Study On The Emulsion Oil Dewatering Device Coupled With Swirl Centrifugal And High Voltage Pulse Electric Fields And Separation Performance

The recycling of industrial waste oil is essential for alleviating energy shortage,saving resource,and environmental protection.The demulsification and dewatering of emulsion are the critical link of recycling technologies.For waste lubricating oil with high water content and complex construction,the technology of multi-field integration or coupling can accomplish the oil and water separation satisfactorily that is unable to achieve by using a single technological means.For this reason,a coupling device integrated swirl centrifugal and high voltage electric fields was proposed.For the device,the deformation dynamics model of dispersed droplets under the double-field coupling action and the simulation model of the coupling device were established,and the separation performance of double-field coupling device was investigated,which provides theoretic support for the improvement of two-field demulsification and dewatering mechanism,development of the regeneration technologies and demulsification and dewatering devices with high efficiency.Firstly,the unit structure and technological processing was illustrated,the deformation dynamics model of dispersed droplets was established by analyzing the forces acted on the droplets under the coupling action,and the first order approximation of the model was obtained by function approximation theory and harmonic balance method.It further improves the demulsification kinetics of high-voltage pulsed electric field.Secondly,the simulation model of double-field coupling device was established by using the user defined function method and the separation performance of coupling dewatering device was analyzed.The internal fluid of the coupling dewatering device was regarded as the computational domain and the influence of electric field force was considered.The force expression of dispersed phase was deduced according to the Maxwell stress.Based on the equations of continuity and momentum,the electric field force,which was expressed by body force and compiled by user defined function,was added to the governing equations of flow field.And the simulation model of double-field coupling dewatering device was established.The effects of voltage amplitude,electric field frequency,inlet velocity and the temperature of emulsion on the distribution of flow field and separation efficiency of double-field coupling dewatering device were analyzed by setting different initial or boundary conditions in the numerical simulation.Thirdly,the separation performance of coupling dewatering device under different geometric structures was simulated and analyzed.By changing the geometric structure of coupling device,the simulation models of device under different geometric structures were established,and the distribution of flow field and separation efficiency of device were analyzed at single,double cylindrical,or rectangular inlets structural styles,and the single,double,three or hyperbolic conical sections.Lastly,the effect of different controlling parameters on separation efficiency was investigated by experimental methods,and the experimental results verified the rationality of numerical simulation analysis by comparing the numerical results.It shows that the results obtained by numerical simulation are reasonable.