Research On Gas Monitoring System In Wangfenggang Coal Preparation Plant

The traditional way of gas monitoring system in raw coal bunkers of coal preparation plant is manual supervisory control. This way needs high labor intensity. As required, the staffs have to always carry a portable gas concentration sensor to detect the gas concentration in raw coal bunkers, and the measurement result is not accurate. At the same time, the small amount of harmful gas in raw coal bunkers of coal preparation plant will cause some damage to the staffs’ body. As a result of the manual supervisory control is not continuous, when the gas concentration will soon exceed the safety production standard, if ventilation can’t strengthened in time, gas concentration would have continued to go up, and it will cause a great impact on the production. The venting practice in raw coal bunkers of Wangfenggang coal preparation plant is mainly blowers on the raw coal bunkers ventilate the raw coal bunkers. If coal preparation plant does not use automatic monitoring, in order to prevent the gas concentration continued to go up and impact the production, the blowers must be opened for a long time. But this will cause the service life of blowers shortened and the electrical energy wasted, and also increase the production cost of the coal preparation plant. Individual coal preparation plants installed mine gas monitoring system, and the system is based on single chip microcomputer. The system has low stability, high cost and poor extensibility.For the elimination of the drawbacks of the method of manual supervisory control and the mine gas monitoring system which is based on single chip microcomputer, we established a gas monitoring system based on the PLC in the raw coal bunkers of Wangfenggang coal preparation plants. In this paper, based on the long-term experiment, we chose some monitoring points for sensor, and these monitoring points are representative. According to real time monitor the monitoring points by gas concentration sensors, and the sensors return corresponding frequency signal to the mine flameproof and intrinsically safe PLC. According to the logic operation, the PLC controls the device like the blowers. The upper computer and human-machine interface real-time remote monitor the distribution of gas concentration in the raw coal bunkers by reading data from the PLC. When the gas monitoring system has been applied, we can real-time monitor the gas concentration in the raw coal bunkers by the upper computer and human-machine interface. The system made the detection timelier and the precision higher, the blowers can not only monitored remotely but also controlled according as the change of the highest gas concentration in the raw coal bunkers. The system not only reduces the staffs’ labor intensity, but also avoids the gas hurt the staffs’ body. It overcomes the disadvantages of the traditional manual supervisory control. The system improve safety factor of production in coal preparation plant production. It decreases the blowers’runtime greatly. It also reduces electricity consumption greatly. Then the production cost of the coal preparation plant can be saved.