A hetero-directional twin-screw extruder with self-cleaning function and a self-cleaning method

Abstract

The present application relates to the technical field of double screw device, and specifically discloses a hetero-directional double screw extruder with self-cleaning function and a self-cleaning method. The extruder comprises a cylinder, double screws arranged in the cylinder, an inlet and an outlet arranged on the cylinder, and a cleaning ball and a cleaning water pipe. The cleaning water pipe is arranged on the cylinder and its pipe opening extends into the cylinder towards the double screws. The cleaning ball enters the cylinder from the inlet and moves around the double screws by following the rotation of the double screws until it moves forward to the outlet and is discharged. The cleaning ball cleans the double screws by contacting the surface of the double screws. Compared with the existing cleaning method, the present application sets the cleaning ball and the cleaning water pipe in the cylinder. During the normal operation of the double screw extruder, the cleaning ball contacts and rubs against the inner wall of the cylinder and the double screws, thereby achieving the cleaning effect. The double screw device does not need to be disassembled, the cleaning process is more convenient and safe, the cleaning ball can be reused, and the cleaning cost is saved.

Description

Technical Field

[0001] This invention relates to the technical field of twin-screw extruders, and specifically discloses a counter-rotating twin-screw extruder with self-cleaning function and a self-cleaning method. Background Technology

[0002] Twin-screw extruders were developed based on single-screw extruders. Due to their excellent feeding performance, mixing and plasticizing performance, venting performance, and extrusion stability, they are now widely used in the field of extrusion or conveying of products.

[0003] However, during the use of the twin-screw device, due to the high viscosity of the mixed particles, solid particles or dust are easy to stick to the screw of the twin-screw device. If not cleaned in time, it will affect the mixing process, reduce the mixing efficiency of the twin-screw device, and affect the quality of the extruded products.

[0004] The current method for cleaning twin-screw extruders involves disassembling the screws and barrel before cleaning, which is inefficient. The specific process involves first heating the barrel to the molding temperature of the residual material inside. After reaching the molding temperature, the die head is removed while it is still hot. The material at the barrel end and screw end is cleared. The power is turned off, and both screws are slowly pulled out in sync. The material on the screw surface is quickly removed while it is still hot using a copper wire brush or copper shovel. After all the screws are pulled out, they are laid flat on a wooden board, and the inner wall of the barrel is cleaned with a brass brush.

[0005] Existing cleaning methods require manual cleaning with brass brushes, resulting in low cleaning efficiency. Furthermore, the enclosed structure of the double-helix device makes disassembly and assembly inconvenient, requiring a significant amount of time each time the screws are installed or removed. This hinders routine maintenance and exposes the device to the environment, posing certain dangers to manual labor. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of the prior art and provide a counter-rotating twin-screw extruder with self-cleaning function and a self-cleaning method.

[0007] On one hand, this invention discloses a counter-rotating twin-screw extruder with self-cleaning function, employing the following technical solution:

[0008] A counter-rotating twin-screw extruder with self-cleaning function includes a barrel, a twin screw disposed within the barrel, and a feed inlet and an extrusion outlet disposed on the barrel. It also includes cleaning balls and a cleaning water pipe. The cleaning water pipe is disposed on the barrel with its opening extending into the barrel and facing the twin screw. The cleaning balls enter the barrel from the feed inlet and rotate around the twin screw as it rotates, until they reach the extrusion outlet and are discharged. The cleaning balls clean the twin screw by contacting its surface.

[0009] Preferably, the cleaning ball includes a cleaning ball shell, a density sensor probe, a cleaning brush ball, and a transmission assembly. The transmission assembly is disposed inside the cleaning ball shell, and the density sensor probe and the cleaning brush ball are distributed on the surface of the cleaning ball shell and connected to the transmission assembly.

[0010] Preferably, the twin screw has an internal current-carrying conductor. When energized, the twin screw becomes magnetic. The density sensor probe is made of a magnetic material. Under the action of the magnetic twin screw, the density sensor probe on the cleaning ball is attracted to the surface of the twin screw. When the power is off, the magnetism of the twin screw disappears, and the density sensor probe on the cleaning ball separates from the twin screw.

[0011] Preferably, the transmission assembly includes a transmission frame, a cleaning ball motor, a sensor detection module, and a control module; the transmission frame is disposed inside the cleaning ball shell and connected to the cleaning ball motor and the cleaning brush ball; the cleaning ball motor is electrically connected to the sensor detection module and the control module; the sensor detection module is used to acquire and transmit information detected by the density sensor probe; the control module is used to analyze and transmit information from the sensor detection module; and the cleaning ball motor controls the rotation of the cleaning ball by driving the transmission frame.

[0012] Preferably, the cleaning brush ball includes a cleaning brush ball shell, and blade rollers, a squeezing brush head, and a sponge roller distributed on the surface of the cleaning brush ball shell; the blade rollers are located on the upper and lower sides of the cleaning brush ball, the sponge rollers are located on the left and right sides of the cleaning brush ball, and the squeezing brush head is located on the front and rear sides of the cleaning brush ball.

[0013] Preferably, the squeezing brush head is detachably installed, the cleaning brush ball housing contains cleaning fluid, the squeezing brush head includes a squeezing nozzle and a brass brush, the squeezing nozzle is connected to the cleaning brush ball housing by an elastic element, and the squeezing nozzle squeezes the elastic element by contacting the twin screws to expel the cleaning fluid.

[0014] Preferably, the surface of the density sensor probe is coated with a hydrophobic coating.

[0015] Preferably, the device further includes a separation box, which is located below the extrusion port of the barrel. The separation box is provided with a partition and a drain outlet. The partition is provided with a mesh, and the drain outlet is located below the partition.

[0016] On the other hand, this invention discloses a self-cleaning method for an anti-rotating twin-screw extruder with self-cleaning function, employing the following technical solution:

[0017] A self-cleaning method for an anti-rotating twin-screw extruder with self-cleaning function includes the following steps:

[0018] Step 1: After the extrusion operation of the counter-rotating twin-screw extruder is completed, a cleaning agent is injected between the barrel and the twin screws through the cleaning water pipe;

[0019] Step 2: Adjust the diameter of the extrusion nozzle of the twin-screw extruder to a size that allows the cleaning balls to pass through;

[0020] Step 3: Turn on the cleaning ball motor switch and feed the cleaning ball into the feed port of the twin-screw extruder. The cleaning ball will start to move around the twin screw as the cleaning agent flows.

[0021] Step 4: The motor of the twin-screw conductor is energized, making the twin-screw magnetic, and the cleaning ball is adsorbed onto the surface of the twin-screw through the density sensor probe;

[0022] Step 5: The density sensor probe is magnetically attached to the surface of the twin screw. The sensor detection module inside the cleaning ball receives the density information of the contact surface. When it is determined that the contact surface is a spot to be cleaned, the control module controls the cleaning ball motor to drive the cleaning brush ball to start rotating through the transmission frame to perform the cleaning work.

[0023] Step 6: The cleaning brush ball rotates to perform cleaning work. The blades on the cleaning brush ball clean the dirt on the twin screw, scraping off a large amount of dirt. The squeezing brush head of the cleaning brush ball contacts the twin screw to clean it. The squeezing brush head squeezes out the cleaning agent remaining in the cleaning brush ball. The sponge ball on the cleaning brush ball taps and shakes the dirt on the twin screw to make it fall off. The sponge ball and the foaming of the cleaning agent can increase the cleaning power.

[0024] Step 7: After the set working time, the motor of the twin-screw energized conductor is turned off. In the power-off state, the magnetism of the twin-screw disappears, and the density sensor probe of the cleaning ball detaches from the surface of the twin-screw. With the flow of the cleaning agent, it moves to the next working point. Then, the motor of the twin-screw energized conductor is turned on again, and steps 4-6 are repeated to start a new round of cleaning process.

[0025] Step 8: After several rounds of cleaning processes, the cleaning ball moves forward with the twin screw to the extrusion port of the twin screw and is discharged along with the used cleaning agent and dirt.

[0026] Preferably, in step 5, when the control module analyzes and determines that the contact surface density is between 1.15 and 7 g / m³... 3 If the density falls within the specified range, it is determined that the contact surface is contaminated with dirt. The control module then activates the cleaning ball motor, and the cleaning brush begins to rotate and perform cleaning. If the control module determines that the contact surface density is outside the range of 1.15–7 g / m³, it indicates that the surface is dirty. 3When the sealing range value is reached, the control module controls the cleaning ball motor to shut down, and the cleaning brush ball stops rotating.

[0027] Compared with the prior art, the present invention has at least the following beneficial effects:

[0028] Compared to existing cleaning methods, this invention uses cleaning balls and cleaning water pipes installed inside the barrel. During normal operation of the twin-screw extruder, the cleaning balls contact and rub against the inner wall of the barrel and the twin screws to achieve a cleaning effect. This process eliminates the need to disassemble the twin screw assembly, avoiding the wear and tear caused by disassembly for cleaning, thus extending the lifespan of the twin screws, improving cleaning efficiency, and enhancing operator safety. This makes the cleaning process more convenient and safer. Furthermore, the cleaning balls can be reused, saving on cleaning costs. Attached Figure Description

[0029] Figure 1 This is a schematic diagram of the overall structure of the counter-rotating twin-screw extruder with self-cleaning function in this embodiment;

[0030] Figure 2 This is a cross-sectional view of the barrel of the counter-rotating twin-screw extruder with self-cleaning function in this embodiment;

[0031] Figure 3 This is a schematic diagram of the cleaning ball of the counter-rotating twin-screw extruder with self-cleaning function in this embodiment.

[0032] Figure 4 This is a cross-sectional view of the cleaning ball of the counter-rotating twin-screw extruder with self-cleaning function in this embodiment;

[0033] Figure 5 This is a cross-sectional view of the cleaning spherical shell of the counter-rotating twin-screw extruder with self-cleaning function in this embodiment;

[0034] Figure 6 This is a schematic diagram of the cleaning ball drive assembly of the counter-rotating twin-screw extruder with self-cleaning function in this embodiment;

[0035] Figure 7 This is a schematic diagram of the cleaning brush ball of the counter-rotating twin-screw extruder with self-cleaning function in this embodiment;

[0036] Figure 8 This is a schematic diagram of the extrusion brush head of the counter-rotating twin-screw extruder with self-cleaning function in this embodiment.

[0037] Figure 9 This is a circuit logic diagram of the cleaning ball of the counter-rotating twin-screw extruder with self-cleaning function in this embodiment;

[0038] Figure 10This is a logic diagram of the cleaning ball control module of the counter-rotating twin-screw extruder with self-cleaning function in this embodiment.

[0039] Explanation of icon numbers:

[0040] 1. Base; 2. Feed inlet; 3. Water pipe; 4. Twin screw; 5. Barrel; 6. Cleaning ball; 7. Extrusion port; 8. Separation box; 61. Cleaning ball shell; 62. Density sensor probe; 63. Cleaning brush ball; 64. Transmission assembly; 611. Cleaning brush ball column; 612. Sensor column; 613. Transmission bracket; 631. Cleaning brush ball shell; 632. Blade roller; 633. Extrusion brush head; 634. Sponge roller; 6331. Extrusion nozzle; 6332. Copper brush; 641. Cleaning ball motor; 642. Sensor detection module; 643. Control module; 644. Transmission frame. Detailed Implementation

[0041] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments.

[0042] Currently, when using twin-screw extruders to prepare polylactic acid (PLA) with different properties, residual synthesized material solidifies on the twin screw. This residue can affect the desired performance of the new PLA when preparing PLA with new properties, thus contaminating the new synthesized material. There are two main cleaning methods currently used: First, the barrel is heated to the molding temperature of the residual material inside. After reaching the molding temperature, the die head is removed while still hot, the power is cut off, and the twin screw is pulled out of the extruder. The residual dirt is then manually cleaned off with a copper brush while still hot. This method is time-consuming, labor-intensive, inefficient, and cannot guarantee the safety of manual labor. Second, polyethylene material is added to clean the twin screw before the PLA preparation experiment. The twin-screw extruder melts and extrudes the polyethylene material and residual dirt. This method leaves some PE material residue, which still affects the preparation of PLA with new properties, wasting the material prepared earlier and resulting in low extrusion efficiency. Therefore, this invention proposes a counter-rotating twin-screw extruder with self-cleaning function and a self-cleaning method.

[0043] A counter-rotating twin-screw extruder with self-cleaning function, as described in the reference. Figure 1-2As shown, the system includes a base 1, a feed inlet 2, a cleaning water pipe 3, a twin screw 4, a barrel 5, a cleaning ball 6, and an extrusion port 7. The barrel 5 is mounted on the base 1, the twin screw is installed inside the barrel 5, and the cleaning water pipe 3 is located on the barrel 5. The end of the cleaning water pipe 3 extends into the barrel 5 and injects water towards the twin screw. The cleaning ball 6 enters the barrel 5 through the feed inlet 2 and moves around the twin screw 4 as it rotates. The working area of ​​the cleaning ball 6 is between the barrel 5 and the twin screw 4, until it reaches the extrusion port 7 and is discharged. The cleaning ball 6 cleans the twin screw 4 by contacting its surface. Compared to existing cleaning methods, by using the cleaning ball 6 and the cleaning water pipe 3, the cleaning effect can be achieved while the twin screw extruder is running normally, without the need to disassemble the twin screw assembly, making the cleaning process more convenient and safer.

[0044] In this embodiment, refer to Figure 3-4 The cleaning ball 6 includes a cleaning ball shell 61, a density sensor probe 62, a cleaning brush ball 63, and a transmission assembly 64. The transmission assembly 64 is disposed inside the cleaning ball shell 61, and the density sensor probe 62 and the cleaning brush ball 63 are distributed on the surface of the cleaning ball shell 61 and connected to the transmission assembly 64.

[0045] Among them, reference Figure 5 The cleaning ball housing 61 includes a cleaning brush ball column 611, a sensor column 612, and a transmission bracket 613. The cleaning brush ball 63 is threadedly connected to the cleaning ball housing 61 through the cleaning brush ball column 611, and the density sensor probe 62 is threadedly connected to the cleaning ball housing 61 through the sensor column 612. The transmission bracket 613 serves as a skeleton to support the internal structure of the cleaning ball housing 61, and the transmission assembly 64 is mounted on the transmission bracket 613.

[0046] Reference Figure 6 The transmission assembly 64 includes a cleaning ball motor 641, a sensor detection module 642, a control module 643, and a transmission frame 644. The transmission frame 644 is located inside the cleaning ball shell 61 and connected to the cleaning ball motor 641 and the cleaning brush balls 63. Specifically, the transmission frame 644 can be multiple connecting rods with bevel gear meshing and linkage. The cleaning ball motor 641 links the cleaning brush balls 63 on the surface of the cleaning ball shell 61 to rotate through the bevel gears of the transmission frame 644. The cleaning ball motor 641 is electrically connected to the sensor detection module 642 and the control module 643. The sensor detection module 642 is used to acquire and transmit information detected by the density sensor probe 62, and the control module 643 is used to analyze and transmit the information from the sensor detection module 642. The cleaning ball motor 641 controls the rotation of the cleaning balls 63 by driving the transmission frame 644.

[0047] Reference Figure 7-8The cleaning brush ball 63 includes a cleaning brush ball housing 631, blade rollers 632, a squeeze brush head 633, and a sponge roller 634. The blade rollers 632 are symmetrically distributed on the upper and lower sides of the cleaning brush ball 63, and the sponge rollers 634 are on the left and right sides of the cleaning brush ball 63. The cleaning brush ball housing 631 has anti-drop grooves to ensure that the sponge rollers 634 will not fall off. The squeeze brush head 633 is installed on the front and rear sides and is detachable. By removing one end of the squeeze brush head 633, cleaning agent can be added to the interior of the cleaning brush ball 63. The blade rollers 632 clean the dirt, which is scraped off with the blades and collected in the groove at the bottom of the blade rollers 632. The sponge ball 634 comprises a sponge and a solid rigid ball. The sponge ball 634 has a certain degree of axial freedom of movement, allowing it to adjust its position during contact with the twin-screw 4, thus better conforming to the grooves and blades of the twin-screw 4. The cleaning agent in the cleaning brush ball 63 can foam through the sponge ball 634 and come into contact with the twin-screw blades, increasing cleaning power. The squeeze brush head 633 includes a squeeze nozzle 6331 and a brass brush 6332. The squeeze nozzle 6331 is connected to the cleaning brush ball housing 631 via an elastic element. The squeeze brush head 633 contacts different grooves and blades on the twin-screw 4. Squeezing the nozzle changes the internal and external pressure, which, through the elastic element, adjusts the position of the squeeze nozzle 6331, squeezing out the cleaning liquid inside the cleaning brush ball 63, thereby increasing the cleaning power of the brass brush 6332.

[0048] In this embodiment, the twin screw 4 is equipped with a high-temperature resistant conductor. When energized, the twin screw 4 will become magnetic. The density sensor probe 62 is made of a magnetic material. Under the action of the magnetic twin screw 4, the density sensor probe 62 on the cleaning ball 6 is attracted to the surface of the twin screw 4. When the power is off, the magnetism of the twin screw 4 disappears, and the density sensor probe 62 on the cleaning ball 6 separates from the twin screw 4.

[0049] In this embodiment, the density sensor probe 62 of the cleaning ball 6 is made of AlNiCo magnet, which has stable high-temperature characteristics, thus preventing poor adsorption force on the twin screw due to excessive temperature. Furthermore, the surface of the density sensor probe 62 is coated with a hydrophobic coating to prevent excessive influence of moisture on density judgment, thereby improving the stability and reliability of the self-cleaning function.

[0050] In this embodiment, the cleaning water pipe 3 is installed inside the barrel 5 and is located between the twin screws 4, allowing the cleaning agent to flow from the water pipe 3 into the space between the barrel 5 and the twin screws 4, resulting in better uniformity of the cleaning effect. Furthermore, a separation box 8 is provided below the extrusion port 7 of the barrel 5. The separation box 8 contains a partition and a drain outlet. The partition has mesh openings, and the drain outlet is located below the partition. The cleaning balls 6 fall into the separation box 8 after exiting the extrusion port 7, allowing workers to separate the cleaning balls 6 for continued use in the barrel 5.

[0051] This invention also discloses a self-cleaning method for a counter-rotating twin-screw extruder screw with self-cleaning function, specifically including the following steps:

[0052] Step 1: After the extrusion operation of the counter-rotating twin-screw extruder is completed, cleaning water pipe 3 injects cleaning agent between the barrel 5 and the twin screw 4;

[0053] Step 2: Adjust the diameter of the extrusion nozzle 7 of the twin-screw extruder to a size that allows the cleaning ball 6 to pass through;

[0054] Step 3: Turn on the cleaning ball motor 641 switch and put the cleaning ball 6 into the feed port 2 of the twin screw extruder. The cleaning ball 6 will start to move around the twin screw 4 as the cleaning agent flows.

[0055] Step 4: The motor of the electric conductor of the twin screw 4 is energized, making the twin screw 4 magnetic. The density sensor probe 62 is magnetically attracted to the surface of the twin screw, thus fixing the cleaning ball 6 to one of the screws. As the twin screw 4 rotates, the cleaning ball 6 moves relative to the other screw and the inner wall of the barrel 5, generating friction to clean.

[0056] Step 5: Refer to Figure 9-10 The density sensor probe 62 is magnetically attached to the surface of the twin screw 4. The sensor detection module 642 inside the cleaning ball 6 receives and acquires the density information of the contact surface and transmits it to the control module 643 for analysis. When the control module 643 determines that the contact surface is a spot to be cleaned, the control module 643 controls the cleaning ball motor 641 to drive the cleaning brush ball 63 to start rotating and perform cleaning work through the transmission frame 644.

[0057] Step 6: When the cleaning brush ball 63 rotates to perform cleaning work, the blade rollers 632 on the cleaning brush ball 63 powerfully clean the dirt on the twin screw 4, scraping off a large amount of dirt. The squeezing brush head 633 of the cleaning brush ball 63 contacts the twin screw 4 for cleaning. The cleaning agent remaining in the cleaning brush ball 63 is squeezed out through the squeezing nozzle 6331. The sponge rollers 634 on the cleaning brush ball 63 knock and vibrate the dirt on the twin screw 4 to make it fall off. The cleaning agent is foamed by the sponge rollers 634 and the brass brush 6332, which can increase the cleaning power.

[0058] Step 7: After the set working time, the motor of the energized conductor of the twin screw 4 is turned off. When the power is off, the magnetism of the twin screw 4 disappears, and the density sensor probe 62 of the cleaning ball 6 detaches from the surface of the twin screw 4. Then the motor of the energized conductor of the twin screw 4 is turned on again, so that the cleaning ball 6 moves to the next working point with the flow of cleaning agent. Repeat steps 4-6 to start a new round of cleaning process.

[0059] Step 8: After several rounds of cleaning processes, the cleaning ball 6 moves forward with the twin screw 4 to the extrusion port 7 of the twin screw 4 and is discharged along with the used cleaning agent and dirt;

[0060] Step 9: The cleaning ball 6 is discharged from the extrusion port 7 and falls into the separation box 8. After the separation box 8 is vibrated, the cleaning ball 6 is shaken off and separated from the attached dirt. The dirt and cleaning liquid are discharged from the drain port for environmentally friendly treatment.

[0061] The density determination logic in step 5 is as follows: when the control module 643 analyzes and determines that the contact surface density is between 1.15 and 7 g / m³... 3 When the sealing range value is not met, the control module 643 determines that the contact surface is the site to be cleaned (i.e., a non-metallic surface contaminated with dirt), and starts the cleaning ball motor 641, causing the cleaning brush ball 63 to rotate and perform cleaning work; when the control module 643 analyzes and determines that the contact surface density is not between 1.15 and 7 g / m³, the cleaning brush ball 63 starts rotating and performs cleaning work. 3 When the sealing range value is reached, the control module 643 controls the cleaning ball motor 641 to shut down, and the cleaning brush ball 63 stops rotating. By judging and setting the contact surface density, when the density sensor probe 62 of the cleaning ball 6 detects that the contact surface is not within the set density range value, it means that the cleaning ball 6 has not yet been stably adsorbed on the surface of the twin screw 4, or the cleaning ball 6 has been adsorbed onto the surface of the twin screw 4 that is not contaminated with dirt. At this time, controlling the cleaning brush ball 63 to stop rotating not only helps the cleaning ball 6 to be successfully adsorbed and avoids the problem of adsorption being hindered by the rotation of the cleaning brush ball 63, but also avoids repeated or over-cleaning, effectively saving energy consumption.

[0062] The self-cleaning method and screw of the counter-rotating twin-screw extruder proposed in this invention, compared with existing technologies that rely on manual cleaning, eliminate the need for human intervention. The process is fully automated, greatly liberating productivity. It not only effectively reduces the labor intensity of personnel but also minimizes the wear and tear on the twin screw caused by disassembly and cleaning, thus extending the twin screw's service life. It also reduces the waste of pre-prepared materials caused by adding polyethylene materials for cleaning. This invention can complete the self-cleaning of the twin-screw extruder in a relatively sealed environment, reducing contact between personnel and the twin-screw extruder components and preventing accidents. Throughout the testing process, simply placing the cleaning ball 6 into the twin-screw extruder allows for cleaning controlled by a timed motor. The cleaning ball 6 is then recycled in the separation box 8 and can be reused multiple times, saving on operating costs.

[0063] The technical solution provided by the present invention has been described in detail above. Specific examples have been used to illustrate the principle and implementation of the present invention. The description of the above embodiments is only for the purpose of helping to understand the method and core idea of ​​the present invention. At the same time, for those skilled in the art, there will be changes in the specific implementation and application scope based on the idea of ​​the present invention. Therefore, the content of this specification should not be construed as a limitation of the present invention.

Claims

1. A counter-rotating twin-screw extruder with self-cleaning function, comprising a barrel, twin screws disposed within the barrel, and a feed inlet and an extrusion outlet disposed on the barrel, characterized in that, It also includes cleaning balls and cleaning water pipes. The cleaning water pipes are set on the barrel and their openings extend into the barrel and face the twin screws. The cleaning balls enter the barrel from the feed port and move around the twin screws as they rotate until they reach the extrusion port and are discharged. The cleaning balls clean the twin screws by contacting their surfaces. The cleaning ball includes a cleaning ball shell, a density sensor probe, a cleaning brush ball, and a transmission assembly. The transmission assembly is disposed inside the cleaning ball shell, and the density sensor probe and the cleaning brush ball are distributed on the surface of the cleaning ball shell and connected to the transmission assembly. The twin screw has an internal conductor that conducts current. When energized, the twin screw becomes magnetic. The density sensor probe is made of a magnetic material. Under the action of the magnetic twin screw, the density sensor probe on the cleaning ball is attracted to the surface of the twin screw. When the power is off, the magnetism of the twin screw disappears, and the density sensor probe on the cleaning ball separates from the twin screw. The transmission assembly includes a transmission frame, a cleaning ball motor, a sensor detection module, and a control module. The transmission frame is disposed inside the cleaning ball shell and connected to the cleaning ball motor and the cleaning brush. The cleaning ball motor is electrically connected to the sensor detection module and the control module. The sensor detection module is used to acquire and transmit information detected by the density sensor probe. The control module is used to analyze and transmit information from the sensor detection module. The cleaning ball motor controls the rotation of the cleaning ball by driving the transmission frame.

2. The counter-rotating twin-screw extruder with self-cleaning function according to claim 1, characterized in that, The cleaning brush ball includes a cleaning brush ball shell, and blade rollers, a squeezing brush head, and a sponge roller distributed on the surface of the cleaning brush ball shell; the blade rollers are located on the upper and lower sides of the cleaning brush ball, the sponge rollers are located on the left and right sides of the cleaning brush ball, and the squeezing brush head is located on the front and rear sides of the cleaning brush ball.

3. The counter-rotating twin-screw extruder with self-cleaning function according to claim 2, characterized in that, The squeeze brush head is detachably installed. The cleaning brush ball housing contains cleaning fluid. The squeeze brush head includes a squeeze nozzle and a brass brush. The squeeze nozzle is connected to the cleaning brush ball housing through an elastic element. The squeeze nozzle squeezes the elastic element by contacting the twin screws, causing the cleaning fluid to be squeezed out.

4. The counter-rotating twin-screw extruder with self-cleaning function according to claim 1, characterized in that, The surface of the density sensor probe is coated with a hydrophobic coating.

5. The counter-rotating twin-screw extruder with self-cleaning function according to claim 1, characterized in that, It also includes a separation box, which is located below the extrusion port of the barrel. The separation box is equipped with a partition and a drain outlet. The partition is provided with a mesh, and the drain outlet is located below the partition.

6. A self-cleaning method for a counter-rotating twin-screw extruder with self-cleaning function, characterized in that, Using the counter-rotating twin-screw extruder with self-cleaning function as described in claim 1, the method includes the following steps: Step 1: After the extrusion operation of the counter-rotating twin-screw extruder is completed, a cleaning agent is injected between the barrel and the twin screws through the cleaning water pipe; Step 2: Adjust the diameter of the extrusion nozzle of the twin-screw extruder to a size that allows the cleaning balls to pass through; Step 3: Turn on the cleaning ball motor switch and feed the cleaning ball into the feed port of the twin-screw extruder. The cleaning ball will start to move around the twin screw as the cleaning agent flows. Step 4: The motor of the twin-screw conductor is energized, making the twin-screw magnetic, and the cleaning ball is adsorbed onto the surface of the twin-screw through the density sensor probe; Step 5: The density sensor probe is magnetically attached to the surface of the twin screw. The sensor detection module inside the cleaning ball receives the density information of the contact surface. When it is determined that the contact surface is a spot to be cleaned, the control module controls the cleaning ball motor to drive the cleaning brush ball to start rotating through the transmission frame to perform the cleaning work. Step 6: The cleaning brush ball rotates to perform cleaning work. The blades on the cleaning brush ball clean the dirt on the twin screw, scraping off a large amount of dirt. The squeezing brush head of the cleaning brush ball contacts the twin screw to clean it. The squeezing brush head squeezes out the cleaning agent remaining in the cleaning brush ball. The sponge ball on the cleaning brush ball taps and shakes the dirt on the twin screw to make it fall off. The sponge ball and the foaming of the cleaning agent can increase the cleaning power. Step 7: After the set working time, the motor of the twin-screw energized conductor is turned off. In the power-off state, the magnetism of the twin-screw disappears, and the density sensor probe of the cleaning ball detaches from the surface of the twin-screw. With the flow of the cleaning agent, it moves to the next working point. Then, the motor of the twin-screw energized conductor is turned on again, and steps 4-6 are repeated to start a new round of cleaning process. Step 8: After several rounds of cleaning processes, the cleaning ball moves forward with the twin screw to the extrusion port of the twin screw and is discharged along with the used cleaning agent and dirt.

7. The self-cleaning method for a counter-rotating twin-screw extruder with self-cleaning function according to claim 6, characterized in that, In step 5, when the control module analyzes and determines that the contact surface density is between 1.15 and 7 g / m³ 3 If the density falls within the specified range, it is determined that the contact surface is contaminated with dirt. The control module then activates the cleaning ball motor, and the cleaning brush begins to rotate and perform cleaning. If the control module determines that the contact surface density is outside the range of 1.15~7 g / m³, it indicates that the surface is dirty. 3 When the sealing range value is reached, the control module controls the cleaning ball motor to shut down, and the cleaning brush ball stops rotating.

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