Multi-point heating recycled asphalt mixture stirring device

Abstract

The invention relates to the technical field of asphalt regeneration, and provides a multi-point heating regenerated asphalt mixture stirring device which comprises a stirring tank and a pressure release valve, an air inlet pipe is installed at the bottom end of the stirring tank, a filtering exhaust port is formed in one side of the top end of the stirring tank, a discharging port is formed in one side of the bottom end of the stirring tank, and an auxiliary structure is arranged in the stirring tank. By arranging an auxiliary structure, dry steam continuously flows in a cavity, so that regenerated raw materials are heated, various materials in the raw materials are fully fused, when the dry steam flows in an air inlet pipe, a part of the dry steam flows into a hollow shaft, and due to the fact that the hollow shaft and a stirring shaft are hollow, the raw materials can be fully mixed. And through cooperation of heating of the outer side of the cavity, mixing and stirring of simultaneous heating of the inside and the outside of the asphalt regeneration raw materials are achieved, the raw materials are heated more uniformly during mixing, and the mixing effect is better.

Description

Technical Field

[0001] This invention relates to the field of asphalt recycling technology, and in particular to a multi-point heating recycling asphalt mixture mixing device. Background Technology

[0002] Asphalt pavement is a flexible road structure with asphalt mixture as the surface material. With its core advantages such as driving comfort, low noise, fast construction, easy maintenance, and recyclability, it has become the mainstream choice for highways and urban arterial roads. Asphalt recycling refers to the technology of restoring the road performance properties such as adhesion and plasticity of aged waste asphalt mixture by adding recycling agents, new asphalt, and new aggregates, and then reusing it for road construction or maintenance. This achieves the resource recycling and utilization of these solid materials. Recycled asphalt mixture mixing equipment is used when recycling asphalt. To address this, patent CN211571273U discloses an asphalt mixture recycling mixing and heating device, comprising a support frame, a mixing drum, and a tail support handle. A mounting base is welded to the top of the support frame, and the mixing drum is mounted on the top of the mounting base via fastening bolts. A mixing motor is mounted on the bottom of the mixing drum via a mounting bracket, and the power output end of the mixing motor passes through the mixing drum and connects to a mixing rod. Arc-shaped electric heating plates are mounted on both sides of the bottom of the mixing drum via fastening bolts, and a chimney is welded to the top of the mixing drum. A temperature controller is mounted on one side of the bottom of the mixing drum via fastening screws, and the output end of the temperature controller is electrically connected to the input end of the arc-shaped electric heating plate via a wire. A timer switch is mounted on one side of the mixing drum via a fixing bracket. This invention provides an asphalt mixture recycling mixing and heating device with a high degree of automation and good operational stability, making it suitable for widespread promotion and use. The existing technical solutions described above have the following drawbacks: although the above technology can heat and stir asphalt during recycling, the heating of the asphalt is not uniform enough, which leads to uneven heating of the asphalt during recycling and stirring, thus affecting the recycling effect. Summary of the Invention

[0003] The purpose of this invention is to provide a multi-point heating recycled asphalt mixture mixing device to solve the defects of existing recycled asphalt mixture mixing devices, which, although capable of heating and mixing asphalt during recycling, do not heat the asphalt evenly, resulting in uneven heating of the asphalt during recycling and affecting the recycling and fusion effect.

[0004] To solve the above-mentioned technical problems, the present invention provides the following technical solution: a multi-point heating recycled asphalt mixture mixing device, comprising a mixing tank and a pressure relief valve; An air inlet pipe is installed at the bottom of the mixing tank, a filter exhaust port is provided on one side of the top of the mixing tank, a discharge port is installed on one side of the bottom of the mixing tank, and an auxiliary structure is provided inside the mixing tank. The auxiliary structure includes a hollow shaft installed inside the mixing tank. A pressure relief valve is installed at the top of the hollow shaft, and an air inlet pipe is rotatably sealed to the bottom of the hollow shaft. A stirring shaft is installed on the outside of the hollow shaft. A cavity is formed in the inner wall of the mixing tank. An installation sleeve is installed on the outside of the stirring shaft. A circular plate is installed inside the installation sleeve. A stirring rod is installed at the top of the circular plate. A return spring is sleeved on the outside of the stirring rod.

[0005] Preferably, the two ends of the return spring are connected to the top end of the mounting sleeve and the top end of the circular plate, respectively, and the return spring and the circular plate form a telescopic structure.

[0006] Preferably, multiple sets of the mounting sleeves are provided, and the multiple sets of mounting sleeves are symmetrically distributed on the outside of the stirring shaft.

[0007] Preferably, the mixing tank has a feed inlet at its top, and a preheating structure is provided at the top of the feed inlet. The preheating structure includes a feed box, which is installed at the top of the feed inlet. A conveyor belt is installed inside the feed box, and a scraper plate is installed at the top of the conveyor belt. One side of the scraper plate has an angled opening, and a groove is formed inside the top of the scraper plate. An intercepting net is installed inside the groove. A movable groove is formed on one side of the groove, and a movable rod is installed inside the movable groove. One end of the movable rod is connected to one end of the intercepting net. A telescopic spring is sleeved on the outside of the movable rod, and both ends of the telescopic spring are fixed to one side of the groove and one side of the intercepting net, respectively. A connecting rod is installed on the other side of the intercepting net, and a fixing block is installed at one end of the connecting rod.

[0008] Preferably, a mounting frame is installed on one side of the feed box, a reciprocating lead screw is installed at the middle position of the mounting frame, a threaded sleeve is installed on the outside of the reciprocating lead screw, and an extrusion block is installed on the outside of the threaded sleeve.

[0009] Preferably, a guide seat is installed on one side of the middle position of the mounting bracket, a guide groove is opened on one side of the guide seat, a guide block is installed inside the guide groove, and one end of the guide block is connected to the outside of the thread sleeve.

[0010] Preferably, the guide block is inserted into the interior of the guide groove, and the guide block and the guide groove form a guide connection.

[0011] Preferably, the threaded sleeve is fitted on the outside of the reciprocating lead screw, and the threaded sleeve and the reciprocating lead screw form a threaded connection. Multiple sets of comb teeth are installed on one side of the bottom end of the scraper plate, and the multiple sets of comb teeth are arranged at equal intervals on one side of the bottom end of the scraper plate.

[0012] Preferably, the conveyor belts are provided in multiple sets, and the multiple sets of conveyor belts are staggered inside the feed box.

[0013] Preferably, an air inlet box is installed on one side of the feed box, a heater is installed inside the air inlet box, a fan is installed on one side of the heater, a dustproof net is installed on one side of the fan, an installation pipe is installed at one end of the air inlet box, the installation pipe is connected to the top of the cavity, and a connecting pipe is installed on one side of the air inlet box, one end of the connecting pipe is connected to one end of the air outlet pipe.

[0014] The present invention provides a multi-point heating recycled asphalt mixture mixing device, the advantages of which are: With the aid structure in place, the preheated raw material falls into the mixing tank. Dry steam continuously flows inside the cavity, heating the recycled material and allowing the various materials in the material to fully blend. When the dry steam flows inside the air inlet pipe, some of it flows into the hollow shaft. Since the hollow shaft and mixing shaft are hollow, the dry steam can heat them, which, combined with the heating of the outside of the cavity, achieves simultaneous heating and mixing of the asphalt recycled material from both the inside and outside. This makes the material more evenly heated during mixing and results in a better mixing effect. Furthermore, by utilizing sufficient pressure inside the hollow shaft and the use of a circular plate, the mixing rod is pushed out from inside the mounting sleeve to mix the raw materials. The use of the pushed-out mixing rod at this time can expand the mixing coverage area, reduce the mixing dead zones, and increase the mixing shear force to efficiently break up raw material lumps. Moreover, the design of pushing out the mixing rod directly uses the internal energy of the dry steam already present in the asphalt recycling process to drive the mixing blades out, without the need to add additional driving components such as motors and cylinders, and without increasing system energy consumption. This achieves better mixing effect during the heating of the asphalt raw materials from the inside and outside, making the mixing of raw materials more effective. By incorporating a preheating structure, three sets of conveyor belts are used during the recycling and mixing of asphalt. These three sets of conveyor belts are staggered, allowing the raw materials to be flipped during transportation, resulting in better preheating. The use of the installation pipe allows the drying steam generated after heating the raw materials to be discharged into the air inlet box, thereby recovering waste heat, reducing the time the heater takes to heat the air, and lowering heating costs. Because the conveyor belt is mesh-shaped, air can pass through the conveyor belt to preheat the raw materials, making the raw materials mix faster in the subsequent mixing process and reducing mixing time. Furthermore, when excessively tall raw materials come into contact with one side of the scraper plate, the scraper plate will first level the raw materials on one side, thereby making the thickness of the raw materials uniform. During the leveling process, coarse and fine aggregates may form local clumps due to compression. These clumps can prevent hot air from penetrating, resulting in local overheating or underheating. When the comb teeth pass through the material layer, the shearing force between the teeth can directly break up these clumps, allowing the coarse and fine aggregates to be redistributed evenly, ensuring the consistency of subsequent preheating. Furthermore, when the comb teeth pass through the material layer, they form longitudinal gap channels on the surface of the material layer that are consistent with the tooth spacing. These channels can guide hot air to pass through the material layer quickly and evenly, and make full contact with the aggregate, avoiding preheating dead zones where the surface is hot and the bottom is cold, thus further improving the preheating effect. Attached Figure Description

[0015] Figure 1 This is a frontal three-dimensional structural schematic diagram of the present invention; Figure 2 This is a three-dimensional structural diagram of the present invention viewed from below; Figure 3 This is a frontal cross-sectional three-dimensional structural schematic diagram of the present invention; Figure 4 This is a top-view partial cross-sectional three-dimensional structural schematic diagram of the present invention; Figure 5 This is a frontal three-dimensional structural diagram of the auxiliary structure of the present invention; Figure 6 for Figure 5 A magnified view of the structure at point A in the middle; Figure 7 This is a three-dimensional structural schematic diagram of the preheating structure of the present invention, viewed from the front and in cross-section. Figure 8 This is a side view of the three-dimensional structure of the preheating structure of the present invention; Figure 9 This is a frontal three-dimensional structural diagram of the scraper plate of the present invention; Figure 10 for Figure 9 A magnified schematic diagram of the structure at point B in the middle; Figure 11 This is a three-dimensional structural diagram of the scraper plate of the present invention, viewed from below. Figure 12 This is a frontal three-dimensional structural schematic diagram of the reciprocating lead screw of the present invention.

[0016] The following are the annotations in the diagram: 1. Mixing tank; 2. Preheating structure; 201. Air inlet box; 202. Feed box; 203. Conveyor belt; 204. Scraper plate; 205. Air outlet pipe; 206. Heater; 207. Fan; 208. Dustproof net; 209. Connecting pipe; 2010. Mounting bracket; 2011. Mounting pipe; 2012. Groove; 2013. Interception net; 2014. Comb teeth; 2015. Connecting rod; 2016. Fixing block; 2017. Extrusion block; 2 018. Movable groove; 2019. Movable rod; 2020. Telescopic spring; 2021. Guide seat; 2022. Guide groove; 2023. Reciprocating screw; 2024. Sleeve; 2025. Guide block; 3. Pressure relief valve; 4. Air inlet pipe; 5. Discharge port; 6. Filter exhaust port; 7. Auxiliary structure; 701. Stirring shaft; 702. Cavity; 703. Hollow shaft; 704. Mounting sleeve; 705. Stirring rod; 706. Return spring; 707. Circular plate; 8. Feed inlet. Detailed Implementation

[0017] 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. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0018] Please see Figures 1-12 The present invention provides a multi-point heating recycled asphalt mixture mixing device, including a mixing tank 1 and a pressure relief valve 3; an air inlet pipe 4 is installed at the bottom of the mixing tank 1, a filter exhaust port 6 is provided on one side of the top of the mixing tank 1, a discharge port 5 is installed on one side of the bottom of the mixing tank 1, and an auxiliary structure 7 is provided inside the mixing tank 1; a feed inlet 8 is opened at the top of the mixing tank 1, and a preheating structure 2 is provided at the top of the feed inlet 8.

[0019] Reference Figures 1-12As shown, the preheating structure 2 includes a feed box 202, which is installed at the top of the feed inlet 8. A conveyor belt 203 is installed inside the feed box 202, and a scraper plate 204 is installed at the top of the conveyor belt 203. One side of the scraper plate 204 has an angled opening, and a groove 2012 is formed inside the top of the scraper plate 204. A blocking net 2013 is installed inside the groove 2012, and a movable groove 2018 is formed on one side of the groove 2012. A movable rod 2019 is installed inside the movable groove 2018, and one end of the movable rod 2019 is connected to one end of the blocking net 2013. A telescopic spring 2020 is fitted on the outer side of the feed box 202. The two ends of the telescopic spring 2020 are fixed to one side of the groove 2012 and one side of the interceptor net 2013, respectively. A connecting rod 2015 is installed on the other side of the interceptor net 2013, and a fixing block 2016 is installed at one end of the connecting rod 2015. A mounting bracket 2010 is installed on one side of the feed box 202. A reciprocating screw 2023 is installed in the middle of the mounting bracket 2010. A threaded sleeve 2024 is installed on the outer side of the reciprocating screw 2023, and a pressing block 2017 is installed on the outer side of the threaded sleeve 2024. A guide is installed on one side of the middle position of the mounting bracket 2010. The guide seat 2021 has a guide groove 2022 on one side, and a guide block 2025 is installed inside the guide groove 2022. One end of the guide block 2025 is connected to the outside of the threaded sleeve 2024. The guide block 2025 is inserted into the guide groove 2022, and a guide connection is formed between the guide block 2025 and the guide groove 2022. The threaded sleeve 2024 is sleeved on the outside of the reciprocating lead screw 2023, and a threaded connection is formed between the threaded sleeve 2024 and the reciprocating lead screw 2023. Multiple sets of comb teeth 2014 are installed on one side of the bottom end of the scraper plate 204. The conveyor belts 203 are arranged at equal intervals on one side; multiple sets of conveyor belts 203 are arranged in a staggered manner inside the feed box 202; an air inlet box 201 is installed on one side of the feed box 202, a heater 206 is installed inside the air inlet box 201, a fan 207 is installed on one side of the heater 206, a dustproof net 208 is installed on one side of the fan 207, an installation pipe 2011 is installed at one end of the air inlet box 201, the installation pipe 2011 is connected to the top of the cavity 702, and a connecting pipe 209 is installed on one side of the air inlet box 201, one end of the connecting pipe 209 is connected to one end of the air outlet pipe 205.

[0020] During the asphalt recycling process, workers pour recycled asphalt granules, mixed with new asphalt and new aggregates, into the feed hopper 202. After pouring, the conveyor belt 203 is started to move the raw material. Since there are three sets of conveyor belts 203, and these three sets are staggered, the raw material can be flipped during transport, resulting in better preheating. While the raw material is being transported, the heater 206 and fan 207 are activated to heat the air, and the heated air is then delivered to the connecting pipe 209. The installation pipe 20... The use of 11 allows the drying steam after heating the raw materials to be discharged into the air inlet box 201, thereby recovering waste heat, reducing the heating time of the heater 206, and reducing heating costs. The air inlet box 201 is equipped with a temperature sensor to monitor the heating temperature. After heating, the air will be discharged into the feed box 202 through the air outlet 205. Since the conveyor belt 203 is mesh-shaped, the air can pass through the conveyor belt 203 to preheat the raw materials, making the raw materials faster during subsequent mixing and reducing the mixing time. As the raw material moves on the conveyor belt 203, three sets of scraper plates 204 are installed as needed to control the different thicknesses of the raw material on the three sets of conveyor belts 203, achieving inconsistent material heights and corresponding to three layers of material thickness: thin → medium → thick. When the raw material first enters the upper conveyor belt 203, the temperature is the lowest. The thin material layer has low resistance to hot air penetration, and the low-temperature hot air will not cause local overheating of the raw material, achieving gentle initial preheating and preventing the aggregate from cracking due to excessive temperature difference. When it reaches the middle conveyor belt 203, the raw material already has a basic temperature, the material layer thickness is moderate, and the coarse and fine aggregates are evenly mixed. After the hot air penetrates, it can eliminate the temperature unevenness caused by particle size differences, achieving uniform heating. Finally, when it reaches the lower conveyor belt 203, the raw material needs to rise to the target temperature. The thick material layer has a larger contact area and longer contact time with the high-temperature hot air, which can ensure that the coarse aggregate can also be fully heated, achieving thorough preheating and thus improving the preheating effect. When excessively thick raw materials come into contact with one side of the scraper plate 204, the scraper plate 204 first flattens the raw materials, ensuring a uniform thickness. During the flattening process, the coarse and fine aggregates may form local clumps due to compression. These clumps can prevent hot air from penetrating, resulting in local overheating or underheating. When the comb teeth 2014 pass through the material layer, the shearing force between the teeth can directly break up these clumps, allowing the coarse and fine aggregates to be redistributed evenly, ensuring the consistency of subsequent preheating. When the comb teeth 2014 pass through the material layer, they form longitudinal gap channels on the surface of the material layer that are consistent with the tooth spacing. These channels can guide the hot air to pass through the material layer quickly and evenly, making full contact with the aggregates and avoiding preheating dead zones where the surface is hot and the bottom is cold, further improving the preheating effect. Because one side of the comb teeth 2014 is angled, during leveling, the intercepted material will enter the interior of the groove 2012. Since one side of the groove 2012 has a slope, the material's own weight and the thrust of the conveyor belt 203 are used to force the material to slide along the slope into the intercepting net 2013. When the material falls into the intercepting net 2013, the mesh of the net 2013 forms a uniform flexible resistance to the material flow, dispersing the impact kinetic energy of the material and causing the high-speed downward flow to suddenly decrease in speed, thus reducing the impact-induced sliding force. The flow becomes a slow seepage. When the scraper plate 204 is working, the start motor drives the three sets of reciprocating screws 2023 to rotate simultaneously. During the rotation of the reciprocating screws 2023, the screw sleeve 2024 will rotate. Since the guide block 2025 at one end of the screw sleeve 2024 is inserted into the guide groove 2022 on one side of the guide seat 2021, the screw sleeve 2024 is guided, so that it can only move back and forth on the outside of the reciprocating screw 2023. Whenever the screw sleeve 2024 drives the extrusion block 2017 past the position of the fixed block 2016, Because the outer side of the fixing block 2016 is angled, the fixing block 2016 will compress and retract to one side. When the fixing block 2016 retracts to one side, it will push the intercepting net 2013 to one side inside the groove 2012 through the connecting rod 2015, and compress the telescopic spring 2020 to retract. When the compression block 2017 disengages from one side of the fixing block 2016, the telescopic spring 2020 will cause the intercepting net 2013 to return to its original position, thereby causing the intercepting net 2013 to reciprocate. The raw material on the surface of the 2013 screen is screened. When the static intercepting net 2013 is slowed down by the resistance of the wires alone, the material flow may locally impact the net. However, when the intercepting net 2013 moves back and forth in a small range, the contact between the wires and the material flow is dynamic and uniform. It can apply continuous and dispersed flexible resistance to the sliding material flow, completely transforming the impact-type sliding flow of the material flow into a slow seepage flow. It can also efficiently break up locally clumps of raw material, improve the uniformity of the material flow, dynamically prevent blockage and remove adhesion, eliminate the risk of mesh blockage, and ensure that the screened raw material falls evenly.

[0021] Reference Figures 1-6As shown, the auxiliary structure 7 includes a hollow shaft 703, which is installed inside the mixing tank 1. A pressure relief valve 3 is installed at the top of the hollow shaft 703, and an air inlet pipe 4 is rotatably sealed to the bottom of the hollow shaft 703. A stirring shaft 701 is installed on the outside of the hollow shaft 703. A cavity 702 is opened in the inner wall of the mixing tank 1. An installation sleeve 704 is installed on the outside of the stirring shaft 701. A circular plate 707 is installed inside the installation sleeve 704. A stirring rod 705 is installed at the top of the circular plate 707. A return spring 706 is sleeved on the outside of the stirring rod 705. The two ends of the return spring 706 are connected to the top of the inside of the installation sleeve 704 and the top of the circular plate 707, respectively. The return spring 706 and the circular plate 707 form a telescopic structure. Multiple sets of installation sleeves 704 are provided, and the multiple sets of installation sleeves 704 are symmetrically distributed on the outside of the stirring shaft 701.

[0022] The preheated raw material falls into the mixing tank 1. At this time, the air inlet pipe 4 is connected to the dry steam delivery pipe, so that the dry steam is delivered into the cavity 702. The heating temperature is monitored by the temperature sensor inside the cavity 702. The dry steam continuously flows inside the cavity 702, thereby heating the recycled raw material and making the various materials in the raw material fully blended. When the dry steam flows inside the air inlet pipe 4, some of the dry steam will flow into the hollow shaft 703. Since the hollow shaft 703 and the mixing shaft 701 are hollow, the dry steam can heat the hollow shaft 703 and the mixing shaft 701. Combined with the heating of the outside of the cavity 702, the asphalt recycled raw material is heated and mixed at the same time from the inside and outside, so that the raw material is heated more evenly during mixing and the mixing effect is better. Furthermore, when dry air enters the hollow shaft 703, setting the opening pressure of the pressure relief valve 3 above the minimum ejection pressure of the stirring rod 705 achieves stable pressure maintenance within the hollow shaft 703, continuous micro-venting, and utilizes sufficient pressure inside the hollow shaft 703 to eject the stirring rod 705 from the mounting sleeve 704 via the use of the circular plate 707. The return spring 706 automatically returns the rod to its original position when the pressure is released. A sealing structure is provided at the connection between the stirring rod 705 and the mounting sleeve 704 to prevent asphalt from entering the mounting sleeve 704. After the stirring rod 705 is ejected, it is driven by the motor... The hollow shaft 703 and the mixing shaft 701 rotate to agitate the raw materials. The use of the ejected mixing rod 705 expands the agitation coverage, reduces dead zones, and increases the shear force, effectively breaking up raw material agglomerates. Furthermore, the ejected design of the mixing rod 705 directly utilizes the internal energy of the dry steam already present in the asphalt recycling process to drive the mixing blades, eliminating the need for additional drive components such as motors and cylinders, thus not increasing system energy consumption. This enhances the agitation effect during the internal and external heating of the asphalt raw materials, resulting in better agitation. Through preheating and internal / external heating and agitation of the asphalt raw materials, multi-point heating of the asphalt raw materials is achieved, leading to better performance in the recycled mixture and completing the mixing process for the recycled asphalt mixture.

[0023] Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A multi-point heating recycled asphalt mixture mixing device, comprising a mixing tank (1) and a pressure relief valve (3); Its features are: An air inlet pipe (4) is installed at the bottom of the mixing tank (1), a filter exhaust port (6) is provided on one side of the top of the mixing tank (1), a discharge port (5) is installed on one side of the bottom of the mixing tank (1), and an auxiliary structure (7) is provided inside the mixing tank (1). The auxiliary structure (7) includes a hollow shaft (703), which is installed inside the mixing tank (1). A pressure relief valve (3) is installed at the top of the hollow shaft (703), and an air inlet pipe (4) is rotatably sealed at the bottom of the hollow shaft (703). A stirring shaft (701) is installed on the outside of the hollow shaft (703). A cavity (702) is opened in the inner wall of the mixing tank (1). An installation sleeve (704) is installed on the outside of the stirring shaft (701). A circular plate (707) is installed inside the installation sleeve (704). A stirring rod (705) is installed at the top of the circular plate (707), and a return spring (706) is sleeved on the outside of the stirring rod (705).

2. The multi-point heating recycled asphalt mixture mixing device according to claim 1, characterized in that: The two ends of the return spring (706) are connected to the top end inside the mounting sleeve (704) and the top end of the circular plate (707), respectively, and the return spring (706) and the circular plate (707) form a telescopic structure.

3. The multi-point heating recycled asphalt mixture mixing device according to claim 1, characterized in that: The mounting sleeve (704) is provided in multiple sets, and the multiple sets of mounting sleeves (704) are symmetrically distributed on the outside of the stirring shaft (701).

4. The multi-point heating recycled asphalt mixture mixing device according to claim 1, characterized in that: The mixing tank (1) has a feed inlet (8) at its top. A preheating structure (2) is provided at the top of the feed inlet (8). The preheating structure (2) includes a feed box (202). The feed box (202) is installed at the top of the feed inlet (8). A conveyor belt (203) is installed inside the feed box (202). A scraper plate (204) is installed at the top of the conveyor belt (203). A chamfer is provided on one side of the scraper plate (204). A groove (2012) is provided inside the top of the scraper plate (204). An intercepting net (2013) is installed inside the groove (2012). A movable groove (2018) is provided on one side inside the groove (2012). A movable rod (2019) is installed inside the movable groove (2018). One end of the movable rod (2019) is connected to one end of the interception net (2013). A telescopic spring (2020) is sleeved on the outside of the movable rod (2019). The two ends of the telescopic spring (2020) are fixed to one side of the groove (2012) and one side of the interception net (2013), respectively. A connecting rod (2015) is installed on the other side of the interception net (2013). A fixing block (2016) is installed at one end of the connecting rod (2015).

5. A multi-point heating recycled asphalt mixture mixing device according to claim 4, characterized in that: A mounting bracket (2010) is installed on one side of the feed box (202). A reciprocating screw (2023) is installed at the middle position of the mounting bracket (2010). A thread sleeve (2024) is installed on the outside of the reciprocating screw (2023). An extrusion block (2017) is installed on the outside of the thread sleeve (2024).

6. The multi-point heating recycled asphalt mixture mixing device according to claim 5, characterized in that: A guide seat (2021) is installed on one side of the middle position of the mounting bracket (2010). A guide groove (2022) is opened on one side of the guide seat (2021). A guide block (2025) is installed inside the guide groove (2022). One end of the guide block (2025) is connected to the outside of the thread sleeve (2024).

7. A multi-point heating recycled asphalt mixture mixing device according to claim 6, characterized in that: The guide block (2025) is inserted into the interior of the guide groove (2022), and the guide block (2025) and the guide groove (2022) form a guide connection.

8. A multi-point heating recycled asphalt mixture mixing device according to claim 5, characterized in that: The threaded sleeve (2024) is sleeved on the outside of the reciprocating lead screw (2023), and the threaded sleeve (2024) and the reciprocating lead screw (2023) form a threaded connection. Multiple sets of comb teeth (2014) are installed on one side of the bottom end of the scraper plate (204), and the multiple sets of comb teeth (2014) are arranged at equal intervals on one side of the bottom end of the scraper plate (204).

9. A multi-point heating recycled asphalt mixture mixing device according to claim 4, characterized in that: The conveyor belt (203) is provided in multiple sets, and the multiple sets of conveyor belts (203) are staggered inside the feed box (202).

10. A multi-point heating recycled asphalt mixture mixing device according to claim 4, characterized in that: An air inlet box (201) is installed on one side of the feed box (202). A heater (206) is installed inside the air inlet box (201). A fan (207) is installed on one side of the heater (206). A dustproof net (208) is installed on one side of the fan (207). An installation pipe (2011) is installed at one end of the air inlet box (201). The installation pipe (2011) is connected to the top of the cavity (702). A connecting pipe (209) is installed on one side of the air inlet box (201). One end of the connecting pipe (209) is connected to one end of the air outlet pipe (205).

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