A method for preventing adhesion of asphalt pavement waste after dehydration and impurity removal

Abstract

The application discloses a method for preventing adhesion of high-temperature asphalt pavement waste after dehydration and impurity removal, and belongs to the technical field of high-temperature mixing material feeding mode. The method is characterized in that, when the high-temperature asphalt pavement waste after impurity removal is fed into a waste metering hopper, gravel originally added into a total mixing cylinder in the last stage of the recycling process is combined with the high-temperature asphalt pavement waste in advance, so that the gravel forms a non-adhesive interstitial layer between the high-temperature asphalt pavement waste falling into and accumulated in the waste metering hopper and the inner wall of the waste metering hopper.

Description

Technical Field

[0001] This invention relates to a method for preventing the adhesion of dehydrated and impurity-removed recycled asphalt pavement waste before feeding it into a hopper, belonging to the technical field of high-temperature mixed material feeding methods. Background Technology

[0002] Asphalt pavement is removed after years of aging and replaced with a fresh mixture of asphalt and aggregate. Although the asphalt in the removed pavement waste is aged, it still retains considerable adhesiveness. After crushing, dehydrating, and removing impurities, the waste is mixed with a certain proportion of aggregate and fresh asphalt, still meeting paving requirements. Therefore, the removed asphalt pavement waste still has recycling value and can solve the problem of landfill disposal, which is highly beneficial to environmental protection.

[0003] The process of recycling asphalt pavement waste is as follows: Figure 1 As shown, the recycled asphalt pavement waste is first crushed according to the particle size requirements for later use. On the day of paving, the crushed asphalt pavement waste is transported to the dewatering and drying tank 1 for dehydration and impurity removal. The dewatered and impurity-removed high-temperature asphalt pavement waste continuously flows from one end of the dewatering and drying tank 1 into the waste metering hopper 3. When the high-temperature asphalt pavement waste flowing into the waste metering hopper 3 is about to reach the set amount, the feeding of waste into the dewatering and drying tank 1 is stopped. After all the waste processed in the dewatering and drying tank 1 has flowed into the waste metering hopper 3, the waste metering hopper 3 is read. The weight of the mixed high-temperature asphalt pavement waste 10 is measured; high-temperature asphalt pavement waste 10, high-temperature asphalt fresh material, and crushed stone are simultaneously transported from the waste material metering hopper 3, the asphalt fresh material metering hopper 4, and the crushed stone from the crushed stone metering hopper 2 into the mixing drum 5. The high-temperature asphalt pavement waste 10, high-temperature asphalt fresh material, and crushed stone are fully mixed in the mixing drum 5, and then fall from the mixing drum 5 into the qualified high-temperature asphalt crushed stone mixture temporary storage hopper 6 for heat preservation and temporary storage, waiting for the special transport vehicle to transport it to the construction site while it is still hot for paving.

[0004] In the process of recycling asphalt pavement waste, the asphalt pavement waste that has just been dehydrated and cleaned is at a very high temperature. When it flows from the cleaning and drying barrel into the waste metering hopper, the asphalt melted by the high temperature always adheres to the inner wall of the waste metering hopper when it comes into contact with it, forming an adhesive layer that is difficult to peel off. This adhesive layer seriously affects the smooth flow of the cleaned waste to the main mixing tank. Therefore, it is necessary to take advantage of the gap between the output of the previous batch of cleaned waste and the flow of the next batch of cleaned waste from the cleaning and drying barrel to manually remove the adhesive layer in time. This not only greatly increases the labor cost, but also poses a certain risk of being burned (caused by the cleaning and drying barrel being rotated prematurely due to misoperation, resulting in the flow of residual material with high temperature in the kiln). At the same time, the adhesive layer is not effectively utilized by this batch, resulting in a certain deviation in the mixing ratio. Summary of the Invention

[0005] The problem this invention aims to solve is: how to prevent the dehydrated and impurity-removed high-temperature asphalt pavement waste flowing out of the dehydration and drying barrel from sticking to the inner wall of the waste metering hopper when it falls into the waste metering hopper.

[0006] To address the aforementioned problems, the technical solution proposed in this invention is: a method for preventing the adhesion of recycled asphalt pavement waste after dehydration and impurity removal before it enters the waste metering hopper. This method involves pre-combining the crushed stone, which would normally be added to the mixing tank at the final stage of the recycling process, with the high-temperature asphalt pavement waste during the input of the waste metering hopper. This results in a non-adhesive interstitial layer of crushed stone forming between the high-temperature asphalt pavement waste falling into and accumulating in the waste metering hopper and the inner wall of the hopper.

[0007] Furthermore, a ring filter is installed between the discharge port of the impurity drying barrel and the waste metering hopper. A crushed stone metering hopper higher than the ring filter is installed next to the waste metering hopper. A sand supply channel is installed between the crushed stone metering hopper and the ring filter. A passageway for high-temperature asphalt pavement waste is installed in the central area of ​​the ring filter. An annular sand leakage port is installed on the outer periphery of the passageway. In application, the sand supply channel continuously supplies crushed stone to the annular sand leakage port. Crushed stone continuously flows from the lower end of the annular sand leakage port to the inner wall of the waste metering hopper, forming an annular sand curtain.

[0008] Furthermore, the ring leak device is designed with an inner cylinder that is open at both ends and an outer cylinder that is fitted outside the inner cylinder. The annular sand leakage port is the annular space between the inner cylinder and the outer cylinder. A slow-speed guiding structure is set in the annular sand leakage port to slow down the speed of the falling gravel. The material outlet is the inner empty space of the inner cylinder. The ring leak device is designed to rotate at a set speed.

[0009] The above-described method of feeding the food into the container includes the following steps:

[0010] S1. The impurity removal and drying barrel starts working, and its discharge port is in the closed state.

[0011] S2. When the asphalt pavement waste in the discharge end of the impurity removal drying barrel has completed dehydration and impurity removal:

[0012] S21. Rotate the ring leak device;

[0013] S22. Open the second outlet of the crushed stone metering hopper to allow the crushed stone to enter the ring filter through the sand supply channel and form an annular sand curtain through the ring filter.

[0014] S3. Open the discharge port one of the impurity removal and drying barrel. The high-temperature asphalt road waste that has been dehydrated and impurity removed from the discharge port one will start to flow into the waste metering hopper through the discharge port.

[0015] S4. When the discharge port stops outputting high-temperature asphalt pavement waste, the crushed stone metering hopper stops feeding material, which continues from step S2 until the annular sand curtain disappears in this step.

[0016] Furthermore, the provision of a slow-flow guiding structure within the annular sand outlet involves installing multiple equally spaced slow-flow guiding plates within the annular sand outlet to slow the falling gravel. The outer edges of the slow-flow guiding plates are fixed to the inner wall of the outer cylinder, and the inner edges of the slow-flow guiding plates are fixed to the outer wall of the inner cylinder.

[0017] Furthermore, the deceleration guide plate is set to a spiral shape, and its guiding direction is consistent with the rotation direction of the ring leak, so that the gravel falling from the sand supply channel into the annular sand leakage port falls onto the deceleration guide plate below that rotates with the ring leak.

[0018] Furthermore, the slow-flow guiding structure set in the annular sand leakage port is to set a conical guiding surface in the annular sand leakage port. The upper end of the conical guiding surface is fixed to the outer wall of the inner cylinder, and the lower end is fixed to the inner wall of the outer cylinder. An annular groove bottom is formed between the conical guiding surface and the inner wall of the outer cylinder. Several sand leakage holes are set at equal intervals in the formed annular groove bottom.

[0019] Furthermore, an annular support plate is fixedly installed on the lower outer periphery of the outer cylinder of the ring leak device. Below the annular support plate is an annular support platform fixed on the mounting frame. There is a gap between the inner ring surface of the annular support platform and the outer cylinder. A pressure bearing is provided between the annular support plate and the annular support platform, which is sleeved on the outside of the ring leak device. The pressure bearing supports the ring leak device and enables the ring leak device to rotate freely around its own axis.

[0020] Furthermore, an annular toothed ring with external teeth is fixedly installed on the outer periphery of the outer cylinder above the annular support plate. A driver is installed next to the annular toothed ring, and the driver's drive gear meshes with the annular toothed ring. The driver drives the annular leaker to rotate. The driver is fixed on the annular support platform by a mounting base.

[0021] Furthermore, the sand supply channel is configured as a herringbone-shaped channel with two branch channels. The inlet end of the sand supply channel is located below the discharge port 2 of the crushed stone metering hopper, and the discharge ports 3 of the two branch channels are respectively located above the two sides of the annular sand leakage port.

[0022] Beneficial effects: It avoids the adhesion of high-temperature asphalt pavement waste to the inner wall of the waste metering hopper when it falls and accumulates, eliminating the labor cost of manual cleaning of the adhesion layer and also eliminating the potential risk of burns to cleaning personnel; the aggregate interlayer also plays a very good role in heat absorption and insulation, greatly reducing the heat loss of high-temperature asphalt pavement waste in the waste metering hopper, thus achieving the unexpected effect of significantly reducing the energy consumption of asphalt aggregate mixing and processing. Attached Figure Description

[0023] Figure 1 This is a flowchart of the existing technology for recycling asphalt pavement waste.

[0024] Figure 2 This is a flowchart of the asphalt pavement waste recycling process described in Example 1;

[0025] Figure 3 This is a schematic diagram of the anti-adhesion feeding hopper for asphalt pavement waste after dehydration and impurity removal as described in Example 1;

[0026] Figure 4 This is a three-dimensional schematic diagram of the sand supply channel, the ring filter and its driving mechanism as described in Embodiment 1. The curved arrow A in the figure indicates the rotation direction of the ring filter.

[0027] Figure 5 This is a three-dimensional schematic diagram of the ring leak device described in Embodiment 1;

[0028] Figure 6 for Figure 3 A partial schematic diagram;

[0029] Figure 7 for Figure 6 A partial schematic diagram;

[0030] Figure 8 This is a schematic diagram of the high-temperature asphalt pavement waste falling into the waste metering hopper as described in Example 1;

[0031] Figure 9 for Figure 8 A partial schematic diagram;

[0032] Figure 10 This is a cross-sectional schematic diagram of the annular leak device described in Embodiment 2;

[0033] Figure 11 This is a flowchart of the asphalt pavement waste recycling process described in Example 3.

[0034] In the diagram: 1. Impurity removal and drying drum; 101. Discharge port one; 2. Crushed stone metering hopper; 201. Discharge port two; 3. Waste material metering hopper; 4. Fresh asphalt material metering hopper; 5. Main mixing tank; 6. High-temperature asphalt crushed stone mixture temporary storage hopper; 7. Sand supply channel; 701. Branch channel; 702. Discharge port three; 8. Annular leakage device; 801. Material passage; 802. Annular sand leakage port; 803. Inner cylinder; 804. Outer cylinder; 805. Decelerating guide plate; 806. 8061. Conical guide surface; 807. Sand leakage hole; 808. Annular support plate; 809. Annular gear ring; 9000. Pressure bearing; 901. Upper top plate; 902. Ball bearing; 903. Lower base plate; 10. High-temperature asphalt pavement waste; 11. Mounting frame; 12. Annular support platform; 13. Annular pallet; 14. Driver; 15. Drive gear; 16. Mounting base; 17. Crushed stone interlayer; 18. Annular sand curtain; 19. Pressure sensor; 20. Material guide chute. Detailed Implementation

[0035] The present invention will now be further described in conjunction with the embodiments and accompanying drawings.

[0036] Example 1: As Figure 2 , 8 As shown in Figures 9 and 1, a method for preventing the adhesion of dehydrated and impurity-removed asphalt pavement waste during hopper loading involves pre-combining the crushed stone, which would normally be added to the mixing tank 5 in the final stage of the reuse process, with the high-temperature asphalt pavement waste 10 after dehydration and impurity removal. This allows a non-adhesive interlayer layer 17 to form between the crushed stone and the inner wall of the waste metering hopper 3 as it falls and accumulates. This prevents the high-temperature asphalt pavement waste 10 from contacting the inner wall of the hopper 3 during its accumulation, thus preventing the high-temperature asphalt in the waste 10 from adhering to the inner wall of the hopper 3. Since the crushed stone will eventually be mixed with the dehydrated and impurity-removed high-temperature asphalt pavement waste 10, this method pre-combining it with the waste 10 will not affect the final application effect. One of the necessary technical measures for asphalt macadam pavement construction is to maintain a sufficiently high temperature (generally 120℃-140℃) for the asphalt macadam from mixing to paving. When the macadam forms a macadam interstitial layer 17 around the high-temperature asphalt pavement waste 10, the macadam interstitial layer 17 also plays a very good role in heat absorption and insulation, greatly reducing the heat loss of the high-temperature asphalt pavement waste 10 (temperature of 130℃-150℃) in the waste metering hopper 3. This can correspondingly reduce the heat required for mixing in the later stage of the general mixing tank 5, thereby significantly reducing the production energy consumption of the asphalt macadam mixing process.

[0037] like Figure 3-8As shown in Figure 9: A ring filter 8 is installed between the discharge port 101 of the impurity drying barrel 1 and the waste metering hopper 3. A crushed stone metering hopper 2, higher than the ring filter 8, is installed next to the waste metering hopper 3. A sand supply channel 7 is installed between the crushed stone metering hopper 2 and the ring filter 8. A passage 801, capable of passing through high-temperature asphalt pavement waste 10, is installed in the central area of ​​the ring filter 8. An annular sand leakage port 802 is installed around the outer periphery of the passage 801. In application, the sand supply channel 7 continuously supplies crushed stone to the annular sand leakage port 802, which is located at the lower end of the annular sand leakage port 802. A ring of gravel continuously flows into the waste metering hopper 3, forming an annular sand curtain 18. The high-temperature asphalt pavement waste 10 flowing from the discharge port 801 is located within the space of the annular sand curtain 18. The annular sand curtain 18 acts as a barrier to prevent the high-temperature asphalt pavement waste 10 from contacting the inner wall of the waste metering hopper 3 as it falls. When the annular sand curtain 18 approaches the bottom of the waste metering hopper 3, it takes over the bottom inner wall first, forming a gravel interstitial layer 17 between the high-temperature asphalt pavement waste 10 accumulated in the waste metering hopper 3 and the inner wall of the waste metering hopper 3.

[0038] like Figure 4 , 5 As shown in Figure 6: The design of the ring leak device 8 has an inner cylinder 803 that is connected from top to bottom and an outer cylinder 804 that is sleeved outside the inner cylinder 803. The annular sand leakage port 802 is the annular space between the inner cylinder 803 and the outer cylinder 804. A slow-speed guiding structure is set in the annular sand leakage port 802 to slow down the speed of the falling gravel. The material outlet 801 is the inner space of the inner cylinder 803. The design of the ring leak device 8 is to be able to rotate at a set speed. In this way, the ring filter 8 can rotate at a set speed, so that each position on the upper part of the annular sand outlet 802 can receive the gravel flowing in from the sand supply channel 7. The setting of the slow flow guiding structure makes the gravel received on the upper part of the annular sand outlet 802 flow down slowly. Due to the rotation of the ring filter 8, the gravel flow received at each point on the upper part of the annular sand outlet 802 can be scattered over an arc distance at the bottom. When the rotation of the ring filter 8 reaches a certain speed, a continuously flowing annular sand curtain 18 is formed on the lower part of the annular sand outlet 802.

[0039] A slow-flow guiding structure is installed inside the annular sand outlet 802. This structure consists of multiple equally spaced slow-flow guiding plates 805 that slow down the falling gravel. The outer edges of the slow-flow guiding plates 805 are fixed to the inner wall of the outer cylinder 804, and the inner edges are fixed to the outer wall of the inner cylinder 803. In this way, each gravel flow received on the front slow-flow guiding plate 805 can spread gravel over an arc distance below through the slow flow. Each gravel flow received on the rear slow-flow guiding plate 805 can continue to spread gravel over the arc distance spread by the front slow-flow guiding plate 805 and extend forward appropriately to supplement the spread. When the rotation of the annular sand filter 8 reaches a certain speed, a continuously flowing annular sand curtain 18 is formed.

[0040] Furthermore, the deceleration guide plate 805 is set in a spiral shape, and its flow direction is consistent with the rotation direction of the ring leak device 8. In this way, the flow velocity of the gravel flow falling from the sand supply channel 7 onto the deceleration guide plate 805 can be significantly reduced.

[0041] like Figure 4 , 6 As shown in Figure 7: A ring support plate 807 is fixedly installed on the lower outer periphery of the outer cylinder 804 of the ring leak device 8. Below the ring support plate 807, there is a ring support platform 12 fixed on the outer periphery of the mounting frame 11. There is a gap between the inner ring surface of the ring support platform 12 and the outer cylinder 804, so as not to interfere with the free rotation of the ring leak device 8. A pressure bearing 9 is provided between the ring support plate 807 and the ring support platform 12, which is sleeved on the outside of the ring leak device 8. The pressure bearing 9 supports the ring leak device 8 and enables the ring leak device 8 to rotate freely around its own axis.

[0042] Furthermore, an annular tray 13 is fixedly mounted on the annular support platform 12, and the lower base plate 903 of the pressure bearing 9 is fixed on the annular tray 13. The upper top plate 901 of the pressure bearing 9 is fixed to the annular support plate 807. The pressure bearing 9 is prior art, and there are balls 902 or rollers between its upper top plate 901 and lower base plate 903.

[0043] An annular gear ring 808 with external teeth is fixedly installed on the outer periphery of the outer cylinder 804 above the annular support plate 807. A driver 14 is installed next to the annular gear ring 808. The drive gear 15 of the driver 14 meshes with the annular gear ring 808, and the driver 14 drives the annular leaker 8 to rotate. The driver 14 is fixed on the annular support 12 by a mounting base 16. The driver 14 is preferably a motor.

[0044] like Figure 4 , 6As shown: Preferably, the sand supply channel 7 is configured as a herringbone-shaped channel with two branch channels 701. The inlet end of the sand supply channel 7 is located below the discharge port 201 of the crushed stone metering hopper 2, and the discharge ports 702 of the two branch channels 701 are respectively located above the two sides of the annular sand leakage port 802. The more branch channels 701 there are, the more discharge ports 201 there are, and the more points the annular sand leakage port 802 of the annular sand filter 8 receives the crushed stone flow. Of course, the density of the crushed stone in the annular sand curtain 18 is higher, but too many branch channels 701 will bring difficulties in the installation. By appropriately increasing the flow rate of the sand supply channel 7 and appropriately increasing the rotation speed of the annular sand filter 8, the density of the crushed stone in the annular sand curtain 18 can also reach the ideal requirements.

[0045] The sand supply channel 7 can be fixed on the mounting frame 11. The fixing structure between the sand supply channel 7 and the mounting frame 11 is not shown in the figure. The sand supply channel 7 does not interfere with the rotation of the ring leak device 8.

[0046] like Figure 3 As shown: Pressure sensors 19 for weighing are installed below both the crushed stone metering hopper 2 and the waste material metering hopper 3.

[0047] like Figure 2 , 3 As shown in Figures 8 and 9: The method for preventing adhesion of dehydrated and impurity-removed asphalt pavement waste into the hopper according to this application includes the following steps:

[0048] S1. The impurity removal and drying barrel 1 starts working, and its discharge port 101 is in the closed state;

[0049] S2. When the asphalt pavement waste in the discharge end of the impurity removal drying barrel 1 has completed dehydration and impurity removal:

[0050] S21. Rotate the ring leak device 8;

[0051] S22. Open the discharge port 201 of the crushed stone metering hopper 2, so that the crushed stone is fed into the ring filter 8 through the sand supply channel 7, and forms an annular sand curtain 18 through the ring filter 8.

[0052] S3. Open the discharge port 101 of the impurity removal and drying barrel 1. The high-temperature asphalt pavement waste 10 that has been dehydrated and impurity removed from the discharge port 101 will flow into the waste metering hopper 3 through the material inlet 801.

[0053] S4. When the discharge port 101 stops outputting high-temperature asphalt pavement waste 10, the crushed stone metering hopper 2 stops feeding material, and the annular sand curtain 18 formed in step S2 and continuing until it disappears in this step.

[0054] Before step S2 begins, the weight of the crushed stone in the crushed stone metering hopper 2 is recorded. After step S4 ends, the total weight of the crushed stone and the high-temperature asphalt pavement waste 10 in the waste material metering hopper 3 and the weight of the remaining crushed stone in the crushed stone metering hopper 2 are read. The weight of the high-temperature asphalt pavement waste 10 and the weight of the crushed stone in the waste material metering hopper 3 are calculated and obtained as the basis for the subsequent asphalt fresh material ratio.

[0055] The working method of the impurity removal and drying barrel 1 is similar to that of a rotary kiln. It has a heating and ventilation mechanism and a guide plate inside. It is horizontal and rotates on its own during operation. During rotation, the processed material inside is continuously pushed from the feed end to the discharge port 101.

[0056] The discharge port 101 of the impurity removal drying barrel 1 can be directly located above the material passage port 801 of the ring filter 8. In this application, a guide groove 20 is provided between the discharge port 101 of the impurity removal drying barrel 1 and the material passage port 801 of the ring filter 8.

[0057] Example 2, as Figure 10 As shown: The difference between this embodiment and the one described above is that a slow-speed guiding structure is provided inside the annular sand leakage port 802. Specifically, a conical guiding surface 806 is provided inside the annular sand leakage port 802. The upper end of the conical guiding surface 806 is fixed to the outer wall of the inner cylinder 803, and the lower end is fixed to the inner wall of the outer cylinder 804. An annular groove bottom is formed between the conical guiding surface 806 and the inner wall of the outer cylinder 804. Several sand leakage holes 8061 are provided at equal intervals in the annular groove bottom. The gravel falling from the sand flow channel 7 is decelerated by the conical guiding surface 806 and slides into the annular groove bottom, and then flows into the waste metering hopper 3 through the sand leakage holes 8061.

[0058] Example 3, as Figure 11 As shown, the difference between this and the above embodiment is that only a portion of the crushed stone is used to combine with the high-temperature asphalt pavement waste 10 in the waste metering hopper 3, while the other portion is still added to the mixing tank 5 in the final stage of the reuse process to facilitate the adjustment of the proportions of various ingredients. Therefore, the crushed stone metering hopper 2 is still set up next to the mixing tank 5.

[0059] The above embodiments are only used to describe the present invention more clearly, and should not be regarded as limiting the scope of protection covered by the present invention. Any equivalent modifications should be regarded as falling within the scope of protection covered by the present invention.

Claims

1. A method for preventing the adhesion of dehydrated and impurity-removed recycled asphalt pavement waste before it is fed into a hopper, characterized in that: When the high-temperature asphalt pavement waste (10) after impurity removal is fed into the waste metering hopper (3), the crushed stone that was originally added to the mixing tank (5) in the final stage of the reuse process is combined with the high-temperature asphalt pavement waste (10) in advance, so that the crushed stone forms a non-adhesive crushed stone interstitial layer (17) between the high-temperature asphalt pavement waste (10) falling into and accumulating in the waste metering hopper (3) and the inner wall of the waste metering hopper (3); a ring leak device (8) is set between the discharge port (101) of the impurity removal drying barrel (1) and the waste metering hopper (3), and a ring leak device (8) is set next to the waste metering hopper (3). The crushed stone metering hopper (2) is higher than the ring leaker (8). A sand supply channel (7) is set between the crushed stone metering hopper (2) and the ring leaker (8). A material outlet (801) that can pass through high-temperature asphalt pavement waste (10) is set in the central area of ​​the ring leaker (8). An annular sand leakage outlet (802) is set on the outer periphery of the material outlet (801). When in use, the sand supply channel (7) continuously supplies crushed stone to the annular sand leakage outlet (802). Crushed stone continuously flows from the lower end of the annular sand leakage outlet (802) to the inner wall of the waste metering hopper (3) to form an annular sand curtain (18).

2. The method for preventing adhesion of dehydrated and impurity-removed recycled asphalt pavement waste in a hopper as described in claim 1, characterized in that: The design of the ring leak device (8) includes an inner cylinder (803) that is connected from top to bottom and an outer cylinder (804) that is fitted outside the inner cylinder (803). The annular sand leakage port (802) is the annular space between the inner cylinder (803) and the outer cylinder (804). A slow-speed guiding structure is provided in the annular sand leakage port (802) to slow down the speed of the falling gravel. The material passage (801) is the inner space of the inner cylinder (803). The design of the ring leak device (8) is to be able to rotate at a set speed.

3. The method for preventing adhesion of dehydrated and impurity-removed recycled asphalt pavement waste in a hopper as described in claim 2, characterized in that... Includes the following steps: S1. The impurity removal and drying barrel (1) starts working, and its discharge port (101) is in the closed state; S2. When the asphalt pavement waste in the discharge end of the impurity removal drying barrel (1) has completed dehydration and impurity removal: S21. Rotate the ring leak device (8); S22. Open the second outlet (201) of the crushed stone metering hopper (2) so that the crushed stone is fed into the ring filter (8) through the sand supply channel (7) and forms an annular sand curtain (18) through the ring filter (8). S3. Open the discharge port 1 (101) of the impurity removal and drying barrel (1). The high-temperature asphalt pavement waste (10) that has been dehydrated and impurity removed from the discharge port 1 (101) begins to flow into the waste metering hopper (3) through the material inlet (801). S4. When the discharge port (101) stops outputting high-temperature asphalt pavement waste (10), the crushed stone metering hopper (2) stops feeding material, and the annular sand curtain (18) formed in step S2 and continues until it disappears in this step.

4. The method for preventing adhesion of dehydrated and impurity-removed recycled asphalt pavement waste in a hopper as described in claim 2, characterized in that: The method of setting a slow flow guiding structure in the annular sand leakage port (802) is to set multiple equally spaced slow flow guiding plates (805) in the annular sand leakage port (802) to slow down the falling gravel. The outer side of the slow flow guiding plate (805) is fixed to the inner wall of the outer cylinder (804), and the inner side of the slow flow guiding plate (805) is fixed to the outer wall of the inner cylinder (803).

5. The method for preventing adhesion of dehydrated and impurity-removed recycled asphalt pavement waste in a hopper as described in claim 4, characterized in that: The slow-speed guide plate (805) is set in a spiral shape, and its guiding direction is consistent with the rotation direction of the ring leaker (8), so that the gravel falling from the sand supply channel (7) into the annular sand leakage port (802) falls onto the slow-speed guide plate (805) below that rotates with the ring leaker (8).

6. The method for preventing adhesion of dehydrated and impurity-removed recycled asphalt pavement waste in a hopper as described in claim 2, characterized in that: The slow-flow guiding structure is set in the annular sand leakage port (802) by setting a conical guiding surface (806) in the annular sand leakage port (802). The upper end of the conical guiding surface (806) is fixed to the outer wall of the inner cylinder (803), and the lower end is fixed to the inner wall of the outer cylinder (804). An annular groove bottom is formed between the conical guiding surface (806) and the inner wall of the outer cylinder (804). A number of sand leakage holes (8061) are set at equal intervals in the formed annular groove bottom.

7. The method for preventing adhesion of dehydrated and impurity-removed recycled asphalt pavement waste in a hopper as described in claim 2, characterized in that: An annular support plate (807) is fixedly installed on the lower outer periphery of the outer cylinder (804) of the ring leaker (8). Below the annular support plate (807), there is an annular support platform (12) fixed on the mounting frame (11). There is a gap between the inner ring surface of the annular support platform (12) and the outer cylinder (804). A pressure bearing (9) is provided between the annular support plate (807) and the annular support platform (12) and is sleeved on the outside of the ring leaker (8). The pressure bearing (9) supports the ring leaker (8) and enables the ring leaker (8) to rotate freely around its own axis.

8. The method for preventing adhesion of dehydrated and impurity-removed recycled asphalt pavement waste in a hopper as described in claim 7, characterized in that: On the outer periphery of the outer cylinder (804) above the annular support plate (807), an annular gear ring (808) with external teeth is fixedly installed. A driver (14) is installed next to the annular gear ring (808). The drive gear (15) of the driver (14) meshes with the annular gear ring (808). The driver (14) drives the ring leaker (8) to rotate. The driver (14) is fixed on the annular support plate (12) by the mounting base (16).

9. The method for preventing adhesion of dehydrated and impurity-removed recycled asphalt pavement waste in a hopper as described in claim 4, characterized in that: The sand supply channel (7) is configured as a herringbone channel with two branch channels (701). The inlet end of the sand supply channel (7) is located below the discharge port 2 (201) of the crushed stone metering hopper (2). The discharge ports 3 (702) of the two branch channels (701) are respectively located above the annular sand leakage port (802) on both sides.

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