Abstract:The ABEL diaphragm pumps HMD-G-32-0250 is one of the key equipments in the Chamber Filter Press Sludge Dewatering System.A modern control technology was used to analyze the reason for easy broken.The result showed that the pump rotary speed was too fast,which caused by a bug in the PLC program,may damage the pump.In the old version of the PLC program,when the outlet pressure of the diaphragm pumps attained and maintained 1.0-1.3 MPa,the outlet frequency of the frequency transfer vibrated around 40Hz.In the revised version,while the outlet pressure of pumps increases from 0.75 MPa to 1.4 MPa,the outlet frequency of the transfer decreases linearly from 80 Hz to 8 Hz,until stop.After the PLC program was revised,the pumps run well,and the vibration of the pumps and pipes are eliminated.