A kind of RAP weighing gravity premix type regenerant constant temperature spraying device and method

Abstract

The application discloses a RAP weighing gravity premixing type regenerant constant-temperature spraying device and method. The device comprises a RAP weighing hopper, a gravity dispersion premixing channel, a flow guide and material turning structure, a regenerant storage and supply unit, an atomization and spraying unit, a control unit and a waste heat insulation unit. The lower part of the RAP weighing hopper is provided with a discharge port, the gravity dispersion premixing channel is arranged below the discharge port, and the flow guide and material turning structure is arranged in the channel and used for forming dispersion, falling and turning and position changing movements of the RAP in the falling process. The atomization and spraying unit is communicated with the regenerant storage and supply unit, the control unit is used for linkage control of spraying according to the RAP weighing value and the discharge state. The waste heat insulation unit is communicated with a mixing station exhaust system, and the waste heat of the exhaust is used for indirect insulation of the regenerant. The method comprises the steps of weighing, discharging and dispersing, synchronous spraying and gravity premixing.

Description

Technical Field

[0001] This invention relates to the field of asphalt pavement recycling technology, and in particular to improvements in the spraying and premixing of recycled asphalt pavement materials during transportation. Background Technology

[0002] In asphalt pavement recycling technology, ensuring the recycling agent evenly coats the surface of the old asphalt mixture particles is crucial to the recycling quality. Traditional methods of adding recycling agents often involve centralized addition within the mixing tank or spraying on a conveyor belt, which suffers from problems such as delayed contact time, uneven dispersion, and easy local accumulation. To improve premixing, some technologies attempt to install spraying devices in the RAP (Recycled Asphalt Pavement Material) drop channel, utilizing the natural tumbling of the material during its descent to achieve preliminary mixing. This method eliminates the need for additional mechanical mixing mechanisms and offers engineering advantages such as compact structure and ease of modification to existing equipment.

[0003] Chinese patent document CN213504941U discloses a regenerant addition device. In this technical solution, a regenerant addition pipe and a compressed air pipe are fixed to the RAP hopper and positioned below the lowest material inlet of the RAP drying drum. The device has multiple nozzles distributed along the pipe, with the nozzle outlets facing the RAP material flow falling from the drying drum into the hopper. Compressed air atomizes the regenerant and sprays it directly onto the surface of the falling material flow, thereby achieving uniform addition of the regenerant.

[0004] However, the aforementioned existing technologies still have significant shortcomings: First, although the spraying position is below the material inlet, there is no dedicated flow guiding and turning structure. The RAP still falls in a relatively concentrated material flow form, making it difficult for the atomized regenerator to penetrate to the surface of the particles inside the material flow, resulting in a spraying blind zone. Second, the above solutions do not insulate the regenerator, causing the regenerator's fluidity to decrease in low-temperature environments, which can easily affect the atomization effect. Third, the spraying control and weighing systems are not linked, making it difficult to accurately adjust the regenerator spraying amount based on the actual weighing value of the RAP, resulting in inaccurate dosage. Summary of the Invention

[0005] To overcome the shortcomings of the prior art, a constant temperature spraying device and method for RAP weighing gravity premixed regenerant is provided.

[0006] This invention is achieved through the following technical solution: a constant-temperature spraying device for RAP weighing gravity premixing regenerant, comprising: a RAP weighing hopper with a discharge port at the bottom; a gravity dispersion premixing channel located below the discharge port; a flow guiding and turning structure located within the gravity dispersion premixing channel to facilitate dispersion, turning, and displacement of RAP during its descent; a regenerant storage and supply unit for storing and transporting the regenerant; and an atomizing spraying unit located in the spraying area of ​​the gravity dispersion premixing channel. It is connected to the regenerant storage and supply unit to atomize and spray the regenerant onto the surface of the falling RAP material flow; the control unit is connected to the weighing signal output terminal of the RAP weighing hopper, the drive mechanism of the discharge port, the regenerant storage and supply unit, and the atomization spraying unit, respectively, to control the spraying timing and spraying amount of the regenerant according to the RAP weighing value and discharge status; the waste heat insulation unit is connected to the regenerant storage and supply unit and to the mixing plant exhaust system, to indirectly insulate the regenerant using the exhaust waste heat.

[0007] In a preferred embodiment of the present invention, the waste heat insulation unit includes a flue gas diversion branch connected to the flue gas exhaust system of the mixing plant and a heat exchange structure disposed inside the regenerator storage and supply unit. The heat exchange structure is used to realize indirect heat exchange between the flue gas and the regenerator.

[0008] In a preferred embodiment of the present invention, a temperature detection element is provided in the regenerant storage and supply unit, and the control unit adjusts the on / off state or flow rate of the flue gas diversion branch according to the detected temperature so that the regenerant is kept within a preset temperature range.

[0009] As a preferred embodiment of the present invention, the flow guiding and turning structure includes at least one turbulence element disposed in the gravity dispersion premixing channel. The turbulence element is used to change the falling trajectory of RAP, so that the concentrated falling RAP material flow is transformed into a dispersed, turning and repositioned material flow.

[0010] In a preferred embodiment of the present invention, the atomizing spraying unit includes at least two atomizing nozzles, which are disposed on both sides of the gravity dispersion premixing channel and arranged in a cross pattern.

[0011] In a preferred embodiment of the present invention, the regenerant storage and supply unit includes a regenerant dispensing tank, a delivery pump, a delivery pipeline, and a flow control component. One end of the delivery pipeline is connected to the regenerant dispensing tank, and the other end is connected to the atomizing spraying unit.

[0012] In a preferred embodiment of the present invention, the atomizing spraying unit is equipped with a pressurizer to achieve atomized spraying of the regenerant under the action of compressed gas.

[0013] In a preferred embodiment of the present invention, the control unit is used to determine the target spraying amount based on the RAP weighing value output by the RAP weighing hopper and the preset regenerator dosage, and to control the conveying time, conveying flow rate and / or atomizing spraying pressure of the regenerator storage and supply unit.

[0014] A method for constant-temperature spraying of RAP weighing gravity premixed regenerant includes the following steps:

[0015] S1. Add RAP to the RAP weighing hopper and weigh it to obtain the RAP weighing value;

[0016] S2. Open the discharge port to allow the weighed RAP to enter the gravity dispersion premixing channel, and form a dispersed, tumbling and displacement cascading flow under the action of the guide and turning structure.

[0017] S3. During the RAP's descent, the regenerant storage and supply unit controls the regenerant to be delivered to the atomizing spraying unit, which then sprays the regenerant onto the RAP surface.

[0018] S4. The sprayed RAP and regenerator are pre-sprayed and gravity-premixed during the falling process, and then enter the subsequent production process.

[0019] In a preferred embodiment of the present invention, before or during the RAP feeding process, the waste heat from the exhaust system of the mixing plant is used to indirectly keep the regenerant warm through a waste heat insulation unit.

[0020] Compared with the prior art, the present invention has the following beneficial effects:

[0021] A constant-temperature spraying device for RAP (Rapid Aponic Acid) weighing gravity premixed recycling agent is disclosed. This device comprises a RAP weighing hopper, a discharge port, a gravity dispersion premixing channel, a flow guiding and turning structure, a recycling agent storage and supply unit, an atomizing spraying unit, and a control unit. The control unit is linked to the weighing signal and discharge action, enabling simultaneous quantitative atomized spraying of the recycling agent during the RAP weighing and discharging process. By moving the recycling agent addition point forward to the RAP falling channel, the pre-action time of the recycling agent on aged asphalt is extended. Furthermore, no additional mechanical mixing mechanism is required; premixing is achieved through natural turning during gravity descent. The device is compact and easily adaptable to existing equipment. By adding a waste heat insulation unit connected to the mixing plant's exhaust system, the waste heat from the exhaust is used for indirect insulation of the recycling agent, eliminating the need for a separate electric heating device, reducing additional energy consumption, and ensuring the fluidity and atomization performance of the recycling agent in low-temperature environments.

[0022] Furthermore, the waste heat insulation unit includes a flue gas diversion branch and a heat exchange structure installed inside the regenerator storage and supply unit, realizing indirect heat exchange between flue gas and regenerator, avoiding regenerator pollution or performance degradation caused by direct contact of flue gas, and improving the safety and reliability of system operation.

[0023] Furthermore, by installing a temperature detection element in the regenerant storage and supply unit, and by having the control unit adjust the on / off state or flow rate of the flue gas diversion branch according to the detected temperature, the regenerant is kept within the preset insulation temperature range, thus achieving precise closed-loop control of the regenerant temperature, avoiding overheating or overcooling, and ensuring consistent spraying effect.

[0024] Furthermore, the flow guiding and turning structure employs at least one turbulence element, which can change the falling trajectory of RAP, transforming the concentrated falling material flow into a dispersed, turning, and repositioned material flow. This significantly increases the sprayed area of ​​the particles, reduces the phenomenon of local enrichment of regenerant and insufficient spraying, and improves the uniformity of spraying.

[0025] Furthermore, the atomizing spraying unit includes at least two cross-arranged atomizing nozzles that cross-spray the dispersed material flow from both sides of the channel, further improving the coverage and eliminating dead angles of the falling material flow, and enhancing the contact probability between the regenerant and the RAP particles.

[0026] Furthermore, the regenerant storage and supply unit includes a regenerant dosing tank, a delivery pump, a delivery pipeline, and a flow control component. The atomizing spraying unit is equipped with a pressurizer and achieves atomizing spraying under the action of compressed air, which ensures the stability of regenerant delivery and the fineness of atomized particles, and is conducive to the uniform spreading of regenerant on the RAP surface.

[0027] Furthermore, the control unit determines the target spraying amount based on the RAP weighing value and the preset dosage, and controls the conveying time, conveying flow rate and / or atomization spraying pressure, thereby achieving accurate metering and on-demand spraying of regenerant dosage, avoiding over- or under-dosing, and reducing material costs.

[0028] A method for constant-temperature spraying of regenerant by weighing and gravity premixing is proposed. This method organically combines the pre-spraying of regenerant with the gravity falling process of RAP through steps such as weighing, material dispersion, synchronous spraying and gravity premixing. Without increasing additional energy consumption and equipment, it achieves efficient pretreatment of RAP by regenerant. The process is simple and easy to automate.

[0029] Furthermore, before or during the RAP feeding process, the waste heat from the flue gas of the mixing plant is used to indirectly insulate the regenerant through a waste heat insulation unit. This makes full use of existing heat sources, reduces carbon emissions and operating costs, and ensures the temperature stability of the regenerant throughout the entire spraying cycle, thereby improving the engineering applicability and economy of the method.

[0030] Other features and advantages of the present invention will be disclosed in detail in the following detailed description and accompanying drawings. Attached Figure Description

[0031] The invention will be further described below with reference to the accompanying drawings:

[0032] Figure 1 This is a schematic diagram of the structure of a RAP weighing gravity premixed regenerant constant temperature spraying device according to the present invention.

[0033] Figure 2 This is a schematic diagram of the flow guiding and turning structure of the present invention.

[0034] The annotations in the attached figures are explained as follows:

[0035] 1. RAP weighing hopper, 2. Gravity dispersion premixing channel, 3. Guide and turning material structure, 4. Regenerant storage and supply unit, 5. Atomizing spraying unit, 6. Control unit, 7. Waste heat insulation unit, 8. Mixing station exhaust system, 9. Turbulence element, 11. Discharge port, 41. Regenerant dosing tank, 42. Conveying pipeline, 51. Atomizing nozzle, 52. Pressurizer, 81. Flue gas diversion branch, 10. Other devices of the mixing station, 12. Mixing tank, 13. Recycled material storage tank. Detailed Implementation

[0036] The technical solutions of the embodiments of the present invention will be explained and described below with reference to the accompanying drawings. However, the following embodiments are only preferred embodiments of the present invention and not all of them. Other embodiments obtained by those skilled in the art based on the embodiments in the implementation methods without creative effort are all within the protection scope of the present invention.

[0037] In the following description, terms such as “inner,” “outer,” “upper,” “lower,” “left,” and “right” are used only to indicate orientation or positional relationship for the convenience of describing the embodiments and simplifying the description, and are not intended to indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of the present invention.

[0038] like Figures 1 to 2 As shown, a RAP weighing gravity premixed regenerant constant temperature spraying device includes a RAP weighing hopper 1, a gravity dispersion premixing channel 2, a flow guiding and turning structure 3, a regenerant storage and supply unit 4, an atomizing spraying unit 5, a control unit 6, and a waste heat insulation unit 7. The lower part of the RAP weighing hopper 1 is provided with a discharge port 11, at which a controllable discharge gate is installed. The drive mechanism of the discharge gate is electrically connected to the control unit 6. The upper part of the RAP weighing hopper 1 is provided with a regenerant storage tank 13, which is used to add regenerant into the RAP weighing hopper 1.

[0039] The gravity dispersion premixing channel 2 is fixedly located directly below the discharge port 11, and its interior is equipped with a flow guiding and turning structure 3 arranged vertically or inclinedly. In this embodiment, the flow guiding and turning structure 3 includes multiple flow-disrupting elements 9, such as... Figure 2As shown, the turbulence element 9 can be an alternating arrangement of material-turning plates or a conical material-distributing body, used to disperse the concentrated falling RAP material flow, so that the RAP particles will disperse, turn over and change position under the action of gravity, forming a uniform falling material flow similar to a material curtain.

[0040] The regenerant storage and supply unit 4 includes a regenerant dispensing tank 41, a delivery pump, a delivery pipeline 42, and flow control components (such as a regulating valve or a metering pump). The regenerant dispensing tank 41 is used to store liquid regenerant, and it is equipped with a waste heat insulation unit 7 externally or internally. The waste heat insulation unit 7 is connected to the mixing plant's exhaust system 8 through a flue gas diversion branch 81, using the waste heat from the exhaust gas to indirectly insulate the regenerant. Specifically, the waste heat insulation unit 7 can adopt a heat exchange jacket or an internal heat exchange coil structure, where the flue gas and regenerant do not directly contact each other, but only transfer heat through the heat exchange wall. The regenerant dispensing tank 41 is also equipped with a temperature detection element (such as a thermocouple), which transmits the signal to the control unit 6. The control unit 6 adjusts the valve opening or the induced draft fan frequency on the flue gas diversion branch 81 according to the measured temperature, so that the regenerant is always kept within a preset insulation temperature range (e.g., 40-60℃, which can be set according to the viscosity characteristics of the regenerant).

[0041] The atomizing spraying unit 5 is installed in the middle or upper spraying area of ​​the gravity dispersion premixing channel 2. The atomizing spraying unit 5 includes at least two atomizing nozzles 51. In this embodiment, two atomizing nozzles 51 are preferred, symmetrically arranged on both sides of the channel, and the axes of the nozzles are arranged in a cross pattern (i.e., the left nozzle points obliquely downwards towards the right-side falling material flow, and the right nozzle points obliquely downwards towards the left-side falling material flow). The atomizing spraying unit 5 is connected to the regenerant dosing tank 41 through the conveying pipeline 42. The atomizing spraying unit 5 is equipped with a pressure booster 52 (e.g., a pneumatic booster pump or compressed air interface) to atomize the regenerant into fine droplets under the action of compressed air. The compressed air source can be provided by the air compressor provided by the mixing plant, and a pressure regulating valve can be installed at the pressure booster 52 to control the atomization pressure.

[0042] The control unit 6 employs a programmable logic controller (PLC) or an embedded industrial controller. The input terminals of the control unit 6 are connected to the weighing sensor signal output terminal of the RAP weighing hopper 1, the status feedback terminal of the drive mechanism of the discharge port 11, and the temperature detection element of the regenerant dosing tank 41, respectively. The output terminals of the control unit 6 are connected to the discharge gate drive mechanism, the delivery pump, the flow control component, the pressurizer 52, and the regulating valve of the flue gas diversion branch 81, respectively. After the RAP weighing hopper 1 completes the weighing of a batch of RAP, the control unit 6 automatically calculates the target spraying amount based on the weighing value and the preset regenerant dosage (mass percentage), then opens the discharge gate of the discharge port 11 and simultaneously starts the delivery pump and pressurizer 52, causing the regenerant to be sprayed from the atomizing nozzle 51 at the set flow rate and atomization pressure. The spraying duration, flow rate, or atomization pressure can be adjusted in real time according to the target spraying amount. Once all RAP material has been discharged (the discharge gate is closed or the weighing hopper is zero), the control unit 6 immediately stops the delivery pump and delays shutting off the pressure booster 52. Compressed air is then used to briefly purge the nozzles and end pipes to prevent regenerant residue from clogging them.

[0043] This embodiment also provides a method for spraying a premixed regenerant based on the above-mentioned device using a falling dispersion method. The specific steps are as follows: First, the RAP material is added to the RAP weighing hopper 1. The weighing sensor obtains the accurate RAP mass value and sends the signal to the control unit 6. Before or during the RAP weighing and feeding, the control unit 6 uses the waste heat insulation unit 7 to indirectly insulate the regenerant in the regenerant feeding tank 41 using the waste heat from the flue gas system 8 of the mixing station, so that the temperature of the regenerant is maintained within a preset range. Then, the control unit 6 opens the discharge gate of the discharge port 11, and the RAP falls into the gravity dispersion premixing channel 2 by gravity. When flowing through the guide and turning structure 3, the turbulence element 9 causes the originally concentrated material flow to repeatedly collide, turn over, and disperse, forming a uniform material curtain.

[0044] Furthermore, as the RAP falls, the control unit 6 calculates the amount of regenerant based on the preset dosage, and starts the delivery pump and pressurizer 52. The regenerant reaches the atomizing nozzle 51 through the delivery pipeline 42, and is atomized into fine droplets under the action of compressed air. These droplets are sprayed crosswise from both sides of the channel into the RAP material stream that is being dispersed and falling. Because the RAP particles are in a highly dispersed and tumbling state, the atomized regenerant can fully coat the surface of each particle, achieving pre-coating of the regenerant. After spraying, the RAP and regenerant continue to tumble under gravity during the remaining falling process to complete further pre-mixing. Finally, it is discharged from the lower end of the gravity dispersion premixing channel 2 and enters the subsequent conveying device, lifting device, heating device, or mixing device (such as...). Figure 1(The remaining devices 10 and mixing tank 12 in the mixing station). Throughout the process, the control unit 6 monitors the regenerant temperature, RAP weighing value and discharge status in real time, and automatically adjusts each actuator to ensure spraying accuracy and uniformity.

[0045] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. Those skilled in the art should understand that the present invention includes, but is not limited to, the contents described in the accompanying drawings and the specific embodiments above. Any modifications that do not depart from the functional and structural principles of the present invention will be included within the scope of the claims.

Claims

1. A RAP weighing gravity premixed regenerant constant temperature spraying device, characterized in that, include: RAP weighing hopper (1), the lower part of which is provided with a discharge port (11). Gravity dispersion premixing channel (2) is located below the discharge port (11); The flow-guiding and turning structure (3) is set in the gravity dispersion premixing channel (2) to enable RAP to form dispersion, turning and displacement motions during the falling process; The regenerant storage and supply unit (4) is used to store and transport regenerant; The atomizing spraying unit (5) is set in the spraying area of ​​the gravity dispersion premixing channel (2) and is connected to the regenerator storage and supply unit (4) for atomizing and spraying the regenerator onto the surface of the falling RAP material flow. The control unit (6) is connected to the weighing signal output terminal of the RAP weighing hopper (1), the drive mechanism of the discharge port (11), the regenerant storage and supply unit (4) and the atomizing spraying unit (5) respectively, and is used to control the spraying timing and spraying amount of the regenerant according to the RAP weighing value and discharge status. Waste heat insulation unit (7) is connected to the regenerator storage and supply unit (4) and connected to the mixing plant exhaust system (8) for indirect insulation of the regenerator by utilizing exhaust waste heat.

2. The RAP weighing gravity premixed regenerant constant temperature spraying device according to claim 1, characterized in that, The waste heat insulation unit (7) includes a flue gas diversion branch (81) connected to the flue gas exhaust system (8) of the mixing plant and a heat exchange structure set inside the regenerator storage and supply unit (4). The heat exchange structure is used to realize indirect heat exchange between the flue gas and the regenerator.

3. The RAP weighing gravity premixed regenerant constant temperature spraying device according to claim 1, characterized in that, The regenerant storage and supply unit (4) is equipped with a temperature detection element. The control unit (6) adjusts the on / off state or flow rate of the flue gas diversion branch (81) according to the detected temperature so that the regenerant is kept within the preset temperature range.

4. The RAP weighing gravity premixed regenerant constant temperature spraying device according to claim 1, characterized in that, The flow guiding and turning structure (3) includes at least one turbulence element (9) disposed in the gravity dispersion premixing channel (2). The turbulence element (9) is used to change the RAP falling trajectory, so that the concentrated falling RAP material flow is transformed into a dispersed, turning and changing material flow.

5. The RAP weighing gravity premixed regenerant constant temperature spraying device according to claim 1, characterized in that, The atomizing spraying unit (5) includes at least two atomizing nozzles (51), which are arranged on both sides of the gravity dispersion premixing channel (2) and are cross-arranged.

6. The RAP weighing gravity premixed regenerant constant temperature spraying device according to claim 1, characterized in that, The regenerant storage and supply unit (4) includes a regenerant dispensing tank (41), a delivery pump, a delivery pipeline (42), and a flow control component. One end of the delivery pipeline (42) is connected to the regenerant dispensing tank (41), and the other end is connected to the atomizing spraying unit (5).

7. The RAP weighing gravity premixed regenerant constant temperature spraying device according to claim 6, characterized in that, The atomizing spraying unit (5) is equipped with a pressurizer (52) to achieve atomized spraying of regenerant under the action of compressed gas.

8. The RAP weighing gravity premixed regenerant constant temperature spraying device according to claim 1, characterized in that, The control unit (6) is used to determine the target spraying amount based on the RAP weighing value output by the RAP weighing hopper (1) and the preset regenerator dosage, and to control the conveying time, conveying flow rate and / or atomizing spraying pressure of the regenerator storage and supply unit (4).

9. A method for constant-temperature spraying of a RAP weighing gravity premixed regenerant, characterized in that, The RAP weighing gravity premixed regenerant constant temperature spraying device according to any one of claims 1-8 includes the following steps: S1. Add RAP to the RAP weighing hopper (1) and weigh it to obtain the RAP weighing value; S2. Open the discharge port (11) so that the weighed RAP enters the gravity dispersion premixing channel (2) and forms a dispersing, tumbling and displacement flow under the action of the guide and turning structure (3); S3. During the RAP's descent, the regenerant storage and supply unit (4) controls the regenerant to be delivered to the atomizing spraying unit (5), and the atomizing spraying unit (5) sprays the regenerant onto the RAP surface. S4. The sprayed RAP and regenerator are pre-sprayed and gravity-premixed during the falling process, and then enter the subsequent production process.

10. A method for constant-temperature spraying of RAP weighing gravity premixed regenerant according to claim 9, characterized in that, Before or during the RAP feeding process, the waste heat from the exhaust system (8) of the mixing plant is used to indirectly insulate the regenerator through the waste heat insulation unit (7).

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