Operation Control And Analysis Of V-filter In Water Treatment Plant

This paper relies on a large-scale coal chemical production enterprises among the filter units to complete.After a deep analysis of the operation and backwashing control process of v-type filter and the related process operating conditions,the overall scheme of the filter control system is determined.The S7 series programmable controller of Siemens is used as the field control unit,and the control mode of slave station plus master station is applied.The master station is s7-300PLC,and set up an extended rack for later production capacity expansion,master station with 8 slave stations,and master station as one of the slave stations.The slave stations are based on s7-300 Plc.each slave station has its own CPU.It communicates and exchanges data with the main station of s7-300 PLC through the Profibus-DP fiber star network.Each PLC sub-station is equipped with a touch screen and communicates directly with the CPU of the sub-station by means of MPI.According to the operating conditions of the filter in the filter cycle and the backwash-ing cycle,the control system has designed the corresponding control program.In the filter cycle,PID algorithm is used to realize the constant control of the filter level.During the backwashing cycle,in order to ensure the sufficient backwashing intensity and to ensure the timely recovery of the filter capacity,the backwashing control program is designed and pro-grammed,at the same time,combined with production experience,the opening and closing sequence and opening and closing time of each valve are improved to ensure air-water joint backwashing to give full play to its advantages of water saving and good backwashing effect.In order to ensure the quality of filtered water in each filter,a turbidity inspection and control system is set up.The operation of the sampling pump and the sampling ball valve ensures the quality of filtered water.In order to ensure the smooth implementation of the control program,the paper designs and allocates the i/o points of the field equipment,backwashing common equipment and logic control condition of each grid filter,and determines the net-work topology structure diagram of the control system.Hardware selection includes filter valve and actuator,liquid level sensor,pressure transmitter and turbidity inspection equip-ment selection.Secondly,for the anti-cleaning equipment and turbidity patrol equipment(sampling pump and sampling ball valve)to draw the electrical schematic diagram.Finally,using WINCC to build the configuration screen,and according to the project design of the running interface.Based on the above discussion,both the filtration and backwashing conditions of the v-type filter have obtained better operation results.The constant liquid level ensures the excellent stability of the filtered water,air-water combined backwashing makes the filter material thoroughly washed to restore its filtering ability,which can complete the function of water purification and ensure the downstream production stability.