distinguish similar objects and are not necessarily used to describe a specific order or sequential order. It should be understood that the data used in this way can be interchangeable where appropriate, so that the embodiments of the embodiments of the present application described herein can, for example, be implemented in an order other than those illustrated or described herein. In addition, the terms "including" and "having" and any of their variations are intended to cover non-exclusive inclusions, for example, a process, method, system, product or device comprising a series of steps or units is not necessarily limited to those steps or units clearly listed, but may include other steps or units that are not clearly listed or inherent to these processes, methods, products or devices.

[0041] In the embodiments of the present application, any device or element referred to or implied must have a specific orientation, be constructed and operate in a specific orientation, and therefore should not be understood as limiting the embodiments of the present application. In the description of the embodiments of the present application, the meaning of "plurality" is two or more, unless otherwise specifically specified.

[0042] The preferred embodiments of the present invention disclosed above are intended only to help illustrate the present invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the present invention to the specific embodiments described. Obviously, many modifications and variations are possible based on the content of this specification. These embodiments are selected and described in detail in this specification to better explain the principles and practical applications of the present invention, thereby enabling those skilled in the art to better understand and utilize the present invention. The present invention is limited only by the claims and their full scope and equivalents.

Claims

1. A constant flow type granulating extruder for recycling waste plastics, comprising an extrusion barrel (3), characterized in that: A cooling box (5) filled with a heat-conducting liquid is provided at the discharge end of the extrusion barrel (3), a die head (10) is provided between the cooling box (5) and the extrusion barrel (3), the die head (10) is fixedly connected to the discharge end of the extrusion barrel (3), a plurality of extrusion holes (11) are provided around the die head (10), a cooling jacket (9) is provided inside the cooling box (5), a plurality of cooling holes (12) are provided around the cooling jacket (9), a cooling barrel (24) is connected to the end of the cooling jacket (9) away from the die head (10), and the number and inner diameter of the cooling barrels (24) are the same as those of the plurality of cooling barrels (11). Corresponding to the cooling hole (12), the outer wall of the cooling cylinder (24) is provided with a plurality of through holes. The plastic raw material enters the cooling hole (12) and the cooling cylinder (24) after being extruded from the extrusion hole (11). A granulation box (25) is provided at the other end of the cooling cylinder (24). The granulation box (25) has a granulation cavity (28). The granulation cavity (28) has a blade (30). The strip-shaped raw material in the cooling hole (12) and the cooling cylinder (24) is blown into the granulation cavity (28) by gas, and the blade (30) cuts the strip-shaped raw material into granular raw material to complete granulation.

2. The constant flow granulating extruder for recycling waste plastics according to claim 1, characterized in that: One side of the cooling box (5) is connected to a liquid inlet pipe (6) and a liquid outlet pipe (7), the liquid inlet pipe (6) and the liquid outlet pipe (7) are respectively fixed to the upper and lower ends of one side of the cooling box (5), and can respectively realize liquid inlet and liquid outlet, the other ends of the liquid inlet pipe (6) and the liquid outlet pipe (7) pass through the rear of the cooling box (5) and are connected to the heat dissipation water tank (8) at the rear of the cooling box (5), the interior of the liquid inlet pipe (6) and the liquid outlet pipe (7) are communicated with the interior of the heat dissipation water tank (8), and the outer wall of the heat dissipation water tank (8) is connected to a heat dissipation fin.

3. The constant flow granulating extruder for recycling waste plastics according to claim 1, characterized in that: An air jacket (13) is provided between the die head (10) and the cooling jacket (9), and the air jacket (13) is rotatably mounted on one end of the die head (10) close to the cooling jacket (9) through a bearing, and one end of the die head (10) close to the air jacket (13) is fixedly connected to a first support block (14), and an outer wall of the air jacket (13) is fixedly connected to a second support block (15), and the first support block (14) and the second support block (15) are arranged on the same plumb line, and a telescopic rod (16) is fixedly connected to the bottom of the first support block (14), and the telescopic end of the bottom of the telescopic rod (16) is against the top of the second support block (15); the outer wall of the air jacket (13) is also connected to a third support block (17), and the outer wall of the die head (10) is connected to a fourth support block (18).

4. A constant flow type granulating extruder for recycling waste plastics as claimed in claim 3, characterized in that: A spring (19) is connected between the fourth support block (18) and the third support block (17). The spring (19) is in a retracted state by default. When the telescopic rod (16) is quantitatively extended, the bottom end of the telescopic rod (16) can exert pressure on the second support block (15), thereby driving the second support block (15) and the air sleeve (13) to rotate.

5. A constant flow type granulating extruder for recycling waste plastics as claimed in claim 3, characterized in that: A plurality of through holes (21) are provided around the air jacket (13), the positions and number of the through holes (21) correspond to the extrusion holes (11), a countersunk hole (22) is provided between every two adjacent through holes (21), one end of the countersunk hole (22) is closed, and the open end of the countersunk hole (22) faces the cooling jacket (9).

6. A constant flow type granulating extruder for recycling waste plastics as claimed in claim 5, characterized in that: An annular groove (23) is provided around the air sleeve (13), and a plurality of countersunk holes (22) are communicated with the annular groove (23). The top of the air sleeve (13) is fixedly connected to an air inlet pipe (20), which is a hose. The top of the air inlet pipe (20) is connected to the air pump.

7. The constant flow granulating extruder for recycling waste plastics according to claim 1, characterized in that: A rotating shaft (26) is rotatably installed through the middle of the granulation box (25), and a plurality of feed holes (29) are opened at one end of the granulation chamber (28) close to the cooling cylinder (24). The number and position of the feed holes (29) correspond to those of the cooling cylinder (24). The blade (30) is fixed on the rotating shaft (26) and rotates synchronously therewith. The outer wall of the rotating shaft (26) is connected to a plurality of spoilers (27), and the spoilers (27) correspond to the positions of the through holes on the cooling cylinder (24).

8. The constant flow granulating extruder for recycling waste plastics according to claim 1, characterized in that: A stirring blade (31) is further provided inside the granulation chamber (28). The width of the stirring blade (31) matches the width of the granulation chamber (28). There are a plurality of stirring blades (31). The stirring blades (31) are fixedly connected to the outer wall of the rotating shaft (26). The stirring blades (31) fully stir the granulated raw materials.

9. The constant flow granulating extruder for recycling waste plastics according to claim 1, characterized in that: The interior of the granulation box (25) is further provided with an air blowing chamber (32). Two fans (33) are provided inside the air blowing chamber (32). The two fans (33) rotate under the drive of the driving device to generate wind force. The wind force is converted into cold air through the cooling pipe (34) and blown into the interior of the granulation chamber (28), thereby finally cooling the granules after granulation, thereby ensuring that the cut parts of the granules are completely cooled and solidified.

10. A constant flow granulation extrusion method for recycling waste plastics, using a constant flow granulation extruder for recycling waste plastics according to any one of claims 1 to 9, characterized in that: The following steps are involved: S1, extruding the molten plastic through the die head (10) at the discharge end of the extrusion barrel (3), so that the plastic raw material is formed into a strip-shaped raw material from a plurality of extrusion holes (11) distributed circumferentially in the die head (10); S2, introducing the strip raw material into the cooling jacket (9) in the cooling box (5), wherein the cooling jacket (9) is provided with a plurality of cooling holes (12) corresponding to the extrusion holes (11), and the end of the cooling jacket (9) away from the die head (10) is connected to a cooling cylinder (24) with a through hole, and the strip raw material is cooled and solidified through the cooling holes (12) and the cooling cylinder (24); S3, introducing gas into the through hole of the cooling cylinder (24) to blow the solidified strip raw material into the granulation cavity (28) of the granulation box (25); S4. The strip-shaped raw material is cut by driving the rotating blade (30) in the granulation chamber (28) to form granular plastic raw material to complete granulation.

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