A constant-flow granulating extruder and method for recycling waste plastics

Abstract

The present application relates to the technical field of plastic extruding machine, and particularly discloses a constant-flow type granulating extruder for waste plastic recycling and a method, which comprises an extruding barrel, a cooling box containing heat-conducting liquid is arranged at the discharging end of the extruding barrel, a die head is arranged between the cooling box and the extruding barrel, the die head is fixedly connected to the discharging end of the extruding barrel, a plurality of extruding holes are formed around the die head, and a cooling jacket is arranged inside the cooling box. The present application realizes accurate cutting and channel switching of the extruding raw material through linkage control of the gas jacket rotation and the telescopic rod, the gas jacket and the die head maintain concentric channels during the cooling and solidification stage, the raw material is automatically deflected and cut after preliminary cooling, unevenness of the cut end caused by manual intervention is avoided, the gas channel is switched synchronously during the cutting process, preparation for subsequent pneumatic discharging is provided, production process automation is realized, and the final cooling is completed after the granulation, and the cooling mode is air cooling, so that the present application occupies less space compared with the water cooling mode of the prior art.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of plastic extruders, in particular to a constant-flow waste plastic recycling granulating extruder and method. BACKGROUND

[0002] After extrusion, the extruded strip-shaped material needs to be cooled and solidified, and then the strip-shaped material is cut to form particles. The internal residual stress of crystalline materials (such as PE and PP) caused by rapid cooling may cause cracking risk of the product. Therefore, the cooling method of the prior art is mainly through water cooling and air cooling for gradual cooling. Water cooling is through segmented cooling (hot water -> warm water -> cold water), which is suitable for PE / PP and other crystalline materials, and can effectively eliminate internal stress. Air cooling is through forced air cooling by a fan, which is suitable for small and medium-sized extruders, and has the advantages of uniformity, cleanliness, but occupies a large space.

[0003] For example, the prior art CN112454860A discloses a waste plastic recycling and granulating production equipment, which comprises an extruder, a hopper, a melting screw and an extrusion screw. The extruder is provided with two groups of sliding grooves and sliding channels corresponding to the position above the hopper, and the sliding channel is movably connected with a gas cylinder through a sliding block. When the melted plastic moves with the rotation of the extrusion screw, the two filter pieces are inserted into the slot of the extrusion screw alternately to filter out the incompletely melted plastic or impurities, increase the purity of the melted material, and improve the quality of the regenerated plastic. Secondly, the plastic in the inner wall of the hopper is extruded by the air flow generated when the gas cylinder moves, so that the side of the bridging plastic is suspended, which assists the movement of the plastic pieces in the hopper. In addition, the rapid pulse airflow also increases the disturbance of the plastic pieces, further reduces the bridging probability, enhances the conveying speed of the broken pieces, and adapts to the processing speed of the granulator.

[0004] The defects of the prior art are that: after gradual cooling by water cooling, the surface of the particles may be left with water due to the cooling of the material by cold water, forming a water film on the surface of the plastic particles, and the water film needs to be dried separately. The time for cooling by water cooling in the prior art is relatively long, so the length of the water cooling pool is also very long, and the occupancy rate of the site is very high. SUMMARY

[0005] This section is intended to summarize some aspects of the embodiments of the present application and briefly introduce some preferred embodiments. Some simplifications or omissions may be made in this section and the abstract and title of the specification of the present application to avoid obscuring the purpose of this section, abstract and title, and such simplifications or omissions cannot be used to limit the scope of the present application.

[0006] The application provides a constant-flow type waste plastic recycling granulating extruder and method, which can solve the problem of high site occupancy rate during cooling in the prior art.

[0007] In one aspect, the application provides a constant-flow type waste plastic recycling granulating extruder, which comprises an extrusion barrel, a cooling box filled with heat-conducting liquid is arranged at the discharge end of the extrusion barrel, a die head is arranged 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 formed around the die head, a cooling jacket is arranged in the cooling box, a plurality of cooling holes are formed around the cooling jacket, a cooling cylinder is connected to one 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 formed in the outer wall of the cooling cylinder, the plastic raw material is extruded from the extrusion holes and then enters the cooling holes and the cooling cylinder, the other end of the cooling cylinder is provided with a granulating box, the granulating box has a granulating cavity, the granulating cavity has a blade, the strip-shaped raw material in the cooling holes and the cooling cylinder is blown into the granulating cavity by gas, and the blade cuts the strip-shaped raw material into granular raw material to complete granulation; the gas jacket is rotatably connected to the extension rod through linkage control, the accurate cutting and channel switching of the extruded raw material are realized, the gas jacket and the die head maintain concentric channels during the cooling and solidification stage, the raw material is automatically deflected and cut after preliminary cooling, the unevenness of the cut end caused by manual intervention is avoided, the gas channel is switched synchronously during the cutting process, preparation is provided for subsequent pneumatic discharge, production process automation is realized, and the final cooling is completed after the cutting, and the cooling mode is carried out through separate cooling, so that the space occupied is smaller compared with the water cooling mode of the prior art.

[0008] Preferably, the cooling box is connected with an inlet pipe and an outlet pipe on one side, the inlet pipe and the outlet pipe are fixed at the upper and lower ends of the one side of the cooling box respectively, and can realize liquid inlet and outlet respectively, the other ends of the inlet pipe and the outlet pipe penetrate to the rear of the cooling box and are connected with a heat dissipation water tank behind the cooling box, the interiors of the inlet pipe and the outlet pipe are communicated with the interior of the heat dissipation water tank, and the outer wall of the heat dissipation water tank is connected with heat dissipation fins.

[0009] Preferably, a gas jacket is arranged between the die head and the cooling jacket, the gas jacket is rotatably installed at one end of the die head close to the cooling jacket through a bearing, a first supporting block is fixedly connected to one end of the die head close to the gas jacket, a second supporting block is fixedly connected to the outer wall of the gas jacket, the first supporting block and the second supporting block are arranged on the same plumb line, a telescopic rod is fixedly connected to the bottom of the first supporting block, and the telescopic end of the bottom of the telescopic rod abuts against the top of the second supporting block; the outer wall of the gas jacket is further connected with a third supporting block, and the outer wall of the die head is connected with a fourth supporting block.

[0010] Preferably, a spring is connected between the fourth supporting block and the third supporting block, the spring is in a default retracted state, when the telescopic rod is quantitatively extended, the bottom end of the telescopic rod can apply pressure to the second supporting block, so as to drive the second supporting block and the gas jacket to rotate.

[0011] Preferably, a plurality of through holes are formed on the periphery of the gas jacket, the positions and number of the through holes correspond to the extrusion holes, a counterbore is arranged between every two adjacent through holes, one end of the counterbore is closed, and the open end of the counterbore faces the cooling jacket.

[0012] Preferably, a ring groove is formed on the periphery of the gas jacket, a plurality of counterbores are communicated with the ring groove, the top of the gas jacket is fixedly connected with an air inlet pipe, the air inlet pipe is a flexible pipe, and the top end of the air inlet pipe is communicated with a gas pump.

[0013] Preferably, a rotating shaft is rotatably arranged in the middle of the granulating box, a plurality of feeding holes are formed on one end of the granulating cavity close to the cooling pipe, the number and positions of the feeding holes correspond to the cooling pipe, the blade is fixed on the rotating shaft and rotates synchronously, a plurality of spoiler plates are connected to the outer wall of the rotating shaft, and the spoiler plates correspond to the through holes on the cooling pipe.

[0014] Preferably, stirring blades are further arranged in the granulating cavity, the width of the stirring blades matches the width of the granulating cavity, a plurality of stirring blades are fixedly connected to the outer wall of the rotating shaft, and the stirring blades fully stir the cut granulated raw materials.

[0015] Preferably, a blowing cavity is further formed in the granulating box, two fans are arranged in the blowing cavity, the two fans rotate to generate wind power under the driving of a driving device, the wind power becomes cold air through the cooling pipe and blows into the granulating cavity, the granulated particles are finally cooled, and the cut parts of the particles are completely cooled and solidified.

[0016] On the other hand, the application provides a constant-flow type granulating and extruding method for recycling waste plastics, which comprises the following steps:

[0017] S1, extruding the molten plastics through the die head at the discharge end of the extruding barrel to form strip-shaped raw materials from the plurality of extrusion holes distributed circumferentially on the die head;

[0018] S2, introducing the strip-shaped raw materials into the cooling jacket in the cooling box, the cooling jacket being provided with a plurality of cooling holes corresponding to the extrusion holes, and the end of the cooling jacket away from the die head being connected with a cooling pipe with a through hole, and the strip-shaped raw materials being cooled and solidified through the cooling holes and the cooling pipe;

[0019] S3, introducing gas into the through hole of the cooling pipe to blow the solidified strip-shaped raw materials into the granulating cavity of the granulating box;

[0020] S4, cutting the strip-shaped raw materials by driving the rotating blade in the granulating cavity to form granular plastic raw materials to complete the granulation.

[0021] Compared with the prior art, the application can at least achieve one of the following beneficial effects:

[0022] 1. The application realizes precise cutting and channel switching of the extruded raw material through the linkage control of the air sleeve rotation and the telescopic rod, the air sleeve and the die head maintain concentric channels during the cooling and solidification stage, the raw material is automatically deflected and cut off after preliminary cooling, avoiding uneven break caused by manual intervention, the gas channel is switched synchronously during the cutting process, providing preparation for subsequent pneumatic discharge, realizing automatic connection of production process, and completing the final cooling after pelletizing, and the cooling mode is air cooling, so compared with the water cooling mode of the prior art, the occupied space is smaller.

[0023] 2. The double cooling mechanism of the application combines indirect cooling of the heat-conducting liquid with contact cooling, the raw material is preliminarily solidified through indirect heat exchange of the cooling sleeve, and then is shaped through direct contact with the heat-conducting liquid of the cooling cylinder. This phased cooling method can not only prevent the cracking of plastic due to sudden cooling, but also ensure the cooling efficiency and effectively maintain the physical property stability of the plastic product.

[0024] 3. The application adopts linkage design of compressed gas pushing and mechanical cutting, the cut-off strip-shaped raw material enters the granulation cavity under the pushing of high-pressure gas flow, and precise cutting is completed by cooperating with the rotating blade, pneumatic pushing not only avoids material deformation caused by mechanical conveying, but also promotes the circulation of heat-conducting liquid through air flow disturbance, improves heat exchange efficiency, and realizes double protection of production continuity and product quality.

[0025] 4. The application integrates the semiconductor refrigeration sheet with the air cooling system, accurately adjusts the granulation environment temperature through the multi-stage temperature control module, and sets independent temperature control units for the cooling pipe and the granulation cavity, so as to adjust the cooling strength according to different plastic properties, which can not only prevent particle adhesion, but also ensure that the cut surface is fully solidified, solving the technical problem of deformation caused by secondary heating of the traditional granulator.

[0026] 5. The application adopts a power spring to control the arc-shaped plate, realizes automatic opening and closing of the discharge port through circuit on-off, keeps closed in normal state to ensure sufficient cooling, quickly opens to realize batch discharge after power-on, and the inclined discharge port cooperates with the arc-shaped deflector design, which not only ensures smooth discharge of particles, but also can observe the discharge state in real time, effectively preventing equipment blockage caused by particle accumulation.

[0027] Other features and advantages of the application will be set forth in the following specification, and in part will become apparent to those skilled in the art upon examination of the following specification or can be learned by practice of the application. The objects and other advantages of the application can be realized and attained by the structure particularly pointed out in the written description and claims hereof. BRIEF DESCRIPTION OF DRAWINGS

[0028] In order to more clearly illustrate the technical solutions of the embodiments of the present application, the drawings needed to be used in the embodiments description will be briefly introduced as follows. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort based on these drawings. Among them:

[0029] Figure 1 It is a perspective view of the whole application;

[0030] Figure 2 It is a state diagram of the extrusion barrel of the present application;

[0031] Figure 3 It is a perspective view of one side of the cooling box of the present application;

[0032] Figure 4 It is a perspective view of the other side of the cooling box of the present application;

[0033] Figure 5 It is an exploded perspective view of the cooling box, the die head and the granulating box of the present application

[0034] Figure 6 It is a perspective view of the air sleeve and the cooling box of the present application;

[0035] Figure 7 It is a partial sectional view of the air sleeve of the present application;

[0036] Figure 8 It is a partial sectional view of the whole application;

[0037] Figure 9 It is a perspective view of the stirring blade and the blade of the present application;

[0038] Figure 10 It is a top sectional view of the granulating box of the present application;

[0039] Figure 11 It is a perspective view of the rotating shaft and the fan of the present application;

[0040] Figure 12 It is a side sectional view of the granulating box of the present application.

[0041] Among them, the reference signs are as follows:

[0042] 1. Feed box; 2. Drive motor; 3. Extrusion barrel; 4. Screw; 5. Cooling tank; 6. Liquid inlet pipe; 7. Liquid outlet pipe; 8. Cooling water tank; 9. Cooling jacket; 10. Die head; 11. Extrusion orifice; 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. Air inlet pipe; 21. Through hole; 22. Countersunk hole; 3. Circular groove; 24. Cooling cylinder; 25. Granulation box; 26. Rotating shaft; 27. Baffle plate; 28. Granulation chamber; 29. ​​Feed hole; 30. Blade; 31. Stirring plate; 32. Air blowing chamber; 33. Fan; 34. Cooling pipe; 35. Semiconductor cooler; 36. Semiconductor cooler chip; 37. Driven gear; 39. Drive gear; 40. Transmission wheel; 41. Transmission belt; 42. Discharge port; 43. Arc plate; 44. Electric spring. Detailed Implementation

[0043] The preferred embodiments of the present invention will now be described in detail with reference to the accompanying drawings, which form part of the present invention and, together with the embodiments of the present invention, serve to illustrate the principles of the present invention.

[0044] Example 1: As Figure 1 , Figure 2 As shown, this embodiment provides a constant flow waste plastic recycling granulation extruder, including a feed box 1. The feed box 1 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. The output shaft of the drive motor 2 is connected to one end of the screw 4 through a gearbox (not shown in the figure), so that the drive motor 2 can drive the screw 4 to rotate.

[0045] 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 heat-conducting liquid, which can be water or heat-conducting oil. An inlet pipe 6 and an outlet pipe 7 are connected to one side of the cooling box 5. The inlet pipe 6 and the outlet pipe 7 are fixed at the upper and lower ends of one side of the cooling box 5, respectively, so as to realize the inlet and outlet of liquid. The other end of the inlet pipe 6 and the outlet pipe 7 passes through to the rear of the cooling box 5 and connects to the heat dissipation water tank 8 behind the cooling box 5. The interior of the inlet pipe 6 and the outlet pipe 7 is connected to the interior of the heat dissipation water tank 8. The outer wall of the heat dissipation water tank 8 is connected with heat dissipation fins. A circulation pump (not shown in the figure) is provided in the inlet pipe 6 or the outlet pipe 7. The heat dissipation pump can circulate the heat-conducting liquid inside the cooling box 5, allowing the hot water inside the cooling box 5 to be injected into the heat dissipation water tank 8. Then, the heat dissipation fins exchange heat between the external cold air and the heat inside the heat dissipation water tank 8, thereby achieving the purpose of heat dissipation of the heat-conducting liquid.

[0046] It should be noted that in the above scheme, the internal structure of the heat dissipation water tank 8 is a multi-layer board structure, which can make the running track of the heat-conducting liquid present an "S" shape.

[0047] As shown in Figure 5 , Figure 6 , Figure 7 , Figure 8 , the inside of the cooling tank 5 is provided with a cooling jacket 9, and a plurality of cooling holes 12 are arranged around the cooling jacket 9. A die head 10 is arranged between the cooling tank 5 and the extrusion barrel 3, and the die head 10 is fixedly connected to the discharge end of the extrusion barrel 3. A plurality of extrusion holes 11 are formed around the die head 10, and the number and position of the extrusion holes 11 correspond to the cooling holes 12. A gas jacket 13 is arranged between the die head 10 and the cooling jacket 9, and the gas jacket 13 is rotatably installed on one end of the die head 10 close to the cooling jacket 9 through a bearing. The die head 10 is fixedly connected to a first support block 14 at one end close to the gas jacket 13. The outer wall of the gas jacket 13 is fixedly connected to a second support block 15. The first support block 14 and the second support block 15 are arranged on the same vertical line. The bottom of the first support block 14 is fixedly connected to an extension rod 16, and the extension end of the bottom of the extension rod 16 abuts against the top of the second support block 15. The outer wall of the gas jacket 13 is further connected to a third support block 17, and the outer wall of the die head 10 is connected to a fourth support block 18.

[0048] As shown in Figure 6 , a spring 19 is connected between the fourth support block 18 and the third support block 17. The spring 19 is in a default state of contraction. In this state, the spring 19 can keep the gas jacket 13 in the state as shown in Figure 6 . When the extension rod 16 is extended by a certain amount, the bottom end of the extension rod 16 can exert pressure on the second support block 15, thereby driving the second support block 15 and the gas jacket 13 to rotate by a small angle.

[0049] As shown in Figure 7 , a plurality of through holes 21 are formed around the gas jacket 13, and the positions and numbers of the through holes 21 correspond to the extrusion holes 11. A counterbore 22 is arranged between every two adjacent through holes 21. One end of the counterbore 22 is closed, and the open end of the counterbore 22 faces the cooling jacket 9. In the above scheme, when the gas jacket 13 and the spring 19 are in the default state, the plurality of through holes 21 are concentric with the extrusion holes 11 and the cooling holes 12. When the second support block 15 and the gas jacket 13 are rotated to a set maximum angle by the extension rod 16, the counterbores 22 are concentric with the extrusion holes 11 and the cooling holes 12. A ring groove 23 is formed around the gas jacket 13, and the plurality of counterbores 22 are in communication with the ring groove 23. The top of the gas jacket 13 is fixedly connected to an air inlet pipe 20, which is a flexible pipe. The top end of the air inlet pipe 20 is connected to an air pump (not shown in the figure).

[0050] As shown in Figure 8As shown, the cooling sleeve 9 is connected with a cooling cylinder 24 at one end away from the die head 10, the cooling cylinder 24 corresponds to the cooling holes 12 in number and inner diameter, and the outer wall of the cooling cylinder 24 is provided with a plurality of through holes for allowing the heat-conducting liquid to directly enter the cooling cylinder 24.

[0051] In the above scheme, in the default state, the screw 4 in the extrusion barrel 3 is continuously driven by the motor 2 to continuously extrude the plastic raw material from the extrusion hole 11 on the die head 10 to form a strip-shaped plastic raw material. When the strip-shaped raw material fills the cooling holes 12 and the cooling cylinder 24, the telescopic rod 16 is elongated downward, so that the bottom end of the telescopic rod 16 abuts against the second supporting block 15, thereby driving the gas sleeve 13 to rotate to a set maximum angle. At this time, the through hole 21 on the gas sleeve 13 is distributed in a staggered manner with the cooling holes 12 on the cooling sleeve 9, so that the counterbore 22 is in a concentric state with the cooling holes 12. During the rotation of the gas sleeve 13, the part of the raw material extruded is cut off. At this time, the screw 4 also stops rotating. Since the cooling sleeve 9 and the cooling cylinder 24 are immersed in the heat-conducting liquid, the raw material is preliminarily cooled by the heat-conducting liquid when passing through the cooling holes 12 on the cooling sleeve 9, so that the paste-shaped raw material is preliminarily solidified. Then, when passing through the cooling cylinder 24, the strip-shaped raw material directly contacts with the heat-conducting liquid for heat exchange, thereby further cooling the raw material. In this scheme, since the cooling sleeve 9 is indirectly cooled, the raw material will not rapidly shrink (thermal expansion and cold contraction), but gradually cool down. Although the cooling cylinder 24 is directly cooled, the temperature of the heat-conducting liquid is controllable, so the raw material will not be suddenly cooled, thereby ensuring the physical properties of the plastic raw material.

[0052] After the above operation is completed, the air pump is started to sequentially introduce compressed gas from the air inlet pipe 20, the annular groove 23 and the counterbore 22 into the cooling holes 12. Under the blowing of the gas, the strip-shaped plastic raw material in the cooling holes 12 and the cooling cylinder 24 is blown into the next process.

[0053] Embodiment Two: The technical scheme of the embodiment is different from that of Embodiment One in that the next process of the preliminarily cooled strip-shaped plastic raw material is described in the embodiment.

[0054] As shown in the drawing, Figure 8 , Figure 9As shown, the cooling box 5 is fixedly connected with a granulating box 25 away from one end of the extrusion barrel 3, a rotating shaft 26 is rotatably installed in the middle of the granulating box 25, the other end of the rotating shaft 26 is rotatably installed in the middle of the die head 10, a granulating cavity 28 is formed in the interior of the granulating box 25, a plurality of feeding holes 29 are formed in one end of the granulating cavity 28 close to the cooling cylinder 24, the number and position of the feeding holes 29 correspond to the cooling cylinder 24, and the inner diameter of the feeding holes 29 is greater than the inner diameter of the cooling cylinder 24, so as to facilitate the strip-shaped raw material to enter the granulating cavity 28, a plurality of spoiler plates 27 are connected to the outer wall of the rotating shaft 26, the spoiler plates 27 function to disturb the heat-conducting liquid when the rotating shaft 26 rotates, so as to make the heat-conducting liquid flow fully, thereby avoiding heat accumulation in the interior of the cooling cylinder 24 and improving the heat exchange efficiency of the raw material and the heat-conducting liquid, a blade 30 is arranged in the interior of the granulating cavity 28, the blade 30 is arranged on one side of the plurality of feeding holes 29, a plurality of blades 30 are fixedly connected to the outer wall of the rotating shaft 26, the rotating shaft is rotated under the driving of the driving source in the process of the raw material being pushed by the gas, so as to rotate the blade 30 and cut the hardened strip-shaped raw material into particles of uniform size, thereby achieving the effect of granulation.

[0055] As shown in Figure 9 , Figure 10 , a stirring blade 31 is further arranged in the interior of the granulating cavity 28, the width of the stirring blade 31 matches the width of the granulating cavity 28, a plurality of stirring blades 31 are fixedly connected to the outer wall of the rotating shaft 26, the stirring blade 31 fully stirs the cut raw material to avoid sticking together.

[0056] As shown in Figure 10 , a blowing cavity 32 is further formed in the interior of the granulating box 25, two fans 33 are arranged in the interior of the blowing cavity 32, the two fans 33 rotate to generate wind under the driving of the driving device, the wind becomes cold wind through the cooling pipe 34 and blows to the interior of the granulating cavity 28 to finally cool the granulated particles, so as to ensure that the cut part of the particles is completely cooled and solidified, and the specific working mechanism of the cooling pipe 34 is that a compressor refrigerating device is arranged outside, cold air is generated and conducted into the cooling pipe 34.

[0057] As shown in Figure 8 , Figure 10 , the cold wind can further pass through a semiconductor refrigerating sheet 36 when passing through the cooling pipe 34, the semiconductor refrigerating sheet 36 is connected to the bottom of a semiconductor refrigerating device 35, so as to be further cooled.

[0058] As shown in Figure 11As shown, as a way to drive the fan 33 to rotate, a driven gear 37 is connected to the shaft of one of the fans 33, and a drive gear 39 is fixedly connected to the rotating shaft 26. The drive gear 39 meshes 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 shaft of both fans 33, and the two transmission wheels 40 are connected by a transmission belt 41. The transmission wheel 40 can be a pulley or a sprocket, and the transmission belt 41 can be a belt or a chain, so that the two fans 33 rotate synchronously and blow air into the air chamber 32.

[0059] like Figure 12 As shown, after the plastic granules have been sufficiently cooled in the granulation chamber 28, they can be discharged from the outlet 42. The outlet 42 is inclined at the bottom of the granulation chamber 28, allowing the plastic granules to roll out. An arc-shaped plate 43 is provided at the end of the outlet 42 closer to the granulation chamber 28. The arc-shaped plate 43 can be matched with the curvature of the granulation chamber 28, so that the interior of the granulation chamber 28 forms a complete circular cavity. The arc-shaped plate 43 is hinged to the bottom of the granulation chamber 28. An electric spring 44 is connected between the bottom of the arc-shaped plate 43 and the bottom of the outlet 42. When energized, the arc-shaped plate 43 is kept closed. When the electric spring 44 is energized and contracts, the arc-shaped plate 43 is opened, allowing the material to be discharged.

[0060] Example 3: This example differs from Examples 1 and 2 in that it provides a constant-flow granulation extrusion method for recycling waste plastics, including the following steps:

[0061] S1. When the granulator is working, the drive motor 2 drives the screw 4 to rotate through the gearbox, conveying the waste plastic raw material from the feed box 1 to the extrusion tank 3. The molten plastic is squeezed by the screw 4 and forms a strip-shaped material through the extrusion hole 11 of the die head 10, which enters the cooling jacket 9 of the cooling box 5. At this time, the air jacket 13 is in the default position, and it maintains a concentric channel with the extrusion hole 11 and cooling hole 12 of the die head 10 through the hole 21.

[0062] The strip-shaped material passes sequentially through the cooling holes 12 of the cooling jacket 9 and the extended cooling cylinder 24, undergoing two cooling stages in the process:

[0063] Indirect slow cooling stage: Indirect heat exchange occurs at the cooling jacket 9 through heat transfer fluid. The coolant circulates between the heat dissipation tank 8 and the cooling tank 5 through the inlet pipe 6 and the outlet pipe 7, so that the surface of the material is initially solidified.

[0064] Direct shaping stage: The material comes into direct contact with the circulating coolant inside the cooling cylinder 24. The through holes on the outer wall of the cooling cylinder 24 accelerate heat exchange and complete the material shaping.

[0065] S2, when the material fills the cooling channel, the telescopic rod 16 pushes down to rotate the air sleeve 13, and the spring 19 is stretched. At this time, the counterbore 22 of the air sleeve 13 is aligned with the cooling hole 12, and the hole 21 is misaligned with the extrusion hole 11, and the air sleeve 13 is cut off during rotation. After cutting, the air pump is started to inject compressed air into the cooling hole 12 through the air inlet pipe 20, the annular groove 23 and the counterbore 22, and blow the solidified plastic strip into the feeding hole 29 of the granulating box 25;

[0066] In the granulating cavity 28:

[0067] 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;

[0068] The semiconductor refrigerating sheet 36 deeply cools the airflow in the blowing cavity 32 through the cooling pipe 34, and the two fans 33 are synchronously rotated through the transmission belt 41 to strengthen the cooling effect;

[0069] S3, the granulated particles accumulated at the bottom of the granulating cavity 28 are rolled out along the inclined discharge port 42 when the set yield is reached, and the whole process realizes continuous production through pneumatic cutting, staged cooling and linkage granulation.

[0070] In the description of the present specification, the description of the terms "one embodiment", "example", "specific example" and the like means that the specific features, structures, materials or characteristics described in combination with the embodiment or example are included in at least one embodiment or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0071] The terms "first", "second", "third", "fourth" and the like (if any) in the specification and claims of the embodiments of the present application and the above-described drawings are used to distinguish similar objects, and do not necessarily refer to a specific order or sequence. It should be understood that the data thus used can be interchanged under appropriate circumstances, so that the embodiments of the present application described herein can be implemented in an order other than those illustrated or described herein. In addition, the terms "include" and "have" and any variations thereof are intended to cover non-exclusive inclusion, for example, a process, method, system, product or device including a series of steps or units does not necessarily have to be limited to those steps or units clearly listed, but can include other steps or units not clearly listed or inherent to these processes, methods, products or devices.

[0072] The devices or elements referred to in the embodiments of this application or implied herein must have a specific orientation, be constructed and operated in a specific orientation, and therefore should not be construed as limiting the embodiments of this application. In the description of the embodiments of this application, "a plurality of" means two or more, unless otherwise precisely specified.

[0073] The preferred embodiments of the present invention disclosed above are merely illustrative of the invention. These preferred embodiments do not exhaustively describe all details, nor do they limit the invention to the specific implementations described. Clearly, many modifications and variations can be made based on the content of this specification. This specification selects and specifically describes these embodiments to better explain the principles and practical applications of the invention, thereby enabling those skilled in the art to better understand and utilize the invention. The 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: The discharge end of the extrusion barrel (3) is provided with a cooling box (5) filled with heat-conducting liquid. The cooling box (5) and the extrusion barrel (3) are provided with a die head (10) fixedly connected to the discharge end of the extrusion barrel (3). The die head (10) is provided with a plurality of extrusion holes (11) around the die head (10). The cooling box (5) is provided with a cooling jacket (9) in the interior of the cooling box (5). The cooling jacket (9) is provided with a plurality of cooling holes (12) around the cooling jacket (9). The cooling jacket (9) is connected to a cooling cylinder (24) at an end away from the die head (10). The number and inner diameter of the cooling cylinder (24) correspond to the number of the cooling holes (12). The cooling cylinder (24) is provided with a plurality of through holes in the outer wall of the cooling cylinder (24). The plastic raw material is extruded from the extrusion holes (11) and then enters the cooling holes (12) and the cooling cylinder (24). The other end of the cooling cylinder (24) is provided with a granulating box (25). The granulating box (25) has a granulating cavity (28) in the interior of the granulating box (25). The granulating cavity (28) has a blade (30) in the interior of the granulating cavity (28). The strip-shaped raw material in the cooling holes (12) and the cooling cylinder (24) is blown into the granulating cavity (28) by gas. The blade (30) cuts the strip-shaped raw material into granular raw material to complete the granulation.

2. A constant current type granulating extruder for recycling waste plastics according to claim 1, characterized in that: One side of the cooling box (5) is connected to an inlet pipe (6) and an outlet pipe (7). The inlet pipe (6) and the outlet pipe (7) are fixedly arranged at the upper end and the lower end of the one side of the cooling box (5) respectively. The inlet pipe (6) and the outlet pipe (7) can realize liquid inlet and liquid outlet respectively. The other end of the inlet pipe (6) and the outlet pipe (7) penetrates to the rear of the cooling box (5) and is connected to a heat dissipation water tank (8) behind the cooling box (5). The interior of the inlet pipe (6) and the outlet pipe (7) is in communication with the interior of the heat dissipation water tank (8). The outer wall of the heat dissipation water tank (8) is connected to heat dissipation fins.

3. A constant current type granulating extruder for recycling waste plastics according to claim 1, characterized in that: The die head (10) and the cooling jacket (9) are provided with a gas jacket (13). The gas jacket (13) is rotatably arranged at one end of the die head (10) close to the cooling jacket (9) through a bearing. The die head (10) is fixedly connected to a first support block (14) at one end close to the gas jacket (13). The outer wall of the gas jacket (13) is fixedly connected to a second support block (15). The first support block (14) and the second support block (15) are arranged on the same plumb line. The bottom of the first support block (14) is fixedly connected to an extension rod (16). The extension end of the bottom of the extension rod (16) is in abutment with the top of the second support block (15). The outer wall of the gas jacket (13) is further connected to a third support block (17). The outer wall of the die head (10) is connected to a fourth support block (18).

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

5. A constant current type granulating extruder for recycling waste plastics as claimed in claim 3 wherein: The gas jacket (13) is provided with a plurality of through holes (21) around the gas jacket (13). The positions and the number of the through holes (21) correspond to the extrusion holes (11). A counterbore (22) is arranged between every two adjacent through holes (21). One end of the counterbore (22) is closed. The open end of the counterbore (22) faces the cooling jacket (9).

6. A constant current type granulating extruder for recycling waste plastics as claimed in claim 5 wherein: The air sleeve (13) is provided with a ring groove (23) around the air sleeve (13), a plurality of counterbores (22) are in communication with the ring groove (23), and the top of the air sleeve (13) is fixedly connected with an air inlet pipe (20).

7. A constant current type granulating extruder for recycling waste plastics according to claim 1, characterized in that: The middle part of the granulation box (25) is rotatably provided with a rotating shaft (26), a plurality of feeding holes (29) are formed in one end of the granulation cavity (28) close to the cooling cylinder (24), the number and position of the feeding holes (29) correspond to the cooling cylinder (24), the blade (30) is fixed on the rotating shaft (26) and rotates synchronously with the rotating shaft (26), and the outer wall of the rotating shaft (26) is connected with a plurality of spoiler plates (27), the spoiler plates (27) correspond to the positions of the through holes on the cooling cylinder (24).

8. A constant current type granulating extruder for recycling waste plastics according to claim 1, characterized in that: The inside of the granulation cavity (28) is also provided with stirring blades (31), the width of the stirring blades (31) matches the width of the granulation cavity (28), the stirring blades (31) are provided in plurality, the plurality of stirring blades (31) are fixedly connected to the outer wall of the rotating shaft (26), and the stirring blades (31) fully stir the cut granules.

9. A constant current type granulating extruder for recycling waste plastics according to claim 1, characterized in that: The inside of the granulation box (25) is also provided with a blowing cavity (32), two fans (33) are arranged in the blowing cavity (32), the two fans (33) rotate to generate wind power under the driving of the driving device, the wind power becomes cold wind through the cooling pipe (34) and blows to the inside of the granulation cavity (28), the completed granules are finally cooled, and it is ensured that the cut part of the granules is completely cooled and solidified.

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

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