Asphalt supply temperature control system for recycled asphalt concrete production

Abstract

The utility model discloses an asphalt supply temperature control system for recycled asphalt concrete production. The asphalt supply temperature control system comprises an asphalt tank, an asphalt filling pipe, an asphalt filling motor, an asphalt discharging pipe, a mixing machine, a circulating pump, an asphalt return pipe and an asphalt circulating pump three-way valve, more than two asphalt tanks are arranged in parallel; each asphalt tank is provided with an electric heating insulation device, a temperature sensor, a liquid level meter, a stirring device and a weighing device; asphalt is supplied to each asphalt tank through an asphalt filling pipe, and an asphalt filling motor is arranged on the asphalt filling pipe; asphalt in each asphalt tank is supplied to the mixing machine through the asphalt discharging pipe, and the circulating pump is arranged on the asphalt discharging pipe; one end of the asphalt return pipe is communicated with a port 2 of the asphalt circulating pump three-way valve, and the other end is branched into more than two paths communicated with the corresponding asphalt tanks; a port 1 of the asphalt circulating pump three-way valve is communicated with one end of the asphalt discharging pipe, and a port 3 of the asphalt circulating pump flows to the mixing machine. The device realizes stable, efficient, safe and continuous supply of asphalt produced from recycled asphalt concrete.

Description

Technical Field

[0001] This utility model relates to a temperature control system for asphalt supply in the production of recycled asphalt concrete, belonging to the field of asphalt supply technology in the production of recycled asphalt concrete. Background Technology

[0002] Asphalt concrete recycling is an environmentally friendly and economical road repair technology. It effectively utilizes waste asphalt concrete materials, reducing the need for new raw materials and minimizing environmental impact. In recent years, with the development of the transportation infrastructure industry, asphalt concrete recycling has become increasingly popular, solving the environmental disposal problem of milling waste while also bringing considerable economic benefits.

[0003] In the production of recycled asphalt concrete, the asphalt supply system is one of the core components, and its stability directly affects the quality stability, production efficiency, and project cost of the recycled mixture. This project aims to provide a temperature control system for the asphalt supply in the production of recycled asphalt concrete, which can achieve stability, efficiency, safety, and continuity in the asphalt supply. Utility Model Content

[0004] This utility model provides a temperature control system for asphalt supply in the production of recycled asphalt concrete, which can achieve a stable, efficient, safe and continuous supply of asphalt in the production of recycled asphalt concrete; and has a simple and reasonable structure, which can reduce labor costs and energy costs, thereby reducing costs and increasing efficiency.

[0005] To solve the above-mentioned technical problems, the technical solution adopted by this utility model is as follows:

[0006] A temperature control system for asphalt supply in the production of recycled asphalt concrete includes an asphalt tank, an asphalt filling pipe, an asphalt filling motor, a filling solenoid valve, an asphalt discharge pipe, a discharge solenoid valve, a mixer, a circulating pump, an asphalt return pipe, a return solenoid valve, and a three-way valve for the asphalt circulating pump.

[0007] There are two or more asphalt tanks, each with the same structure and arranged in parallel; each asphalt tank has a feed inlet and a return outlet at the top, and a discharge outlet at the bottom; each asphalt tank is equipped with a weighing device at the bottom, and each asphalt tank is also equipped with an electric heating and insulation device, a temperature sensor and a level gauge, and a stirring device inside each asphalt tank.

[0008] One end of the asphalt filling pipe is connected to the asphalt supply source, and the other end branches into two or more asphalt filling branches. The number of asphalt filling branches, asphalt tanks, and filling solenoid valves are equal and correspond one-to-one. The asphalt filling branches are connected to the feed inlet at the top of the corresponding asphalt tanks, and the filling solenoid valves are located on the corresponding asphalt filling branches. The asphalt filling motor is located on the asphalt filling pipe before the branch.

[0009] The three ports of the asphalt circulation pump three-way valve are port 1, port 2, and port 3. One end of the asphalt discharge pipe is connected to port 1 of the asphalt circulation pump three-way valve, and the other end branches into two or more asphalt discharge branches. The number of asphalt discharge branches, asphalt tanks, and discharge solenoid valves are equal and correspond one-to-one. The asphalt discharge branches are connected to the discharge ports at the bottom of the corresponding asphalt tanks, and the discharge solenoid valves are located on the corresponding asphalt discharge branches. The circulation pump is located on the unbranched asphalt discharge pipe.

[0010] One end of the asphalt return pipe is connected to port 2 of the three-way valve of the asphalt circulation pump, and the other end branches into two or more asphalt return branches. The number of asphalt return branches, asphalt tanks and return solenoid valves are equal and correspond one-to-one. The asphalt return branches are connected to the return ports on the corresponding asphalt tanks, and the return solenoid valves are located on the corresponding asphalt return branches.

[0011] Port 3 of the asphalt circulation pump three-way valve leads to the mixing plant.

[0012] The aforementioned weighing device is used to sense the weight of the corresponding asphalt tank. The electric heating device is used to heat the asphalt inside the asphalt tank. The temperature sensor is used to sense the temperature of the asphalt inside the asphalt tank. The level gauge is used to sense the level of asphalt inside the asphalt tank.

[0013] In this application, "connected" means that the two entities are linked and interconnected.

[0014] The upstream-to-downstream direction of this application is consistent with the direction of material flow.

[0015] The aforementioned mixing plant refers to an asphalt mixture mixing plant, with the asphalt outlet pipe supplying the required asphalt to the mixing plant.

[0016] It is common knowledge that three-way valves have three ports, and this application will not elaborate further.

[0017] Each of the aforementioned asphalt tanks is equipped with a feed inlet and a return outlet at its top. Alternatively, both the feed inlet and the return outlet can be located at the top of the side wall of the asphalt tank, or one can be located at the top of the asphalt tank and the other at the top of the side wall of the asphalt tank. The specific arrangement depends on the available space on site, as long as it does not affect the feeding and return processes.

[0018] The aforementioned asphalt tanks are arranged in parallel in two or more units to achieve continuous supply to the mixing plant. Each asphalt tank is equipped with a weighing device at its bottom to indicate the amount of asphalt inside. When the level falls below the minimum value (minimum weight), the corresponding solenoid valve and asphalt filling motor are opened to replenish the asphalt. When the maximum value (maximum weight) is reached, the corresponding solenoid valve and asphalt filling motor are closed to stop replenishment. Each asphalt tank is also equipped with an electric heating and insulation device, a temperature sensor, and a level gauge for heating and insulation of the asphalt inside the tank, as well as temperature and level indication. When the temperature value sensed by the temperature sensor is lower than the specified temperature (the temperature required for mixing), heating begins. When the specified stable temperature is reached, insulation begins. The level gauge and weighing device provide dual protection. In the event of a weighing device malfunction, the level gauge can provide feedback on the maximum and minimum values ​​of asphalt inside the tank (the maximum and minimum liquid level values ​​corresponding to the maximum and minimum weights), improving safety and continuity. Each asphalt tank is equipped with a stirring device, which is activated during heating and insulation to ensure the uniformity of the asphalt.

[0019] The aforementioned asphalt filling pipe is connected to an asphalt supply source at one end and branches into two or more asphalt filling branches at the other end, which are respectively connected to the corresponding asphalt tanks. Each asphalt filling branch is equipped with a filling solenoid valve. Asphalt is filled into each asphalt tank through the asphalt supply source (such as a special asphalt storage tank with heat preservation function). By controlling the opening and closing of the filling solenoid valve, the asphalt tank to which asphalt is filled is controlled.

[0020] The asphalt in the aforementioned asphalt tank is used to feed the mixing plant. The asphalt circulation pump's three-way valve port 3 and the circulation pump are opened, simultaneously opening the discharge solenoid valve corresponding to the asphalt tank that can discharge, thus feeding the mixing plant. When it is necessary to temporarily stop feeding, the asphalt circulation pump's three-way valve port 2 and the return solenoid valve corresponding to the asphalt tank are opened, and the asphalt circulation pump's three-way valve port 3 is closed, allowing the asphalt to flow back into the corresponding asphalt tank. Because starting and stopping the circulation pump generates significant energy consumption and impact, it should not be shut down unless absolutely necessary.

[0021] To further improve the safety and stability of the system operation, the above-mentioned recycled asphalt concrete production asphalt supply temperature control system also includes an asphalt overflow pipe and an asphalt overflow pool; each asphalt tank has an overflow port on the top of its side wall; one end of the asphalt overflow pipe is connected to the asphalt overflow pool, and the other end branches into two or more asphalt overflow branches, the number of asphalt overflow branches and asphalt tanks are equal and correspond one-to-one, and the asphalt overflow branches are connected to the overflow ports on the corresponding asphalt tanks.

[0022] When the asphalt in the asphalt tank reaches its maximum value and the asphalt filling motor is not shut off, the asphalt overflows and enters the asphalt overflow pool through the overflow pipe.

[0023] To reduce energy consumption and provide timely countermeasures, the aforementioned temperature control system for asphalt supply in recycled asphalt concrete production also includes an electronic flow meter. The electronic flow meter is installed on the unbranched asphalt overflow pipe. The flow meter provides an overflow signal, indicating that overflow has occurred. This overflow signal can be interlocked with the asphalt filling motor to promptly cut off the motor and stop the overflow.

[0024] To further enhance safety, the aforementioned temperature control system for asphalt supply in the production of recycled asphalt concrete also includes an overflow audible and visual alarm. This alarm is located near the unbranched asphalt overflow pipe and operates based on feedback signals from the electronic flow meter when overflow occurs. The flow meter provides an overflow signal (a reading on the flow meter indicates overflow, which is considered an overflow signal), proving that overflow has occurred. This overflow signal can be interlocked with the asphalt filling motor to promptly shut off the motor and stop the overflow. The overflow signal triggers the overflow audible and visual alarm, alerting staff to take emergency measures.

[0025] This application does not improve the control methods, etc.; you can directly refer to the product manual or mature existing technology.

[0026] To improve asphalt utilization, the aforementioned recycled asphalt concrete production asphalt supply temperature control system also includes an overflow return pipe, an asphalt backflow motor, and manual valves. Each asphalt tank has a return port on its side wall top. One end of the overflow return pipe connects to the bottom of the asphalt overflow pool, and the other end branches into two or more return branches. The number of return branches, asphalt tanks, and manual valves are equal and correspond one-to-one. Each return branch connects to the return port on its corresponding asphalt tank, and the manual valve is located on the corresponding return branch. This allows asphalt in the asphalt overflow pool to be pumped into asphalt tanks with insufficient liquid levels as needed.

[0027] When the electronic flow meter on the asphalt overflow pipe counts and sends an overflow signal, the overflow signal is interlocked with the asphalt filling motor, promptly cutting off the motor and stopping the overflow. Simultaneously, the overflow signal triggers an audible and visual alarm, alerting personnel to take emergency action. The asphalt backflow pump is then manually activated to pump the overflow asphalt back into the designated asphalt tank.

[0028] The temperature sensor used is a PT100 platinum resistance temperature sensor. The level gauge is a guided wave radar level gauge.

[0029] To improve the insulation effect, a 50-100mm thick rock wool insulation layer is installed around the asphalt discharge pipe.

[0030] For easy observation, each of the above-mentioned asphalt tanks is equipped with an observation hole on its top, and a shielding door is hinged to the observation hole.

[0031] To facilitate operation and control and improve efficiency, the above-mentioned recycled asphalt concrete production asphalt supply temperature control system also includes a PLC control system. The asphalt filling motor, filling solenoid valve, discharge solenoid valve, mixer, circulating pump, return solenoid valve, asphalt circulating pump three-way valve, weighing device, electric heating and heat preservation device, temperature sensor, level gauge and stirring device are all connected to the PLC control system and controlled by the PLC control system.

[0032] The aforementioned electronic flow meter and overflow audible and visual alarm are also connected to and controlled by the PLC control system. When the PLC control system receives a flow signal from the electronic flow meter, it indicates that an overflow has occurred, triggering the overflow audible and visual alarm to alert staff to take immediate action.

[0033] PLC control systems are a mature existing technology. This application does not make any special improvements to the structure or methods of the PLC control system itself, so it will not be described in detail here.

[0034] The working principle of the above-mentioned recycled asphalt concrete production asphalt supply temperature control system is as follows: 1. Asphalt tank replenishment: According to the asphalt usage plan, the usage sequence of each asphalt tank is set, and then the automatic asphalt replenishment is started. A weighing device is installed at the bottom of the asphalt tank. When the total weight of the asphalt tank is lower than the set minimum value, the asphalt tank is at a low level. The system automatically opens the corresponding filling solenoid valve, and then automatically starts the asphalt filling motor to fill the asphalt tank. When the asphalt filling causes the total weight of the asphalt tank to reach the set maximum value, the asphalt tank is at a high level. The system automatically cuts off the asphalt filling motor, stops asphalt filling, and simultaneously closes the corresponding filling solenoid valve. During the asphalt filling process, the asphalt level is simultaneously fed back through a level gauge. If the asphalt weighing device malfunctions, and the level gauge indicates that the asphalt tank has reached a high level, the asphalt filling motor is cut off, stopping asphalt filling, and the corresponding filling solenoid valve is closed. This dual control reduces asphalt tank overflow. When a system malfunction occurs, such as the failure of the maximum liquid level signal to shut off the asphalt filling motor, asphalt overflows through the overflow pipe. The electronic flow meter on the asphalt overflow pipe counts the overflow and sends an overflow signal. This overflow signal is interlocked with the asphalt filling motor, promptly shutting it off to stop the overflow. Simultaneously, the overflow signal triggers an audible and visual alarm, alerting personnel to handle the situation urgently. The asphalt back-pump is then manually activated to pump the overflow asphalt back into the designated asphalt tank. 2. Asphalt Tank Heating System: Asphalt heating is achieved electrically. Based on factors such as the usage time of each asphalt tank, real-time temperature monitoring, hourly temperature rise parameters, and asphalt storage capacity, the preheating start time for each asphalt tank is calculated. Once the set heating temperature is reached, the asphalt tank enters a heat preservation state; heating automatically starts when the temperature falls below the set lower limit and automatically stops when the temperature rises above the set upper limit. During the production of recycled asphalt concrete, the temperature and asphalt balance of each asphalt tank can be remotely monitored in real time from the control room of the asphalt mixing plant. When the weight of the asphalt tank in use is lower than the set minimum value, the system automatically switches the asphalt tank and automatically completes the corresponding oil return operation. That is, the asphalt circulation oil returns to the asphalt tank that is used.

[0035] Any technologies not mentioned in this utility model are based on existing technologies.

[0036] This utility model relates to a temperature control system for asphalt supply in the production of recycled asphalt concrete, which enables a stable, efficient, safe, and continuous supply of asphalt for recycled asphalt concrete production. The design of the return material structure further improves the stability of the supply and extends the service life of the circulating pump. The addition of an overflow structure further enhances safety and stability, avoids or reduces asphalt waste, and lowers the labor intensity of operators. Moreover, the system has a simple and reasonable structure, which can reduce labor and energy costs, thereby reducing costs and increasing efficiency. Attached Figure Description

[0037] Figure 1Schematic diagram of the temperature control system for asphalt supply in the production of recycled asphalt concrete according to this utility model. Figure 1 (The mixing plant and asphalt supply source are omitted from the diagram.)

[0038] Figure 2 Schematic diagram of the temperature control system for asphalt supply in the production of recycled asphalt concrete according to this utility model. Figure 2 (The mixing plant and asphalt supply source are omitted from the diagram.)

[0039] In the diagram, 1 is the asphalt tank, 2 is the asphalt filling pipe, 3 is the asphalt filling motor, 4 is the filling solenoid valve, 5 is the asphalt discharge pipe, 6 is the discharge solenoid valve, 7 is the circulating pump, 8 is the asphalt return pipe, 9 is the return solenoid valve, 10 is the asphalt circulating pump three-way valve, 11 is the manual valve, 12 is the weighing device, 13 is the electric heating and heat preservation device, 14 is the temperature sensor, 15 is the level gauge, 16 is the stirring device, 17 is the asphalt overflow pipe, 19 is the asphalt overflow pool, 20 is the electronic flow meter, 21 is the overflow audible and visual alarm, 22 is the overflow return pipe, and 23 is the asphalt back-pump motor. Detailed Implementation

[0040] To better understand this utility model, the following embodiments further illustrate the content of this utility model, but the content of this utility model is not limited to the following embodiments.

[0041] The directional terms used in this application, such as up and down, left and right, horizontal, vertical, top and bottom, are all based on the relative orientations or positional relationships shown in the attached drawings and should not be construed as absolute limitations on this application. The structural diagrams provided in this application are merely schematic diagrams and should not be construed as absolute limitations. Supports, supporting walls, etc., can be installed as needed according to the actual conditions of the installation site.

[0042] Example 1

[0043] like Figure 1 As shown, a temperature control system for asphalt supply in the production of recycled asphalt concrete includes an asphalt tank, an asphalt filling pipe, an asphalt filling motor, a filling solenoid valve, an asphalt discharge pipe, a discharge solenoid valve, a mixer, a circulating pump, an asphalt return pipe, a return solenoid valve, and a three-way valve for the asphalt circulating pump.

[0044] The number of asphalt tanks is two or more, and each asphalt tank has the same structure and is set in parallel. Each asphalt tank has a feed inlet at the top and a discharge outlet at the bottom. Each asphalt tank has a return outlet at the top of its side wall (through experiments, the return outlet can also be located at the top of each asphalt tank and the feed inlet at the top of the side wall; or both the return outlet and the feed inlet can be located at the top of each asphalt tank, depending on the on-site installation space, to facilitate pipeline installation and maintenance). Each asphalt tank has a weighing device at the bottom, an electric heating and insulation device, a PT100 platinum resistance temperature sensor, and a guided wave radar level gauge on its surface, and a stirring device inside each asphalt tank.

[0045] One end of the asphalt filling pipe is connected to the asphalt supply source, and the other end branches into two or more asphalt filling branches. The number of asphalt filling branches, asphalt tanks, and filling solenoid valves are equal and correspond one-to-one. The asphalt filling branches are connected to the feed inlet on the top of the side wall of the corresponding asphalt tank, and the filling solenoid valve is located on the corresponding asphalt filling branch. The asphalt filling motor is located on the asphalt filling pipe before the branch.

[0046] The three ports of the asphalt circulation pump three-way valve are port 1, port 2, and port 3. One end of the asphalt discharge pipe is connected to port 1 of the asphalt circulation pump three-way valve, and the other end branches into two or more asphalt discharge branches. The number of asphalt discharge branches, asphalt tanks, and discharge solenoid valves are equal and correspond one-to-one. The asphalt discharge branches are connected to the discharge ports at the bottom of the corresponding asphalt tanks, and the discharge solenoid valves are located on the corresponding asphalt discharge branches. The circulation pump is located on the unbranched asphalt discharge pipe. An 80mm thick rock wool insulation layer is installed around the asphalt discharge pipe.

[0047] One end of the asphalt return pipe is connected to port 2 of the three-way valve of the asphalt circulation pump, and the other end branches into two or more asphalt return branches. The number of asphalt return branches, asphalt tanks and return solenoid valves are equal and correspond one-to-one. The asphalt return branches are connected to the return ports on the corresponding asphalt tanks, and the return solenoid valves are located on the corresponding asphalt return branches.

[0048] The aforementioned asphalt tanks are arranged in parallel in two or more units to achieve continuous supply to the mixing plant. Each asphalt tank is equipped with a weighing device at its bottom to indicate the amount of asphalt inside. When the level falls below the minimum value (minimum weight), the corresponding solenoid valve and asphalt filling motor are opened to replenish the asphalt. When the maximum value (maximum weight) is reached, the corresponding solenoid valve and asphalt filling motor are closed to stop replenishment. Each asphalt tank is also equipped with an electric heating and insulation device, a temperature sensor, and a level gauge for heating and insulation of the asphalt inside the tank, as well as temperature and level indication. When the temperature value sensed by the temperature sensor is lower than the specified temperature (the temperature required for mixing), heating begins. When the specified stable temperature is reached, insulation begins. The level gauge and weighing device provide dual protection. In the event of a weighing device malfunction, the level gauge can provide feedback on the maximum and minimum values ​​of asphalt inside the tank (the maximum and minimum liquid level values ​​corresponding to the maximum and minimum weights), improving safety and continuity. Each asphalt tank is equipped with a stirring device, which is activated during heating and insulation to ensure the uniformity of the asphalt.

[0049] The aforementioned asphalt filling pipe is connected to an asphalt supply source at one end and branches into two or more asphalt filling branches at the other end, which are respectively connected to the corresponding asphalt tanks. Each asphalt filling branch is equipped with a filling solenoid valve. Asphalt is filled into each asphalt tank through the asphalt supply source (such as a special asphalt storage tank with heat preservation function). By controlling the opening and closing of the filling solenoid valve, the asphalt tank to which asphalt is filled is controlled.

[0050] The asphalt in the aforementioned asphalt tank is used to feed the mixing plant. The asphalt circulation pump port 3 and the circulation pump are opened, and the discharge solenoid valve corresponding to the discharge tank is also opened to feed the mixing plant. When it is necessary to temporarily stop feeding, the asphalt circulation pump port 2 and the return solenoid valve corresponding to the asphalt tank are opened, and the asphalt circulation pump port 3 is closed, allowing the asphalt to flow back into the corresponding asphalt tank. Because starting and stopping the circulation pump generates significant energy consumption and impact, it should not be shut down unless absolutely necessary.

[0051] Example 2

[0052] Based on Example 1, the following improvements were made: Figure 1 As shown, the asphalt supply temperature control system for recycled asphalt concrete production also includes an asphalt overflow pipe and an asphalt overflow pool; each asphalt tank has an overflow port on its top; one end of the asphalt overflow pipe is connected to the asphalt overflow pool, and the other end branches into two or more asphalt overflow branches. The number of asphalt overflow branches and asphalt tanks are equal and correspond one-to-one. The asphalt overflow branches are connected to the overflow ports on the corresponding asphalt tanks. In the figure, the overflow ports are located on the back side of the asphalt tanks, and the asphalt overflow branches rise from the back side of the asphalt tanks to the overflow ports on the top of the corresponding asphalt tanks.

[0053] When the asphalt in the asphalt tank reaches its maximum value and the asphalt filling motor is not shut off, the asphalt overflows and enters the asphalt overflow pool through the overflow pipe.

[0054] Example 3

[0055] Based on Example 2, the following improvements were made: Figure 1 As shown, the temperature control system for asphalt supply in the production of recycled asphalt concrete also includes an electronic flow meter; the electronic flow meter is installed on the unbranched asphalt overflow pipe. The flow meter can provide an overflow signal, indicating that overflow has occurred. The overflow signal can be interlocked with the asphalt filling motor to promptly cut off the asphalt filling motor and stop the overflow.

[0056] Example 4

[0057] Based on Example 3, the following improvements were further made: Figure 1 As shown, the temperature control system for asphalt supply in recycled asphalt concrete production also includes an overflow audible and visual alarm; the overflow audible and visual alarm is located next to the unbranched asphalt overflow pipe. The flow meter can provide an overflow signal (the flow meter starts to read, indicating an overflow signal), proving that overflow has occurred. The overflow signal can be interlocked with the asphalt filling motor to promptly cut off the motor and stop the overflow. The overflow signal triggers the overflow audible and visual alarm, alerting staff to take emergency measures.

[0058] Example 5

[0059] Based on Example 4, the following improvements were made: Figure 2 As shown, the temperature control system for asphalt supply in recycled asphalt concrete production also includes an overflow return pipe, an asphalt backflow motor, and manual valves. Each asphalt tank has a return port on its side wall top. One end of the overflow return pipe connects to the bottom of the asphalt overflow pool, and the other end branches into two or more return branches. The number of return branches, asphalt tanks, and manual valves are equal and correspond one-to-one. Each return branch connects to the return port on the corresponding asphalt tank, and the manual valve is located on the corresponding return branch. This allows asphalt in the asphalt overflow pool to be pumped into asphalt tanks with insufficient liquid levels as needed.

[0060] When the electronic flow meter on the asphalt overflow pipe counts and sends an overflow signal, the overflow signal is interlocked with the asphalt filling motor, promptly cutting off the motor and stopping the overflow. Simultaneously, the overflow signal triggers an audible and visual alarm, alerting personnel to take emergency action. The asphalt backflow pump is then manually activated to pump the overflow asphalt back into the designated asphalt tank.

[0061] Example 6

[0062] Based on Example 5, the following improvements were made: each asphalt tank is provided with an observation hole on its top, and a shielding door is hinged to the observation hole.

[0063] Example 7

[0064] Based on Example 6, the following improvements were made: The temperature control system for asphalt supply in the production of recycled asphalt concrete further includes a PLC control system. The asphalt filling motor, filling solenoid valve, discharge solenoid valve, mixer, circulating pump, return solenoid valve, asphalt circulating pump three-way valve, weighing device, electric heating and insulation device, temperature sensor, level gauge, stirring device, electronic flow meter, and overflow audible and visual alarm are all connected to and controlled by the PLC control system. The PLC control system is a mature existing technology; this application does not make any special improvements to the structure or method of the PLC control system itself, and therefore will not be described in detail.

[0065] The working principle of the above-mentioned recycled asphalt concrete production asphalt supply temperature control system is as follows: 1. Asphalt tank replenishment: According to the asphalt usage plan, the usage sequence of each asphalt tank is set, and then the automatic asphalt replenishment is started. A weighing device is installed at the bottom of the asphalt tank. When the total weight of the asphalt tank is lower than the set minimum value, the asphalt tank is at a low level. The system automatically opens the corresponding filling solenoid valve, and then automatically starts the asphalt filling motor to fill the asphalt tank. When the asphalt filling causes the total weight of the asphalt tank to reach the set maximum value, the asphalt tank is at a high level. The system automatically cuts off the asphalt filling motor, stops asphalt filling, and simultaneously closes the corresponding filling solenoid valve. During the asphalt filling process, the asphalt level is simultaneously fed back through a level gauge. If the asphalt weighing device malfunctions, and the level gauge indicates that the asphalt tank has reached a high level, the asphalt filling motor is cut off, stopping asphalt filling, and the corresponding filling solenoid valve is closed. This dual control reduces asphalt tank overflow. When a system malfunction occurs, such as the failure of the maximum liquid level signal to shut off the asphalt filling motor, the asphalt overflows through the electronic flow meter. The electronic flow meter on the asphalt overflow pipe counts the overflow and sends an overflow signal. This overflow signal is interlocked with the asphalt filling motor, promptly shutting it off and stopping the overflow. Simultaneously, the overflow signal triggers an overflow audible and visual alarm, alerting personnel to handle the situation urgently. The asphalt back-pump is then manually activated to pump the overflow asphalt back into the designated asphalt tank. 2. Asphalt Tank Heating System: Asphalt heating is achieved electrically. Based on factors such as the usage time of each asphalt tank, real-time temperature monitoring, hourly temperature rise parameters, and asphalt storage capacity, the preheating start time for each asphalt tank is calculated. Once the set heating temperature is reached, the asphalt tank enters a heat preservation state; heating automatically starts when the temperature falls below the set lower limit and automatically stops when the temperature rises above the set upper limit. During the production of recycled asphalt concrete, the temperature and asphalt balance of each asphalt tank can be remotely monitored in real time from the control room of the asphalt mixing plant. When the weight of the asphalt tank in use is lower than the set minimum value, the system automatically switches the asphalt tank and automatically completes the corresponding oil return operation. That is, the asphalt circulation oil returns to the asphalt tank that is used.

[0066] Practical Case: In this case, there are 3 asphalt tanks, numbered 1, 2 and 3 from left to right. On March 20, 2025 at 7:00, recycled asphalt concrete will be produced, requiring 60 tons of asphalt. The production time will last for 10 hours, and the asphalt heating temperature will be controlled within the range of 150-155℃.

[0067] Detailed operation steps:

[0068] 1. Create a task sheet. On March 19, 2025 at 22:00, set asphalt tanks 1 and 2 as the tanks to be used. Use asphalt tank 1 first, then use asphalt tank 2. The full capacity of each tank is 30 tons. Set the start time of use for asphalt tank 1 to 7:00 and the start time of use for asphalt tank 2 to 12:00. Set the asphalt heating temperature control range for asphalt tanks 1 and 2 to 150-155℃.

[0069] 2. Upon starting the task, asphalt tank 1 is detected as empty. The system automatically opens the solenoid valve for filling asphalt tank 1, confirms the valve is in the correct position, and starts the asphalt filling motor to begin filling asphalt tank 1. At 22:30, the weighing device displays an asphalt storage of 30 tons (at this point, asphalt tank 1 reaches its maximum weight). Simultaneously, a high liquid level signal is triggered, and the maximum weight signal and high liquid level signal are fed back to the control system. The control system automatically cuts off the asphalt filling motor and then closes the solenoid valve for filling asphalt tank 1. The real-time temperature of asphalt tank 1 is detected as 105℃. The system initially predicts that it needs to be heated 3 hours in advance to ensure that the temperature of asphalt tank 1 reaches 150℃ when it is used at 7:00. Afterward, asphalt tank 1 continuously monitors the real-time temperature and feeds it back to the system to determine the start time of heating, continuously correcting the temperature to ensure that the temperature of asphalt tank 1 meets 150-155℃ when it is used at 7:00. One minute later, the weight of asphalt tank 2 was checked, and the result showed that the tank was empty. The system automatically opened the solenoid valve for filling asphalt tank 2. After confirming that the solenoid valve was in the correct position, the asphalt filling motor was started, and asphalt tank 2 began filling with asphalt. Half an hour later, the weighing device showed that the asphalt storage reached 30 tons (at this time, asphalt tank 2 reached its maximum weight). At the same time, a high liquid level signal was triggered. The maximum weight signal and the high liquid level signal were fed back to the control system, which automatically cut off the asphalt filling motor and then closed the solenoid valve for filling asphalt tank 2. The real-time temperature of asphalt tank 2 was measured at 105℃. The system initially predicted that it needed to be heated 3 hours in advance to ensure that the temperature of asphalt tank 2 would reach 150℃ when used at 12:00. Afterwards, asphalt tank 2 continuously monitored the real-time temperature and fed it back to the system to determine the start time of heating, continuously correcting the temperature to ensure that the temperature of asphalt tank 2 would meet 150-155℃ when used at 12:00.

[0070] 3. Before the production of recycled asphalt concrete, the asphalt circulation pump is turned on, and the signal is fed back to the control system. The system first opens the return oil solenoid valve 1 of asphalt tank 1, and at the same time opens the discharge solenoid valve of asphalt tank 1. Asphalt from asphalt tank 1 begins to be supplied to the mixing plant through the asphalt discharge pipe, and the circulating asphalt flows back to asphalt tank 1 through the asphalt return pipe. When the weight of asphalt tank 1 is detected by weighing and found to be lower than the set minimum value, the system automatically opens the return solenoid valve of asphalt tank 2, and at the same time opens the discharge solenoid valve 2 of asphalt tank 2. Then, it closes the discharge solenoid valve of asphalt tank 1 and the return solenoid valve 1 of asphalt tank 1.

[0071] 4. After production is completed, the task order is closed, and the system automatically closes the discharge solenoid valve and return solenoid valve 2 of asphalt tank 2.

[0072] In practice, the above-mentioned temperature control system for asphalt supply in recycled asphalt concrete production can achieve a stable, efficient, safe, and continuous supply of asphalt for recycled asphalt concrete production. The design of the return material structure further improves the stability of the supply and extends the service life of the circulating pump. The addition of an overflow structure further enhances safety and stability, avoids or reduces asphalt waste, and reduces the labor intensity of operators. Moreover, the system has a simple and reasonable structure, which can reduce labor and energy costs, thereby reducing costs and increasing efficiency.

Claims

1. A temperature control system for asphalt supply in the production of recycled asphalt concrete, characterized in that: Includes asphalt tank, asphalt filling pipe, asphalt filling motor, filling solenoid valve, asphalt discharge pipe, discharge solenoid valve, mixer, circulating pump, asphalt return pipe, return solenoid valve and asphalt circulating pump three-way valve; There are two or more asphalt tanks, each with the same structure and arranged in parallel; each asphalt tank has a feed inlet and a return outlet at the top, and a discharge outlet at the bottom; each asphalt tank has a weighing device at the bottom, and each asphalt tank is also equipped with an electric heating and insulation device, a temperature sensor and a level gauge, and a stirring device inside each asphalt tank. One end of the asphalt filling pipe is connected to the asphalt supply source, and the other end branches into two or more asphalt filling branches. The number of asphalt filling branches, asphalt tanks, and filling solenoid valves are equal and correspond one-to-one. The asphalt filling branches are connected to the feed inlet at the top of the corresponding asphalt tanks, and the filling solenoid valves are located on the corresponding asphalt filling branches. The asphalt filling motor is located on the asphalt filling pipe before the branch. The three ports of the asphalt circulation pump three-way valve are port 1, port 2, and port 3. One end of the asphalt discharge pipe is connected to port 1 of the asphalt circulation pump three-way valve, and the other end branches into two or more asphalt discharge branches. The number of asphalt discharge branches, asphalt tanks, and discharge solenoid valves are equal and correspond one-to-one. The asphalt discharge branches are connected to the discharge ports at the bottom of the corresponding asphalt tanks, and the discharge solenoid valves are located on the corresponding asphalt discharge branches. The circulation pump is located on the unbranched asphalt discharge pipe. One end of the asphalt return pipe is connected to port 2 of the three-way valve of the asphalt circulation pump, and the other end branches into two or more asphalt return branches. The number of asphalt return branches, asphalt tanks and return solenoid valves are equal and correspond one-to-one. The asphalt return branches are connected to the return ports on the corresponding asphalt tanks, and the return solenoid valves are located on the corresponding asphalt return branches. Port 3 of the asphalt circulation pump three-way valve leads to the mixing plant.

2. The temperature control system for asphalt supply in recycled asphalt concrete production according to claim 1, characterized in that: It also includes asphalt overflow pipes and asphalt overflow pools; each asphalt tank has an overflow port on the top of its side wall; one end of the asphalt overflow pipe is connected to the asphalt overflow pool, and the other end branches into two or more asphalt overflow branches. The number of asphalt overflow branches and asphalt tanks are equal and correspond one-to-one. The asphalt overflow branches are connected to the overflow ports on the corresponding asphalt tanks.

3. The temperature control system for asphalt supply in recycled asphalt concrete production according to claim 2, characterized in that: It also includes electronic flow meters; the electronic flow meters are installed on the unbranched asphalt overflow pipe.

4. The temperature control system for asphalt supply in recycled asphalt concrete production according to claim 3, characterized in that: It also includes an overflow audible and visual alarm; the overflow audible and visual alarm is installed next to the unbranched asphalt overflow pipe.

5. The temperature control system for asphalt supply in recycled asphalt concrete production according to claim 4, characterized in that: It also includes an overflow return pipe, an asphalt backflow motor, and a manual valve; each asphalt tank has a return port on the top of its side wall; one end of the overflow return pipe is connected to the bottom of the asphalt overflow pool, and the other end branches into two or more return branches. The number of return branches, asphalt tanks, and manual valves are equal and correspond one-to-one. The return branches are connected to the return ports on the corresponding asphalt tanks, and the manual valves are located on the corresponding return branches.

6. The temperature control system for asphalt supply in recycled asphalt concrete production according to any one of claims 1-5, characterized in that: The temperature sensor is a PT100 platinum resistance temperature sensor; the level gauge is a guided wave radar level gauge.

7. The temperature control system for asphalt supply in recycled asphalt concrete production according to any one of claims 1-5, characterized in that: The asphalt discharge pipe is surrounded by a 50-100mm thick rock wool insulation layer.

8. The temperature control system for asphalt supply in recycled asphalt concrete production according to any one of claims 1-5, characterized in that: Each asphalt tank is equipped with an observation hole on its top, and a shielding door is hinged to the observation hole.

9. The temperature control system for asphalt supply in recycled asphalt concrete production according to any one of claims 1-5, characterized in that: It also includes a PLC control system. The asphalt filling motor, filling solenoid valve, discharge solenoid valve, mixer, circulating pump, return solenoid valve, asphalt circulating pump three-way valve, weighing device, electric heating and heat preservation device, temperature sensor, level gauge and stirring device are all connected to the PLC control system and controlled by the PLC control system.

10. The temperature control system for asphalt supply in recycled asphalt concrete production according to claim 9, characterized in that: The electronic flow meter and overflow audible and visual alarm are also connected to and controlled by the PLC control system.

Images