Asphalt mixing plant is indispensable in highway construction, and it’s a key mechanical equipment. The failure of the machine will reduce the utilization rate of the equipment and will also affect the construction progress, but how to deal with the common failures and maintenance, pls see details as below:
1. Cold aggregate feed failure
The fault may be caused by the rubble or foreign material stuck under the cold tape. If there is a fault in the circuit, the circuit must be checked to see if there is a cable short circuit. The deviation of the belt conveyor is generally caused by the following factors: belt slippage and belt tension varies. If so, the staff need make another adjustment, and must ensure that the belt conveyor is in a stable and safe operating state.
The value of the ammeter in the manufacturing room must be monitored. The value is the key basis for judging which motor equipment is faulty. For example, the increase in load torque is generally caused by the mechanical failure of the equipment. At this time, the current of the motor is much larger than the current during normal operation. Therefore, we preliminarily judge that the equipment has hidden troubles and needs maintenance or shutdown inspection.
2. Failure of the mixer
The main performance of the mixer's failure is abnormal noise, which is directly related to bearing damage and misalignment. The bearing problems are caused by the transient overload of the hybrid drive motor. In order to eliminate the fault, the bearing need to be maintained. If there is any heavy wear or internal shedding, it should be replaced, such as: liners, mixing plates, mixing blades. When the mixer is discharging, the aggregate temperature sometimes changes abnormally. We need to thoroughly clean the temperature sensor and check whether the cooling device is working properly.
3. Burner ignition failure
When the burner ignition failure occurs, the following work needs to be carried out:
(1) Check the inside of the operation room to see if its ignition and combustion conditions are available.
(2) Check the on and off status of the power switch.
In addition, it also includes whether the blower door is activated, whether the blower door is in the ignition position, and whether the drying cylinder and the internal pressure gauge are in the manual position. If the ignition is not affected, you need to check whether the fuel passage is blocked.
Otherwise, check the operation of the oil pump and the pressure at the outlet of the oil pump.
4. Sensor failure
The sensors of asphalt mixing plant include: temperature sensor, material level sensor and weighing sensor. If the measurement of the sensor is inaccurate or the work fails, it will interfere with the operation of the asphalt mixing plant. Therefore, the staff needs regular maintenance and inspection. Calibration of measurement accuracy also need be carried out once a year.
5. PLC module failure
PLC programmable controller plays an important role in the mixer, which has the following advantages: short average failure time, high reliability, easy to program, and can be easily mastered.
When the PLC module fails, the indicator device must be checked first.
Next, find out the specific location, and you need to refer to the fault indication.
In view of this situation, the module can be replaced, so that the system will be recovered as quickly as possible.
Check whether the input switch signal is in place. Whether the wiring board is loose, whether the logic output of the output terminal meets the requirements, etc. If there is a problem with the module, use a new module to replace it in time
6. Asphalt thermal oil system failure and troubleshooting
The oil guide heating furnace will be affected by the following factors:
(1) The diesel filter is not cleaned in time, so the situation where the fuel line is not smooth will occur, and the fire alarm signal will warn it. Therefore, the staff should clean the diesel filter first from the first-level filter. When the first-level filter is very dirty, the second-level filter and the third-level filter need to be cleaned also. Regarding the method of cleaning, it is possible to combine diesel soaking and air blowing.
(2) Poor oil atomization from the oil pump is also an important cause of failure. The solution is to replace it with better diesel and clean the oil line valve and damper control valve.
(3) The continuity of fuel injection is poor, which has a great relationship with the air entering the fuel pipeline. The solution is to control the diesel pump contactor.
(4) The fuel pressure is insufficient, which has a great relationship with normal mechanical wear. The solution is to increase the pressure regulating valve on the high-pressure oil pump.
(5) The heat transfer oil pressure is abnormal. Solution: Turn off the burner and open the exhaust valve. In this way, the circulation pump will continue to operate. If the pressure does not stabilize after a long time, the oil needs to be cooled down, and then the filter is checked.
Asphalt mixing equipment plays an important role in the construction of urban highways, especially in the construction of some large asphalt pavements, the quality need to be effectively guaranteed. As a technician in the construction industry, how to troubleshoot and repair asphalt concrete stations is the focus of work. Only in this way will the interests of the enterprise be guaranteed.
