First: Pre-startup inspection
In the production process of asphalt concrete, the safe operation of the asphalt mixing plant is crucial. Following a series of safety regulations can ensure the smooth progress of the production process and the safety of operators. These regulations cover everything from inspections before equipment startup, monitoring during production, to maintenance after equipment shutdown, and every link is crucial.
Before starting the asphalt mixing plant, a comprehensive inspection must be carried out. This includes confirming the integrity of each component of the equipment, such as agitators, conveyor belts, etc., to ensure that they are in good working condition. At the same time, the electrical system, control system, and safety protection devices must be checked to ensure that they can work properly and provide reliable protection for the production process.
Carefully check whether the gear oil, air compressor oil, etc. are sufficient, and pay attention to any leakage.
Use a blowtorch to preheat the asphalt metering hopper.
Confirm whether the temperature of the heat transfer oil and asphalt meets the set standards.
Carefully check whether the screws of key components such as the vibrating screen are tightened and whether there are any signs of looseness.
Ensure that all drive belts, chains, etc. are in good condition and there is no slack.

Second: Mixer start and operation
Next, start the mixer and start the production process. Before starting the mixer, a bell must be sounded to remind people in the danger zone to pay attention to safety. Turn on the main power supply of the console, the secondary power switch, and the power supply of the burner console, and start the equipment one by one in sequence. The induced draft fan and the mixing cylinder need to be started twice, and make sure they are secondary suction before starting other equipment.
Start the industrial computer and turn on the blower after it is fully started. It should be noted that the blower is also secondary started, and the current is large when starting. Therefore, it is necessary to wait until the current drops to normal value and the secondary suction is completed before starting the next unit to avoid accidents.
About 3 minutes after the induced draft fan and blower are started, the "START" indicator light on the burner console begins to flash, indicating that ignition is available.
Open the gas or acetylene valve, then press the "START" key and hold it for 3 seconds, and the electronic ignition device will perform the ignition operation. If ignition is successful, the "START", "HEAVY OIL" and "PUMP ON" indicators will remain on, and the gas or acetylene valve should be closed. If ignition fails, repeat the above steps until it is successful.
At the same time, open the dampers of the induced draft fan and the blower, and start the inverter for feeding. At the beginning, the amount of sand and stone fed should be small to prevent the temperature from rising too quickly. When the temperature reaches above 100°C, the amount of feeding can be gradually increased to the normal level. When the temperature reaches 130°C, adjust the blower damper to the "AUTO" position.

Third: Normal operation steps
At the beginning of the daily mixing, 9-12 batches of materials should be mixed manually to ensure that the mixing cylinder is fully preheated. After that, turn the mixing mode knob to the "automatic" position and press the "auto start" button to start automatic mixing.
At the fifth batch of materials before shutdown, the inverter feeding speed needs to be reduced to half or one-third of the normal speed, depending on the amount of materials required.
When the fourth batch of materials before shutdown, the inverter should be turned off to stop feeding. When the current of the drying drum begins to decrease, press and hold the "STOP" button on the burner control console for about 3 seconds to extinguish the fire. At this time, the "HEAVY OIL", "START" and "PUMP ON" indicators will go out. Then, turn the blower damper to the "MAN" position and press the damper control button "CLOSE" until the "START" indicator starts to flash. At this time, the blower can be turned off.
At the last batch of materials, turn the mixing mode knob to "manual" and manually click the "interrupt batching" button at the bottom of the screen to manually put down the last batch of materials.
Add fine stone and a small amount of sand to the mixing tank, stir for a while, and then clean the residue and asphalt in the mixing tank. Finally, empty all the remaining materials in the silo.
Turn off each motor in the opposite order of starting up, and make sure that the temperature of the drying cylinder drops below 90°C before turning it off. Then, turn off the power of the industrial computer, secondary power supply, main power supply, and burner control console, and cut off the main switch.