Research and application of unattended intelligent filter pressing system

Fine coal slime dewatering by filter press is an important link in coal preparation process. Wangpo Coal Preparation Plant used to face a multiple of problems in operation of its filter press, such as determination of the start/stop of feeding by reliance on experience of operators, no interconnection with associated equipment, plate pulling bogie acting occasionally out of step, etc. In line with the current state of the operation of the filter press, an unattended intelligent system is specifically designed with the points focusing on the ways to determine the time for making automatic start/stop of feeding, automatic filling of surge tank and for keeping in-step action of plate pulling bogies. With the help of monitoring and control functions in automatic queuing, filtration and filling operators, as well as the use of bogie action synchronism monitoring device, the system is made possible to operate in an automatic and highly effective manner. Field application of the system shows that the system can maintain continuous and stable operation and is capable of operating under remote or online monitoring and control, and issuing alarm in the event of any abnormalities; six operators can be reduced, saving a labor cost of 720,000 yuan per year; compared with the manually operated filter press, the average feeding time is reduced by 92.1 seconds, and the average moisture of cake product is lowered by 1.65 percentage point with the standard deviations of both indicators being far less than those of manually operated filter press; and the use of the system can lead to dispense of attendance, cut of dewatering time, improvement of dewatering efficiency, consistency of quality of cake product, and a favorable economic result.