Study On Pulse Switch In Ballast Water Treatment System

How to treat the ballast water has always been a big problem to the people all over the world. Pulsed Arc Electrohydraulic Discharge (PAED) is now an effective method to solve the problem. As the critical part of the equipment, the pulse switch determines the performance of the whole system.By researching on two types of pulse switch, this paper points out that triggered vacuum switch and pseudo spark switch is not able to be used in PAED system.Based on the requirements of the switch lifetime that used in PAED system, the research designed a gas switch by theoretical analysis and emulational calculation. First, the research determined the distance between the electrodes by empirical formula; second, the research simulated the electric field in the gap by using finite element analysis software in order to optimize the profile of the electrodes; then, the research demonstrated that different materials will perform different in arc erosion by theoretical calculation. In order to maintain good performance of the switch in long time, the research designed a gap distance controlling system by using step motor.Then, the research did experiment on the switch in order to analysis some elements in the discharging circuit that will affect the performance of the switch. The results pointed out that the higher settled discharging voltage and the larger capacitance will lead to larger dispersibility of the discharging voltage. By the way, the gap distance controlling system will remarkably optimize the performance of the switch that work for long time.