Extruder annular discharge device and control method thereof

Abstract

The application provides an extruder annular gap discharging device and a control method thereof, and relates to an extruder structure which comprises a discharging bushing, a tail end screw, a top cone and an annular gap driving device. The tail end screw is installed at the tail end of the equipment main shaft of the extruder, the axial position of the tail end screw in the equipment cylindrical body is in the discharging bushing at the tail end thereof, the annular gap driving device is installed on the mounting seat at the tail end of the equipment cylindrical body, the driving end of the annular gap driving device is installed with the top cone, the top cone moves towards the tail end screw under the driving of the annular gap driving device, and the discharging bushing and the top cone jointly form the discharging annular gap of the material when the top cone extends into the discharging bushing. The application realizes the automatic control of the size of the annular gap through hydraulic driving, thereby improving the flexibility of the size adjustment of the annular gap of the extruder during use, and ensuring the uniformity of the quality of the discharging products.

Description

Technical Field

[0001] This invention relates to an extruder structure, and more particularly to an annular discharge device for an extruder and its control method. Background Technology

[0002] Annular discharge involves creating an annular gap at the equipment outlet, where material is extruded under the pressure and temperature provided by the screw inside the equipment, achieving an expansion effect. This process significantly increases the volume of the material, improves its texture and taste, and increases raw material utilization. Furthermore, due to the continuous, uniform, and controllable technical characteristics of annular discharge, it is now widely used in various fields, such as food processing (popcorn, potato chips, etc.), feed processing (livestock feed, aquatic feed, pig feed, pet food, etc.), and the plastics industry (for manufacturing plastic pellets and their products).

[0003] However, existing annular discharge systems still have several application defects as shown below:

[0004] 1) Blockage problem, specifically: the annular gap is small, which is prone to blockage due to the accumulation of particulate matter or other impurities. This will cause the production line to stop and affect production efficiency.

[0005] 2) Wear problem, specifically: under high pressure and high temperature conditions, especially in continuous production processes, the annular gap is prone to wear. In addition, the friction of materials against the inner wall of the equipment will also exacerbate the wear problem.

[0006] 3) The setup is complex, specifically: the size of the annular gap needs to be precisely set to ensure that the material can be extruded evenly; in the early traditional annular gap discharge, the annular gap was set by manually adjusting the position of the nut. If the setting is not correct, it will lead to uneven discharge and affect product quality.

[0007] 4) The phenomenon of "cloaking" is as follows: due to uneven pressure during discharge, some material will adhere to the inside of the equipment, forming a "cloaking" phenomenon. This will reduce the discharge efficiency and may lead to irregular product size and shape. Summary of the Invention

[0008] To address the aforementioned technical problems, the present invention aims to provide an annular gap discharge device and its control method for an extruder. Through hydraulic drive, the device achieves automatic control of the annular gap size, thereby improving the flexibility of adjusting the annular gap size during extruder operation and ensuring the uniformity of the output product quality. Furthermore, through a specially designed tail screw and hydraulic top cone, the material flows more smoothly through the annular gap, resulting in a more uniform pressure distribution, reducing the "blowing" phenomenon, and improving production efficiency and product quality.

[0009] This invention provides the following technical solution:

[0010] An annular discharge device for an extruder includes a discharge bushing, a tail screw, a top cone, and an annular discharge drive device. The tail screw is installed at the tail end of the extruder's main shaft and rotates with the main shaft. The main shaft of the extruder is configured to rotate within a cylindrical body of the extruder. This structure, where the main shaft is configured within the cylindrical body to extrude material, is existing technology for extruders and will not be elaborated upon here. The axial position of the tail screw within the cylindrical body is located within the discharge bushing at its tail end, and its axial position remains unchanged. The annular discharge drive device is installed on a mounting base at the tail end of the cylindrical body, and the top cone is mounted on its driving end. The top cone moves towards the tail screw under the drive of the annular discharge drive device, and when it extends into the discharge bushing, it forms an annular discharge gap for the material together with the discharge bushing and the top cone.

[0011] In the discharge device of the present invention, the discharge annular gap can be driven and adjusted by the annular gap driving device to realize automatic control of the annular gap size, thereby improving the flexibility of the annular gap size adjustment during the use of the extruder and ensuring the uniformity of the quality of the discharged product.

[0012] Preferably, the annular gap drive device uses a hydraulic cylinder, whose piston rod is connected to the top cone, and the rodless chamber inside the cylinder is connected to an overflow valve to control the oil pressure in the rodless chamber. When the oil pressure in the rodless chamber exceeds the pressure setting value, the overflow valve releases pressure. That is, the hydraulic system of the hydraulic cylinder can achieve the following effect: after the oil pump drives the hydraulic oil into the rodless chamber, if there is not enough load at the outlet, the piston rod of the hydraulic cylinder will continue to extend until the full stroke, and when the oil pressure in the rodless chamber exceeds the pressure setting value (e.g., the set pressure is 20 bar), the overflow valve releases pressure. If there is enough load at the outlet, the piston rod will extend to the equilibrium position, and when the oil pressure in the rodless chamber is also set to exceed 20 bar, the overflow valve releases pressure to avoid blockage. Thus, the effect of intelligent blockage prevention can be achieved, that is, the annular gap is adjusted by driving the hydraulic system.

[0013] Preferably, the tail screw includes a cone block one for fixed connection with the tail end of the main shaft of the equipment and multiple sets of claws uniformly fixed around the cone block one. The claws are inclined from their fixed ends toward the top cone one. The top cone includes a cone block two and a rim surrounding the cone block two. When the top cone is connected to the tail screw, the rim is wrapped around the claws, and its outer diameter is slightly smaller than the inner diameter of the discharge bushing. Multiple sets of channels for material to flow out are also uniformly opened on the rim. Thus, the tail screw and the top cone are used together to make the discharge pressure more uniform, reduce material adhesion, and reduce the "blowing" phenomenon. The discharge channel is opened on the top cone. The tail screw rotates with the main shaft of the equipment, and the material that has been collided and matured in the extruder can be discharged through the discharge channel of the top cone. At the same time, the channels can be designed in different numbers or different shapes according to different needs.

[0014] Preferably, the channel is a plurality of through circular holes evenly arranged on the perimeter.

[0015] Preferably, the channel is a plurality of through slots evenly arranged on the perimeter.

[0016] Preferably, when the top cone is connected to the tail screw, the claw is fitted to the outer cone surface of the second cone block. This structure of the claw and the cone block ensures that the tail screw will not touch the top cone when rotating. At the same time, the annular gap formed between the rotating cone surface and the top cone is more uniform, making the discharge pressure at different positions of the discharge port more uniform.

[0017] Preferably, the tail screw, the top cone, and the discharge bushing are all made of wear-resistant materials, which can extend the service life of the device; and they can be disassembled and replaced, reducing maintenance costs.

[0018] Preferably, it also includes a control system, which adopts PLC control and integrates PID automatic adjustment; through parameter settings, it can automatically adjust the size of the annular gap according to the actual production situation, reduce human error, and ensure product quality uniformity.

[0019] A method for controlling an annular discharge device of an extruder includes the following steps:

[0020] S1: In the initial state, the annular gap drive device drives the top cone to retract to the end away from the tail screw, forming the maximum gap between the top cone and the tail screw, which makes it easy to start production;

[0021] S2: After the system starts production, the material enters from the feed port of the cylindrical body of the equipment and is discharged from the discharge bushing port. The oil pump drives the hydraulic oil into the rodless chamber of the hydraulic cylinder to provide the pressure required for the extruder to produce. This pressure is then used to control the piston rod of the annular gap drive device to move, thereby driving the top cone to move slowly along the axial direction towards the tail screw. This causes the tail screw, the top cone, and the discharge bushing to form a material discharge annular gap. At this time, the internal pressure inside the extruder increases, which is used to make the material expand and mature.

[0022] Preferably, the limits on equipment load, such as the oil pressure in the rodless chamber and the limits on equipment mechanical energy, are set in the control system. When the equipment load exceeds the set value, the annular gap is automatically increased to reduce the equipment load, avoid blockage and shutdown, and improve production continuity.

[0023] This system does not require the participation of traditional pressure sensors, has fewer components, and lower costs. It can achieve richer control modes through reasonable control logic. The system can also control the annular gap discharge in three modes: constant annular gap, constant annular gap pressure, and automatic annular gap adjustment.

[0024] The constant annular gap will not be discussed here. The constant annular gap pressure is set according to the logic shown above, such as setting the oil pressure in the rodless chamber to 20 bar. Regarding the automatic adjustment of the annular gap, PID automatic adjustment is executed. During adjustment, parameters can be set according to the mechanical energy of the extruder, and then the system can switch to automatic mode. The mechanical energy is the energy input by the extruder to the processed material, and its unit is Wh / kg (watt-hours per kilogram) or kWh / t (kilowatt-hours per ton). Its actual calculation method is: drive power of the main shaft (W) / output (kg / h). The drive motor of the extruder's main shaft operates at industrial frequency, so the motor current corresponds to the drive power. By collecting the feed rate from the feeder, the output can be determined. Dividing the two gives the mechanical energy SME. During production, by maintaining a constant mechanical energy, stable product quality = stable curing effect can be obtained.

[0025] During automatic adjustment, when the actual mechanical energy (Wh / kg) of the extruder exceeds the set mechanical energy value and exceeds the overflow deviation range, the control system will control the output of the overflow valve to reduce the pressure of the rodless chamber of the annular gap drive device. At this time, the pressure of the rodless chamber of the annular gap drive device decreases, the top cone retracts under the thrust of the material, the annular gap increases, the load of the extruder main unit decreases, and the actual mechanical energy decreases.

[0026] When the actual mechanical energy (Wh / kg) is less than the set mechanical energy value and exceeds the overflow deviation range, the control system will increase the output of the overflow valve. At this time, the pressure in the rodless chamber of the annular gap drive increases, the top cone extends under the thrust of the oil, the annular gap decreases, the load of the extruder increases (but is still lower than the safe value of the extruder load), and the actual mechanical energy increases.

[0027] When a sudden event causes the extruder host load to exceed the safe value (e.g., reaching 100% and lasting for 3 seconds), the control system will pause the automatic mode and open the overflow valve according to the preset ratio (e.g., 20%) to quickly release pressure, reduce the load on the extruder host, and protect the equipment safety.

[0028] The beneficial effects of this invention are:

[0029] 1. In the discharge device of the present invention, the discharge annular gap can be driven and adjusted by the annular gap driving device to realize automatic control of the annular gap size, thereby improving the flexibility of the annular gap size adjustment when the extruder is in use and ensuring the uniformity of the quality of the discharged product.

[0030] 2. In the discharge device of the present invention, the annular gap drive device adopts a hydraulic cylinder, the piston rod of the hydraulic cylinder is connected to the top cone, and the rodless chamber inside the cylinder is connected to an overflow valve to control the oil pressure in the rodless chamber.

[0031] When the oil pressure in the rodless chamber exceeds the pressure setting value, the relief valve releases pressure. The hydraulic system of the hydraulic cylinder can achieve the following effect: after the oil pump drives hydraulic oil into the rodless chamber, if there is insufficient load at the outlet, the piston rod of the hydraulic cylinder will continue to extend until its full stroke. When the oil pressure in the rodless chamber exceeds the setting value (e.g., the set pressure is 20 bar), the relief valve releases pressure. If there is sufficient load at the outlet, the piston rod will extend to the equilibrium position, and the oil pressure in the rodless chamber will also exceed 20 bar, at which point the relief valve releases pressure to prevent blockage. Thus, intelligent blockage prevention can be achieved, i.e., through the hydraulic system driving the annular gap adjustment.

[0032] 3 The discharge device of the present invention may further include a control system. The control system may be controlled by PLC and integrates PID automatic adjustment. Through parameter setting, it can automatically adjust the size of the annular gap according to the actual production situation, reduce human error, and ensure product quality uniformity.

[0033] The system sets load limits for the equipment, such as the oil pressure in the rodless chamber and the mechanical energy limit. When the load exceeds the set value, the annular gap is automatically increased to reduce the load, prevent blockages and shutdowns, and improve production continuity. This system does not require traditional pressure sensors, has fewer components, and lower costs. It achieves richer control modes through reasonable control logic. Furthermore, the system can control the annular gap discharge in three modes: constant annular gap, constant annular gap pressure, and automatic annular gap adjustment.

[0034] The constant annular gap will not be discussed here. The constant annular gap pressure is set according to the logic described above, such as setting the oil pressure in the rodless chamber to 20 bar. Regarding the automatic adjustment of the annular gap, when performing PID automatic adjustment, the parameters can be set according to the mechanical energy of the extruder and then switched to automatic mode. The mechanical energy is the energy input by the extruder to the processed material, and its unit is Wh / kg (watt-hours per kilogram) or kWh / t (kilowatt-hours per ton). Its actual calculation method is: drive power of the main shaft of the equipment (W) / output (kg / h). The drive motor of the main shaft of the extruder operates at industrial frequency, so the motor current can correspond to the drive power. By collecting the feed rate of the feeder, the output can be known. Dividing the two gives the mechanical energy SME. During the production process, by maintaining a constant mechanical energy, a stable product quality can be obtained = a stable curing effect.

[0035] During automatic adjustment, when the actual mechanical energy (Wh / kg) of the extruder exceeds the set mechanical energy value and exceeds the overflow deviation range, the control system will control the output of the overflow valve to reduce the pressure of the rodless chamber of the annular gap drive device. At this time, the pressure of the rodless chamber of the annular gap drive device decreases, the top cone retracts under the thrust of the material, the annular gap increases, the load of the extruder main unit decreases, and the actual mechanical energy decreases.

[0036] When the actual mechanical energy (Wh / kg) is less than the set mechanical energy value and exceeds the overflow deviation range, the control system will increase the output of the overflow valve. At this time, the pressure in the rodless chamber of the annular gap drive increases, the top cone extends under the thrust of the oil, the annular gap decreases, the load of the extruder increases (but is still lower than the safe value of the extruder load), and the actual mechanical energy increases.

[0037] When a sudden event causes the extruder host load to exceed the safe value (e.g., reaching 100% and lasting for 3 seconds), the control system will pause the automatic mode and open the overflow valve according to the preset ratio (e.g., 20%) to quickly release pressure, reduce the load on the extruder host, and protect the equipment safety. Attached Figure Description

[0038] The accompanying drawings are provided to further illustrate the invention and form part of the specification. They are used in conjunction with embodiments of the invention to explain the invention and do not constitute a limitation thereof. In the drawings:

[0039] Figure 1 This is a cross-sectional view of the structure when the tail screw and the top cone are connected in this invention;

[0040] Figure 2 This is a cross-sectional view of the structure of the tail screw and the top cone in this invention when they are far apart;

[0041] Figure 3 This is a cross-sectional view of the structure when the tail screw and the top cone form an annular gap in this invention;

[0042] Figure 4 This is a schematic diagram of the tail screw structure;

[0043] Figure 5 This is a schematic diagram of the top cone structure when the channel is a through circular hole;

[0044] Figure 6 This is a schematic diagram of the top cone structure when the channel is a through-hole;

[0045] Figure 7 This is a schematic diagram of the top cone structure when the channel is another type of through-slot opening;

[0046] Markings in the diagram:

[0047] 1. Tail end screw; 2. Top cone; 3. Annular gap drive device; 4. Discharge bushing; 5. Mounting base; 11. Cone block one; 12. Claw; 21. Cone block two; 22. Surrounding edge; 23. Through round hole; 24. Through slot. Detailed Implementation

[0048] Example 1

[0049] like Figure 1-7As shown, an annular discharge device for an extruder, in this embodiment, includes a discharge bushing 4, a tail screw 1, a top cone 2, and an annular discharge drive device 3. The tail screw 1 is installed at the tail end of the extruder's main shaft and rotates with the main shaft. The extruder's main shaft is configured to rotate within the cylindrical body of the equipment. The structure of the main shaft being configured within the cylindrical body of the equipment for extruding materials is existing technology for extruders and will not be described in detail here. The axial position of the tail screw 1 within the cylindrical body of the equipment is located in the discharge bushing 4 at its tail end, and its axial position remains unchanged. The annular discharge drive device 3 is installed on a mounting base 5 at the tail end of the cylindrical body of the equipment. The top cone 2 is installed at its driving end. The top cone 2 moves toward the tail screw 1 under the drive of the annular discharge drive device 3, and when it extends into the discharge bushing 4, it forms a material discharge annular gap together with the discharge bushing 4 and the top cone 2.

[0050] In the discharge device of the present invention, the discharge annular gap can be driven and adjusted by the annular gap drive device 3 to realize automatic control of the annular gap size, thereby improving the flexibility of the annular gap size adjustment during the use of the extruder and ensuring the uniformity of the quality of the discharged product.

[0051] The annular gap drive device 3 uses a hydraulic cylinder, whose piston rod is connected to the top cone 2. The rodless chamber inside the cylinder is connected to an overflow valve to control the oil pressure in the rodless chamber. When the oil pressure in the rodless chamber exceeds the set value, the overflow valve releases pressure. The hydraulic system of the hydraulic cylinder can achieve the following effect: after the oil pump drives the hydraulic oil into the rodless chamber, if there is not enough load at the outlet, the piston rod of the hydraulic cylinder will continue to extend until the full stroke. When the oil pressure in the rodless chamber exceeds the set value (e.g., the set pressure is 20 bar), the overflow valve releases pressure. If there is enough load at the outlet, the piston rod will extend to the equilibrium position. When the oil pressure in the rodless chamber is also set to exceed 20 bar, the overflow valve releases pressure to avoid blockage. Thus, the effect of intelligent blockage prevention can be achieved, that is, the annular gap is adjusted by driving the hydraulic system.

[0052] The tail screw 1 includes a cone block 11 for fixed connection with the tail end of the main shaft of the equipment and multiple sets of claws 12 uniformly surrounding the cone block 11. The claws 12 are inclined from their fixed ends toward the top cone 2. The top cone 2 includes a cone block 21 and a perimeter 22 surrounding the cone block 21. When the top cone 2 is connected to the tail screw 1, the perimeter 22 is wrapped around the claws 12, and its outer diameter is slightly smaller than the inner diameter of the discharge bushing 4. Multiple sets of channels for material to flow out are also uniformly opened on the perimeter 22. Thus, the tail screw 1 and the top cone 2 are used together to make the discharge pressure more uniform, reduce material adhesion, and reduce the "blowing" phenomenon. The discharge channel is opened on the top cone 2. The tail screw 1 rotates with the main shaft of the equipment, and the material that has been collided and matured in the extruder can be discharged through the discharge channel of the top cone 2. At the same time, the channels can be designed in different numbers or different shapes according to different needs, as follows:

[0053] See example 5, where the channel consists of several through circular holes 23 evenly arranged on the perimeter 22.

[0054] See 6-7 for examples, where the channels are several through slots 24 evenly arranged on the perimeter 22.

[0055] When the top cone 2 is connected to the tail screw 1, the claw 12 is set to fit on the outer cone surface of the second cone 21. This structure of the claw 12 and the cone block can ensure that the tail screw 1 will not touch the top cone 2 when rotating. At the same time, the annular gap formed between the cone surface formed by the rotation and the top cone 2 is more equal, so that the discharge pressure at different positions of the discharge port is more uniform.

[0056] The tail screw 1, top cone 2, and discharge bushing 4 are all made of wear-resistant materials, which can extend the service life of the device; and they can be disassembled and replaced, reducing maintenance costs.

[0057] Example 2

[0058] A method for controlling an annular discharge device of an extruder includes the following steps:

[0059] S1: In the initial state, the annular gap drive device 3 drives the top cone 2 to retract to the end away from the tail screw 1, forming the maximum gap between the top cone 2 and the tail screw 1, which makes it easy to start production;

[0060] S2: After the system starts production, the material enters from the feed port of the cylindrical body of the equipment and is discharged from the discharge bushing 4 port. The oil pump drives the hydraulic oil into the rodless chamber of the hydraulic cylinder to provide the pressure required for the extruder to produce. Then, by controlling the piston rod movement of the annular gap drive device 3, the top cone 2 is driven to move slowly along the axial direction towards the tail screw 1, so that the tail screw 1, the top cone 2, and the discharge bushing 4 form a material discharge annular gap. At this time, the internal pressure in the extruder increases, which is used to make the material expand and mature.

[0061] The discharge device of the present invention may also include a control system, which may be controlled by a PLC and integrate PID automatic adjustment. Through parameter setting, it can automatically adjust the size of the annular gap according to the actual production situation, reduce human error, and ensure product quality uniformity.

[0062] The system sets load limits for the equipment, such as the oil pressure in the rodless chamber and the mechanical energy limit. When the load exceeds the set value, the annular gap is automatically increased to reduce the load, prevent blockages and shutdowns, and improve production continuity. This system does not require traditional pressure sensors, has fewer components, and lower costs. It achieves richer control modes through reasonable control logic. Furthermore, the system can control the annular gap discharge in three modes: constant annular gap, constant annular gap pressure, and automatic annular gap adjustment.

[0063] The constant annular gap will not be discussed here. The constant annular gap pressure is set according to the logic shown above, such as setting the oil pressure in the rodless chamber to 20 bar. Regarding the automatic adjustment of the annular gap, PID automatic adjustment is executed. During adjustment, parameters can be set according to the mechanical energy of the extruder, and then the system can switch to automatic mode. Mechanical energy is the energy input by the extruder to the processed material, and its unit is Wh / kg (watt-hours per kilogram) or kWh / t (kilowatt-hours per ton). Its actual calculation method is: drive power of the main shaft (W) / output (kg / h). The drive motor of the extruder's main shaft operates at industrial frequency, so the motor current corresponds to the drive power. By collecting the feed rate from the feeder, the output can be determined. Dividing the two gives the mechanical energy (SME). During production, by maintaining a constant mechanical energy, stable product quality = stable curing effect can be obtained.

[0064] During automatic adjustment, when the actual mechanical energy (Wh / kg) of the extruder exceeds the set mechanical energy value and the overflow deviation range is exceeded, the control system will control the output of the overflow valve to be reduced. At this time, the pressure in the rodless chamber of the annular gap drive device 3 decreases, the top cone 2 retracts under the thrust of the material, the annular gap increases, the load of the extruder main unit decreases, and the actual mechanical energy decreases.

[0065] When the actual mechanical energy (Wh / kg) is less than the set mechanical energy value and exceeds the overflow deviation range, the control system will control the increase of the overflow valve output. At this time, the pressure in the rodless chamber of the annular gap drive device 3 increases, the top cone 2 extends under the thrust of the oil, the annular gap decreases, the load of the extruder main unit increases (but is still lower than the safe value of the extruder main unit load), and the actual mechanical energy increases.

[0066] When a sudden event causes the extruder host load to exceed the safe value (e.g., reaching 100% and lasting for 3 seconds), the control system will pause the automatic mode and open the overflow valve according to the preset ratio (e.g., 20%) to quickly release pressure, reduce the load on the extruder host, and protect the equipment safety.

[0067] The above description is merely a preferred embodiment of the present invention and is not intended to limit the present invention. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. An annular discharge device for an extruder, characterized in that, The device includes a discharge bushing (4), a tail screw (1), a top cone (2), and an annular gap drive device (3). The tail screw (1) is installed at the tail end of the extruder's main shaft and rotates with the main shaft. The main shaft of the extruder is configured to rotate within the cylindrical body of the device. The axial position of the tail screw (1) within the cylindrical body of the device is located in the discharge bushing (4) at its tail end, and its axial position remains unchanged. The annular gap drive device (3) is installed on a mounting base (5) at the tail end of the cylindrical body of the device. The top cone (2) is installed at its driving end. The top cone (2) moves toward the tail screw (1) under the drive of the annular gap drive device (3), and when it extends into the discharge bushing (4), it forms a discharge annular gap for the material together with the discharge bushing (4) and the top cone (2). The annular gap drive device (3) uses a hydraulic cylinder, whose piston rod is connected to the top cone (2), and the rodless chamber inside the cylinder is connected to an overflow valve to control the oil pressure in the rodless chamber; The tail screw (1) includes a cone block (11) for fixed connection with the tail end of the main shaft of the equipment and multiple sets of claws (12) uniformly surrounding the cone block (11). The claws (12) are inclined from their fixed ends toward the top cone (2). The top cone (2) includes a cone block (21) and a perimeter (22) surrounding the cone block (21). When the top cone (2) is connected to the tail screw (1), the perimeter (22) is wrapped around the claws (12) and its outer diameter is slightly smaller than the inner diameter of the discharge bushing (4). Multiple sets of channels for material to flow out are also uniformly opened on the perimeter (22).

2. The extruder annular discharge device according to claim 1, characterized in that, The channel is a number of through circular holes (23) evenly arranged on the perimeter (22).

3. The extruder annular discharge device according to claim 1, characterized in that, The channel is a number of through slots (24) evenly arranged on the perimeter (22).

4. The extruder annular discharge device according to claim 1, characterized in that, When the top cone (2) is connected to the tail screw (1), the claw (12) is attached to the outer cone surface of the second cone (21), and this claw (12) and the cone are in a cooperative structure.

5. The extruder annular discharge device according to claim 1, characterized in that, The tail screw (1), the top cone (2), and the discharge bushing (4) are all made of wear-resistant material.

6. The extruder annular discharge device according to claim 1, characterized in that, It also includes a control system, which uses PLC control and integrates PID automatic adjustment.

7. A control method for an annular discharge device of an extruder, based on the annular discharge device of an extruder according to claim 1, characterized in that, Includes the following steps: S1: In the initial state, the annular gap drive device (3) drives the top cone (2) to retract to the end away from the tail screw (1), forming the maximum gap between the top cone (2) and the tail screw (1); S2: After the system process starts production, the material enters from the feed port of the cylindrical body of the equipment and is discharged from the discharge bushing (4) port. The oil pump drives the hydraulic oil into the rodless chamber of the hydraulic cylinder to provide the pressure required for the extruder to produce. Then, by controlling the piston rod movement of the annular gap drive device (3), the top cone (2) is driven to move slowly along the axial direction towards the tail screw (1), so that the tail screw (1), the top cone (2), and the discharge bushing (4) form a material discharge annular gap. At this time, the internal pressure in the extruder increases, which is used to make the material expand and mature.

8. The control method for an annular discharge device of an extruder according to claim 7, characterized in that, For automatic adjustment of the annular gap, when performing PID automatic adjustment, the system switches to automatic mode after setting parameters based on the mechanical energy of the extruder in the control system. The mechanical energy is the energy input by the extruder to the material being processed. During automatic adjustment, when the actual mechanical energy of the extruder exceeds the set mechanical energy value and overflows the deviation range, the control system will control the output of the overflow valve to reduce the pressure of the rodless chamber of the annular gap drive device. At this time, the pressure of the rodless chamber of the annular gap drive device decreases, the top cone retracts under the thrust of the material, the annular gap increases, the load of the extruder main unit decreases, and the actual mechanical energy decreases. When the actual mechanical energy is less than the set mechanical energy value and exceeds the deviation range, the control system will control the increase of the overflow valve output. At this time, the pressure in the rodless chamber of the annular gap drive increases, the top cone extends under the thrust of the oil, the annular gap decreases, the load of the extruder main unit increases, but it is still lower than the safe value of the extruder main unit load, and the actual mechanical energy increases. When an unexpected event causes the extruder host load to exceed the safe value, the control system will pause the automatic mode and open the overflow valve according to the preset proportional overflow valve opening degree to quickly release pressure, reduce the extruder host load, and protect the equipment safety.

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