Visualization Investigation on Coalescence Behavior of the Water Droplets in W/O Emulsion Under Pulsed Electric Field

Based on microscopic experiment,the coalescence behavior of water droplets in W/O emulsion under pulsed electric field was comprehensively investigated.Experimental results showed that,water droplets approaching velocity in W/O emulsion increased with the increases of pulsed electric field intensity,duty ratio and electric frequency in the experimental ranges. When coalescing time ratio was larger than 0.8,water droplets approaching velocity increased rapidly.There was little relationship between coalescing time of droplets in pulsed electric field and electric field parameters,while the coalescing time was closely related to oil-water interfacial tension of the W/O emulsion.The larger the interfacial tension,the faster the coalescing velocity.During electrostatic dewatering process,the electric field intensity applied to the W/O emulsion should be less than the critical electric field intensity of excessive polarization,otherwise the emulsion demulsification and dewatering effects would be significantly reduced.These investigated results will provide good foundation for further investigation on the mechanism of electrostatic coalescing demulsification.