Internal core shaft cooling system of double-screw extruder

Abstract

The invention relates to a double-screw extruder internal core shaft cooling system which comprises a speed reducer and a core shaft which are installed on an extruder, an output shaft is arranged on the speed reducer, a linkage assembly is arranged between the output shaft and the core shaft, a cooling assembly is arranged on the speed reducer, and the cooling assembly comprises a cooling pipe, a cooling box, a water delivery pump and an installation base. The mounting seat is mounted on the speed reducer, a water inlet ring groove and a water outlet ring groove are formed in the mounting seat, cooling channels are formed between the output shaft and the mandrel, the cooling pipe is mounted between the two cooling channels, a cooling gap is reserved between the cooling channels, the cooling pipe is provided with a drainage hole, a water inlet hole and a water outlet hole are formed in the cooling channels, the water inlet hole is communicated with the water inlet ring groove, and the water outlet hole is communicated with the water outlet ring groove. The water delivery pump is installed on the cooling box, the water inlet end of the water delivery pump is communicated with the interior of the cooling box, the water outlet end of the water delivery pump is communicated with the water inlet ring groove, and the cooling box is communicated with the water outlet ring groove. According to the mandrel cooling system, the normal cooling of the mandrel can be met, and the mounting of the discharging template can also be met.

Description

Technical Field

[0001] This application relates to the technical field of mandrel cooling, and in particular to a mandrel cooling system inside a twin-screw extruder. Background Art

[0002] The twin-screw extruder is a plastic processing equipment developed on the basis of the single-screw extruder, and has characteristics such as good feeding performance, mixing and plasticizing performance, exhaust performance, extrusion stability, etc., and is widely used in the forming processing of extruded products.

[0003] Since the twin-screw extruder controls the processing temperature of the material by heating and cooling the barrel, and the friction temperature will be generated due to the shear of the material in the screw, this temperature control method will cause a certain difference between the surface temperature of the material and the actual temperature inside the material, affecting the quality of the final product. Therefore, it is necessary to design a cooling channel from the mandrel closest to the inside of the material to make up for this temperature difference. This design can also avoid the abnormal thermal expansion and contraction caused by the sudden change of the mandrel temperature, and ensure the operation stability of the equipment.

[0004] However, the conventional mandrel cooling design installs the water inlet and return water interfaces for internal mandrel cooling at the end of the extruder. This design will affect the discharge die plate installed at the end of the extruder (extruding the molten plastic material through a specific die shape to obtain the required product), resulting in the material being unable to be extruded and formed through the end die plate, and thus affecting the extrusion granulation function of the equipment.

[0005] Content of the Application In order to solve the above defects, this application provides a mandrel cooling system inside a twin-screw extruder.

[0006] The mandrel cooling system inside the twin-screw extruder provided by this application adopts the following technical solutions: An internal mandrel cooling system for a twin-screw extruder, comprising a speed reducer and a mandrel installed on the extruder. An output shaft is provided on the speed reducer, and a linkage assembly for driving the mandrel to rotate is provided between the output shaft and the mandrel. A cooling assembly is provided on the speed reducer. The cooling assembly includes a cooling pipe, a cooling tank, a water pump and a mounting seat. The cooling tank is arranged below the speed reducer. A coolant is provided in the cooling tank. The mounting seat is installed on the speed reducer. The output shaft is located within the mounting seat. An inlet ring groove and an outlet ring groove are formed on the mounting seat. Cooling channels are formed between the output shaft and the mandrel. The cooling pipe is installed between the two cooling channels and a cooling gap is left between the cooling pipe and the inner wall of the cooling channel. Drain holes are formed on the surface of the cooling pipe. Inlet holes and outlet holes are formed in the cooling channels on the output shaft. The inlet holes communicate with the inlet ring groove and the interior of the cooling pipe, and the outlet holes communicate with the outlet ring groove. The water pump is installed on the cooling tank. The inlet end of the water pump communicates with the interior of the cooling tank, and the outlet end communicates with the inlet ring groove. The cooling tank communicates with the outlet ring groove.

[0007] By adopting the above technical solution, when the temperature of the mandrel exceeds the specified temperature, the water pump is started. The coolant enters the inlet ring groove, then enters the interior of the cooling pipe through the inlet holes, and then discharges from the drain holes, and then moves reversely in the cooling gap. The coolant after heat exchange enters the outlet ring groove through the outlet holes and finally flows into the cooling tank, achieving the effect of heat-exchanging the mandrel. By arranging the cooling pipe to separate the flow path of the coolant in the cooling channel, the coolant can smoothly exchange heat with the inner wall of the cooling channel. In this way, the inlet and outlet of the coolant are both on the mounting seat, avoiding the discharge template at the end of the mandrel, so that the mandrel cooling system can not only meet the cooling of the mandrel, but also avoid the installation conflict with the discharge template, improving the applicability of the mandrel cooling system.

[0008] Optionally, a melting part and a shearing part are provided on the mandrel. A plurality of drain holes are provided at positions corresponding to the melting part and the shearing part. The diameter of the drain holes at the position of the melting part is larger than the diameter of the drain holes at the position of the shearing part.

[0009] By adopting the above technical solution, the melting part is used for melting the material, and the shearing part is used for shearing the material. Therefore, the temperature at the position of the mandrel corresponding to the melting part is higher than the temperature at the position of the shearing part of the mandrel. The diameter of the drain holes at the position of the melting part is larger than the diameter of the drain holes at the position of the shearing part, so that the water discharge volume at the position of the melting part of the mandrel per unit time is larger than the water discharge volume at the position of the shearing part, enabling the position of the melting part of the mandrel to be quickly cooled down and reducing the possibility of damage to the mandrel.

[0010] Optionally, a cooling water pipe is connected to the cooling box. The cooling water pipe is arranged in a spiral cone shape with the smaller end facing downward. A plurality of drip holes are opened on the surface of the cooling water pipe. A connecting water pipe is connected between the cooling water pipe and the water outlet ring groove.

[0011] By adopting the above technical solution, the cooling water pipe arranged in a spiral truncated cone shape is used to increase the flow path of the coolant, so that the cooling water pipe discharges the coolant by dripping. During the falling process, the water droplets contact the air in the cooling box, thereby increasing the evaporation rate of the water droplets, thereby accelerating the heat dissipation of the coolant and achieving the effect of rapid cooling of the coolant.

[0012] Optionally, two drain boards are connected to the position below the cooling water pipe in the cooling box. The two drain boards are arranged opposite to each other and inclined, with the distance between the two drain boards gradually increasing from bottom to top as the reference direction.

[0013] By adopting the above technical solution, the drain plate is used to receive the water droplets falling from the cooling water pipe. The water droplets then move along the direction of the drain plate and finally gather at the bottom of the cooling box, thereby increasing the contact time between the water droplets and the cooling box, so that the water droplets have sufficient time to exchange heat with the cooling box and achieve the effect of coolant cooling.

[0014] Optionally, a plurality of cooling fans are installed on the surface of the cooling box, the cooling fans face the cooling water pipe, and a plurality of exhaust slots are opened on the side wall of the cooling box.

[0015] By adopting the above technical solution, the cooperation of the cooling fan and the exhaust slot forms an air flow path in the cooling box to accelerate the flow rate of the air in the cooling box, thereby increasing the evaporation rate of the coolant in the cooling box to accelerate the cooling effect of the coolant.

[0016] Optionally, a refrigerator is installed on the side wall of the cooling box, and the refrigerator is connected to the interior of the cooling box.

[0017] By adopting the above technical solution, the refrigerator is used to assist in cooling the coolant. When the cooling rate of the core shaft is slow, the refrigerator is used to accelerate the cooling effect of the coolant to ensure that the core shaft can be cooled quickly.

[0018] Optionally, the linkage assembly includes a fixing ring, a connecting tube and a locking ring, wherein one fixing ring is connected to the surface of the output shaft and the surface of the core shaft, the two fixing rings are arranged opposite to each other, a plurality of linkage teeth are connected to the fixing ring, the connecting tube is sleeved between the output shaft and the core shaft, and is located between the two fixing rings, a linkage groove is opened on the connecting tube, the linkage teeth are embedded in the linkage groove, and one locking ring is sleeved on the output shaft and the core shaft, the cross-section of the locking ring is L-shaped, the locking ring contacts the fixing ring, and cooperates with the thread of the connecting tube.

[0019] By adopting the above technical solution, when installing the output shaft and the core shaft, the connecting cylinder is sleeved between the output shaft and the core shaft, the linkage teeth are inserted into the linkage grooves, at this time the output shaft and the core shaft are in contact, and finally the locking ring is rotated to make the locking ring in threaded cooperation with the connecting cylinder, and the locking ring abuts against the fixed ring, realizing the linkage cooperation between the output shaft and the core shaft.

[0020] Optionally, the linkage assembly includes a first connecting ring, a second connecting ring, a pressing claw and a pressing ring. The first connecting ring is connected to the output shaft, the second connecting ring is connected to the core shaft, and a plurality of mounting notches are formed on both the first connecting ring and the second connecting ring. One end of the pressing claw is rotatably connected to the mounting notch on the first connecting ring, and the other end presses against the side wall of the second connecting ring. The pressing ring is sleeved on the core shaft, and a pressing ring wall is arranged on the pressing ring. The pressing ring is in threaded cooperation with the first connecting ring, and the pressing ring wall presses against the other end of the pressing claw. The second connecting ring is located inside the pressing ring.

[0021] By adopting the above technical solution, when installing the output shaft and the core shaft, the output shaft is abutted against the core shaft, the pressing claw is flipped to press against the side wall of the second connecting ring, and finally the pressing ring is rotated to make the pressing ring wall press against the pressing claw, realizing the linkage cooperation between the output shaft and the core shaft.

[0022] In summary, the present application includes at least one of the following beneficial technical effects: 1. When the temperature of the core shaft exceeds the specified temperature, the water pump is started, the coolant enters the water inlet ring groove, then enters the interior of the cooling pipe through the water inlet holes, and then is discharged from the drain holes, and then moves reversely in the cooling gap. The coolant after heat exchange enters the water outlet ring groove through the water outlet holes and finally flows into the cooling tank, realizing the effect of heat exchange of the core shaft. By arranging the cooling pipes to separate the flow path of the coolant in the cooling channels, the coolant can smoothly exchange heat with the inner wall of the cooling channels. In this way, the inlet and outlet of the coolant are both on the mounting seat, avoiding the discharge template at the end of the core shaft, so that the core shaft cooling system can not only meet the cooling of the core shaft, but also avoid the installation conflict with the discharge template, improving the applicability of the core shaft cooling system; 2. When installing the output shaft and the core shaft, the connecting cylinder is sleeved between the output shaft and the core shaft, the linkage teeth are inserted into the linkage grooves, at this time the output shaft and the core shaft are in contact, and finally the locking ring is rotated to make the locking ring in threaded cooperation with the connecting cylinder, and the locking ring abuts against the fixed ring, realizing the linkage cooperation between the output shaft and the core shaft; 3. When installing the output shaft and the core shaft, the output shaft is abutted against the core shaft, the pressing claw is flipped to press against the side wall of the second connecting ring, and finally the pressing ring is rotated to make the pressing ring wall press against the pressing claw, realizing the linkage cooperation between the output shaft and the core shaft. Description of the Drawings

[0023] Figure 1 It is a schematic diagram of the overall structure of the mandrel cooling system in Embodiment 1 of the present application.

[0024] Figure 2 It is an exploded view for showing the structure of the linkage assembly in Embodiment 1 of the present application.

[0025] Figure 3 It is a cross-sectional view for showing the internal structures of the output shaft and the mandrel in Embodiment 1 of the present application.

[0026] Figure 4 It is Figure 3 The enlarged view at position A in

[0027] Figure 5 It is Figure 3 The enlarged view at position B in

[0028] Figure 6 It is a cross-sectional view for showing the internal structure of the cooling tank in Embodiment 1 of the present application.

[0029] Figure 7 It is a schematic diagram of the structure of the linkage assembly in Embodiment 2 of the present application.

[0030] Figure 8 It is an exploded view for showing the structure of the linkage assembly in Embodiment 2 of the present application.

[0031] Figure 9 It is a cross-sectional view for showing the structure of the linkage assembly in Embodiment 2 of the present application.

[0032] Explanation of reference numerals: 01, speed reducer; 1, output shaft; 11, water inlet hole; 12, water outlet hole; 2, mandrel; 21, melting part; 22, shearing part; 3, linkage assembly; 31, fixing ring; 311, linkage teeth; 32, connecting cylinder; 33, locking ring; 34, first connecting ring; 35, second connecting ring; 36, pressing claw; 37, pressing ring; 4, cooling assembly; 41, cooling pipe; 411, drainage hole; 412, supporting ring; 42, cooling tank; 421, drainage plate; 422, exhaust slot; 423, cooling fan; 424, heat dissipation rib plate; 425, refrigerator; 43, water pump; 44, mounting seat; 441, water inlet ring groove; 442, water outlet ring groove; 5, cooling channel; 6, cooling water pipe. Detailed Description of the Invention

[0033] The following further describes the present application in detail with reference to the Figures 1-9 drawings.

[0034] Embodiment 1 of the present application discloses a mandrel cooling system inside a twin-screw extruder. Refer to Figure 1 and Figure 2, the internal mandrel cooling system of the twin-screw extruder includes a speed reducer 01 and a mandrel 2 installed on the extruder. An output shaft 1 is installed at the output end of the speed reducer 01, and the output shaft 1 and the mandrel 2 are coaxially arranged.

[0035] Refer to Figure 2 , Figure 3 and Figure 4 , a linkage component 3 is arranged between the output shaft 1 and the mandrel 2. The linkage component 3 includes a fixing ring 31, a connecting cylinder 32 and a locking ring 33. A fixing ring 31 is fixedly connected to each of the end portions of the output shaft 1 and the mandrel 2. A number of linkage teeth 311 are fixedly connected to the opposite side walls of the two fixing rings 31. The connecting cylinder 32 is sleeved between the output shaft 1 and the mandrel 2. Linkage grooves are formed at the end portions of the connecting cylinder 32, and the linkage teeth 311 are inserted into the linkage grooves, and the output shaft 1 and the mandrel 2 are in contact. A locking ring 33 is sleeved on each of the output shaft 1 and the mandrel 2. The cross section of the locking ring 33 is L-shaped. The locking ring 33 is in threaded cooperation with the connecting cylinder 32, and the fixing ring 31 is located inside the locking ring 33.

[0036] When installing the mandrel 2, the connecting cylinder 32 is sleeved on the output shaft 1 and the mandrel 2, so that the linkage teeth 311 are inserted into the linkage grooves. Finally, the locking ring 33 is rotated so that the locking ring 33 is in threaded cooperation with the connecting cylinder 32 and abuts against the fixing ring 31, realizing the linkage effect between the output shaft 1 and the mandrel 2.

[0037] Refer to Figure 2 , Figure 3 and Figure 6 , a cooling component 4 is arranged on the speed reducer 01. The cooling component 4 includes a cooling pipe 41, a cooling box 42, a water pump 43 and a mounting seat 44. Cooling channels 5 are formed between the output shaft 1 and the mandrel 2. Mounting heads are installed at both ends of the cooling pipe 41. The cooling pipe 41 is installed between the two cooling channels 5 through the mounting heads. The mounting heads are in contact with the inner walls of the cooling channels 5. Water passing holes are formed in the mounting heads. A cooling gap is left between the cooling pipe 41 and the inner wall of the cooling channel 5. A supporting ring 412 is installed between the cooling pipe 41 and the cooling gap. A number of water flowing holes are formed in the supporting ring 412.

[0038] Refer to Figure 3 , a melting part 21 and a shearing part 22 are arranged on the mandrel 2. A number of drain holes 411 are formed in the cooling pipe 41 corresponding to the positions of the melting part 21 and the shearing part 22. The diameter of the drain holes 411 at the position of the melting part 21 is larger than the diameter of the drain holes 411 at the position of the shearing part 22. With such a setting, the cooling pipe 41 at the position of the melting part 21 can be quickly cooled per unit time.

[0039] Refer to Figure 5, water inlet holes 11 and water outlet holes 12 are opened on the cooling channel 5 of the output shaft 1. The mounting seat 44 is installed on the speed reducer 01. The output shaft 1 is located inside the mounting seat 44. An inlet water ring groove 441 and an outlet water ring groove 442 are opened on the mounting seat 44. The inlet water ring groove 441 communicates with the water inlet hole 11, and the outlet water ring groove 442 communicates with the water outlet hole 12.

[0040] Refer to Figure 1 、 Figure 3 and Figure 6 , the cooling box 42 is arranged below the speed reducer 01. A coolant is arranged inside the cooling box 42. In this embodiment, the coolant is water. The water pump 43 is installed on the cooling box 42. The inlet end of the water pump 43 communicates with the inside of the cooling box 42, and a water inlet pipe is installed between the outlet end and the inlet water ring groove 441. A cooling water pipe 6 is fixedly connected inside the cooling box 42. The cooling water pipe 6 is arranged in a spiral frustum shape with the smaller end facing downward. An outlet pipe is installed between the cooling water pipe 6 and the outlet water ring groove 442. A number of water dripping holes are opened on the surface of the cooling water pipe 6. Two drainage plates 421 are fixedly connected to the inner wall of the cooling box 42. The two drainage plates 421 are arranged oppositely. Taking the top-down direction as the reference direction, the distance between the two drainage plates 421 gradually decreases. The drainage plates 421 are used to increase the contact time between the coolant and the cooling box 42 and assist the heat transfer of the coolant to the cooling box 42.

[0041] During cooling, the water pump 43 is started. The coolant enters the inlet water ring groove 441 through the water pump 43, then enters the inside of the cooling pipe 41 through the water inlet hole 11. The coolant is discharged from the drain hole 411 and enters the cooling gap. While flowing back, it exchanges heat with the inner wall of the cooling channel 5. The coolant after heat exchange enters the outlet water ring groove 442 and is then discharged into the cooling box 42 through the outlet pipe, achieving the effect of cooling the mandrel 2.

[0042] Refer to Figure 1 and Figure 6 , a number of installation openings and exhaust slots 422 are opened on the side wall of the cooling box 42. A cooling fan 423 is installed at the installation opening. The cooling fan 423 faces the cooling water pipe 6. An air flow is formed between the cooling fan 423 and the exhaust slots 422 to accelerate the evaporation rate of the coolant. A number of heat dissipation rib plates 424 are also fixedly connected to the side wall of the cooling box 42. The heat dissipation rib plates are used to increase the heat dissipation area of the cooling box 42 to accelerate the cooling efficiency of the coolant.

[0043] Refer to Figure 1 and Figure 6 , in order to improve the cooling efficiency, a refrigerator 425 is also installed on the side wall of the cooling box 42. The refrigerator 425 communicates with the inside of the cooling box 42. The refrigerator 425 is used to cool the coolant.

[0044] In Embodiment 1 of the present application, the implementation principle of the cooling system for the inner mandrel 2 of a twin-screw extruder is as follows: When the temperature of the mandrel 2 is greater than the specified temperature, the water pump 43 is started, so that the coolant enters the water inlet ring groove 441 through the water inlet pipe, and then enters the inside of the cooling pipe 41 through the water inlet hole 11. The coolant is discharged at the melting part 21 and the shearing part 22, and moves within the cooling gap, exchanges heat with the mandrel 2. The heated coolant enters the water outlet ring groove 442, and then enters the cooling water pipe 6 through the water outlet pipe. The coolant falls on the drainage plate 421 in the form of water droplets, and exchanges heat with the drainage plate 421. At the same time, the cooling fan 423 is started to accelerate the evaporation of the coolant. Finally, the coolant converges at the bottom of the cooling tank 42. If the temperature of the mandrel 2 drops slowly, the refrigerator 425 is started to further cool the coolant to meet the rapid cooling requirement of the mandrel 2, achieving the effect of rapid cooling of the mandrel 2.

[0045] By setting the cooling pipe 41, the flow path of the coolant in the cooling channel 5 is separated, so that the coolant can smoothly exchange heat with the inner wall of the cooling channel 5. In this way, the inlet and outlet of the coolant are both on the mounting seat 44, avoiding the discharge template at the end of the mandrel 2. The cooling system of the mandrel 2 can not only meet the cooling of the mandrel 2, but also avoid the installation conflict with the discharge template, improving the applicability of the cooling system of the mandrel 2.

[0046] Embodiment 2: The difference between this embodiment and Embodiment 1 lies in the different structure of the linkage assembly 3.

[0047] Refer to Figure 7 、 Figure 8 and Figure 9 , the linkage assembly 3 includes a first connecting ring 34, a second connecting ring 35, a clamping claw 36 and a clamping ring 37. The first connecting ring 34 is fixedly connected to the output shaft 1, the second connecting ring 35 is fixedly connected to the mandrel 2, and both the first connecting ring 34 and the second connecting ring 35 are provided with a plurality of mounting notches. One end of the clamping claw 36 is hinged at the mounting notch of the first connecting ring 34, and the other end abuts against the side wall of the second connecting ring 35 away from the first connecting ring 34. The clamping ring 37 is sleeved on the mandrel 2, and a pressing ring wall is provided on the clamping ring 37. The clamping ring 37 is in threaded cooperation with the first connecting ring 34, and the second connecting ring 35 is located inside the clamping ring 37.

[0048] During installation, the end of the mandrel 2 is attached to the end of the output shaft 1. Then, the clamping claw 36 is flipped so that the other end of the clamping claw 36 presses against the side wall of the second connecting ring 35. Finally, the clamping ring 37 is rotated so that the clamping ring 37 is in threaded cooperation with the first connecting ring 34, and the pressing ring wall presses against the clamping claw 36, achieving the effect of linking the mandrel 2.

[0049] The above are all the preferred embodiments of the present application. The protection scope of the present application is not limited by this. Therefore, all equivalent changes made according to the structure, shape and principle of the present application should be covered within the protection scope of the present application.

Claims

1. A twin-screw extruder internal mandrel cooling system, comprising a reducer (01) and a mandrel (2) installed on the extruder, characterized in that: The reducer (01) is provided with an output shaft (1), and a linkage assembly (3) for driving the core shaft (2) to rotate is provided between the output shaft (1) and the core shaft (2). The reducer (01) is provided with a cooling assembly (4), and the cooling assembly (4) comprises a cooling pipe (41), a cooling box (42), a water pump (43) and a mounting seat (44). The cooling box (42) is arranged below the reducer (01), and a coolant is provided in the cooling box (42). The mounting seat (44) is mounted on the reducer (01), and the output shaft (1) is located in the mounting seat (44). A water inlet ring groove (441) and a water outlet ring groove (442) are provided on the mounting seat (44). A cooling ring (441) and a water outlet ring groove (442) are provided between the output shaft (1) and the core shaft (2). The cooling tube (41) is installed between two cooling channels (5) and has a cooling gap with the inner wall of the cooling channel (5). The surface of the cooling tube (41) is provided with a drainage hole (411). The cooling channel (5) on the output shaft (1) is provided with a water inlet hole (11) and a water outlet hole (12). The water inlet hole (11) is connected to the water inlet annular groove (441) and the interior of the cooling tube (41). The water outlet hole (12) is connected to the water outlet annular groove (442). The water delivery pump (43) is installed on the cooling box (42). The water inlet end of the water delivery pump (43) is connected to the interior of the cooling box (42), and the water outlet end is connected to the water inlet annular groove (441). The cooling box (42) is connected to the water outlet annular groove (442).

2. The internal mandrel cooling system of the twin-screw extruder according to claim 1, characterized in that: The core shaft (2) is provided with a melting portion (21) and a shearing portion (22); a plurality of drainage holes (411) are provided at positions corresponding to the melting portion (21) and the shearing portion (22); the diameter of the drainage holes (411) located at the melting portion (21) is greater than the diameter of the drainage holes (411) located at the shearing portion (22).

3. The internal mandrel cooling system of the twin-screw extruder according to claim 1, characterized in that: The cooling box (42) is connected to a cooling water pipe (6), the cooling water pipe (6) is arranged in a spiral cone shape, and the smaller end faces downward. A plurality of drip holes are opened on the surface of the cooling water pipe (6), and a connecting water pipe is connected between the cooling water pipe (6) and the water outlet ring groove (442).

4. The internal mandrel cooling system of the twin-screw extruder according to claim 3, characterized in that: Two drain plates (421) are connected to the positions below the cooling water pipe (6) in the cooling box (42). The two drain plates (421) are arranged opposite to each other and tilted. From bottom to top is the reference direction, the distance between the two drain plates (421) gradually increases.

5. The internal mandrel cooling system of the twin-screw extruder according to claim 3, characterized in that: A plurality of cooling fans (423) are installed on the surface of the cooling box (42), the cooling fans (423) face the cooling water pipe (6), and a plurality of exhaust slots (422) are opened on the side wall of the cooling box (42).

6. The internal mandrel cooling system of the twin-screw extruder according to claim 1, characterized in that: A refrigerator (425) is installed on the side wall of the cooling box (42), and the refrigerator (425) is connected to the interior of the cooling box (42).

7. The internal mandrel cooling system of the twin-screw extruder according to claim 1, characterized in that: The linkage assembly (3) comprises a fixing ring (31), a connecting tube (32) and a locking ring (33); one fixing ring (31) is connected to the surface of the output shaft (1) and the surface of the core shaft (2); the two fixing rings (31) are arranged opposite to each other; a plurality of linkage teeth (311) are connected to the fixing ring (31); the connecting tube (32) is sleeved between the output shaft (1) and the core shaft (2) and is located between the two fixing rings (31); a linkage groove is formed on the connecting tube (32); the linkage teeth (311) are embedded in the linkage groove; one locking ring (33) is sleeved on the output shaft (1) and the core shaft (2); the cross section of the locking ring (33) is L-shaped; the locking ring (33) abuts against the fixing ring (31) and is threadedly matched with the connecting tube (32).

8. The internal mandrel cooling system of the twin-screw extruder according to claim 1, characterized in that: The linkage assembly (3) comprises a first connecting ring (34), a second connecting ring (35), a clamping claw (36) and a clamping ring (37); the first connecting ring (34) is connected to the output shaft (1); the second connecting ring (35) is connected to the core shaft (2); a plurality of mounting notches are provided on the first connecting ring (34) and the second connecting ring (35); one end of the clamping claw (36) is rotatably connected to the mounting notch on the first connecting ring (34); the other end presses the side wall of the second connecting ring (35); the clamping ring (37) is sleeved on the core shaft (2); a pressure ring wall is provided on the clamping ring (37); the clamping ring (37) is threadedly matched with the first connecting ring (34); the pressure ring wall presses the other end of the clamping claw (36); and the second connecting ring (35) is located inside the clamping ring (37).

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