A washing and drying line for recycling PE agricultural film

Abstract

This application discloses a washing and drying line for recycling PE agricultural film, relating to the technical field of plastic recycling. It includes a pretreatment module, a main treatment module, and a dewatering device. The dewatering device includes a body with a rotating drum and a rotating shaft rotatably mounted on it. The rotating shaft is coaxially arranged inside the drum and has spiral blades for propelling the material. A drive mechanism on the body drives the drum and shaft to rotate at different speeds. The body has an inlet communicating with a separation chamber and a solid outlet communicating with the separation chamber. A water guiding chamber is provided inside the drum, and several micropores communicating with the water guiding chamber are provided on the inner wall of the drum. A drain pipe communicating with the water guiding chamber is provided on the body. A pump unit is located on the side of the drain pipe away from the water guiding chamber, capable of inflating, deflating, and pumping water. This application has the effect of reducing the moisture content of the material.

Description

Technical Field

[0001] This application relates to the technical field of plastic recycling, and in particular to a washing and drying line for recycling PE agricultural film. Background Technology

[0002] With the development of agricultural modernization, the use of agricultural film is increasing day by day. Its recycling and disposal after disposal has become an important environmental issue. Efficient recycling and cleaning is a key prerequisite for the reuse of agricultural film.

[0003] Currently, the process typically involves breaking bundles of waste agricultural film into smaller pieces using a hydraulic slitter, followed by initial washing and screening using a rotary washing screen to remove most of the mud and sand. After being finely broken into even smaller fragments by a comprehensive crusher, the surface dirt is removed by mechanical friction and rubbing using a high-power friction washing machine and a square scrubbing machine. Finally, the fragments are rinsed in a washing tank and centrifuged in a high-speed dewatering machine to obtain recycled fragments.

[0004] However, existing centrifugal dewatering machines rely solely on the centrifugal force generated by the rotation of the screen, which is insufficient to remove the moisture "locked" in the material by its own entangled structure. Summary of the Invention

[0005] The purpose of this application is to provide a washing and drying line for recycling PE agricultural film, which can reduce the moisture content of the material in order to improve the production quality of subsequent extrusion processes.

[0006] The cleaning and drying line for recycling PE agricultural film provided in this application adopts the following technical solution:

[0007] The pretreatment module is used to coarsely crush and coarsely wash the agricultural film;

[0008] The main processing module is used to finely crush and clean the pre-treated agricultural film;

[0009] A dewatering device includes a body on which a drum and a shaft are rotatably mounted. The shaft is coaxially arranged inside the drum and has spiral blades for propelling the material. The body has a drive mechanism for differentially rotating the drum and shaft. A separation chamber is formed between the drum and the shaft. The body has a feed inlet and a solid discharge outlet communicating with the separation chamber. A water guiding chamber is provided inside the drum, and several micropores communicating with the water guiding chamber are provided on the inner wall of the drum. A drain pipe communicating with the water guiding chamber is provided on the body. A pump set is provided on the side of the drain pipe away from the water guiding chamber, and the pump set is capable of inflating, deflating, and pumping water.

[0010] Optionally, the spiral blade is provided with a plurality of soft blocks, and the soft blocks abut against the inner wall of the drum.

[0011] Optionally, the inner wall of the drum is provided with a plurality of protrusions, each of which corresponds to a plurality of micropores, and the micropores are provided on the protrusions.

[0012] Optionally, the feed inlet is located at one end of the drum, and the discharge outlet is located at the other end of the drum.

[0013] Optionally, each of the soft blocks is embedded with a first pressure sensor, and the dehydration device further includes a control unit, which is electrically connected to the first pressure sensor, the drive mechanism, and the pump group.

[0014] Optionally, the dehydration device further includes a separation component, which includes a separation tank mounted on the machine body. The side wall of the separation tank is connected to a drain pipe that is connected to the water outlet of the pump unit, and the drain pipe on the side wall of the separation tank is close to the bottom of the separation tank. The upper end of the separation tank is connected to a return pipe that is connected to the feed inlet.

[0015] Optionally, the separation tank is further equipped with a detection component for detecting sediment content, and a solenoid valve is also provided at the bottom of the separation tank. Both the solenoid valve and the detection component are electrically connected to the control unit.

[0016] Optionally, the detection component includes a support plate and a second pressure sensor. The support plate is installed on the inner wall of the separation tank and is a certain distance away from the bottom of the separation tank. The second pressure sensor is installed on one end of the support plate near the bottom of the separation tank.

[0017] In summary, this application includes at least one of the following beneficial technical effects:

[0018] 1. This invention uses a pretreatment unit to coarsely crush and wash agricultural film, achieving early separation of impurities from the plastic. Then, the main processing module further refines and washes the pretreated film, thoroughly removing firmly attached organic stains and pesticide residues. This ensures the recycled plastic sheets have extremely high cleanliness, meeting the production requirements of high-end recycled products. Simultaneously, the dewatering device in this invention applies negative pressure to the agricultural film material through a pump set, water guide chamber, and micropores. The combination of negative pressure and centrifugal force increases the external force on the film, allowing for better extraction of water. Furthermore, the water flows radially within the film, aligning with the direction of the external force. Compared to axial water flow in traditional equipment, water in the separation chamber exits faster, minimizing secondary contact between the film and water. This further improves the dewatering effect and efficiency, significantly reducing the moisture content of the agricultural film and improving the production quality of subsequent extrusion processes.

[0019] 2. The spiral arrangement of multiple soft blocks not only pushes the plastic along the discharge port, but also allows the soft blocks to contact the inner wall of the drum. Compared with the existing dewatering devices where there is a gap between the screw blades and the inner wall of the drum, the soft blocks in this invention can push the material adhering to the inner wall of the drum all the way to the discharge port, thereby minimizing the situation where some material adheres to the inner wall of the drum, resulting in a reduction in the discharge volume at the discharge port. At the same time, the soft blocks can scrape off the material adhering to the inner wall of the drum, achieving a self-cleaning effect on the inner wall of the drum and minimizing the situation where the plastic blocks the micropores.

[0020] 3. The arrangement of several protrusions makes the inner wall of the drum uneven. Therefore, when the plastic is in the concave surface of the inner wall of the drum, the soft block, due to its spiral arrangement, will exert an axial force on the plastic in the concave surface. Since the plastic is in the concave surface, it will come into contact with the inclined surface of the protrusion when it moves in the axial direction. This inclined surface will exert an axial reaction force on the plastic. Therefore, the soft block and the protrusion will squeeze the plastic together, thereby further squeezing out the water in the plastic and further improving the dehydration effect of the dewatering device on the plastic. The overall external force on the plastic is still along the direction closer to the discharge port. Therefore, the material will undergo repeated squeezing from the inlet to the outlet, which greatly improves the dehydration effect of the dewatering device on the plastic.

[0021] 4. As initially set, the distance between the spiral blades on the rotating shaft and the inner wall of the drum is usually constant. Therefore, the pressure of the inner wall of the drum on each soft block is basically equal, and the values ​​displayed by each first pressure sensor are also basically equal. However, due to the protrusion and the vibration generated by the drum and rotating shaft during operation, the soft blocks will contract to a certain extent, so the values ​​of the first pressure sensors will also fluctuate. A range value can be preset in the control unit. When the value displayed by the first pressure sensor is within this range, it means that the drum and rotating shaft are in normal condition. When the value of one of the first pressure sensors exceeds this range, it means that the drum or rotating shaft has undergone serious deformation. At this time, the drum and rotating shaft will experience dynamic imbalance during rotation, which may easily lead to breakage of the drum or rotating shaft. Therefore, when the value of one of the first pressure sensors is abnormal, the control unit will immediately stop the machine and trigger the alarm system so that the technicians can carry out maintenance work.

[0022] 5. The discharged wastewater is guided into the separator from a position relatively close to the bottom. The less dense plastics float on the surface, while the denser sand and metals settle to the bottom. As more wastewater enters the separator, the water level gradually rises until it reaches the upper pipe. When the water level reaches the inlet, some of the wastewater and the plastic on the surface re-enter the drum for further dehydration. Therefore, the separator not only separates plastics and impurities from the wastewater but also allows the separated plastics to return to the drum for dehydration, minimizing plastic waste. Simultaneously, when some water from the separator returns to the inlet, it flushes the inlet, washing away any plastic adhering to it into the drum, further reducing the overall material loss rate of the production line. Attached Figure Description

[0023] Figure 1 This is a schematic diagram of the overall structure of an embodiment of this application;

[0024] Figure 2 This is a schematic diagram of the overall structure of the dehydration device in the embodiments of this application;

[0025] Figure 3 This is a schematic diagram of the structure of the driving component in the embodiments of this application;

[0026] Figure 4 yes Figure 3 Enlarged structural diagram at point A;

[0027] Figure 5 This is a schematic diagram of the connection between the top shell and the bottom shell in an embodiment of this application;

[0028] Figure 6 This is a schematic diagram of the connection of the first semi-annular sealing sheet in an embodiment of this application;

[0029] Figure 7 This is a schematic diagram showing the position of the rotating shaft in an embodiment of this application;

[0030] Figure 8 This is a partial structural cross-sectional view of an embodiment of this application;

[0031] Figure 9 This is a schematic diagram of the internal structure of the drum in an embodiment of this application;

[0032] Figure 10 yes Figure 9 Enlarged structural diagram at point B;

[0033] Figure 11 yes Figure 9 Enlarged structural diagram at point C;

[0034] Figure 12 This is a schematic diagram of the structure of the rotating shaft in an embodiment of this application;

[0035] In the diagram, 1. Pre-treatment module; 11. Slitting machine; 12. Rotary washing screen; 2. Main treatment module; 21. Integrated crushing vehicle; 22. Friction washing machine; 23. Scrubbing machine; 24. Washing tank; 3. Dewatering device; 31. Machine body; 311. Feed inlet; 312. Solid discharge outlet; 313. Drainage pipe; 314. Pump set; 315. Mounting cavity; 3151. First sealing space; 3152. Second sealing space; 3153. Third sealing space; 316. Top shell; 317. Bottom shell; 318. First semi-annular sealing sheet; 319. Second semi-annular sealing sheet; 32. Rotary drum; 321. Water guide cavity; 322. Micropore; 323. Convex 324. Outlet; 325. Solid discharge port; 326. First sealing groove; 327. Second sealing groove; 33. Rotating shaft; 331. Spiral blade; 333. Soft block; 335. First pressure sensor; 336. Discharge port; 337. Feed channel; 338. Feed pipe; 339. Feed pump; 34. Drive mechanism; 341. Rotating shaft motor; 342. Rotating drum motor; 343. Differential; 35. Separation assembly; 351. Separation tank; 352. Drain pipe; 353. Return pipe; 354. Solenoid valve; 36. Detection assembly; 361. Support plate; 362. Second pressure sensor; 4. Conveyor belt device; 5. Moving hopper. Detailed Implementation

[0036] The following is in conjunction with the appendix Figure 1-12 This application will be described in further detail below.

[0037] A washing and drying line for recycling PE agricultural film, as described in the following example. Figure 1 It includes a pretreatment module, a main treatment module, and a dehydration device.

[0038] The pretreatment module in this embodiment includes a slitting machine and a rotary washing screen.

[0039] In this embodiment, the slitting machine is a twelve-grid hydraulic slitting machine with a power of 30KW, and the rotary washing screen has a power of 4KW. A conveyor belt device is installed between the slitting machine and the rotary washing screen. The slitting machine cuts the agricultural film into small segments, and then the conveyor belt device sends the small segments of agricultural film into the rotary washing screen. When the agricultural film enters the rotary washing screen, the rotary washing screen can separate qualified materials from unqualified materials and discharge them separately. The twelve-grid hydraulic slitting machine and the rotary washing screen are both existing technologies and will not be described in detail here.

[0040] The main processing module in this embodiment includes a comprehensive crushing vehicle, a mobile hopper, two friction washing machines, a scrubbing machine, and a cleaning water tank.

[0041] The integrated crusher in this embodiment is a large integrated crusher with a power of 200KW. It can further crush small segments of agricultural film. A conveyor belt device is installed between the integrated crusher and the mobile hopper. The conveyor belt device transports the crushed agricultural film to the mobile hopper, which serves as a temporary storage device for the crushed agricultural film. A conveyor belt is also installed at the bottom of the mobile hopper. A conveyor belt device is also installed between the mobile hopper and the friction washer. The conveyor belt at the bottom of the mobile hopper can transport the material in the hopper to the discharge port, and then transport it to one of the friction washer devices via the conveyor belt device. The function of the mobile hopper is to control the amount of material entering the friction washer per unit time. The friction washer in this embodiment is a high-power friction washer with a power of 30KW. The friction washer can remove mud, sand, oil, and paper adhering to the material. The washing process removes various impurities such as slurry and wastewater, and rapidly separates the wastewater generated in this stage from the raw materials. The washed material is then sent to a scrubbing machine (a square scrubbing machine with a power of 75KW in this embodiment), which further removes impurities adhering to the material surface. The material is simultaneously sprayed and scrubbed, rapidly separating the wastewater and raw materials generated in this stage. The raw material is then sent to another friction washing machine for further friction cleaning. This friction washing machine then sends the cleaned material to a rinsing tank (30KW in this embodiment) for rinsing. This rinsing tank removes mud, sand, and paper scraps from the plastic. The device has a sludge and impurity removal machine at the bottom and a floating material washing and pushing roller at the top, which pushes the cleaned plastic to a dewatering device for dehydration. The integrated crushing vehicle, mobile hopper, two friction washing machines, scrubbing machine, rinsing tank, and conveyor belt device in this embodiment are all existing technologies and will not be described in detail here.

[0042] Traditional processes often involve crushing large rolls of agricultural film into very small sizes at once, simultaneously breaking down hard impurities such as mud, sand, stones, and metal, which become mixed with the plastic film and are extremely difficult to separate later. This leads to rapid deterioration of the washing water quality, poor washing effect, and a high impurity content in the final recycled material. In contrast, the washing line in this embodiment first performs "coarse crushing," breaking large rolls of film into medium-sized sheets that are easier to process. This is followed by a "transfer washing" stage, where hydraulic tumbling and screening are used to separate most of the attached mud, sand, stones, and other heavy impurities before the material is further crushed. This significantly reduces the load on subsequent crushing equipment and cleaning systems, preventing excessive fragmentation of impurities and laying the foundation for obtaining high-purity recycled fragments. At the same time, traditional processes may rely on only one or two cleaning methods (such as only friction washing or only rinsing), which are not thorough in cleaning firmly attached organic stains, pesticide residues, etc. This cleaning line adopts a "rotation washing (pre-washing) + strong friction washing + rubbing washing + rinsing" method. This step-by-step cleaning process ensures that the recycled plastic sheets have extremely high cleanliness, which can meet the production requirements of high-end recycled products and greatly improve the quality of plastic granules produced in subsequent extrusion processes.

[0043] Reference Figure 2 Figure 3 The dehydration device in this embodiment includes a body, a drum, and a shaft (combined with...). Figure 5 and Figure 7 ).

[0044] A bottom shell is fixedly installed on the top of the machine body, and a top shell is detachably installed on top of the bottom shell. The top shell and the bottom shell form the mounting cavity of the drum. The drum is arranged horizontally in the mounting cavity, and both ends of the drum are rotatably mounted on the bottom shell. The rotating shaft is coaxially located inside the drum, forming a separation cavity between the drum and the rotating shaft. Spiral blades for pushing the material are provided on the outer wall of the rotating shaft. There is a certain distance between the spiral blades and the inner wall of the drum. The machine body is provided with a drive mechanism for driving the drum and the rotating shaft to rotate at different speeds. In this embodiment, the drive mechanism includes a main drive motor, a main drive pulley, an auxiliary motor, an auxiliary motor pulley, and a differential gear. In this embodiment, one end of the rotating shaft extends to the outside of the drum, and the other end of the rotating shaft is rotatably connected to the inner wall of the drum. A sealed bearing (not shown in the figure) is provided between the rotating shaft and the drum. A feed inlet is provided at the end of the rotating shaft extending to the outside of the drum. In this embodiment, the feed inlet is a feed funnel. One end of the rotating shaft is inserted into the feed inlet, and a feed channel is coaxially opened at the end of the rotating shaft located at the feed inlet (in conjunction with...). Figure 8 and Figure 9The rotating shaft is rotatably connected to a feed pipe at one end of the feed inlet. The feed pipe communicates with the feed channel and is equipped with a feed pump. The end of the feed pipe away from the rotating shaft is connected to the feed inlet, and the feed funnel is sealed to the outer peripheral wall of the feed pipe. A discharge port communicating with the feed channel is opened on the outer wall of the rotating shaft. In this embodiment, the feed channel is relatively short, and the discharge port is located inside the drum and relatively close to the end of the drum near the feed inlet. The main drive pulley is coaxially fixedly mounted on the outer peripheral wall of the rotating shaft and located outside the drum. The main drive motor is mounted on the machine body and located at the end of the rotating shaft near the feed inlet. A connection is established between the output shaft of the main drive motor and the main drive pulley. A belt is provided, and the rotation of the main drive motor drives the rotating shaft to rotate. The differential and auxiliary motor are both located at the other end of the rotating shaft. The differential is coaxially arranged with the rotating drum, and the output end of the differential is fixedly connected to the rotating drum coaxially. The auxiliary motor pulley is fixedly connected to the output shaft of the differential coaxially. A belt is provided between the output shaft of the auxiliary motor and the auxiliary motor pulley. The rotation of the auxiliary motor drives the differential to start, thereby driving the rotating drum to rotate. Through specific settings, the rotating drum and the rotating shaft rotate in the same direction, but the rotation speed of the rotating drum is different from that of the rotating shaft. The motor, main drive pulley, auxiliary motor, auxiliary motor pulley and differential in this embodiment are all existing technologies and will not be described in detail here.

[0045] Reference Figure 5 , Figure 6 and Figure 7 A solid discharge port is provided on the peripheral wall of the drum, which is relatively close to the auxiliary motor. A solid discharge port is provided on the machine body. In this embodiment, a first sealing groove is provided on the outer wall of the drum. A first semi-annular sealing plate is provided on the top shell and the bottom shell respectively. When the top shell and the bottom shell are fastened together, the first semi-annular sealing plates on the top shell and the bottom shell will be inserted into the first sealing groove of the drum, and the two semi-annular sealing plates will form a complete first annular sealing plate. At this time, the first annular sealing plate divides the mounting cavity into a first sealing space and a second sealing space. The second sealing space is relatively close to the feed port, and the solid discharge port is connected to the first sealing space. The solid discharge port is provided on the bottom shell and is connected to the first sealing space.

[0046] Reference Figure 8 and Figure 9In this embodiment, a water-guiding cavity is provided within the peripheral wall of the drum. A plurality of micropores communicating with the water-guiding cavity are evenly arrayed on the inner wall of the drum. In this embodiment, the diameter of the micropores is 1-2 mm, allowing water to pass through but preventing plastic from passing through. Two sets of second semi-annular sealing plates are also provided on the inner walls of the bottom and top shells in this embodiment. Each set contains two second semi-annular sealing plates, arranged horizontally. The two second semi-annular sealing plates in the two sets correspond one-to-one. Two second sealing grooves are provided on the outer wall of the drum, each corresponding one-to-one with one of the two second semi-annular sealing plates in one set. When the top and bottom shells are joined together, one of the second semi-annular sealing plates on the top shell and its corresponding second semi-annular sealing plate on the bottom shell form a second annular seal. The second semi-annular sealing sheet on the top shell and the corresponding second semi-annular sealing sheet on the bottom shell are combined to form a second annular sealing sheet, and each second semi-annular sealing sheet is inserted into a second sealing groove. Therefore, the two sets of second semi-annular sealing sheets, the top shell, the bottom shell, and the drum independently create a third sealing space within the second sealing space, and the third sealing space is located in the center of the mounting cavity. Several water outlets communicating with the water guiding cavity are located on the outer peripheral wall of the drum. These water outlets are evenly spaced around the axis of the drum and are all located within the third sealing space. A water outlet groove communicating with the third sealing space is provided on the bottom shell, and a drainage pipe communicating with it is provided at the bottom of the bottom shell. The end of the drainage pipe away from the water outlet groove is connected to a pump set. In this embodiment, the pump set can perform air filling, air extraction, and water pumping. It should be noted that all sealing sheets in this embodiment are made of fluororubber with extremely high wear resistance, high temperature resistance, and oil resistance.

[0047] When the material, after undergoing multiple cleaning processes, enters the feed inlet of the dewatering unit, the main drive motor, auxiliary motor, feed pump, and pump set are all running. The pump set is currently pumping water, so both the drum and the shaft are rotating in the same direction, with the drum rotating slightly faster than the shaft. Simultaneously, driven by the feed pump, the feed pipe draws the material from the feed inlet into the feed channel within the shaft. Because the shaft is rotating, the material in the feed channel is thrown into the separation chamber from the discharge port on the shaft due to centrifugal force. The material entering the separation chamber is subjected to strong centrifugal force due to the rotation of the drum, causing it to adhere tightly to the inner wall of the drum. Even then, the material remains compressed by the centrifugal force, squeezing out the water and achieving dehydration. The water squeezed out passes through micropores on the inner wall of the drum into the water guiding chamber. These micropores are relatively small, allowing only water to pass through, while the dehydrated material (plastic) cannot pass through them, thus separating the plastic from the water. Furthermore, the plastic on the inner wall of the drum is subjected to [further action] under the propulsion of the spiral blades on the rotating shaft. The axial thrust causes the plastic on the inner wall of the drum to move towards the first sealed space. When the plastic reaches the solid discharge port on the drum, it is thrown into the first sealed space due to centrifugal force. The plastic in the first sealed space has already undergone dehydration and is then discharged from the dehydration device through the fixed discharge port below the bottom shell under gravity. Simultaneously, water in the material on the inner wall of the drum enters the water guiding chamber due to pressure. At this time, the water is forced from the separation chamber into the water guiding chamber by centrifugal force. Since the pressure in the separation chamber is higher than that in the water guiding chamber, the water can only pass through the separation chamber when the pressure is higher than that in the water guiding chamber. The material enters the water guiding chamber from the separation chamber. Under the action of the pump, the water and air in the water guiding chamber are further extracted through the third sealed space and the drainage pipe. As a result, the pressure in the water guiding chamber is further reduced, and the pressure difference between the water guiding chamber and the separation chamber is further increased. Therefore, the plastic on the inner wall of the drum is subjected to centrifugal force and negative pressure generated by the pump. Under this dual force, the plastic will be further squeezed, and the water remaining inside the plastic will be more easily squeezed out, thereby greatly improving the dehydration rate of the plastic, that is, improving the dehydration effect of the dehydration device on the material.

[0048] Furthermore, in this embodiment, the distance between the discharge port on the rotating shaft (i.e., the position where the material enters the separation chamber) and the solid discharge port on the rotating drum (i.e., the position where the dehydrated material exits the separation chamber) is basically the axial length of the rotating drum. Therefore, in this embodiment, the distance that the material in the separation chamber moves axially is equal to the length of the rotating drum. In contrast, in the prior art, the discharge port on the rotating shaft is usually located in the middle of the separation chamber. Therefore, the distance that the material in the separation chamber moves axially is half the length of the rotating drum. Thus, under the same rotation speed and the same angle of the spiral blades, the material in the separation chamber in this embodiment undergoes a longer dehydration time. Therefore, the dehydration device in this embodiment has a better dehydration effect than the prior art.

[0049] In this embodiment, the spiral blade is provided with multiple soft blocks, preferably twelve soft blocks, which are evenly spaced on the spiral blade. The soft blocks in this embodiment are also made of fluororubber (combined with...). Figure 12 ).

[0050] When materials are dehydrated in the separation chamber, due to the gap between the spiral blades and the inner wall of the drum, a small amount of plastic may remain on the inner wall of the drum because it cannot be pushed axially by the spiral blades. This results in a reduction in the production of dehydrated plastic. Furthermore, this plastic may clog some micropores, leading to a decrease in the drainage rate. In this embodiment, the soft blocks on the spiral blades are in constant contact with the inner wall of the drum. These soft blocks can scrape off the plastic that cannot move axially on the inner wall of the drum. Additionally, in this embodiment, all twelve soft blocks are positioned on the spiral blades, which are angled to allow for axial pushing of the material. The twelve soft blocks arranged on the spiral blades are also at a certain angle to the axis of rotation. Therefore, when the soft blocks scrape off the plastic on the inner wall of the drum, they can also push the plastic adhering to the inner wall of the drum axially, so that the plastic adhering to the drum can also move to the fixed discharge port on the drum, thus ensuring the normal output of dewatered material. At the same time, during the axial scraping process, the soft blocks also try to avoid the plastic clogging the micropores, thus ensuring the drainage efficiency of the dewatering device as much as possible, and keeping the micropores unobstructed. This helps to maintain the maximum pressure difference between the separation chamber and the water guiding chamber, so that the plastic in the separation chamber is always under relative maximum pressure, thus ensuring the dewatering effect of this dewatering device as much as possible.

[0051] It should be noted that the soft block in this embodiment is made of fluororubber. The friction between the soft block and the inner wall of the drum is not rigid, and the separation chamber is primarily filled with water. Therefore, the friction between the soft block and the inner wall of the drum has virtually no impact on the drum. Furthermore, due to the elasticity of the soft block, it can maintain constant contact with the inner wall of the drum to facilitate the scraping of plastic, while also minimizing excessive radial contact force between the soft block and the drum, thus preventing radial deformation of the drum and shaft. Therefore, it also provides overall protection for the drum and shaft, reducing... This reduces the probability of equipment damage. In addition, in this embodiment, the twelve soft blocks are continuously arranged on the horizontal plane and spaced apart on the vertical plane. This arrangement ensures that the total area swept by each of the twelve soft blocks on the inner wall of the drum is equal to the total area of ​​the inner wall of the drum's curved surface. In other words, the twelve soft blocks can scrape every part of the inner wall of the drum's curved surface. At the same time, the spaced arrangement of the twelve soft blocks on the vertical plane also allows the torque generated on the rotating shaft to counteract each other when the shaft rotates, that is, the rotating shaft can maintain a dynamic balance, thereby reducing the probability of shaft damage.

[0052] It should be further noted that after the dewatering device completes the dewatering of all materials, some plastic inevitably remains on the inner wall of the drum and the outer wall of the shaft. If this residual plastic is not cleaned, it will accumulate over time and become difficult to remove, severely disrupting the dynamic balance of the drum and shaft during operation and easily leading to damage. Therefore, in existing technologies, the drum and shaft are periodically disassembled to clean the residual plastic before being reinstalled. However, in this embodiment, the soft block begins to dewater the drum and shaft during operation. The plastic adhering to the inner wall of the drum is scraped and cleaned, and this adhering plastic is also cleaned to the solid discharge port on the drum so that the dehydrated plastic can be discharged smoothly. Therefore, the soft block in this embodiment has achieved the function of cleaning while working, and after the dehydration device completes the dehydration work, it can continue to operate to facilitate the soft block to clean the inner wall of the drum. More importantly, the pump set in this embodiment can also be inflated. Therefore, when the dehydration work is completed, the pump set can be used to inflate the drain pipe. The gas will pass through the drain pipe, the third sealing space, the water guide cavity, the micropores and... In the separation chamber, during the operation of the dehydration device, some plastic may enter the micropores and clog them. This plastic inside the micropores is difficult to remove by the soft block. When gas flows from the water guide chamber to the separation chamber, the gas can blow the plastic clogged in the micropores back into the separation chamber. Since the dehydration device is still running, this small amount of plastic will undergo another dehydration step. After dehydration, it is pushed by the soft block to the solid discharge port on the inner wall of the drum. Simultaneously, in this embodiment, all micropores are directly opposite the rotating shaft, so the gas exiting the micropores will directly spray onto the outer wall of the rotating shaft, thus... Some plastic from the dead corners of the spiral blades is blown off. Then, under the centrifugal force applied by the drum, this plastic will undergo dehydration again and be axially pushed by the soft blocks, and finally be discharged from the solid discharge port of the drum outside the dehydration device. In summary, the soft blocks and pump set are designed to remove residual plastic from the inner wall of the drum, the outer wall of the shaft and the spiral blades, and finally discharge it outside the dehydration device. It achieves the self-cleaning function of the device as a whole. Therefore, the staff does not need to perform relatively high-frequency disassembly and installation work for cleaning the equipment, which greatly reduces the workload of the staff.

[0053] Reference Figure 9 , Figure 10 and Figure 11 In order to further enhance the dehydration effect of this device, multiple protrusions are evenly arrayed on the inner wall of the drum in this embodiment. In this embodiment, the protrusions are set as quarter-spheres, and several protrusions correspond one-to-one with several micropores. The micropores are located on the protrusions, and there is a gap between the spiral blades and the protrusions.

[0054] The raised design makes the inner wall of the drum uneven. Since the soft block is made of fluororubber, it has a certain degree of elasticity and can deform to perfectly fit the uneven surface. Therefore, when the plastic is in the concave area of ​​the inner wall of the drum, the soft block will apply an axial component force to the plastic in the concave area. As the plastic is in the concave area, it will come into contact with the inclined surface of the raised part when it moves in the axial direction. This inclined surface will apply an axial reaction force to the plastic. Therefore, the soft block and the raised part will squeeze the plastic together. Thus, the plastic in the separation chamber will be subjected to the centrifugal force of the drum, the negative pressure of the pump, and the squeezing force of the soft block. The application of these three forces can further squeeze out the water in the plastic, thereby further improving the dehydration effect of the dewatering device on the plastic. The total external force on the plastic is still along the part closer to the discharge port. Therefore, the material will undergo repeated squeezing from the discharge port on the rotating shaft to the solid discharge port on the drum, which greatly improves the dehydration effect of the dewatering device on the plastic.

[0055] In addition, each soft block in this embodiment is embedded with a first pressure sensor (not shown in the figure). The dehydration device also includes a control unit, which is electrically connected to the first pressure sensor, the main drive motor, the auxiliary motor and the pump group. The first pressure sensor in this embodiment can be a wireless sensor module such as a WIFI signal sensor or a Bluetooth signal sensor.

[0056] As initially set, the distance between the spiral blades on the rotating shaft and the inner wall of the drum is usually constant. Therefore, the pressure of the inner wall of the drum on each soft block is basically equal, and the values ​​displayed by each first pressure sensor are also basically equal. However, due to the protrusion and the vibration generated by the drum and rotating shaft during operation, the soft blocks will contract to a certain extent. Therefore, the values ​​of the first pressure sensors will also change within a certain range. A range value can be preset in the control unit. When the value displayed by the first pressure sensor is within this range, it means that the drum and rotating shaft are in normal condition. When the value of one of the first pressure sensors exceeds this range, it means that the drum or rotating shaft has undergone serious deformation. At this time, the drum and rotating shaft will experience dynamic imbalance during rotation, which may easily lead to breakage of the drum or rotating shaft. Therefore, when the value of one of the first pressure sensors is abnormal, the control unit will immediately stop the machine and trigger the alarm system so that the technicians can carry out maintenance work.

[0057] Secondly, refer to Figure 3 and Figure 4 The dehydration device in this embodiment also includes a separation component, which includes a separation tank.

[0058] The separator is installed on the machine body. A drain pipe connected to the outlet of the pump unit is connected to the side wall of the separator. The drain pipe on the side wall of the separator is close to the bottom of the separator. A return pipe connected to the feed inlet is connected to the top of the separator.

[0059] The drain pipe and pump set guide the discharged wastewater into the separator tank from a position relatively close to the bottom. The less dense plastics float on the surface, while the denser sand and metals settle to the bottom. As more wastewater enters the separator tank, the water level gradually rises to the return pipe at the top. When the water level reaches the connection between the return pipe and the feed inlet, some of the wastewater and the plastic on the surface re-enter the drum for dehydration. Therefore, the separator tank not only separates plastics and impurities from the wastewater but also allows the separated plastics to return to the drum for further dehydration, minimizing plastic waste. Simultaneously, when some water from the separator tank returns to the feed inlet, it flushes the inlet, washing away any plastic adhering to it into the drum, further reducing the overall material loss rate of the production line.

[0060] Furthermore, the separator is equipped with a detection component for detecting sediment content. The detection component includes a support plate and a second pressure sensor. The support plate is installed on the inner wall of the separator and is a certain distance away from the bottom of the separator. The height of the separation plate is lower than the connection between the drain pipe and the separator. The second pressure sensor is the same as the first pressure sensor and is installed on the support plate near the bottom of the separator. A solenoid valve is also installed at the bottom of the separator. Both the solenoid valve and the second pressure sensor are electrically connected to the control unit.

[0061] As impurities accumulate in the separator, their height increases. When a certain amount of impurities accumulate at the bottom of the separator, they touch and press against the second pressure sensor. When the value detected by the second pressure sensor exceeds the preset value in the control unit, the control unit opens the solenoid valve to facilitate the discharge of impurities and some wastewater from the separator. The discharge of wastewater causes the liquid level in the separator to drop, which in turn lowers the water pressure at the bottom of the separator. Therefore, when the value detected by the second pressure sensor drops to a certain value, the control unit closes the solenoid valve to continue the above-mentioned repetitive operation.

[0062] Finally, the pump set in this embodiment mainly consists of a pneumatic double diaphragm pump and an air pump. The pneumatic double diaphragm pump can perform liquid pumping, and since it can also run dry, it can also pump air. The pneumatic double diaphragm pump is connected to the water inlet pipe, allowing it to extract liquid and gas from the water guide chamber. The air pump is a common air pump. The main working principle of the pump set is to install a three-way solenoid valve between the drain pipe, the pneumatic double diaphragm pump, and the air pump. The three-way solenoid valve is also electrically connected to the control unit. When the dehydration device is performing dehydration, the control unit controls the valve between the pneumatic double diaphragm pump and the drain pipe to open, and controls the valve between the air pump and the drain pipe to close. When the dehydration device is performing self-cleaning, the control unit controls the valve between the pneumatic double diaphragm pump and the drain pipe to close, and controls the valve between the air pump and the drain pipe to open.

[0063] The working principle of a washing and drying line for PE agricultural film recycling in this embodiment is as follows: the workers put the recycled agricultural film into a twelve-grid hydraulic slitting machine for coarse crushing, and then the coarsely crushed material is sent to a rotary washing screen by a conveyor belt device. The material processed by the rotary washing screen is then sent to a large integrated crushing vehicle for fine crushing. The finely crushed material is then sent to a mobile hopper by a conveyor belt device. The material in the mobile hopper is then sent to a friction washer by a conveyor belt device. The material washed by the friction washer is then sent to a scrubbing machine. After scrubbing, the material is sent to another friction washer for washing. The material washed by the second friction washer is sent to a washing tank for rinsing. After rinsing, the material is sent to a dewatering device for dewatering.

[0064] The material first enters the inlet, where the feed pump draws it into the feed channel within the rotating shaft. As the shaft rotates, the material in the feed channel is thrown into the separation chamber from the discharge port due to centrifugal force. Inside the separation chamber, the rotating drum experiences strong centrifugal force, causing the material to adhere tightly to the inner wall of the drum. Simultaneously, the material is further compressed by the centrifugal force of the drum and the negative pressure generated by the pump, thus squeezing out moisture. Furthermore, the spiral blades and soft blocks cause the material to move axially within the drum. The raised sections on the inner wall of the drum further contribute to this effect. The soft blocks exert axial compressive force on the plastic, thus the material on the inner wall of the drum is subjected to centrifugal force, negative pressure, and the compressive force of the soft blocks, which greatly improves the dehydration rate of the plastic. The water extracted from the plastic enters the water guiding chamber through micropores under the action of the pump and centrifugal force. Then the water flows through the water guiding chamber, the third closed space, the drainage channel, and the water inlet pipe into the separation tank. The separation tank separates the plastic from the impurities and sends the plastic back to the feed port on the machine body. The dehydrated plastic moves from the discharge port on the rotating shaft to the solid discharge port on the rotating drum under the axial push of the spiral blades and soft blocks, and is finally discharged from the dehydration device, thus completing the dehydration of the material.

[0065] After the dehydration process is complete, the control unit continues to control the drum, shaft, and pump assembly, and controls the pump assembly to blow air. The air passes sequentially through the drain pipe, the third sealing space, the water guide chamber, the micropores, and the separation chamber. During the operation of the dehydration device, some plastic may have entered the micropores and blocked them. This plastic inside the micropores is difficult to remove with soft materials. When the air flows from the water guide chamber to the separation chamber, it can blow the plastic blocked in the micropores back into the separation chamber. At this point, the dehydration device is still in operation. Therefore, this small portion of plastic will undergo another dehydration step, and after dehydration, it will be pushed by the soft block to the solid discharge port on the inner wall of the drum. At the same time, all the micropores in this embodiment are directly facing the rotating shaft, so the gas coming out of the micropores will be sprayed directly onto the outer wall of the rotating shaft, thus blowing off some plastic in the dead corner of the rotating shaft and the spiral blades. Then, under the centrifugal force applied by the drum, this plastic blown off the rotating shaft and the spiral blades will also undergo dehydration again and be axially pushed by the soft block, and finally be discharged from the solid discharge port of the drum outside the dehydration device.

[0066] The embodiments described in this specific implementation are preferred embodiments of this application and are not intended to limit the scope of protection of this application. Identical components are represented by the same reference numerals. Therefore, all equivalent changes made to the structure, shape, and principle of this application should be covered within the scope of protection of this application.

Claims

1. A washing and drying line for recycling PE agricultural film, characterized in that, include: The pretreatment module is used to coarsely crush and coarsely wash the agricultural film; The main processing module is used to finely crush and clean the pre-treated agricultural film; A dewatering device includes a body on which a drum and a shaft are rotatably mounted. The shaft is coaxially arranged inside the drum and has spiral blades for propelling the material. The body is equipped with a drive mechanism for differentially rotating the drum and shaft. A separation chamber is formed between the drum and the shaft. The body has a feed inlet and a solid discharge outlet communicating with the separation chamber. A water guiding chamber is provided inside the drum, and several micropores communicating with the water guiding chamber are provided on the inner wall of the drum. A drain pipe communicating with the water guiding chamber is provided on the body. A pump set is provided on the side of the drain pipe away from the water guiding chamber, and the pump set is capable of inflating, deflating, and pumping water. The spiral blades are provided with multiple soft blocks, and the soft blocks abut against the inner wall of the drum. Each of the soft blocks is embedded with a first pressure sensor. The dehydration device also includes a control unit, which is electrically connected to the first pressure sensor, the drive mechanism, and the pump group.

2. The washing and drying line for recycling PE agricultural film according to claim 1, characterized in that, The inner wall of the drum is provided with a number of protrusions, and each of the protrusions corresponds to a number of micropores. The micropores are provided on the protrusions.

3. The washing and drying line for recycling PE agricultural film according to claim 1, characterized in that, The feed inlet is located at one end of the drum, and the discharge outlet is located at the other end of the drum.

4. A washing and drying line for recycling PE agricultural film according to claim 1, characterized in that, The dehydration device also includes a separation component, which includes a separation tank mounted on the machine body. The side wall of the separation tank is connected to a drain pipe that is connected to the outlet of the pump unit, and the drain pipe on the side wall of the separation tank is close to the bottom of the separation tank. The upper end of the separation tank is connected to a return pipe that is connected to the feed inlet.

5. A washing and drying line for recycling PE agricultural film according to claim 4, characterized in that, The separation tank is also equipped with a detection component for detecting sediment content, and a solenoid valve is installed at the bottom of the separation tank. Both the solenoid valve and the detection component are electrically connected to the control unit.

6. A washing and drying line for recycling PE agricultural film according to claim 5, characterized in that, The detection assembly includes a support plate and a second pressure sensor. The support plate is installed on the inner wall of the separation tank and is a certain distance away from the bottom of the separation tank. The second pressure sensor is installed on the end of the support plate near the bottom of the separation tank.

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