A waste plastic powder grinding machine for asphalt modifier production and a processing method thereof

Abstract

The application provides a waste plastic powder grinding machine for asphalt modifier production and a processing method. The machine comprises feeding device, freezing device and powder grinding device which are connected with each other. The feeding device comprises a hopper which is provided with an opening at the top. A spraying assembly is arranged on the opening at the top of the hopper. A cutting assembly is arranged in the hopper and located below the spraying assembly. The freezing device comprises a freezing tank and a liquid nitrogen conveying assembly. The freezing tank is connected with the hopper. The output end of the liquid nitrogen conveying assembly is connected with the freezing tank. The powder grinding device comprises a powder grinding tank and a circulating air cooling assembly. The powder grinding tank is connected with the freezing tank which is away from the hopper. The output end of the circulating air cooling assembly is arranged on the top of the powder grinding tank. An air return device is arranged on the bottom wall in the powder grinding tank. The air return device is connected with the input end of the circulating air cooling assembly. The application can improve the powder grinding effect of waste plastics and the production quality of asphalt modifier.

Description

Technical Field

[0001] This invention relates to the field of solid waste treatment technology, and more specifically, to a waste plastic grinding mill and processing method for the production of asphalt modifiers. Background Technology

[0002] The content in this section only provides background information related to this invention and may not constitute prior art.

[0003] Asphalt modifiers are substances added to base road asphalt to significantly improve its physical, chemical, and road performance properties. Base asphalt has shortcomings in extreme temperatures, fatigue resistance, and durability. Modifiers can enhance various properties of asphalt through physical mixing or chemical reactions. Common types of modifiers include polymers, rubbers, plastics, and others such as sulfur, rock asphalt, and natural asphalt.

[0004] Using waste plastics to make asphalt modifiers has several benefits, including effectively solving white pollution, realizing the resource utilization of waste, reducing landfill and incineration, reducing the raw material cost of asphalt modifiers, extending road life, and effectively improving the performance of asphalt pavements.

[0005] In the actual production process of asphalt modifiers, waste plastic powder is usually ground into fine particles, typically at the millimeter or even micrometer level. This increases the specific surface area, promotes melting and dispersion, and ensures uniform dispersion during mixing with asphalt, preventing clumping. It also optimizes the coating and adhesion with aggregates, thereby improving the final pavement performance.

[0006] However, the grinding process of waste plastics generates a lot of heat. Since plastics have a low melting point, the large amount of heat generated during grinding can easily cause the plastics to melt, which in turn reduces the grinding effect and makes it impossible to grind them into suitable plastic powder. This leads to a decrease in the quality of asphalt modifiers and ultimately affects the pavement performance of asphalt pavements. Summary of the Invention

[0007] In order to solve the above-mentioned technical problems, the purpose of this invention is to provide a waste plastic grinding mill and processing method for the production of asphalt modifiers, which can improve the grinding effect of waste plastics and improve the production quality of asphalt modifiers.

[0008] On the one hand, the present invention provides a waste plastic grinding mill for the production of asphalt modifiers.

[0009] The objective of this invention is achieved through the following technical solution:

[0010] A waste plastic grinding mill for asphalt modifier production includes a feeding device, a freezing device, and a grinding device that are interconnected. The feeding device includes a hopper with an opening at the top. A spraying assembly is installed at the top opening of the hopper, and a cutting assembly is installed inside the hopper, located below the spraying assembly. The freezing device includes a freezing chamber and a liquid nitrogen conveying assembly. The freezing chamber is connected to the hopper, and the output end of the liquid nitrogen conveying assembly is connected to the freezing chamber. The grinding device includes a grinding chamber and a circulating air-cooling assembly. The grinding chamber is connected to the end of the freezing chamber away from the hopper. The output end of the circulating air-cooling assembly is located at the top of the grinding chamber, and a return air device is installed on the bottom wall of the grinding chamber, connected to the input end of the circulating air-cooling assembly.

[0011] By adopting the above technical solution, in actual use, when it is necessary to grind waste plastics, the waste plastics are first put into the hopper, and the spraying component is activated to spray the plastics to achieve the effect of wetting the surface of the waste plastics and removing static electricity. Then, the waste plastics are cut by the cutting component, and the cut plastic blocks enter the freezing box through the bottom of the hopper. Liquid nitrogen is transported into the freezing box by the liquid nitrogen conveying component to freeze the plastic blocks in the freezing box. The frozen plastic blocks enter the grinding box for grinding. During the grinding process, the grinding mill is circulated and cooled by the circulating air cooling component to achieve the effect of cooling. After grinding is completed, the grinding mill can be opened to take out the ground plastic powder. Freezing the plastic with liquid nitrogen can, on the one hand, change the plastic fragments from a tough state to a brittle state, which is convenient for subsequent grinding. On the other hand, pre-cooling the plastic fragments can effectively reduce the temperature in the grinding box, thereby further reducing the heat melting during the plastic grinding process, thus effectively improving the grinding effect, thereby improving the production quality of asphalt modifiers, and thus improving the pavement performance of asphalt pavement to a certain extent.

[0012] In some possible embodiments, the cutting assembly includes a cutting roller and an abutment portion, the abutment portion being fixedly disposed inside the hopper, and two cutting rollers being disposed on opposite sides of the abutment portion. The two cutting rollers are provided with helical cutting blades rotating in opposite directions, and abutment grooves adapted to the cutting blades are provided on both sides of the abutment portion. A driving assembly is provided on the hopper, the driving assembly being used to drive the two cutting rollers to move in a direction that approaches or moves away from each other, and a driving source is provided on the hopper for driving the cutting rollers to rotate.

[0013] By adopting the above technical solution, when cutting waste plastics, the drive source drives the cutting roller to rotate. As the cutting roller rotates, it drives the cutting blade to rotate. The waste plastics can be cut by the mutually adapted cutting blade and the abutting groove. In actual use, depending on the type and size of the waste plastics, the drive component drives the two cutting rollers to move, thereby adjusting the distance between the cutting blade and the abutting groove. This makes it suitable for waste plastics of different types and sizes, effectively improving the applicability of the device.

[0014] In some possible embodiments, the drive assembly includes a first lead screw and a first motor. A first groove is provided on the hopper, the first lead screw is rotatably disposed in the first groove, the first motor is disposed on the hopper, the output shaft of the first motor is drivenly connected to the first lead screw, and two first sliders are slidably disposed in the first groove. The two first sliders are connected to two cutting rollers in a one-to-one correspondence, and the first sliders are threaded onto both ends of the first lead screw.

[0015] By adopting the above technical solution, when it is necessary to move the cutting rollers, the first motor is started to drive the first lead screw to rotate. As the first lead screw rotates, it drives the first slider to move in the first slide groove, thereby driving the two cutting rollers to move. This achieves the purpose of adjusting the distance between the cutting blade and the abutting groove. In the above transmission process, the transmission is carried out through the interlocking threads between the first lead screw and the first slider. The transmission is more stable and reliable, and the thread transmission accuracy is higher. At the same time, the thread transmission has a certain self-locking effect, which can effectively prevent the cutting rollers from slipping when cutting waste plastic, thus improving the overall reliability of the device in actual use.

[0016] In some possible embodiments, two strip-shaped holes are opened horizontally on the inner wall of the hopper, and strip-shaped blocks are slidably disposed in the strip-shaped holes. The cutting roller is rotatably disposed on the strip-shaped blocks. The top of the first groove is connected to the bottom of the strip-shaped hole. The strip-shaped blocks are connected to the first slider in a one-to-one correspondence. A baffle is fixedly disposed on the inner wall of the hopper. The baffle is disposed at the opening of the strip-shaped hole. The baffle slides in contact with the side wall of the strip-shaped block near the cutting roller.

[0017] By adopting the above technical solution, when adjusting the distance between the cutting blade and the abutting groove, as the first slider moves within the first groove, the corresponding strip block moves within the strip hole. During the movement of the strip block, the baffle slides into contact with the side wall of the strip block, which can block the gap between the strip block and the hopper. When cutting hard plastics such as plastic sheets, some plastic chips are inevitably generated. By blocking the plastic chips with the baffle, it is possible to effectively prevent the plastic chips from falling into the first groove through the strip hole. This provides good protection for the transmission components such as the first lead screw and the first slider within the first groove, reducing the maintenance cost of the device in later use.

[0018] In some possible embodiments, a drive shaft is rotatably mounted on each strip block, one end of which is fixedly connected to the cutting roller, and the other end extends out of the hopper. A driven wheel is coaxially fixed at the end of each drive shaft away from the cutting roller. An mounting block is slidably mounted on the outer wall of the hopper in a vertical direction. The mounting block is located in the middle of two strip blocks. An mounting shaft is rotatably mounted on the mounting block. A first drive wheel and a second drive wheel are sequentially mounted on the mounting shaft along its axial direction. A drive belt is wound around both the first and second drive wheels. The other end of the drive belt on the first drive wheel is wound around the driven wheel on the left, and the other end of the drive belt on the second drive wheel is wound around the driven wheel on the right. The drive source is used to drive the first and second drive wheels to rotate in opposite directions. A lifting assembly is provided on the hopper, which is used to move the mounting block on the hopper.

[0019] By adopting the above technical solution, when cutting waste plastic, the first and second drive wheels are driven to rotate by a drive source, which in turn drives the driven wheel to rotate via the corresponding drive belt. As the driven wheel rotates, it drives the drive shaft to rotate, thereby driving the corresponding cutting roller to rotate, thus achieving the cutting of waste plastic. When adjusting the horizontal position of the cutting roller, the first motor drives the first lead screw to rotate, and at the same time, the horizontal assembly drives the mounting block to move accordingly on the hopper. When the two cutting rollers are close to each other, the mounting block moves downward on the hopper; when the two cutting rollers are far apart, the mounting block moves upward on the hopper. This ensures that the drive belt is always taut, thus guaranteeing the drive of the driven wheel. By setting up a single drive source, the two cutting rollers can be driven to rotate synchronously, ensuring that the rotation speed of the two cutting rollers and the distance between them and the contact part are the same, ensuring that the cutting effect of the plastic fed into the hopper is the same, and to a certain extent, ensuring the quality and effect of subsequent grinding.

[0020] In some possible embodiments, receiving grooves are provided on the inner walls of both sides of the hopper along the axial direction of the cutting roller, and a collection box is slidably arranged in the receiving groove along the length direction of the receiving groove. An abutment plate is fixedly arranged on the collection box, and the end of the abutment plate away from the collection box is used to abut against the cutting roller. The collection box is detachably connected to the hopper.

[0021] By adopting the above technical solution, after the waste plastic is cut, the drive assembly drives two cutting rollers to move towards the receiving groove, so that the abutment plate abuts against the cutting rollers. At this time, the drive source is activated to drive the cutting rollers to rotate. The abutment plate slides in the receiving groove under the action of the spiral cutting blades on the surface of the cutting rollers. During the above process, as the abutment plate moves, the nylon braided tape, plastic oil film and other materials wrapped around the cutting rollers can be removed. The scraped nylon braided tape and plastic oil film fall into the collection box below the abutment plate. After cleaning, the collection box can be removed from the hopper to recycle and sort the waste plastic in the collection box, thereby ensuring the cutting effect of the cutting rollers in the next operation of the device.

[0022] In some possible embodiments, a buffer groove is provided at the top of the first slider along the length of the first slide groove, and a buffer block is slidably disposed in the buffer groove. The top of the buffer block is fixedly connected to the bottom of the strip block. An elastic element is disposed in the buffer groove, and the elastic element acts on the strip block to drive the strip block to move in a direction away from each other.

[0023] By adopting the above technical solution, during the process of moving the cutting roller toward the receiving groove, the first slider moves in the first groove, thereby moving the strip block, which in turn moves the cutting roller. After the cutting roller comes into contact with the abutment plate, the first slider continues to move in the first groove. At this time, the strip block cannot move because the cutting roller comes into contact with the abutment plate, thereby moving the buffer block in the buffer groove and squeezing the elastic element, so that the elastic element is compressed and stores elastic potential energy, and finally makes the cutting roller and the abutment plate come into close contact. At this time, as the cutting roller rotates, the waste plastic wrapped on the cutting roller can be effectively scraped and cleaned.

[0024] In some possible embodiments, a downwardly inclined feeding pipe is provided at the bottom of the hopper, and the other end of the feeding pipe is connected to the freezing chamber. The liquid nitrogen conveying assembly includes a liquid nitrogen source and a conveying pipe. The conveying pipe includes a top branch pipe and a bottom branch pipe. One end of the top branch pipe is connected to the liquid nitrogen source and the other end is connected to the top of the freezing chamber. One end of the bottom branch pipe is connected to the liquid nitrogen source and the other end is connected to the bottom of the freezing chamber.

[0025] By adopting the above technical solution, the cut plastic fragments leave the hopper through the feeding pipe and enter the freezing chamber. At this time, the liquid nitrogen source is turned on, and the liquid nitrogen for freezing is introduced into the freezing chamber from the top through the top pipe and enters the freezing chamber from the bottom through the bottom branch pipe. Inside the freezing chamber, a liquid nitrogen freezing airflow is formed that flows vertically, which can quickly freeze the plastic fragments in the freezing chamber and improve the freezing efficiency.

[0026] In some possible embodiments, a discharge hole is provided at the bottom of the freezing chamber, and a discharge plate for closing the discharge hole is slidably arranged inside the freezing chamber. The discharge hole is connected to a discharge pipe, and the other end of the discharge pipe is connected to the grinding chamber. The circulating air-cooled assembly includes a cyclone separator, a filter dust collector, and a cooler. A first return air pipe is connected between the return air unit and the cyclone separator, a second return air pipe is connected between the cyclone separator and the filter dust collector, a third return air pipe is connected between the filter dust collector and the cooler, and a fourth return air pipe is connected between the cooler and the top of the grinding chamber.

[0027] By adopting the above technical solution, after freezing the plastic fragments, the feeding plate is opened, and the plastic fragments enter the grinding chamber through the feeding pipe. At the same time as starting the grinding chamber, the circulating air-cooling component is turned on. While grinding the plastic fragments, a circulating air-cooled airflow channel is formed in the grinding chamber. The airflow enters the first return air duct through the return air device, and then enters the cyclone separator. The cyclone separator separates the intake airflow, separating the plastic powder that meets the grinding standard and unifying the non-standard plastic powder. The airflow then enters the filter dust collector through the second return air duct to filter out the dust in the airflow. Then, it enters the cooler through the third return air duct to cool the airflow. The cooled airflow flows back into the grinding chamber through the fourth return air duct to circulate and cool the grinding chamber.

[0028] On the other hand, the present invention provides a method for processing waste plastic powder using a grinding mill for the production of asphalt modifiers.

[0029] A method for processing waste plastics for asphalt modification and production using a grinding mill, comprising the following steps:

[0030] Waste plastic is fed into the hopper through the top of the hopper. The spray system is activated to spray a mixture of glycerin and liquid water onto the waste plastic. The drive source is activated to rotate the cutting roller, which initially cuts the waste plastic into plastic fragments. The plastic fragments pass through the hopper and feed pipe into the freezing chamber. The liquid nitrogen source is turned on, and liquid nitrogen is conveyed through the delivery pipe to create a low-temperature environment of less than -40°C in the freezing chamber, which quickly embrittles the plastic fragments, changing them from a tough state to a brittle state. The discharge plate is opened, and the embrittled plastic fragments pass through the discharge pipe into the grinding chamber. The grinding chamber is started to grind the plastic fragments. The circulating air-cooling system is turned on to cool the grinding chamber. The grinding chamber operates for 30-40 seconds, grinding the plastic fragments into particles with a diameter of less than 1 mm. The grinding chamber is then opened to remove the plastic particles.

[0031] In summary, the technical solutions of the embodiments of the present invention have at least the following advantages and beneficial effects:

[0032] 1. By spraying a mixture of glycerin and water, the static electricity on the plastic surface is effectively reduced and the material is initially softened. Combined with a bidirectional spiral cutting blade and an adjustable spacing design, it can adapt to waste plastics of different hardness and size. The baffle structure prevents plastic chips generated during cutting from falling into the transmission mechanism, ensuring long-term stable operation of the system and creating a uniform material basis for subsequent cryogenic embrittlement.

[0033] 2. Liquid nitrogen is injected bidirectionally into the freezing chamber through top and bottom branch pipes, forming a convective low-temperature airflow that rapidly and uniformly embrittles the plastic fragments. This brittle-to-brittle transition significantly reduces grinding energy consumption and avoids thermal adhesion.

[0034] 3. The circulating air-cooled assembly uses a cyclone separator to sort qualified particles, a filter dust collector to remove dust, and a cooler to recover and cool the airflow. This effectively suppresses the temperature rise during the grinding process, effectively reduces the plastic melting phenomenon during plastic grinding, and improves the uniformity and purity of plastic powder.

[0035] 4. When cleaning the cutting roller, the elastic element makes the cutting roller and the abutment plate fit tightly together. At this time, as the cutting roller rotates, the waste plastic wrapped on the cutting roller can be effectively scraped and cleaned. Attached Figure Description

[0036] Figure 1 This is a schematic diagram of the overall structure of an embodiment of the present invention;

[0037] Figure 2 This is a schematic diagram of the internal structure of the hopper according to an embodiment of the present invention;

[0038] Figure 3 This is a schematic diagram of the cutting assembly according to an embodiment of the present invention;

[0039] Figure 4 This is a schematic diagram of the structure of the driving component according to an embodiment of the present invention;

[0040] Figure 5 This is a schematic diagram of the structure of the driving source according to an embodiment of the present invention;

[0041] Figure 6 This is a schematic diagram of the lifting assembly according to an embodiment of the present invention;

[0042] Figure 7 This is a schematic diagram of the structure of the receiving groove according to an embodiment of the present invention;

[0043] Figure 8 for Figure 7 Enlarged view of part A in the image;

[0044] Figure 9 This is a schematic diagram of the structure of the acquisition box and the contact plate according to an embodiment of the present invention.

[0045] Figure 10 This is a schematic diagram of the structure of the buffer groove according to an embodiment of the present invention;

[0046] Figure 11 This is a schematic diagram of the structure of the refrigeration device according to an embodiment of the present invention;

[0047] Figure 12 This is a schematic diagram of the grinding device according to an embodiment of the present invention.

[0048] Icons: 1. Feeding device; 11. Hopper; 12. Drive source; 13. Mounting cover; 14. Guide block; 15. Perforation; 16. Sealing plate; 17. Bolt; 18. Feeding pipe; 101. Receiving tank; 102. Collection box; 103. Abutment plate; 104. Top plate; 105. Bottom plate; 106. T-slot; 107. T-block; 108. Magnetic insert; 109. Slot; 2. Refrigeration device; 21. Freezing box; 22. Liquid nitrogen conveying assembly; 221. Liquid nitrogen source; 222. Conveying pipe; 223. Top branch pipe; 224. Bottom branch pipe; 23. Drop hole; 24. Drop plate; 25. Drop pipe; 3. Grinding device; 31. Grinding box; 32. Circulating air-cooled assembly; 321. Cyclone separator; 322. Filter dust collector; 323. Cooler; 3 24. First return air duct; 325. Second return air duct; 326. Third return air duct; 327. Fourth return air duct; 33. Return air unit; 4. Spray assembly; 41. Spray pipe; 42. Nozzle; 5. Cutting assembly; 51. Cutting roller; 52. Abutment part; 53. Cutting blade; 54. Abutment blade groove; 6. Drive assembly; 61. First lead screw; 62. First motor; 63. First slide groove; 64. First slider; 7. Strip hole; 71. Strip block; 72. Baffle; 73. Drive shaft; 74. Driven wheel; 75. Mounting block; 76. Mounting shaft; 77. First drive wheel; 78. Second drive wheel; 79. Drive belt; 8. Lifting assembly; 81. Second lead screw; 82. Second motor; 83. Second slide groove; 9. Buffer groove; 91. Buffer block; 92. Elastic element. Detailed Implementation

[0049] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. The components of the embodiments of the present invention described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.

[0050] The following is for reference Figures 1 to 12 The present invention will be described in further detail below.

[0051] On the one hand, the present invention provides a waste plastic grinding mill for the production of asphalt modifiers.

[0052] Reference Figure 1 It includes a feeding device 1, a freezing device 2, and a grinding device 3 that are interconnected.

[0053] Reference Figure 2 The feeding device 1 includes a hopper 11 with an opening at the top. A spraying assembly 4 is provided at the opening at the top of the hopper 11, and a cutting assembly 5 is provided inside the hopper 11, located below the spraying assembly 4.

[0054] Reference Figure 1 The refrigeration device 2 includes a refrigeration chamber 21 and a liquid nitrogen conveying assembly 22. The refrigeration chamber 21 is connected to the hopper 11, and the output end of the liquid nitrogen conveying assembly 22 is connected to the refrigeration chamber 21.

[0055] Reference Figure 1 The grinding device 3 includes a grinding box 31 and a circulating air-cooling component 32. The grinding box 31 is connected to the end of the freezing box 21 away from the hopper 11. The output end of the circulating air-cooling component 32 is located at the top of the grinding box 31. A return air device 33 is provided on the bottom wall of the grinding box 31. The return air device 33 is connected to the input end of the circulating air-cooling component 32.

[0056] Reference Figure 2 and Figure 3 The cutting assembly 5 includes a cutting roller 51 and an abutment part 52. The abutment part 52 is fixedly installed inside the hopper 11. There are two cutting rollers 51, which are respectively located on both sides of the abutment part 52. The two cutting rollers 51 are provided with spiral cutting blades 53 with opposite rotation directions. Abutment grooves 54 that are adapted to the cutting blades 53 are opened on both sides of the abutment part 52.

[0057] In actual use, the two cutting rollers 51 rotate in opposite directions, so that... Figure 3 The positions in the diagram are for illustrative purposes only. During the plastic cutting process, the left cutting roller 51 rotates clockwise, and the right cutting roller 51 rotates counterclockwise. When waste plastic is fed into the hopper 11, after the waste plastic comes into contact with the surface of the cutting roller 51, since the top of the cutting roller 51 is deflected toward the contact part 52, the waste plastic will move toward the contact part 52 under its own weight and the drive of the cutting roller 51. Then, the waste plastic can be cut by the cutting blade 53 and the contact groove 54.

[0058] Reference Figure 1 and Figure 2 In one embodiment of the present invention, the spray assembly 4 includes a spray pipe 41 and a nozzle 42. There are two spray pipes 41, which are respectively disposed above the two cutting rollers 51. Each spray pipe 41 is connected to a plurality of nozzles 42. The plurality of nozzles 42 are evenly arranged along the length direction of the spray pipe 41, and the nozzles 42 are inclined at 30-45° toward the gap between the cutting roller 51 and the contact part 52.

[0059] In actual use, the spray pipe 41 is connected to an external liquid source through the water inlet pipe. The liquid in the liquid source is a mixture of liquid water and glycerin. When cutting waste plastics, especially when cutting nylon braided tape and plastic film (PP / PE), the spraying of the mixture of liquid water and glycerin can effectively reduce the toughness of the nylon braided tape and plastic film, thereby effectively reducing the entanglement of the nylon braided tape and plastic film on the cutting roller 51. This ensures that the cutting blade 53 on the cutting roller 51 always has a good cutting effect on the plastic during a long working process.

[0060] Reference Figure 4 and Figure 5 A drive assembly 6 is provided on the hopper 11. The drive assembly 6 is used to drive the two cutting rollers 51 to move toward each other or away from each other. A drive source 12 is provided on the hopper 11 to drive the cutting rollers 51 to rotate.

[0061] Reference Figure 4 and Figure 5 In one embodiment of the present invention, the drive assembly 6 includes a first lead screw 61 and a first motor 62. A first groove 63 is provided on the hopper 11. The first lead screw 61 is rotatably disposed in the first groove 63. The first motor 62 is disposed on the hopper 11. The output shaft of the first motor 62 is connected to the first lead screw 61 for transmission. Two first sliders 64 are slidably disposed in the first groove 63. The two first sliders 64 are connected to the two cutting rollers 51 one-to-one. The first sliders 64 are threaded onto both ends of the first lead screw 61.

[0062] Reference Figure 4 and Figure 5 In one embodiment of the present invention, the first lead screw 61 is configured as a bidirectional lead screw, that is, the two ends of the first lead screw 61 are provided with helical grooves with opposite directions of rotation, and the two first sliders 64 are threaded onto the two ends of the first lead screw 61. As the first lead screw 61 rotates, the two first sliders 64 can be driven to move toward each other or away from each other.

[0063] Reference Figure 4 and Figure 5 Two strip-shaped holes 7 are opened horizontally on the inner wall of the hopper 11. A strip-shaped block 71 is slidably arranged in the strip-shaped hole 7. The cutting roller 51 is rotatably arranged on the strip-shaped block 71. The top of the first sliding groove 63 is connected to the bottom of the strip-shaped hole 7. The strip-shaped block 71 and the first slider 64 are connected one-to-one. A baffle 72 is fixedly arranged on the inner wall of the hopper 11. The baffle 72 is arranged at the opening of the strip-shaped hole 7. The baffle 72 and the strip-shaped block 71 slide in contact with the side wall near the cutting roller 51.

[0064] Reference Figure 5 and Figure 6A drive shaft 73 is rotatably mounted on each strip block 71. One end of the drive shaft 73 is fixedly connected to the cutting roller 51, and the other end extends out of the hopper 11. A driven wheel 74 is coaxially fixed at the end of each drive shaft 73 away from the cutting roller 51. An mounting block 75 is slidably mounted on the outer wall of the hopper 11 in the vertical direction. The mounting block 75 is located in the middle of the two strip blocks 71. An mounting shaft 76 is rotatably mounted on the mounting block 75. A first drive wheel 77 and a second drive wheel 78 are sequentially mounted on the mounting shaft 76 along the axial direction of the mounting shaft 76. A drive belt 79 is wound around both the first drive wheel 77 and the second drive wheel 78. The other end of the drive belt 79 on the first drive wheel 77 is wound around the driven wheel 74 on the left side, and the other end of the drive belt 79 on the second drive wheel 78 is wound around the driven wheel 74 on the right side. The drive source 12 is used to drive the first drive wheel 77 and the second drive wheel 78 to rotate in opposite directions.

[0065] As another possible embodiment of the present invention, the driven wheel 74, the first drive wheel 77 and the second drive wheel 78 can all be configured as gears, and the drive belt 79 can be configured as a chain.

[0066] Reference Figure 6 A lifting assembly 8 is provided on the hopper 11. The lifting assembly 8 is used to drive the mounting block 75 to move on the hopper 11. As one embodiment of the present invention, the lifting assembly 8 includes a second motor 82 and a second lead screw 81. A second sliding groove 83 is formed vertically on the outer side wall of the hopper 11. The mounting block 75 is slidably disposed in the second sliding groove 83. The second motor 82 is fixedly disposed on the hopper 11. The second lead screw 81 is rotatably disposed in the second sliding groove 83 in the vertical direction. The mounting block 75 is threadedly sleeved on the second lead screw 81. The second lead screw 81 is coaxially fixedly connected to the output shaft of the second motor 82.

[0067] In one embodiment of the present invention, the drive source 12 is configured as a drive motor, the output shaft of the drive motor is connected to the mounting shaft 76 for transmission, and the drive motor is configured as a dual-axis motor, that is, the output shaft of the drive motor is connected to two coaxial rotating shafts, and the two rotating shafts are connected by a planetary gear mechanism for transmission, thereby enabling the two rotating shafts to rotate coaxially but in opposite directions (this is prior art, and the specific structure is not described in detail).

[0068] In one embodiment of the present invention, the drive motor drives the first drive wheel 77 and the second drive wheel 78 to rotate coaxially and in opposite directions in the manner described above, so as to achieve the purpose of driving the cutting roller 51 to rotate.

[0069] At the same time, refer to Figure 6 and Figure 7A mounting cover 13 is fixedly installed on the outer wall of the hopper 11. The mounting cover 13 covers the driven wheel 74, the first drive wheel 77, the second drive wheel 78, and the drive source 12. (Refer to...) Figure 6 A guide block 14 is fixedly provided on the drive source 12, and a guide groove (not shown in the figure) is provided on the inner wall of the mounting cover 13 in the vertical direction for the guide block 14 to slide and connect, so that the drive source 12 can still drive the first drive wheel 77 and the second drive wheel 78 to rotate during the up and down movement.

[0070] Reference Figure 7 and Figure 8 A receiving groove 101 is provided on the inner walls of both sides of the hopper 11 along the axial direction of the cutting roller 51. A collection box 102 is slidably arranged in the receiving groove 101 along the length direction of the receiving groove 101. An abutment plate 103 is fixedly arranged on the collection box 102. The end of the abutment plate 103 away from the collection box 102 is used to abut against the cutting roller 51.

[0071] After the waste plastic is cut, the two cutting rollers 51 are moved toward the receiving groove 101 by the drive assembly 6, so that the abutment plate 103 abuts against the cutting rollers 51. At this time, the drive source 12 is started to drive the cutting rollers 51 to rotate. The abutment plate 103 slides in the receiving groove 101 under the drive of the spiral cutting blades 53 on the surface of the cutting rollers 51. During the above process, as the abutment plate 103 moves, the nylon braided tape, plastic oil film and other materials wrapped on the cutting rollers 51 can be removed. The scraped nylon braided tape and plastic oil film fall into the collection box 102 below the abutment plate 103.

[0072] Reference Figure 7 A top plate 104 and a bottom plate 105 are fixedly arranged on the inner wall of the hopper 11 along the length of the cutting roller 51. There are two top plates 104 and two bottom plates 105. The space between the top plate 104 and the bottom plate 105 on the same side forms a receiving groove 101.

[0073] Reference Figure 7 , Figure 8 and Figure 9 The collection box 102 is detachably connected to the hopper 11. A T-shaped groove 106 is provided on the top of the bottom plate 105 along the length of the bottom plate 105. A T-shaped block is provided at the bottom of the collection box 102. The T-shaped block is slidably disposed in the T-shaped groove 106.

[0074] Reference Figure 9 A magnetic insert 108 is fixedly installed on the top of the T-shaped block, and a slot 109 is provided at the bottom of the collection box 102 for inserting the magnetic insert 108. A magnetic suction piece (not shown in the figure) is provided on the inner wall of the slot 109.

[0075] Reference Figure 7 and Figure 8 A through hole 15 is provided on the side wall of the hopper 11, and the through hole 15 is connected to the receiving groove 101. A sealing plate 16 is provided on the side wall of the hopper 11. The sealing plate 16 is used to close the through hole 15. The sealing plate 16 is detachably connected to the hopper 11 by bolts 17.

[0076] In actual use, when it is necessary to disassemble the collection box 102, unscrew the bolt 17 to remove the sealing plate 16, and then the staff can remove the collection box 102 from the strip block 71 through the through hole 15. The operation is convenient, simple and quick.

[0077] Reference Figure 5 and Figure 10 A buffer groove 9 is provided at the top of the first slider 64 along the length of the first slide groove 63. A buffer block 91 is slidably disposed in the buffer groove 9. The top of the buffer block 91 is fixedly connected to the bottom of the strip block 71. An elastic element 92 is provided in the buffer groove 9. The elastic element 92 acts on the strip block 71 to drive the strip block 71 to move in a direction away from each other.

[0078] As one embodiment of the present invention, refer to Figure 10 The elastic element 92 is configured as a compression spring. One end of the elastic element 92 is fixedly connected to the side wall of the buffer block 91, and the other end is fixedly connected to the inner wall of the buffer groove 9.

[0079] Reference Figure 11 A downwardly inclined feeding pipe 18 is provided at the bottom of the hopper 11. The other end of the feeding pipe 18 is connected to the freezing box 21. The liquid nitrogen conveying assembly 22 includes a liquid nitrogen source 221 and a conveying pipe 222. The conveying pipe 222 includes a top branch pipe 223 and a bottom branch pipe 224. One end of the top branch pipe 223 is connected to the liquid nitrogen source 221, and the other end is connected to the top of the freezing box 21. One end of the bottom branch pipe 224 is connected to the liquid nitrogen source 221, and the other end is connected to the bottom of the freezing box 21.

[0080] After being cut, the plastic fragments leave the hopper 11 through the feeding pipe 18 and enter the freezing chamber 21. At this time, the liquid nitrogen source 221 is turned on, and the liquid nitrogen for freezing is introduced into the freezing chamber 21 from the top through the top placement pipe and enters the freezing chamber 21 from the bottom through the bottom branch pipe 224. Inside the freezing chamber 21, a liquid nitrogen freezing airflow is formed that flows up and down, which can quickly freeze the plastic fragments in the freezing chamber 21 and improve the freezing efficiency.

[0081] Reference Figure 11 and Figure 12 A discharge hole 23 is provided at the bottom of the freezing box 21. A discharge plate 24 for sealing the discharge hole 23 is slidably arranged inside the freezing box 21. The discharge hole 23 is connected to a discharge pipe 25, and the other end of the discharge pipe 25 is connected to the grinding box 31.

[0082] Reference Figure 12 The circulating air-cooled assembly 32 includes a cyclone separator 321, a filter dust collector 322, and a cooler 323. A first return air duct 324 connects the return air unit 33 to the cyclone separator 321, a second return air duct 325 connects the cyclone separator and the filter dust collector 322, a third return air duct 326 connects the filter dust collector 322 and the cooler 323, and a fourth return air duct 327 connects the cooler 323 to the top of the grinding chamber 31. In one embodiment of the invention, a fan is integrated within the cyclone separator 321 and the cooler 323.

[0083] After freezing the plastic fragments, the discharge plate 24 is opened, and the plastic fragments enter the grinding chamber 31 through the discharge pipe 25. At the same time as starting the grinding chamber 31, the circulating air-cooling component 32 is turned on. While grinding the plastic fragments, a circulating air-cooled airflow channel is formed in the grinding chamber 31. The airflow enters the first return air pipe 324 through the return air device 33, and then enters the cyclone separator 321. The cyclone separator 321 separates the intake airflow, separating the plastic powder that meets the grinding standard and unifying the non-compliant plastic powder. The airflow then enters the filter dust collector 322 through the second return air pipe 325 to filter out the dust in the airflow. Then it enters the cooler 323 through the third return air pipe 326 to cool the airflow. The cooled airflow flows back into the grinding chamber 31 through the fourth return air pipe 327 to circulate and cool the grinding chamber 31.

[0084] On the other hand, the present invention provides a method for processing waste plastic powder using a grinding mill for the production of asphalt modifiers.

[0085] A method for processing waste plastics for asphalt modification and production using a grinding mill, comprising the following steps:

[0086] Waste plastic is fed into hopper 11 through the top of hopper 11, and the spray assembly 4 is activated to spray a mixture of glycerin and liquid water onto the waste plastic;

[0087] The drive source 12 is activated to drive the cutting roller 51 to rotate, which initially cuts the waste plastic into plastic fragments.

[0088] The plastic block enters the freezing box 21 through the hopper 11 and the feeding pipe 18. The liquid nitrogen source 221 is turned on and liquid nitrogen is transported through the conveying pipe 222 to form a low temperature environment of less than -40℃ in the freezing box 21, which quickly embrittles the plastic fragments and makes the plastic fragments change from a tough state to a brittle state.

[0089] Open the discharge plate 24, and the brittle plastic fragments enter the grinding box 31 through the discharge pipe 25. Start the grinding box 31 to grind the plastic fragments.

[0090] Turn on the circulating air-cooling component 32 to cool down the inside of the grinding chamber 31.

[0091] The grinding chamber 31 operates for 30-40 seconds to grind plastic fragments into particles with a diameter of less than 1 mm;

[0092] Open the grinding chamber 31 and take out the plastic granules.

[0093] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Various modifications and variations can be made to the present invention by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the scope of protection of the present invention.

Claims

1. A waste plastic grinding mill for the production of asphalt modifiers, characterized in that: It includes a feeding device (1), a freezing device (2), and a grinding device (3) that are interconnected. The feeding device (1) includes a hopper (11) with an opening at the top. A spraying assembly (4) is provided at the opening at the top of the hopper (11). A cutting assembly (5) is provided inside the hopper (11). The cutting assembly (5) is located below the spraying assembly (4). The spraying assembly (4) sprays a mixture of glycerol and liquid water into the hopper (11). The refrigeration device (2) includes a refrigeration chamber (21) and a liquid nitrogen conveying assembly (22). The refrigeration chamber (21) is connected to the hopper (11), and the output end of the liquid nitrogen conveying assembly (22) is connected to the refrigeration chamber (21) so that a low temperature environment of <-40℃ is formed inside the refrigeration chamber (21). The grinding device (3) includes a grinding box (31) and a circulating air-cooling component (32). The grinding box (31) is connected to the end of the freezing box (21) away from the hopper (11). The output end of the circulating air-cooling component (32) is located at the top of the grinding box (31). A return air device (33) is provided on the bottom wall of the grinding box (31). The return air device (33) is connected to the input end of the circulating air-cooling component (32). The cutting assembly (5) includes a cutting roller (51) and an abutment part (52). The abutment part (52) is fixedly installed in the hopper (11). There are two cutting rollers (51), which are respectively located on both sides of the abutment part (52). The two cutting rollers (51) are provided with spiral cutting blades (53) with opposite rotation directions. Abutment grooves (54) adapted to the cutting blades (53) are provided on both sides of the abutment part (52). A drive assembly (6) is provided on the hopper (11). The drive assembly (6) is used to drive the two cutting rollers (51) to move in a direction that is closer to or further away from each other. A drive source (12) is provided on the hopper (11) to drive the cutting rollers (51) to rotate. A receiving groove (101) is provided on the inner walls of both sides of the hopper (11) along the axial direction of the cutting roller (51). A collection box (102) is slidably arranged in the receiving groove (101) along the length direction of the receiving groove (101). An abutment plate (103) is fixedly arranged on the collection box (102). The end of the abutment plate (103) away from the collection box (102) is used to abut against the cutting roller (51). The collection box (102) is detachably connected to the hopper (11).

2. The waste plastic grinding mill for producing asphalt modifier according to claim 1, characterized in that: The drive assembly (6) includes a first lead screw (61) and a first motor (62). A first groove (63) is provided on the hopper (11). The first lead screw (61) is rotatably disposed in the first groove (63). The first motor (62) is disposed on the hopper (11). The output shaft of the first motor (62) is connected to the first lead screw (61) for transmission. Two first sliders (64) are slidably disposed in the first groove (63). The two first sliders (64) are connected to the two cutting rollers (51) one by one. The first sliders (64) are threaded onto both ends of the first lead screw (61).

3. A waste plastic grinding mill for producing asphalt modifiers according to claim 2, characterized in that: Two strip-shaped holes (7) are opened horizontally on the inner wall of the hopper (11). A strip block (71) is slidably arranged in the strip-shaped hole (7). The cutting roller (51) is rotatably arranged on the strip block (71). The top of the first sliding groove (63) is connected to the bottom of the strip-shaped hole (7). The strip block (71) is connected to the first slider (64) in a one-to-one correspondence. A baffle (72) is fixedly arranged on the inner wall of the hopper (11). The baffle (72) is arranged at the opening of the strip-shaped hole (7). The baffle (72) slides and contacts the strip block (71) near the side wall of the cutting roller (51).

4. A waste plastic grinding mill for producing asphalt modifiers according to claim 3, characterized in that: A drive shaft (73) is rotatably mounted on each strip block (71). One end of the drive shaft (73) is fixedly connected to the cutting roller (51), and the other end extends out of the hopper (11). A driven wheel (74) is coaxially fixed at the end of each drive shaft (73) away from the cutting roller (51). An mounting block (75) is slidably mounted on the outer wall of the hopper (11) in the vertical direction. The mounting block (75) is located in the middle of the two strip blocks (71). An mounting shaft (76) is rotatably mounted on the mounting block (75). A first drive wheel (77) and a second drive wheel (74) are sequentially mounted on the mounting shaft (76) along the axial direction of the mounting shaft (76). The second drive wheel (78) has a drive belt (79) wound around both the first drive wheel (77) and the second drive wheel (78). The other end of the drive belt (79) on the first drive wheel (77) is wound around the driven wheel (74) on the left side, and the other end of the drive belt (79) on the second drive wheel (78) is wound around the driven wheel (74) on the right side. The drive source (12) is used to drive the first drive wheel (77) and the second drive wheel (78) to rotate in opposite directions. A lifting assembly (8) is provided on the hopper (11). The lifting assembly (8) is used to drive the mounting block (75) to move on the hopper (11).

5. A waste plastic grinding mill for producing asphalt modifiers according to claim 1, characterized in that: A buffer groove (9) is provided at the top of the first slider (64) along the length of the first slide groove (63). A buffer block (91) is slidably disposed in the buffer groove (9). The top of the buffer block (91) is fixedly connected to the bottom of the strip block (71). An elastic element (92) is provided in the buffer groove (9). The elastic element (92) acts on the strip block (71) to drive the strip block (71) to move in a direction away from each other.

6. A waste plastic grinding mill for producing asphalt modifiers according to claim 1, characterized in that: A downward-sloping feeding pipe (18) is provided at the bottom of the hopper (11). The other end of the feeding pipe (18) is connected to the freezer (21). The liquid nitrogen conveying assembly (22) includes a liquid nitrogen source (221) and a conveying pipe (222). The conveying pipe (222) includes a top branch pipe (223) and a bottom branch pipe (224). One end of the top branch pipe (223) is connected to the liquid nitrogen source (221), and the other end is connected to the top of the freezer (21). One end of the bottom branch pipe (224) is connected to the liquid nitrogen source (221), and the other end is connected to the bottom of the freezer (21).

7. A waste plastic grinding mill for producing asphalt modifiers according to claim 6, characterized in that: A material discharge hole (23) is provided at the bottom of the freezing box (21). A material discharge plate (24) for closing the material discharge hole (23) is slidably provided inside the freezing box (21). The material discharge hole (23) is connected to a material discharge pipe (25). The other end of the material discharge pipe (25) is connected to the grinding box (31). The circulating air-cooled assembly (32) includes a cyclone separator (321), a filter dust collector (322), and a cooler (323). The return air unit (33) is connected to the cyclone separator (321) by a first return air duct (324), the cyclone separator (321) is connected to the filter dust collector (322) by a second return air duct (325), the filter dust collector (322) is connected to the cooler (323) by a third return air duct (326), and the cooler (323) is connected to the top of the grinding box (31) by a fourth return air duct (327).

8. A processing method for asphalt modification and waste plastic powder grinding mill, characterized in that, Processing using a grinding mill as described in any one of claims 1-7 includes the following steps: Waste plastic is fed into the hopper (11) through the top of the hopper (11), and the spray assembly (4) is started to spray a mixture of glycerin and liquid water onto the waste plastic; Start the drive source (12) to drive the cutting roller (51) to rotate, and initially cut the waste plastic into plastic fragments; The plastic block enters the freezing box (21) through the hopper (11) and the feeding pipe (18). The liquid nitrogen source (221) is turned on, and liquid nitrogen is transported through the conveying pipe (222). A low temperature environment with a temperature of less than -40°C is formed in the freezing box (21), which quickly embrittles the plastic fragments and makes the plastic fragments change from a tough state to a brittle state. Open the discharge plate (24), and the brittle plastic fragments enter the grinding box (31) through the discharge pipe (25). Start the grinding box (31) to grind the plastic fragments. Turn on the circulating air-cooling component (32) to cool down the inside of the grinding box (31); The grinding chamber (31) operates for 30-40 seconds to grind plastic fragments into particles with a diameter of less than 1 mm; Open the grinding box (31) and take out the plastic granules.

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