Twin screw extruder for PP plastic granules production

Abstract

The present application relates to a twin-screw extruder for the production of plastic granules PP, including a hopper, a barrel, a die, a mold and a control system, wherein an extrusion device is arranged in the barrel, and a heat recovery system is arranged on the periphery of the barrel, wherein the heat recovery system includes a heat recovery part wrapped around the periphery of the barrel, and a heat recovery channel is arranged in the heat recovery part; and further includes a coolant tank, wherein the coolant tank is filled with coolant, and a pump body for pumping coolant into the heat recovery channel is arranged on the coolant tank; and a heating chamber is arranged in the hopper, and an inlet and an outlet are arranged on the heating chamber, wherein the inlet is connected to the heat recovery space, and the outlet is connected to the coolant tank. The present application utilizes the waste heat of the extruder by arranging a heat recovery system.

Description

Technical Field

[0001] The present application relates to the technical field of waste plastic recycling, and in particular to a twin-screw extruder for producing plastic granules PP. Background Art

[0002] Plastic granules PP, namely polypropylene (PP for short) plastic granules, are thermoplastic resin granules made by propylene polymerization. As an environmentally friendly choice in the renewable resource industry, PP plastic granules are mostly recycled granules obtained by processing waste PP plastic products. This type of recycled granules has obvious advantages in reducing waste plastic emissions and reducing energy consumption. In the recycling process of waste plastics, they usually go through a series of processing processes, such as cleaning, screening, crushing, melting, etc., to remove impurities and prepare them into granules. These recycled granules are similar to original PP plastic granules in performance and can meet the production needs of most plastic products.

[0003] In the process of producing plastic granules PP, the extruder is one of the important types of machinery. The extruder generally includes a screw, a barrel, a hopper, a die and a mold. The plastic raw material enters the barrel through the hopper, and is plasticized into a uniform melt through heating and shearing under the rotation and push of the screw. Subsequently, the melt is pushed by the screw through the die and the mold to form the desired product shape. On the periphery of the barrel of the extruder, the cooling system can discharge excess heat in time to ensure that the material is extruded within a suitable temperature range. On the other hand, it can protect the various components of the extruder to avoid damage to the parts of the extruder due to overheating. However, the current cooling system generally does not reuse the heat after taking it away, resulting in waste. Summary of the invention

[0004] In order to improve the problem of energy waste caused by the inability to reuse waste heat in the current waste plastic recycling process. The present application provides a twin-screw extruder for the production of plastic granules PP, including a hopper, a barrel, a die, a mold and a control system, an extrusion device is arranged in the barrel, a heat recovery system is arranged on the periphery of the barrel, the heat recovery system includes a heat recovery part wrapped around the periphery of the barrel, and a heat recovery channel is arranged in the heat recovery part;

[0005] It also includes a coolant tank filled with coolant, and a pump body for pumping coolant into the heat recovery channel is provided on the coolant tank;

[0006] A heating chamber is arranged in the hopper, and an inlet and an outlet are arranged on the heating chamber. The inlet is communicated with the heat recovery space, and the outlet is communicated with the coolant tank.

[0007] By adopting the above scheme, the hopper can be heated by introducing the heat on the heat recovery component into the heating chamber of the hopper, thereby realizing preheating of the material in the hopper. Furthermore, the heat recovery channel is arranged in a winding manner in the heat recovery component, and the head end and the tail end of the heat recovery channel are located at the same end of the heat recovery component, and the heat recovery channel includes a plurality of straight-through portions and a plurality of bent portions, and the straight-through portions are arranged along the length direction of the heat recovery component, and the plurality of bent portions are divided into two groups, namely group one and group two, and the plurality of bent portions in group one are located at the same end as the head end of the heat recovery channel, and the head end of the heat recovery channel is connected to the coolant tank;

[0008] A transition chamber is provided in the heat recovery member, the transition chamber is communicated with the heating chamber, and a connection hole communicating with the transition chamber is provided at the tail end of the heat recovery channel and the inner wall of the bent portion in the first group;

[0009] An annular arrangement chamber is coaxially arranged in the heat recovery element, and an annular adjustment element is coaxially rotatably connected in the arrangement chamber;

[0010] The arrangement chamber includes an arrangement cavity and a connection cavity, the connection cavity passes through the head end, the tail end and the bending parts in the group one of the heat recovery channel, the adjustment member includes a rotating part and an adjustment part, the rotating part is arranged in the arrangement cavity, the adjustment part is arranged in the connection cavity, and the adjustment part is provided with an adjustment hole used in conjunction with the connection hole;

[0011] The heat recovery member is provided with a driving assembly for driving the adjusting member to rotate.

[0012] By adopting the above scheme, the coolant heat recovery system forms neutral gear, flow rate control gear, first gear, second gear, third gear... Neutral gear is the state where the pump body stops working, and the barrel of the extruder does not need to be heat controlled. In the flow rate control gear state, the pump body pumps the coolant in the coolant tank to the head end of the heat recovery channel and then enters the heat recovery channel. The adjustment hole on the adjustment part of the adjustment member is connected with the connecting hole in the bending part 1. At this time, the coolant entering the heat recovery channel enters the transition cavity through the adjustment hole and the connecting hole in the bending part 1, and then enters the heating cavity to preheat the material in the hopper, and then flows back to the coolant tank. In this process, if the temperature detector at the barrel detects that the temperature of the barrel is too high, the control system can first control the pump body power to increase the flow rate of the coolant for control. When the flow rate of the coolant reaches the maximum value and is still insufficient to meet the demand. The adjusting member can be rotated to align the adjusting hole of the adjusting member with the connecting holes in the second and third bending parts in turn, so as to increase the length of the flow path of the coolant in the heat recovery member, so that the coolant can carry more heat into the hopper. When the adjusting hole is aligned with the connecting hole in the second bending part, it is the first gear state; when the adjusting hole is aligned with the connecting hole in the third bending part, it is the second gear state. In the first, second or third gear state, the flow rate control gear can also adjust the power of the pump body according to the actual work. In this way, multi-gear control of the barrel temperature is achieved, and the waste heat is also recovered.

[0013] Furthermore, the plurality of connecting holes are evenly arranged around the axial direction of the heat recovery component, and the adjusting hole is a long hole arranged circumferentially along the adjusting portion, and the length of the adjusting hole is equal to the sum of the diameter of the adjusting hole and the distance between the two adjacent adjusting holes.

[0014] By adopting the above scheme, when it is necessary to adjust the connecting hole on the adjusting part from being aligned with the connecting hole in the bending part one to being aligned with the connecting hole in the bending part two, during the process of rotating the adjusting part, the coolant can continue to enter the transition cavity through the connecting hole in the bending part one before the adjusting hole is aligned with the connecting hole in the bending part two, thereby ensuring the continuity of the operation of the heat recovery system.

[0015] Furthermore, a recovery component for recovering residual heat is disposed on the periphery of the heat recovery component, and the recovery component includes an outer cover sleeved on the periphery of the heat recovery component, and an air duct is formed between the outer cover and the heat collection shell;

[0016] Also included is a blower for blowing air into the air duct;

[0017] The hopper is provided with an air blast port, and the air duct is communicated with the air blast port.

[0018] By adopting the above scheme, the residual heat diffused from the heat recovery component is recovered to improve the heat utilization efficiency, while reducing the impact of heat diffusion on the surrounding environment. When the temperature fluctuation range of the barrel is small, the coolant heat recovery system can be put in an idle state. At this time, the cooling effect of the barrel 1 can be achieved by simply changing the power of the blower. At the same time, the waste heat and the heat diffused outward from the barrel can be collected, so that the energy-saving effect is further improved. This is the airflow adjustment gear of the heat recovery system.

[0019] Furthermore, the tuyere is arranged obliquely downward.

[0020] By adopting the above solution, the impact on the material falling downward in the hopper can be reduced as much as possible.

[0021] Furthermore, the air blast port is located above the heating chamber.

[0022] By adopting the above scheme, the material will gradually accumulate from bottom to top after entering the hopper. The heating chamber is located at the bottom, which can continuously heat the material and improve the heating efficiency. At the same time, since the blast port is located at the top, it can also reduce the obstruction of the blast port.

[0023] Furthermore, a ventilation mesh is provided in the air blast port, a plurality of ventilation zones are provided on the ventilation mesh, the diameters of the ventilation holes in the plurality of ventilation zones become smaller successively, a wind shield is provided on the ventilation mesh, and a driving member is also provided on the hopper for driving the wind shield to move on the ventilation mesh along the arrangement direction of the plurality of ventilation zones.

[0024] By adopting the above solution, the air flow velocity entering the hopper can be controlled to adapt to more working conditions.

[0025] Furthermore, a blast chamber is provided in the hopper, the blast chamber is communicated with the air duct, the blast port is communicated with the blast chamber, and a connecting pipeline between the heating chamber and the coolant tank passes through the blast chamber.

[0026] By adopting the above solution, the connecting pipe between the heating chamber and the coolant tank passes through the blast chamber, and the airflow in the blast chamber can take away the excess heat in the connecting pipe, thereby reducing the subsequent cooling cost of the coolant tank.

[0027] In summary, the present invention has at least the following beneficial effects: 1. It realizes heat recovery and utilization of the basic device and realizes multi-level adjustment of the barrel temperature.

[0028] 2. By setting up a recycling component, the utilization efficiency of the heat released by the extruder is further improved, while also reducing the impact on the surrounding environment. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a schematic diagram showing the overall structure of the extrusion device in this embodiment;

[0030] Figure 2 is a cross-sectional view showing a heat recovery system in this embodiment;

[0031] Figure 3 is a cross-sectional view showing a heat recovery system in this embodiment;

[0032] Figure 4 is a schematic diagram showing the hopper structure in an embodiment of the present application;

[0033] Figure 5 yes Figure 3 A partial enlarged schematic diagram of part A;

[0034] Figure 6 yes Figure 4 A partial enlarged schematic diagram of part B.

[0035] Description of reference numerals:

[0036] 1. Cylinder; 2. Heat recovery component; 21. Heat recovery channel; 211. Head end; 212. Tail end; 213. Straight-through portion; 214. Bending portion; 2141. Bending portion 1; 2142. Bending portion 2; 2143. Bending portion 3; 215. Group 1; 22. Arrangement chamber; 221. Arrangement chamber; 222. Connecting chamber; 23. Driving assembly; 231. Motor; 24. Transition chamber; 25. Connecting hole; 3 , hopper; 31, heating chamber; 32, blast port; 33, blast chamber; 34, ventilation mesh; 35, driving member; 36, wind shield; 361, horizontal part; 362, vertical part; 37, air guide cover; 4, coolant tank; 41, pump body; 5, adjusting member; 51, rotating part; 52, adjusting part; 521, adjusting hole; 6, air heat recovery system; 61, outer cover; 611, air duct; 62, blower. DETAILED DESCRIPTION

[0037] The twin-screw extruder for producing plastic granules PP provided in the application example is referred to Figure 1 , including a hopper, a barrel, a head, a mold and a central control system. The barrel is equipped with an extrusion equipment. The above equipment is relatively existing equipment on the market and will not be described in detail in this case.

[0038] A temperature detector is provided at barrel 1, which is used to feed back the temperature change of barrel 1 to the central control system in real time. A heat recovery system is provided on the periphery of barrel 1. The purpose of the heat recovery system is to recycle the heat emitted by barrel 1 of the extruder on the one hand, so as to achieve energy saving effect, and on the other hand, to control the temperature at barrel 1 of the extruder to avoid damage to the extrusion equipment parts in barrel 1 due to excessive temperature as much as possible.

[0039] Reference Figure 2 and Figure 3 Specifically, the heat recovery system includes a coolant heat recovery system, and the coolant heat recovery system is wrapped around a heat recovery member 2 on the periphery of the barrel 1, and the cross section of the heat recovery member 2 is circular. A heat recovery channel 21 is arranged inside the heat recovery member 2.

[0040] Reference Figure 4 A heating chamber 31 is provided in the hopper 3, and an inlet and an outlet are provided in the heating chamber 31.

[0041] Reference Figure 1 The heat recovery system further includes a cooling liquid tank 4. One end of the heat recovery channel 21 is connected to the cooling liquid tank 4 through a connecting pipe, and the other end of the heat recovery channel 21 is connected to the inlet of the heating chamber 31 through a connecting pipe. The outlet of the heating chamber 31 is connected to the cooling liquid tank 4 through a connecting pipe. The cooling liquid tank 4 is provided with cooling liquid, and a pump body 41 for pumping the cooling liquid to the heat recovery channel 21 is provided at the cooling liquid tank 4.

[0042] The pump body 41 pumps the coolant into the heat recovery channel 21 of the heat recovery unit 2. The cold zone liquid takes away the heat of the heat recovery unit 2 and enters the heating chamber 31 of the hopper 3 to increase the temperature of the hopper 3, thereby preheating the material in the hopper 3 and making it easier for the material in the hopper 3 to melt after entering the extrusion device, thus achieving an energy-saving effect. At the same time, the coolant can also control the temperature of the barrel 1 by taking away the heat from the heat recovery unit 2, so that the temperature of the barrel 1 is maintained within a reasonable range, thereby enabling the extrusion equipment in the barrel 1 to work continuously and stably.

[0043] Reference Figure 2 The heat recovery channel 21 is arranged in a winding manner in the heat recovery member 2, and the head end 211 and the tail end 212 of the heat recovery channel 21 are located at the same end of the heat recovery member 2. The head end 211 of the heat recovery member 2 is connected to the coolant tank 4 through a connecting pipe.

[0044] Since the heat recovery channel 21 is arranged in a winding manner in the heat recovery component 2, the heat recovery channel 21 forms a plurality of straight portions 213 and a plurality of bent portions 214 in the heat recovery component 2. The plurality of straight portions 213 are parallel to each other, and the straight portions 213 are arranged along the length direction of the heat recovery component 2. The plurality of bent portions 214 are divided into two groups, and the two groups of bent portions 214 are respectively located at the two ends of the heat recovery component 2. For the convenience of description, the two groups of bent portions 214 are respectively named as group one 215 and group two. For the convenience of subsequent description, the plurality of bent portions 214 in group one 215 between the head end 211 and the tail end 212 of the heat recovery channel 21 are sequentially named as bent portion one 2141, bent portion two 2142, bent portion three 2143...

[0045] The head end 211 and tail end 212 of the heat recovery channel 21 and the bent portions 214 in the group 1 215 are located at the same end of the heat recovery element 2. For the convenience of subsequent description, the end of the heat recovery element 2 where the head end 211 of heat recovery is located is named end 1, and the other end is named end 2.

[0046] Reference Figure 2 and Figure 5 A transition chamber 24 is provided in one end of the heat recovery element 2. The shape of the transition chamber 24 can be circular, square, etc. In the present case, the transition chamber 24 is an annular chamber coaxial with the heat recovery element 2. The transition chamber 24 is provided on the periphery of the heat recovery channel 21.

[0047] Connection holes 25 are provided between the tail end 212 of the heat recovery element 2 and the bending parts 214 in the first group 215 and the transition cavity 24. The bending parts 214 in the first group 215 are evenly arranged around the axis of the heat recovery element 2, and the connection holes 25 are evenly arranged around the axis of the heat recovery element 2.

[0048] Reference Figure 5 The heat recovery element 2 is coaxially provided with a circular arrangement chamber 22, which is located at one end. The arrangement chamber 22 includes an arrangement chamber 221 and a connecting chamber 222. The connecting chamber 222 passes through the head end 211, the tail end 212 and the bending parts 214 in the plurality of groups 215 of the heat recovery channel 21.

[0049] An annular adjusting member 5 is coaxially arranged in the arrangement chamber 22. The adjusting member 5 is slidably connected to the arrangement chamber 22. The adjusting member 5 includes a rotating portion 51 and an adjusting portion 52. The rotating portion 51 is located in the arrangement cavity 221, and the adjusting portion 52 is located in the connecting cavity 222. An adjusting hole 521 is opened on the adjusting portion 52 for use with the connecting hole 25.

[0050] The heat recovery member 2 is provided with a driving assembly 23 for driving the adjusting member 5 to rotate. The driving assembly 23 can be provided on the heat recovery member 2, or on an external device or the ground. The driving assembly 23 includes a driving motor 231, which is connected to the adjusting member 5 via a gear set, and the driving motor 231 drives the adjusting member 5 to rotate via the gear set.

[0051] Through the above technical scheme, the coolant heat recovery system forms a neutral gear, a flow rate control gear, a first gear, a second gear, a third gear...; the neutral gear means that the pump body stops working, and the barrel of the extruder does not need to be heat controlled at this time. In the flow rate control gear state, the pump body 41 pumps the coolant in the coolant tank 4 to the head end 211 of the heat recovery channel 21 and then enters the heat recovery channel 21. The adjustment hole 521 on the adjustment part 52 of the adjustment member 5 is connected with the connection hole 25 in the bending part 1 2141. At this time, the coolant entering the heat recovery channel 21 enters the transition chamber 24 through the adjustment hole 521 and the connection hole 25 in the bending part 1 2141, and then enters the heating chamber 31 to preheat the material in the hopper 3, and then flows back to the coolant tank 4. In this process, if the temperature detector at the barrel 1 detects that the temperature of the barrel 1 is too high, the pump body 41 can be controlled by the control system to increase the flow rate of the coolant for control. When the flow rate of the coolant reaches the maximum value and is still insufficient to meet the demand. The adjusting member 5 can be rotated to align the adjusting hole 521 of the adjusting member 5 with the connecting holes 25 in the second bending part 2142 and the third bending part 2143 in turn, so as to increase the length of the flow path of the coolant in the heat recovery member 2, so that the coolant can carry more heat into the hopper 3. When the adjusting hole 521 is aligned with the connecting hole 25 in the second bending part 2142, it is the first gear state; when the adjusting hole 521 is aligned with the connecting hole 25 in the third bending part 2143, it is the second gear state. In this way, the multi-gear control of the temperature of the barrel 1 is realized, and the waste heat is also recovered.

[0052] The adjustment hole 521 is set as a long hole, and the length of the adjustment hole 521 is equal to the sum of the diameter of the connection hole 25 and the distance between two adjacent connection holes 25. By setting the adjustment hole 521 as a long hole, when it is necessary to adjust the connection hole 25 on the adjustment member 5 from being aligned with the connection hole 25 in the bending portion 1 2141 to being aligned with the connection hole 25 in the bending portion 214, in the process of rotating the adjustment member 5, before the adjustment hole 521 is aligned with the connection hole 25 in the bending portion 2142, the coolant can continue to pass through the connection hole 25 in the bending portion 1 2141 and enter the transition chamber 24, thereby ensuring the continuity of the operation of the heat recovery system.

[0053] Reference Figure 3The heat recovery system also includes an air heat recovery system. Specifically, the air heat recovery system is wrapped around the periphery of the heat recovery component 2. The purpose of setting the air heat recovery system 6 is to recover the residual heat diffused from the heat recovery component 2 to improve the heat utilization efficiency and reduce the impact of heat diffusion on the surrounding environment.

[0054] Specifically, the air heat recovery system 6 includes an outer cover 61 wrapped around the heat recovery component 2 , and an air duct 611 is formed between the outer cover 61 and the heat recovery component 2 .

[0055] Reference Figure 4 and Figure 6 , one end of the air duct 611 is connected to the hopper 3, and a blast port 32 is provided on the inner wall of the hopper 3. A blower 62 is provided at the other end of the air duct 611, and the blower 62 is used to blow air into the air duct 611. The airflow carries the residual heat in the air duct 611 and enters the hopper 3 through the blast port 32 to heat the material in the hopper 3. When the temperature fluctuation range of the barrel 1 is small, the coolant heat recovery system can be placed in a neutral state. At this time, the cooling effect of the barrel 1 can be achieved by simply changing the power of the blower 62. At the same time, the waste heat and the heat diffused outward from the barrel 1 can be collected, so that the energy-saving effect is further improved. This is the airflow adjustment gear of the heat recovery system.

[0056] In the process of feeding materials into the hopper 3, in order to reduce the interference of airflow with materials, the air blast port 32 is arranged obliquely downward.

[0057] In the actual production process, the types and sizes of materials entering the hopper 3 may be different. In this case, the air flow velocity of the blast port 32 has a great influence on whether the materials can be stably heated and then fall into the hopper 3. For this reason, a ventilation mesh plate 34 is provided at the blast port 32, and a plurality of ventilation areas are provided on the ventilation mesh plate 34. The apertures of the ventilation holes on the plurality of ventilation areas increase or decrease in sequence. A windshield plate 36 is provided at the ventilation mesh plate 34, and a driving member 35 for driving the windshield plate 36 to move along the arrangement direction of the plurality of ventilation areas is also provided on the hopper 3. The driving member 35 can be a hydraulic cylinder, a cylinder, etc. In this case, the driving member 35 uses a cylinder.

[0058] The driving member 35 can change the air flow velocity of the air blast port 32 by driving the wind shield plate 36 to move in sequence along the arrangement direction of the plurality of ventilation zones on the ventilation mesh plate 34, so as to meet various working conditions.

[0059] In order to achieve a better preheating effect of the airflow on the material, the blast port 32 is arranged in a ring shape.

[0060] The blast port 32 is arranged above the heating chamber 31 so that the material is not easy to enter and affect the ventilation mesh plate 34.

[0061] Furthermore, a blast chamber 33 is provided in the hopper 3, and the blast chamber 33 is an annular chamber arranged axially around the hopper 3, and the air passage is connected to the blast chamber 33. The blast port 32 is connected to the blast chamber 33. The connecting pipe between the heating chamber 31 and the coolant tank 4 passes through the blast chamber 33, and the connecting pipe of the heating chamber 31 is arranged in a spiral shape around the axis of the hopper 3.

[0062] The connecting pipe between the heating chamber 31 and the coolant tank 4 passes through the blast chamber 33 , and the airflow in the blast chamber 33 can take away the excess heat in the connecting pipe, thereby reducing the subsequent cooling cost of the coolant tank 4 .

[0063] In order to reduce the influence of the wind shield 36 on the materials in the hopper 3, the wind shield 36 is arranged in the blast chamber 33. The cross section of the wind shield 36 is "L" shaped. The wind shield 36 includes a horizontal portion 361 and a vertical portion 362 which are integrally arranged. The side of the horizontal portion 361 away from the vertical portion 362 is closely attached to the ventilation mesh plate 34 and is slidably connected to the ventilation mesh plate 34. The vertical portion 362 of the horizontal portion 361 is attached to and slidably connected to the inside of the blast chamber 33. The above arrangement can maximize the utilization of the ventilation area on the ventilation mesh plate 34.

[0064] A flow guide hood 37 is provided on the top of the hopper 3, and the flow guide hood 37 can guide the gas discharged from the blast port 32 to a designated area to reduce the impact on the production workshop.

[0065] The implementation principle of this scheme is as follows: the pump body 41 pumps the coolant into the heat recovery channel 21 of the heat recovery component 2, and the cold zone liquid takes away the heat of the heat recovery component 2 and enters the heating chamber 31 of the hopper 3 to increase the temperature of the hopper 3 and preheat the material in the hopper 3, so that the material in the hopper 3 is more easily melted after entering the extrusion device, thereby achieving an energy-saving effect. At the same time, the coolant can also control the temperature of the barrel 1 by taking away the heat from the heat recovery component 2, so that the temperature of the barrel 1 is maintained within a reasonable range, thereby enabling the extrusion equipment in the barrel 1 to work continuously and stably. In the above process, the control system can change the flow rate of the coolant by controlling the power of the pump body 41, and then can adjust the temperature of the barrel 1, thereby forming a first-level control of the temperature of the barrel 1. The control system drives the adjusting member 5 to rotate through the driving component 23 so that the adjusting hole on the adjusting member 5 is aligned with the connecting holes 25 in the bending part 1 2141, the bending part 2142, and the bending part 3 2143 in turn, and the second gear, third gear, and fourth gear control are realized by changing the flow path length of the coolant in the heat recovery member 2.

[0066] The air heat recovery system 6 collects the hot air around the heat recovery unit 2 and blows it into the hopper 3 to heat the material. On the one hand, this improves the utilization rate of heat, and on the other hand, it reduces the impact on the environment around the basic device.

[0067] The embodiments of this specific implementation are all preferred embodiments of the present application, and are not intended to limit the protection scope of the present application. The same components are represented by the same figure marks. Therefore, any effective changes made based on the structure, shape, and principle of the present application should be included in the protection scope of the present application.

Claims

1. A twin-screw extruder for producing plastic granules PP, comprising a hopper (3), a barrel (1), a die, a mold and a control system, wherein an extrusion device is arranged in the barrel (1), and characterized in that: A heat recovery system is arranged on the periphery of the barrel (1), wherein the heat recovery system comprises a heat recovery component (2) wrapped around the periphery of the barrel (1), and a heat recovery channel (21) is arranged in the heat recovery component (2); It also includes a cooling liquid tank (4), the cooling liquid tank (4) is filled with cooling liquid, and the cooling liquid tank (4) is provided with a pump body (41) for pumping cooling liquid into the heat recovery channel (21); A heating chamber (31) is provided in the hopper (3), and an inlet and an outlet are provided on the heating chamber (31), the inlet is communicated with the heat recovery space, and the outlet is communicated with the coolant tank (4); The heat recovery channel (21) is arranged in a winding manner in the heat recovery component (2), and the head end (211) and the tail end (212) of the heat recovery channel (21) are located at the same end of the heat recovery component (2), the heat recovery channel (21) comprises a plurality of straight-through portions (213) and a plurality of bent portions (214), the straight-through portions (213) are arranged along the length direction of the heat recovery component (2), the plurality of bent portions (214) are divided into two groups, namely group one (215) and group two, the plurality of bent portions (214) in group one (215) are located at the same end as the head end (211) of the heat recovery channel (21), and the head end (211) of the heat recovery channel (21) is connected to the coolant tank (4); A transition chamber (24) is provided in the heat recovery element (2), the transition chamber (24) is communicated with the heating chamber (31), and a connection hole (25) communicating with the transition chamber (24) is provided at the tail end (212) of the heat recovery channel (21) and the inner wall of the bent portion (214) in the group one (215); An annular arrangement chamber (22) is coaxially arranged in the heat recovery element (2), and an annular adjustment element (5) is coaxially rotatably connected in the arrangement chamber (22); The arrangement chamber (22) comprises an arrangement cavity (221) and a connection cavity (222); the connection cavity (222) passes through the head end (211), the tail end (212) of the heat recovery channel (21) and a plurality of bent portions (214) in the group one (215); the adjustment member (5) comprises a rotating portion (51) and an adjustment portion (52); the rotating portion (51) is arranged in the arrangement cavity (221); the adjustment portion (52) is arranged in the connection cavity (222); and an adjustment hole (521) for use in conjunction with the connection hole (25) is provided on the adjustment portion (52); The heat recovery member (2) is provided with a driving assembly (23) for driving the adjusting member (5) to rotate.

2. The twin-screw extruder for producing plastic granules PP according to claim 1, characterized in that: The plurality of connection holes (25) are evenly arranged around the axial direction of the heat recovery element (2), and the adjustment hole (521) is a long hole arranged along the circumference of the adjustment portion (52), and the length of the adjustment hole (521) is equal to the sum of the diameter of the adjustment hole (521) and the distance between two adjacent adjustment holes (521).

3. The twin-screw extruder for producing plastic granules PP according to any one of claims 1-2, characterized in that: A recovery component (6) for recovering residual heat is disposed on the periphery of the heat recovery component (2), the recovery component (6) comprising an outer cover (61) sleeved on the periphery of the heat recovery component (2), and an air duct (611) is formed between the outer cover (61) and the heat collection shell; Also included is a blower (62) for blowing air into the air duct (611); The hopper (3) is provided with an air blast port (32), and the air duct (611) is in communication with the air blast port (32).

4. The twin-screw extruder for producing plastic granules PP according to claim 3, characterized in that: The blast port (32) is arranged obliquely downward.

5. The twin-screw extruder for producing plastic granules PP according to claim 3, characterized in that: The blast port (32) is located above the heating chamber (31).

6. The twin-screw extruder for producing plastic granules PP according to claim 3, characterized in that: A ventilation mesh plate (34) is arranged in the air blast port (32), a plurality of ventilation zones are arranged on the ventilation mesh plate (34), the diameters of the ventilation holes in the plurality of ventilation zones are successively smaller, a wind shield plate (36) is arranged at the ventilation mesh plate (34), and a driving member (35) for driving the wind shield plate (36) to move on the ventilation mesh plate (34) along the arrangement direction of the plurality of ventilation zones is also arranged on the hopper (3).

7. The twin-screw extruder for producing plastic granules PP according to claim 6, characterized in that: The hopper (3) is provided with a blast chamber (33), the blast chamber (33) is connected to the air duct (611), the blast port (32) is connected to the blast chamber (33), and the connecting pipeline between the heating chamber (31) and the coolant tank (4) passes through the blast chamber (33).

8. The twin-screw extruder for producing plastic granules PP according to claim 7, characterized in that: The cross section of the wind shield (36) is "L"-shaped. The wind shield (36) comprises a horizontal portion (361) and a vertical portion (362). The horizontal portion (361) is in contact with the wind shield (36), and the vertical portion (362) is in contact with the inner wall of the blowing chamber (33).

9. The twin-screw extruder for producing plastic granules PP according to claim 7, characterized in that: A flow guide cover (37) is arranged above the hopper (3).

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