A screw extrusion device capable of being used for plastic recycling

Abstract

The application discloses a screw extruding device capable of being used for plastic recycling, which comprises a barrel, a detection unit, a screw, a screw motor and a die head; the barrel is connected with a discharge pipe, and the discharge pipe is connected with a discharging pipe; the detection unit comprises a rack, a blocking unit, an electric lifting rod, a circular lifting plate, a lower annular rotating plate, an inner barrel part, an outer barrel part, a rotating motor, a rotating frame, an upper annular rotating plate and a plurality of detection barrel units. The screw extruding device can detect whether there is air bubble in the U-shaped channel of the first detection barrel through the ultrasonic detection unit. The light emitter and the light receiver can be used to detect the discharging time of the discharging pipe, so as to judge whether the fluidity of the molten body is qualified. The pressurizing pump is used for pressurizing, so that the material at the filter screen part can pass through the filter screen part as much as possible, and the image acquisition unit can be used to detect whether there is impurity in the filter screen part. The cleaning unit can scrape off the solidified molten body possibly remaining around the through hole unit.

Description

Technical Field

[0001] This invention relates to the field of screw extrusion technology, and more specifically, to a screw extrusion apparatus capable of being used for plastic recycling. Background Technology

[0002] Screw extruders are one of the most important pieces of equipment in plastic molding and processing. Their working principle involves using the rotational motion of a screw to compress, melt, and plasticize the plastic raw material, ultimately extruding the molten plastic into a mold. Plastic recycling refers to the process of reprocessing waste plastic products into reusable plastic raw materials or products through a series of treatment processes.

[0003] Screw extruders used in plastic recycling typically feed crushed, washed, and dried plastic fragments and films from plastic products such as bottles and films. Compared to standard granular feed, the melt at the screw extrusion end is more prone to impurities, and its flowability, viscosity, and air bubbles may not meet standards, severely impacting product quality. Existing screw extruders for plastic recycling lack timely monitoring and feedback mechanisms, making it impossible to assess their operational status and perform timely maintenance. Summary of the Invention

[0004] The present invention aims to overcome the shortcomings of the prior art and provide a screw extrusion device that can be used for plastic recycling.

[0005] To achieve the above objectives, the present invention provides the following technical solution: a screw extrusion device, comprising a cylinder, a detection unit, a screw, a screw motor, and a die head; the cylinder is connected to a discharge pipe, and a feed pipe is connected to the discharge pipe; the detection unit includes a frame, a sealing unit, an electric lifting rod, a circular lifting plate fixedly connected to the movable end of the electric lifting rod, a lower annular rotating plate connected to the circular lifting plate via a bearing unit, an inner cylinder fixedly connected to the circular lifting plate via a connecting bracket, an outer cylinder fixedly connected to the frame, a rotary motor mounted on the frame, a rotating frame driven by the rotary motor, and an upper annular rotating plate fixedly connected to the rotating frame. The system comprises a plate and multiple detection cylinder units. The upper annular rotating plate has multiple through-hole units. The detection cylinder units include a first detection cylinder, a second detection cylinder, and a third detection cylinder. The through-hole units include a first through-hole, a second through-hole, and a third through-hole. The first detection cylinder has a receiving groove and a U-shaped channel communicating with the receiving groove. The first detection cylinder also has a detection plane. The second detection cylinder has a feeding hopper installed inside and two light-transmitting plates installed thereon. A light emitter is installed in the inner cylinder and a light receiver is installed in the outer cylinder. The third detection cylinder has a filter section installed inside. An electric push rod is installed in the outer cylinder, and an ultrasonic detection unit is installed at the movable end of the electric push rod.

[0006] Furthermore, the multiple through-hole units are distributed in a ring with equal spacing.

[0007] Furthermore, the light emitted by the light emitter can pass through the two light-transmitting plates of the second detection tube and be received by the light receiver.

[0008] Furthermore, the screw is installed inside the cylinder.

[0009] Furthermore, the screw motor is used to drive the screw.

[0010] Furthermore, the die head is mounted on the end of the cylinder.

[0011] Furthermore, the sealing unit is used to seal the discharge pipe.

[0012] Furthermore, the detection cylinder unit is installed between the upper annular rotating plate and the lower annular rotating plate.

[0013] Furthermore, the inner cylinder portion has an inner cylinder heating unit.

[0014] Furthermore, the outer cylinder portion has an outer cylinder heating unit.

[0015] By utilizing the heating units in the inner cylinder and the outer cylinder, the temperature between the inner and outer cylinders can be controlled, thereby achieving better detection.

[0016] Furthermore, multiple primary temperature sensors are installed on the side wall of the inner cylinder.

[0017] Furthermore, multiple second temperature sensors are installed on the side wall of the outer cylinder.

[0018] Furthermore, the screw is divided into a feeding section, a compression section, and a homogenization section.

[0019] Furthermore, the connection point between the discharge pipe and the cylinder is located in the homogenization section.

[0020] Furthermore, the lower annular rotating plate is rotatable relative to the inner cylinder.

[0021] In some embodiments, the sealing unit can be replaced by a valve installed at the discharge pipe.

[0022] Furthermore, an annular support is fixed inside the third detection cylinder, the filter screen is circular and supported by the annular support, and a vent pipe is connected to the third detection cylinder.

[0023] Furthermore, the feeding hopper includes a cylindrical ring, an inverted conical hopper connected to the cylindrical ring, and a discharge pipe connected to the inverted conical hopper, and the second detection cylinder has a vent hole.

[0024] The vent pipe and vent hole are designed to facilitate the falling of materials and prevent air pressure from interfering with the falling of materials.

[0025] Furthermore, one end of the U-shaped channel of the first detection cylinder is connected to the outer wall of the first detection cylinder.

[0026] Furthermore, a fixing block is connected between the vent pipe and the third detection cylinder, and the vent pipe passes through the fixing block.

[0027] This fixing block makes the vent tube more stable.

[0028] Furthermore, the bottom ends of the first detection cylinder, the second detection cylinder, and the third detection cylinder are all sealed.

[0029] Furthermore, the first through hole is located above the first detection cylinder, the second through hole is located above the second detection cylinder, and the third through hole is located above the third detection cylinder.

[0030] Furthermore, the number of detection cylinder units is equal to the number of through-hole units.

[0031] Furthermore, a first connecting block is connected between the first detection cylinder and the second detection cylinder, and a second connecting block is connected between the second detection cylinder and the third detection cylinder.

[0032] Furthermore, the top of the first detection cylinder, the second detection cylinder, and the third detection cylinder are all provided with an upper positioning hole, and the bottom of each cylinder is provided with a lower positioning hole. The upper annular rotating plate is provided with an upper positioning post that mates with the upper positioning hole, and the lower annular rotating plate is provided with a lower positioning post that mates with the lower positioning hole.

[0033] Thus, the detection cylinder unit is installed between the upper and lower annular rotating plates and can rotate synchronously.

[0034] Furthermore, the top of the first detection cylinder, the second detection cylinder, and the third detection cylinder each have three upper positioning holes, and the bottom of each have three lower positioning holes.

[0035] Furthermore, the upper surface of the upper annular rotating plate is fixed with an inner annular convex edge and an outer annular convex edge.

[0036] Furthermore, the rotating frame includes a rotating sleeve driven by a rotary motor and a plurality of radial rods connecting the rotating sleeve and the upper annular rotating plate.

[0037] Furthermore, the frame includes a base plate, a vertical plate fixedly connected to the base plate, a horizontal plate fixedly connected to the vertical plate, and a connecting plate connecting the vertical plate and the outer cylinder.

[0038] Furthermore, the electric lifting rod is fixedly connected to the base plate.

[0039] Furthermore, the rotary motor is mounted on the horizontal plate.

[0040] Furthermore, a pressurizing air pump is installed at the vertical plate. The pressurizing air pump is connected to a pressurizing cylinder through an air outlet pipe. The top of the pressurizing cylinder is closed, and the bottom is open and can face the first through hole.

[0041] Furthermore, a light source and an image acquisition unit are installed inside the pressure cylinder.

[0042] Furthermore, the vent pipe is a rigid pipe.

[0043] Furthermore, a connecting rod connects the vertical plate and the pressure cylinder.

[0044] Furthermore, it also includes a cleaning unit, which includes an electric telescopic rod installed on the horizontal plate, a lifting cover connected to the electric telescopic rod, and multiple scraping units installed on the lifting cover. The scraping unit includes a drive motor installed on the lifting cover, a first plate body driven to rotate by the drive motor, a second plate body connected to the first plate body by a spring, and multiple scrapers installed on the second plate body. The first plate body has a guide hole, and the second plate body has a guide rod passing through the guide hole. The lifting cover has a lifting cover heating unit.

[0045] Thus, the lifting hood heating unit can heat and melt the solidified molten material, and scrape it off with a scraper.

[0046] Furthermore, the scraping unit has three parts.

[0047] Furthermore, both the first plate and the second plate are circular.

[0048] Furthermore, the first plate has three guide holes, the second plate has three guide rods, and there are three springs, with each guide rod passing through a spring.

[0049] Furthermore, when a certain through-hole unit is located below the lifting cover, the three scraping units are located above the first through-hole, the second through-hole, and the third through-hole, respectively.

[0050] Furthermore, both the outer cylinder and the inner cylinder are annular cylindrical; the connecting bracket is L-shaped, and there are multiple connecting brackets distributed in a ring at equal intervals.

[0051] Furthermore, the sealing unit includes a limiting tube fixedly connected to the cylinder, a limiting rod inserted into the limiting tube, a sealing rod inserted into the discharge pipe, a lead screw, and a lead screw motor for driving the lead screw. The limiting rod is L-shaped and fixedly connected to the sealing rod, and the sealing rod has a threaded channel that mates with the lead screw.

[0052] Furthermore, the discharge pipe is a horizontal pipe, the feed pipe is a vertical pipe, and the discharge pipe and the feed pipe are connected by a connecting pipe.

[0053] Furthermore, a feeding hopper is installed at the cylinder body; a vacuum unit is installed at the cylinder body.

[0054] Beneficial effects:

[0055] 1. The screw extrusion device of this application uses a rotary motor to drive the upper annular rotating plate, so that the three detection cylinders of the detection cylinder unit rotate sequentially to the bottom of the feeding pipe, thereby realizing the feeding operation of different detection cylinders.

[0056] 2. The screw extrusion device of this application can detect whether there are air bubbles in the material in the U-shaped channel of the first detection cylinder through the ultrasonic detection unit.

[0057] 3. The screw extrusion apparatus of this application uses a light emitter and a light receiver to detect the feeding time of the material in the feeding tube inside the second detection cylinder, thereby determining whether the melt flowability is qualified.

[0058] 4. The screw extrusion device of this application pressurizes the third detection cylinder by a pressure pump, so that the material in the filter section passes through the filter section as much as possible, and the image acquisition unit can detect whether there are impurities in the filter section.

[0059] 5. In the screw extrusion apparatus of this application, after a through-hole unit is used up, the cleaning unit can scrape off any solidified melt that may remain around the through-hole unit, so as to avoid the residual material affecting the through-hole unit when it is used again. Attached Figure Description

[0060] Figure 1 Schematic diagram of the sealing unit sealing the discharge pipe;

[0061] Figure 2 A schematic diagram showing the material being fed into the first through hole through the discharge pipe of the sealing unit.

[0062] Figure 3 A schematic diagram of the upper annular rotating plate rotating to block the discharge pipe of the sealing unit;

[0063] Figure 4 A schematic diagram showing the third through hole located below the pressure cylinder;

[0064] Figure 5 A schematic diagram of cleaning the through-hole unit using the cleaning unit;

[0065] Figure 6 A schematic diagram showing the descent of multiple detection cylinder units as the electric lifting boom descends.

[0066] Figure 7 This is a first-person perspective diagram of component separation.

[0067] Figure 8 This is a magnified view of region A;

[0068] Figure 9 This is a magnified view of region B.

[0069] Figure 10 This is a magnified view of region C;

[0070] Figure 11 This is a first-person perspective diagram of component separation.

[0071] Figure 12 This is a magnified view of region D;

[0072] Figure 13 This is a magnified view of region E.

[0073] Figure 14 This is a first-person perspective diagram of component separation.

[0074] Figure 15 This is a magnified view of region F;

[0075] Figure 16 This is a magnified view of region G;

[0076] Figure 17 This is a first-person perspective diagram of component separation.

[0077] Figure 18 This is a magnified view of region H;

[0078] For ease of illustration, Figures 7 to 17 The middle cylinder is not drawn.

[0079] Explanation of reference numerals in the attached drawings: 1. Cylinder body; 1.1 Screw motor; 1.2 Die head; 1.3 Discharge pipe; 1.4 Connecting pipe; 1.5 Feed pipe; 1.6 Feed hopper; 2. Frame; 2.1 Base plate; 2.2 Vertical plate; 2.3 Horizontal plate; 2.4 Connecting plate; 2.5 Rotary motor; 2.6 Air outlet pipe; 2.7 Pressure cylinder; 3.1 Limiting pipe; 3.2 Limiting rod; 3.3 Sealing rod; 3.4 Lead screw; 3.5 Lead screw motor; 4. Electric lifting rod; 5. Circular lifting plate; 5.1 Bearing unit; 5.2 Connecting bracket; 6. Lower annular rotating plate; 6.1 Lower positioning column; 7. Inner cylinder; 7.1 Light emitter; 8. Outer cylinder; 8.1 Light receiver; 8.2 Electric push rod; 8.3 Ultrasonic detection unit; 9. Rotating frame; 10. Rotating sleeve. 9.1; Radial rod 9.2; Upper annular rotating plate 10; First through hole 10.1; Second through hole 10.2; Third through hole 10.3; Upper positioning post 10.4; First detection cylinder 11; Receiving trough 11.1; U-shaped channel 11.2; Detection plane 11.3; Second detection cylinder 12; Circular cylindrical cylinder 12.1; Inverted conical hopper 12.2; Material discharge pipe 12.3; Light-transmitting plate 12.4; Ventilation hole 12.5; First connecting block 12.6; Second connecting block 12.7; Third detection cylinder 13; Filter section 13.1; Ventilation pipe 13.2; Fixing block 13.3; Electric telescopic rod 14; Lifting cover 15; First plate 16.1; Second plate 16.2; Drive motor 16.3; Scraper 16.4. Detailed Implementation

[0080] Embodiments of the present invention are described in detail below, examples of which are illustrated in the accompanying drawings, wherein the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the present invention, and should not be construed as limiting the present invention.

[0081] This invention provides a screw extrusion device for plastic recycling, as shown in the figure, comprising a barrel 1, a detection unit, a screw installed inside the barrel 1, a screw motor 1.1 for driving the screw, and a die head 1.2 installed at the end of the barrel 1; the barrel 1 is connected to a discharge pipe 1.3, and a feed pipe 1.5 is connected to the discharge pipe 1.3; the detection unit includes a frame 2, a sealing unit for sealing the discharge pipe 1.3, an electric lifting rod 4, a circular lifting plate 5 fixedly connected to the movable end of the electric lifting rod, a lower annular rotating plate 6 connected to the circular lifting plate 5 via a bearing unit 5.1, an inner cylinder 7 fixedly connected to the circular lifting plate 5 via a connecting bracket 5.2, an outer cylinder 8 fixedly connected to the frame 2, a rotary motor 2.5 installed on the frame 2, a rotating frame 9 driven by the rotary motor 2.5, an upper annular rotating plate 10 fixedly connected to the rotating frame 9, and multiple upper annular rotating plates 10 installed on the upper annular rotating plate 10. The detection cylinder unit between the moving plate 10 and the lower annular rotating plate 6 has multiple through-hole units at the upper annular rotating plate 10. The detection cylinder unit includes a first detection cylinder 11, a second detection cylinder 12, and a third detection cylinder 13. The through-hole units include a first through-hole 10.1, a second through-hole 10.2, and a third through-hole 10.3. The first detection cylinder 11 has a receiving groove 11.1 and a U-shaped channel 11.2 communicating with the receiving groove 11.1. The first detection cylinder 11 also has a detection plane 11.3. The second detection cylinder 12 is equipped with a feeding hopper and two light-transmitting plates 12.4. The inner cylinder 7 is equipped with a light emitter 7.1, and the outer cylinder 8 is equipped with a light receiver 8.1. The third detection cylinder 13 is equipped with a filter section 13.1. The outer cylinder 8 is equipped with an electric push rod 8.2, and the movable end of the electric push rod is equipped with an ultrasonic detection unit 8.3.

[0082] The third detection cylinder 13 has an annular support fixed inside. The filter screen is circular and supported by the annular support. A vent pipe 13.2 is connected to the third detection cylinder 13. The feeding hopper includes a cylindrical annular cylinder 12.1, an inverted conical hopper 12.2 connected to the cylindrical annular cylinder 12.1, and a discharge pipe 12.3 connected to the inverted conical hopper 12.2. The second detection cylinder 12 has a vent hole 12.5. One end of the U-shaped channel of the first detection cylinder is connected to the outer wall of the first detection cylinder. A first connecting block 12.6 connects the first detection cylinder 11 and the second detection cylinder 12, and a second connecting block 12.7 connects the second detection cylinder 12 and the third detection cylinder 13. The top ends of the first detection cylinder 11, the second detection cylinder 12, and the third detection cylinder 13 all have upper positioning holes, and the bottom ends all have lower positioning holes. The upper annular rotating plate 10 has an upper positioning post 10.4 that mates with the upper positioning holes, and the lower annular rotating plate 6 has a lower positioning post 6.1 that mates with the lower positioning holes. The top ends of the first detection cylinder 11, the second detection cylinder 12, and the third detection cylinder 13 all have three upper positioning holes, and the bottom ends all have three lower positioning holes. The upper surface of the upper annular rotating plate 10 is fixed with an inner annular protrusion and an outer annular protrusion. The rotating frame 9 includes a rotating sleeve 9.1 driven by a rotary motor 2.5 and multiple radial rods 9.2 connecting the rotating sleeve 9.1 and the upper annular rotating plate 10. The frame 2 includes a base plate 2.1, a vertical plate 2.2 fixedly connected to the base plate 2.1, a horizontal plate 2.3 fixedly connected to the vertical plate 2.2, and a connecting plate 2.4 connecting the vertical plate 2.2 and the outer cylinder 8; the electric lifting rod is fixedly connected to the base plate 2.1; the rotary motor is installed at the horizontal plate 2.3; a pressurizing air pump is installed at the vertical plate 2.2, and the pressurizing air pump is connected to a pressurizing cylinder 2.7 through an air outlet pipe 2.6. The top of the pressurizing cylinder 2.7 is closed, and the bottom is open and can face the first through hole 10.1. A light source and an image acquisition unit are installed inside the pressurizing cylinder 2.7. The screw extrusion device further includes a cleaning unit, which includes an electric telescopic rod 14 installed on the horizontal plate 2.3, a lifting cover 15 connected to the electric telescopic rod 14, and a plurality of scraping units installed on the lifting cover 15. The scraping unit includes a drive motor 16.3 installed on the lifting cover 15, a first plate 16.1 driven to rotate by the drive motor 16.3, a second plate 16.2 connected to the first plate 16.1 by a spring, and a plurality of scrapers 16.4 installed on the second plate 16.2. The first plate 16.1 has a guide hole, and the second plate 16.2 has a guide rod passing through the guide hole. The lifting cover 15 has a lifting cover heating unit.

[0083] Both the outer cylinder 8 and the inner cylinder 7 are annular cylindrical; the connecting bracket 5.2 is L-shaped, and there are multiple connecting brackets 5.2 distributed in a ring at equal intervals. The sealing unit includes a limiting tube 3.1 fixedly connected to the cylinder 1, a limiting rod 3.2 inserted into the limiting tube 3.1, a sealing rod 3.3 inserted into the discharge pipe 1.3, a lead screw 3.4, and a lead screw motor 3.5 for driving the lead screw 3.4. The limiting rod 3.2 is L-shaped and fixedly connected to the sealing rod 3.3, and the sealing rod 3.3 has a threaded channel that mates with the lead screw 3.4. The discharge pipe 1.3 is a horizontal pipe, and the discharge pipe 1.5 is a vertical pipe. The discharge pipe 1.3 and the discharge pipe 1.5 are connected by a connecting pipe 1.4. A feeding hopper 1.6 is installed at the cylinder 1; a vacuum unit is installed at the cylinder 1.

[0084] Working principle: The screw extrusion device of this application can discharge material from the discharge pipe at the end of the cylinder and feed material from the feed pipe. The discharge pipe can be opened for discharge by driving a lead screw motor, or it can be sealed using a sealing rod. Furthermore, driven by a rotary motor, the upper annular rotating plate can rotate, carrying multiple detection cylinder units and the lower annular rotating plate. The feed pipe can feed material into the first, second, and third detection cylinders.

[0085] Specifically, such as Figure 1 As shown, the sealing rod blocks the discharge pipe at this time. Testing is required when needed (the testing operation can be performed periodically); as... Figure 2 As shown, the rotary motor can drive the first through hole to be located below the feed pipe, and the sealing rod moves backward to open the discharge pipe, allowing the feed pipe to discharge into the first detection cylinder. Then, the sealing rod is used again to seal the discharge pipe (after sealing the discharge pipe, wait slightly to allow the molten material at the feed pipe to finish discharging). Figure 3 As shown, the upper annular rotating plate is rotated again using a rotary motor so that the second through hole is located below the feed pipe. The feed pipe feeds material into the second detection cylinder. After feeding, the discharge pipe is blocked again using a sealing rod (after blocking the discharge pipe, wait slightly to allow the molten material at the feed pipe to finish feeding). The upper annular rotating plate is rotated again using a rotary motor so that the third through hole is located below the feed pipe. The feed pipe feeds material into the third detection cylinder. After feeding is complete, as shown... Figure 4As shown, the discharge pipe is blocked again using a sealing rod, and the rotating motor drives the upper annular rotating plate to rotate, positioning the third through hole below the pressure cylinder. At this time, the ultrasonic detection unit can be used to contact the detection plane to detect whether there are air bubbles in the material within the U-shaped channel. The material in the hopper of the second detection cylinder can continuously fall from the discharge pipe. The falling material can block the light emitted by the light emitter, preventing the light receiver from receiving it. Thus, the light emitter and light receiver can detect the duration of the material falling from the discharge pipe. Theoretically, the duration of the material falling should be within a set threshold range. A reasonable threshold range can be obtained by experimentally determining the duration of the material falling during normal system operation. When the fluidity of the melt changes significantly and becomes unqualified, the duration of the material falling will not be within the reasonable threshold range. In the third detection cylinder, the pressure pump can pressurize the material, ensuring that as much of the material as possible passes through the filter screen. The image acquisition unit can easily capture images to see whether there are impurities at the filter screen. Furthermore, during the detection process, the inner cylinder heating unit and the outer cylinder heating unit can be used to control the temperature between the inner and outer cylinders, for example, maintaining the molten state of the material, thereby achieving better detection.

[0086] There are three sets of detection cylinder units between the upper and lower annular rotating plates, enabling automatic execution of three detection cycles. Furthermore, after one through-hole unit is used, during the detection of the next through-hole unit, if... Figure 5 As shown, this detection cylinder unit is located directly below the lifting hood. The lifting hood can descend and be heated to melt any solidified molten material that may remain around the first, second, and third through holes. A scraping unit then removes this molten material, ensuring that as much of the remaining material as possible falls into the first, second, and third detection cylinders. Therefore, the first, second, and third through holes will not be affected by residual material during subsequent use.

[0087] After all three detection cylinder units have been used, such as Figure 6 As shown, the electric lifting rod can be lowered, causing multiple detection cylinder units to descend as well. This allows the detection cylinder units to be removed and replaced with new ones, preparing for the next inspection. Furthermore, the filter screen can be manually removed at this time to further determine if there are impurities there.

[0088] Although the present invention has been illustrated and described with reference to preferred embodiments, those skilled in the art should understand that various changes and modifications can be made to the present invention without departing from the scope defined by the claims.

Claims

1. A screw extrusion apparatus for plastic recycling, characterized in that, The system includes a cylinder, a detection unit, a screw, a screw motor, and a die head. The cylinder is connected to a discharge pipe, which in turn is connected to a feed pipe. The detection unit includes a frame, a sealing unit, an electric lifting rod, a circular lifting plate fixedly connected to the movable end of the electric lifting rod, a lower annular rotating plate connected to the circular lifting plate via a bearing unit, an inner cylinder fixedly connected to the circular lifting plate via a connecting bracket, an outer cylinder fixedly connected to the frame, a rotary motor mounted on the frame, a rotating frame driven by the rotary motor, an upper annular rotating plate fixedly connected to the rotating frame, and multiple detection cylinder units. The moving plate has multiple through-hole units. The detection cylinder unit includes a first detection cylinder, a second detection cylinder, and a third detection cylinder. The through-hole unit includes a first through hole, a second through hole, and a third through hole. The first detection cylinder has a receiving groove and a U-shaped channel communicating with the receiving groove. The first detection cylinder also has a detection plane. The second detection cylinder has a feeding hopper installed inside and two light-transmitting plates installed there. A light emitter is installed in the inner cylinder and a light receiver is installed in the outer cylinder. The third detection cylinder has a filter section installed inside. An electric push rod is installed in the outer cylinder, and an ultrasonic detection unit is installed at the movable end of the electric push rod. The third detection cylinder has an annular support fixed inside, the filter screen is circular and supported by the annular support, and a vent pipe is connected to the third detection cylinder; the hopper includes a cylindrical annular cylinder, an inverted conical hopper connected to the cylindrical annular cylinder, and a discharge pipe connected to the inverted conical hopper, and a vent hole is provided at the second detection cylinder; one end of the U-shaped channel of the first detection cylinder is connected to the outer wall of the first detection cylinder; A first connecting block connects the first and second detection cylinders, and a second connecting block connects the second and third detection cylinders; the top of the first, second, and third detection cylinders each has an upper positioning hole, and the bottom of each has a lower positioning hole; the upper annular rotating plate has an upper positioning post that mates with the upper positioning hole, and the lower annular rotating plate has a lower positioning post that mates with the lower positioning hole. The frame includes a base plate, a vertical plate fixedly connected to the base plate, a horizontal plate fixedly connected to the vertical plate, and a connecting plate connecting the vertical plate and the outer cylinder. An electric lifting rod is fixedly connected to the base plate. A rotary motor is installed on the horizontal plate. A pressurized air pump is installed on the vertical plate. The pressurized air pump is connected to a pressurized cylinder through an air outlet pipe. The top of the pressurized cylinder is closed, and the bottom is open and can face the first through hole. A light source and an image acquisition unit are installed inside the pressurized cylinder.

2. The screw extruder for plastic recycling according to claim 1, characterized in that, The first, second, and third detection cylinders each have three upper positioning holes at their top ends and three lower positioning holes at their bottom ends; the upper surface of the upper annular rotating plate is fixed with an inner annular convex edge and an outer annular convex edge; the rotating frame includes a rotating sleeve driven by a rotary motor and multiple radial rods connecting the rotating sleeve and the upper annular rotating plate.

3. The screw extruder for plastic recycling according to claim 1, characterized in that, It also includes a cleaning unit, which includes an electric telescopic rod installed on the horizontal plate, a lifting cover connected to the electric telescopic rod, and multiple scraping units installed on the lifting cover. The scraping unit includes a drive motor installed on the lifting cover, a first plate body driven to rotate by the drive motor, a second plate body connected to the first plate body by a spring, and multiple scrapers installed on the second plate body. The first plate body has a guide hole, and the second plate body has a guide rod passing through the guide hole. The lifting cover has a lifting cover heating unit.

4. The screw extruder for plastic recycling according to claim 1, characterized in that, Both the outer cylinder and the inner cylinder are annular cylindrical; the connecting bracket is L-shaped, and there are multiple connecting brackets distributed in a ring at equal intervals.

5. The screw extruder for plastic recycling according to claim 1, characterized in that, The sealing unit includes a limiting tube fixedly connected to the cylinder, a limiting rod inserted into the limiting tube, a sealing rod inserted into the discharge pipe, a lead screw, and a lead screw motor for driving the lead screw. The limiting rod is L-shaped and fixedly connected to the sealing rod, and the sealing rod has a threaded channel that mates with the lead screw.

6. The screw extruder for plastic recycling according to claim 1, characterized in that, The discharge pipe is a horizontal pipe, and the feed pipe is a vertical pipe. The discharge pipe and the feed pipe are connected by a connecting pipe.

7. The screw extruder for plastic recycling according to claim 1, characterized in that, A feeding hopper is installed in the cylinder; a vacuum unit is installed in the cylinder.

Images