An asphalt heating device and method for an asphalt pavement maintenance vehicle

Abstract

This invention discloses an asphalt heating device and method for asphalt pavement maintenance vehicles. The asphalt heating device includes a microwave generator, a rotating reflector, and a hot air duct. The rotating reflector is located at the outlet of the hot air duct. The microwave generator and the rotating reflector are connected through a heater housing. The rotating reflector is tilted, and the microwaves generated by the microwave generator are reflected by the rotating reflector and coupled with the hot air to heat the asphalt pavement. This invention can maximize thermal efficiency. Through this dual heat source and rotating electromagnetic field design, not only can the speed and depth of asphalt heating be improved, but thermal efficiency can also be maximized, energy consumption can be reduced, and environmental impact can be minimized. Microwave heating can quickly and evenly penetrate heat into the asphalt, while hot air heating can maintain the surface temperature of the asphalt and prevent excessive internal and external temperature differences caused by rapid surface cooling, thereby ensuring the uniformity of asphalt heating.

Description

Technical Field

[0001] This invention relates to the field of asphalt pavement heating technology, specifically to an asphalt heating device and method for asphalt pavement maintenance vehicles. Background Technology

[0002] The maintenance and repair of asphalt pavements are crucial for ensuring road quality and driving safety, playing a vital role in promoting economic and social development. Asphalt pavement heating technology is a relatively new road maintenance method that involves heating the road surface to a specific temperature (typically between 150 and 180 degrees Celsius) for repair and renovation. The specific steps include using specialized heating equipment to heat the asphalt pavement to a temperature suitable for reshaping, then using equipment such as forklifts to mix the heated asphalt with new asphalt materials to restore the asphalt's structure and strength, while filling any cracks or depressions. Finally, the new pavement needs to be compacted to ensure its strength and durability.

[0003] Hot recycling of asphalt pavements is an effective, economical, and environmentally friendly method for pavement repair and maintenance, suitable for repairing pavements with minor to moderate damage. However, it requires precise equipment and skilled operators to achieve optimal results. A major advantage of this technology is that it significantly reduces the need for new materials, as most existing asphalt can be reused. Furthermore, it reduces environmental impact because there is no need to transport old asphalt materials to waste sites. However, this technology also has some potential drawbacks, such as uneven heating or inaccurate temperature control potentially leading to a decline in pavement quality.

[0004] Various methods of heating asphalt pavements, such as direct flame heating, hot air heating, and even the newer microwave heating, each have their own advantages and disadvantages. Although newer heating methods, such as microwave heating, can achieve rapid and uniform heating with high thermal efficiency and low energy consumption, the equipment cost is high, and the electromagnetic radiation generated may have an impact on the environment and human health.

[0005] Direct flame heating is one of the earliest and simplest heating methods. Its advantages include simple equipment and low cost. However, the problems with direct flame heating are uneven heating and the high temperature of the flame can easily damage the chemical properties of asphalt, reducing the quality and service life of the road. Furthermore, direct flame heating poses a significant safety hazard as it can potentially cause fires.

[0006] Hot air heating is a common heating method. This method uses a blower to direct hot air onto the road surface, heating it with the hot air. The advantages of hot air heating are its uniform heating and preservation of the asphalt's chemical properties. However, the problems with hot air heating include lower thermal efficiency, slower heating speed, higher energy consumption, and some environmental impact.

[0007] Microwave heating offers the advantages of rapid and uniform heating with high thermal efficiency and low energy consumption. However, microwave heating equipment is expensive, and microwave heating may generate electromagnetic radiation, which can negatively impact the environment and human health.

[0008] In-situ recycling asphalt pavement maintenance vehicles are equipment used for the repair and maintenance of asphalt pavements. They can recycle old asphalt pavements to reduce resource waste and extend the service life of the pavement. However, this equipment also has some problems. For example, inaccurate heating methods may lead to aging and coking of the surface asphalt, resulting in a decline in the pavement's performance after recycling, and the toxic blue smoke produced may cause serious environmental pollution. In addition, the heating depth of existing equipment is limited, and deep-seated defects cannot be effectively treated, resulting in poor adaptability to different working conditions. At the same time, energy utilization is low, and most of the heating energy may be wasted. Vehicles driving over the pavement may cause the deep asphalt material to be pushed up, changing the original pavement gradation and affecting the quality of the recycled pavement. Summary of the Invention

[0009] In view of the problems existing in the prior art, the present invention provides an asphalt heating device for asphalt pavement maintenance vehicles, which can improve the heating efficiency, depth and uniformity of asphalt pavement, while reducing environmental impact and energy consumption.

[0010] The technical solution of the present invention is as follows:

[0011] In a first aspect of the present invention, an asphalt heating device for an asphalt pavement maintenance vehicle is provided, comprising a microwave generator, a rotating reflector, and a hot air duct. The rotating reflector is disposed at the outlet of the hot air duct. The microwave generator and the rotating reflector are connected through a heater housing. The rotating reflector is inclined. The microwaves generated by the microwave generator are reflected by the rotating reflector and coupled with the hot air to heat the asphalt pavement.

[0012] In some embodiments of the present invention, the rotating reflector includes a duct baffle, a wing plate fixed shaft, and a reflector moving blade. The reflector moving blade is mounted on the wing plate fixed shaft, and the reflector moving blade is adjustable in angle.

[0013] In some embodiments of the present invention, one end of the air duct baffle is connected to a hot air duct, and the other end is connected to a heater housing.

[0014] In some embodiments of the invention, the opening of the heater housing faces the asphalt pavement.

[0015] In some embodiments of the present invention, multiple moving blades of the reflector are provided, and the material of the moving blades of the reflector is a microwave-emitting metal.

[0016] In some embodiments of the present invention, a heat dissipation device is provided between the microwave generator and the heater housing.

[0017] In some embodiments of the present invention, the microwave generator employs a magnetron.

[0018] In a second aspect of the invention, an asphalt pavement maintenance vehicle is provided, including an asphalt heating device installed at the bottom of the maintenance vehicle, with the opening of the heater housing facing the asphalt pavement, a microwave generator connected to a diesel generator via a microwave cable, and a hot air duct connected in sequence to a hot air rotary heater and a diesel burner.

[0019] In some embodiments of the present invention, multiple asphalt heating devices are installed at intervals on the bottom of the maintenance vehicle.

[0020] In a third aspect of the invention, an asphalt heating method is provided, which uses microwave and hot air dual heat sources coupled together to heat the asphalt pavement. Microwave heating penetrates the heat into the interior of the asphalt, while hot air heating maintains the temperature of the asphalt surface, thereby uniformly heating the asphalt pavement.

[0021] One or more technical solutions of the present invention have the following beneficial effects:

[0022] (1) The asphalt heating device provided by this invention has the following characteristics: hot air not only serves as a heat source but also as a power source. The hot air blows the reflector to rotate, and the reflector rotates under the blowing of the hot air. During the rotation, each blade rotates periodically with respect to the reflected microwaves, making the microwave irradiation more uniform. At the same time, each blade of the reflector has a certain tilt angle, so that after the microwaves irradiate the reflector, the irradiation area of ​​the reflected microwaves in the set area is wider. In the above way, the energy of the microwaves is transferred to the asphalt, improving the energy utilization rate of the microwaves; the dual heat source of microwaves and hot air improves the heating depth: using microwaves and hot air as dual heat sources can effectively improve the efficiency and depth of asphalt heating. Microwave heating uses the vibration of the electromagnetic field to generate heat, which can quickly and uniformly penetrate the heat into the interior of the asphalt, accelerating the heating speed and improving the heating depth.

[0023] (2) The asphalt heating device provided by this invention can maximize thermal efficiency. Through this dual heat source and rotating electromagnetic field design, not only can the speed and depth of asphalt heating be improved, but thermal efficiency can also be maximized, energy consumption reduced, and environmental impact minimized. Microwave heating can quickly and evenly penetrate heat into the asphalt, while hot air heating can maintain the surface temperature of the asphalt and prevent excessive internal and external temperature differences caused by rapid surface cooling, thereby ensuring the uniformity of asphalt heating.

[0024] (3) The asphalt heating device provided by the present invention adopts an integrated vehicle-mounted design. The device can be installed in one piece at the bottom of the maintenance vehicle, so that the asphalt pavement can be continuously and evenly heated during the movement of the maintenance vehicle, thereby improving the efficiency of maintenance work. At the same time, this integrated design also makes the equipment more compact, reduces the space occupied by the equipment, and facilitates the transportation and use of the equipment.

[0025] (4) The asphalt heating method provided by the present invention uses microwave coupled hot air to heat the asphalt pavement, which not only solves the limitations of traditional heating methods and improves heating efficiency and uniformity, but also reduces energy consumption and environmental impact, improves road quality and service life, and ensures driving safety. Attached Figure Description

[0026] Figure 1 This is a schematic diagram of the asphalt heating device for asphalt pavement maintenance vehicles according to the present invention;

[0027] Figure 2 This is a schematic diagram of the rotating reflector of the present invention;

[0028] Figure 3 This is a schematic diagram of the structure of the single hot air inlet coupled with dual rotating reflectors of the present invention;

[0029] Figure 4 This is a schematic diagram of the structure of the present invention, which is a single microwave generator driving dual rotating reflectors coupled with dual hot air inlets.

[0030] Figure 5 This is a schematic diagram of a conventional microwave reflector box coupled with hot air.

[0031] Figure 6 Simulation results of fixed electromagnetic field coupled hot air heating of asphalt without rotating reflector;

[0032] Figure 7 Simulation results of electromagnetic field coupled hot air heating of asphalt with rotating reflector;

[0033] Figure 8 Simulation results of electromagnetic field coupled hot air heating of asphalt with rotating reflector;

[0034] Figure 9 This is a schematic diagram of the asphalt pavement maintenance vehicle of the present invention;

[0035] In the diagram: 1. Microwave generator; 2. Heat dissipation device; 3. Heater housing; 4. Rotating reflector; 4-1. Air duct baffle; 4-2. Wing plate fixing shaft; 4-3. Reflector moving blade; 5. Guide plate; 6. Hot air duct interface; 7-1. Hot air flow; 7-2. Microwave irradiation; 8. Diesel generator; 9. Diesel burner; 10. Hot air rotary heater; 11. Hot air duct; 12. Microwave cable; 13. Maintenance vehicle. Detailed Implementation

[0036] The present invention will be further described below with reference to the accompanying drawings and embodiments.

[0037] Example 1

[0038] In a typical embodiment of the present invention, an asphalt heating device for an asphalt pavement maintenance vehicle is provided, such as... Figure 1 and Figure 2 As shown, it includes a microwave generator 1, a rotating reflector 4, and a hot air duct 11. The rotating reflector 4 is connected to the outlet of the hot air duct 11 through the hot air duct interface 6. The microwave generator 1 and the rotating reflector 4 are connected through the heater housing 3. The rotating reflector 4 is set at an angle. The microwaves generated by the microwave generator 1 are reflected by the rotating reflector 4 and coupled with the hot air to heat the asphalt pavement.

[0039] like Figure 2 As shown, the rotating reflector 4 includes a duct baffle 4-1, a wing plate fixing shaft 4-2, and a reflector moving blade 4-3. The reflector moving blade 4-3 is mounted on the wing plate fixing shaft 4-2, and the reflector moving blade 4-3 is angle-adjustable. Multiple reflector moving blades are provided, preferably three. The reflector moving blades rotate under the action of hot air. The reflector moving blades are made of microwave reflective metals, such as copper, aluminum, or stainless steel.

[0040] Furthermore, one end of the air duct baffle 4-1 is connected to the hot air duct through the hot air duct interface, and the other end is connected to the heater housing 3. The heater housing 3 serves as a heating space formed by the heat source, and the opening of the heater housing faces the asphalt pavement to heat the asphalt pavement.

[0041] In this embodiment, multiple guide plates 5 are provided inside the hot air duct interface. The guide plates are arc-shaped and adapted to the airflow direction, which can guide the hot air and ensure the stability of the hot air.

[0042] In this embodiment, a heat dissipation device 2 is provided between the microwave generator 1 and the heater housing 3 to ensure the stable operation of the microwave generator. Specifically, the heat dissipation device can be a heat sink, fan cooling, liquid cooling system, heat pipe, PELTIER element, etc. The mechanism shown in this embodiment is a heat sink, which can directly dissipate the generated heat into the air. The heat sink material is usually chosen to be a material with good thermal conductivity, such as aluminum or copper.

[0043] In this embodiment, the microwave generating device 1 uses a magnetron, which is essentially a diode placed in a constant magnetic field. Under the control of the mutually perpendicular constant magnetic field and constant electric field, the electrons inside the tube interact with the high-frequency electromagnetic field, converting the energy obtained from the constant electric field into microwave energy, thereby achieving the purpose of generating microwave energy.

[0044] In this embodiment, in order to improve the heating efficiency of the asphalt pavement, such as Figure 3 He Ru Figure 4 As shown, a hot air duct can be used to drive the symmetrically arranged double rotating reflectors, thereby achieving electromagnetic field coupling of the double rotating reflectors through a single hot air inlet; alternatively, a microwave generator can be used to provide microwaves to the double rotating reflectors within the two hot air ducts, thereby achieving electromagnetic field coupling of the double rotating reflectors through a single microwave generator and coupling of the double hot air inlets.

[0045] The working principle of the asphalt heating device provided in this embodiment is as follows:

[0046] Hot air is delivered to the rotating reflector via a hot air duct. The hot air blows the moving blades of the reflector, and the rotation of the moving blades causes the angle of the microwave reflector surface to change periodically. Then the hot air enters the heater housing and heats the asphalt pavement together with the microwave. The rotating reflector can change the direction of the microwave and hot air by adjusting the position of the moving blades of the reflector, so that the heating is more uniform. The heat dissipation device ensures the stable operation of the microwave generator.

[0047] according to Figure 1 The structural model shown has a heating area of ​​30cm × 30cm at the bottom where microwaves and hot air are coupled, a left wall height of 40cm, and a horizontal tilt angle of 45° for the rotating reflector. To compare the reflection effect between the rotating reflector with tilted blades and a conventional microwave reflector box, a conventional 30cm × 30cm × 40cm microwave reflector box was constructed with the same dimensions, as shown in the diagram. Figure 5 As shown. The device heats the asphalt pavement, with a hot air flow rate of 1.875 m³ / h. 3 The heating parameters were: hot air temperature 450℃, microwave power 900W, and heating time 20min. The multiphysics modeling software COMSOL was used to simulate both models, and the heating temperature of the horizontal cross-section of the asphalt pavement at a depth of 4cm was calculated.

[0048] Figure 6 As shown in the figure, the temperature simulation results of a conventional microwave reflector box without rotating reflector wings and electromagnetic field coupling hot air heating asphalt device are shown. It can be seen from the figure that if only the microwave generator is placed in the hot air duct without rotating reflector wings, the high temperature of the asphalt pavement with a horizontal cross-section of 4cm depth is mainly concentrated in the middle position, while the asphalt pavement on both sides is at a lower temperature. The heating temperature of the asphalt pavement is very uneven and cannot achieve a good heating effect.

[0049] Figure 7 The figure shows the simulation results of electromagnetic field coupling hot air heating of asphalt with a rotating reflector with tilted blades. The blades are fixed and do not rotate. It can be seen from the figure that the high temperature of the asphalt pavement with a horizontal cross-section of 4cm depth is mainly concentrated in the part that can reflect microwaves through the blades. Therefore, it can be concluded that the heating temperature of the asphalt pavement can be increased to a certain extent by setting the blades. However, the area occupied by the high temperature asphalt pavement is small, and there is still a problem of uneven heating temperature.

[0050] Figure 8 The figure shows the simulation results of electromagnetic field coupling hot air heating of asphalt using a rotating reflector with tilted blades. The blades rotate periodically due to the driving force of the hot air. As can be seen from the figure, the rotating blades effectively reflect microwaves periodically, increasing the area irradiated by the microwaves and simultaneously increasing the area occupied by the high-temperature asphalt pavement, resulting in more uniform heating of the asphalt pavement.

[0051] The simulation results show that, compared with conventional microwave reflector boxes, the addition of reflector wings with tilted blades results in a more uniform heating effect of microwave and hot air coupling within the irradiation area.

[0052] Example 2

[0053] An asphalt road maintenance vehicle, such as Figure 9 As shown, the device includes the asphalt heating device described in Example 1. The asphalt heating device is installed at the bottom of the maintenance vehicle, with the opening of the heater housing facing the asphalt road surface. The microwave generator is connected to the diesel generator via a microwave cable, and the hot air duct is connected in sequence to the hot air rotary heater and the diesel burner.

[0054] Furthermore, multiple asphalt heating devices are installed at intervals on the bottom of the maintenance vehicle. Since the asphalt heating devices adopt an integrated design, they can be directly installed on the bottom of the maintenance vehicle. By installing multiple asphalt heating devices, the asphalt pavement can be continuously and evenly heated during the movement of the maintenance vehicle, thereby improving the efficiency of the maintenance work.

[0055] The working principle of the asphalt pavement maintenance vehicle provided in this embodiment is as follows:

[0056] Hot air is generated by the diesel burner 9 and delivered to the rotating reflector 4 via the hot air duct 11. The hot air blows the rotating blades 4-3 of the reflector, causing a periodic change in the angle of the microwave reflector surface. The hot air then enters the heater housing 3, where it heats the asphalt pavement in conjunction with the microwaves. Electrical energy generated by the diesel generator is transmitted to the microwave generator 1 (magnetron) via the microwave cable 12. The microwave generator 1 converts the electrical energy into electromagnetic energy and emits microwave energy. This microwave radiation enters the heater housing 3, heating the asphalt pavement. By adjusting the position of the rotating reflector 4, the direction of the microwaves and hot air can be changed, achieving coupling between the hot airflow 7-1 and microwave irradiation 7-2, resulting in more uniform heating of the asphalt pavement. The heat dissipation device 2 ensures the stable operation of the microwave generator.

[0057] Example 3

[0058] A method for heating asphalt utilizes a dual heat source coupling of microwaves and hot air to heat the asphalt pavement. After periodic reflection by a rotating reflector, the microwaves penetrate deep into the asphalt, while the hot air maintains the surface temperature, achieving uniform heating of the asphalt pavement. The hot air serves not only as a heat source but also as a power source, driving the reflector to rotate. During rotation, the reflector periodically reflects the microwaves, effectively transferring microwave energy into the asphalt and improving energy utilization. Furthermore, using microwaves and hot air as dual heat sources significantly improves the efficiency and depth of asphalt heating. Microwave heating generates heat through electromagnetic field vibrations, rapidly and uniformly penetrating the asphalt. Simultaneously, the reflection by the rotating reflector expands the irradiation area, increasing the heating speed, depth, and area of ​​the asphalt pavement.

[0059] While the specific embodiments of the present invention have been described above in conjunction with the accompanying drawings, this is not intended to limit the scope of protection of the present invention. Those skilled in the art should understand that various modifications or variations that can be made by those skilled in the art without creative effort based on the technical solutions of the present invention are still within the scope of protection of the present invention.

Claims

1. An asphalt heating device for an asphalt pavement maintenance vehicle, characterized in that, It includes a microwave generator, a rotating reflector, and a hot air duct. The rotating reflector is located at the outlet of the hot air duct. The microwave generator and the rotating reflector are connected through a heater housing. The rotating reflector is tilted. The microwaves generated by the microwave generator are reflected by the rotating reflector and then coupled with the hot air to heat the asphalt pavement. The rotating reflector includes a duct baffle, a wing plate fixed shaft, and a reflector moving blade. The reflector moving blade is mounted on the wing plate fixed shaft and the reflector moving blade can adjust its angle. The reflector is provided with multiple moving blades, and the material of the moving blades is microwave reflective metal; One end of the air duct baffle is connected to the hot air duct, and the other end is connected to the heater housing; The opening of the heater housing faces the asphalt road surface.

2. The asphalt heating device for asphalt pavement maintenance vehicles as described in claim 1, characterized in that, A heat dissipation device is provided between the microwave generator and the heater housing.

3. The asphalt heating device for asphalt pavement maintenance vehicles as described in claim 1, characterized in that, The microwave generator device uses a magnetron.

4. An asphalt pavement maintenance vehicle, comprising the asphalt heating device as described in any one of claims 1-3, characterized in that, The asphalt heating device is installed at the bottom of the maintenance vehicle, with the opening of the heater housing facing the asphalt road surface. The microwave generator is connected to the diesel generator via a microwave cable, and the hot air duct is connected in sequence to the hot air rotary heater and the diesel burner.

5. The asphalt pavement maintenance vehicle as described in claim 4, characterized in that, The maintenance vehicle has multiple asphalt heating devices installed at intervals on its bottom.

6. A method for heating asphalt, implemented using the asphalt heating device according to any one of claims 1-3, characterized in that, The asphalt pavement is heated by coupling microwave and hot air as dual heat sources. After the microwave is periodically reflected by the rotating reflector, the heat penetrates deep into the asphalt, while the hot air heats the surface of the asphalt, thus achieving uniform heating of the asphalt pavement.

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