Double-Field Union Demulsification And Dewatering Device For Large-Flow Industrial Waste Oil And Experimental Research

Lubricating oil is widely used in the fields of manufacturing,petrochemical,national defense.However,lubricating oil is highly susceptible to water pollution during transportation,filling and use,and produces emulsified oil,which leads to a rapid decrease in lubricating performance and eventually becomes industrial waste oil.It is difficult to achieve high-efficiency demulsification and dewatering treatment of emulsified oil by using the traditional single physical means.This study proposes a dewatering process of emulsified oil achieved by uniting high voltage pulsed electric field and swirl centrifugal field,and designs a double-field union demulsification and dewatering device for large-flow industrial waste oil by using three-dimensional modeling.Through the combination of theoretical analysis and experimental research,the basic structural parameters and operating parameters of the device were studied,which provided experimental data and theoretical basis for the design,manufacture and application of the double-field union demulsification and dewatering device for large-flow industrial waste oil.Firstly,for the high-voltage pulsed electric field unit of the double-field union demulsification and dewatering device,the vibration amplitude-frequency characteristics of single-emulsion droplets under high-voltage pulsed electric field were studied from the perspective of nonlinear vibration dynamics theory,and the effects of system parameters of the emulsion oil on the droplet vibration characteristics were analyzed.The structure of the two electrode units was designed and studied by simulation analysis and experimental research.The results show that the vertical electrode has a better demulsification effect.Secondly,considering the swirl centrifugal unit of the device as the research object,the influences of the different structural parameters of the conical section(large cone angle,small cone angle and nominal diameter)and the installation inclination angle on the separation efficiency were studied by FLUENT software.And the optimal geometric parameters were obtained under the single factor conditions.At the same time,the structural strength of the hydrocyclone is analyzed by the fluid-solid coupling calculation method to verify whether the structure of the hydrocyclone is reliable and provide a basis for the processing and manufacturing of the hydrocyclone.Based on the theoretical research,a light and efficient liquid-liquid dewatering hydrocyclone was designed and manufactured,and a swirl centrifugal experimental device was established.Finally,a double-field union demulsification and dewatering test platform was built by using the developed small electric demulsifier demulsification experimental device and thehydrocyclone centrifugal dewatering test device.The dewatering efficiency of single swirl field and double-field union demulsification and dewatering was compared by experiments.At the same time,the effects of hydrocyclone inlet velocity,pulsed power supply voltage and pulsed electric field frequency on the dewatering efficiency of the device were studied.The results show that the double-field union demulsification and dewatering device can realize the complementary advantages of the high voltage pulsed electric field and the hydrocyclone centrifugal field in the dewatering process of the waste oil emulsion.Compared with the single swirl centrifugal field,the waste oil emulsification can be greatly improved by the double-field union demulsification and dewatering device,and it can be used to pretreat the waste oil emulsion in actual production.