轴向涡流分离器内分散相油滴的破碎机制研究OA

Dynamic hydrocyclone technology is widely applied in the field of produced water treatment in oilfields.Clarifying the breakup mechanism of dispersed oil droplets in the strong oil-water swirl field is of great significance for optimizing the structure of low-shear swirler and determining the operational process parameter boundaries.In this study,with the help of a high-speed camera and Image J graphic processing software,the deformation and breakup process of dispersed oil droplets in oily wastewater within an axial vortex separator were observed and analyzed.Meanwhile,the computational fluid dynamics(CFD)software was employed to calculate the flow field parameters at the locations where oil droplet deformation and breakup occur.Coupled with experimental and CFD simulation results,the critical droplet breakup diameter(dcri)under different turbulent kinetic energy dissipation rates was analyzed.The constant C of the Hinze formula in the strong swirling flow field was corrected,and the coefficient of determination R² of the corrected formula was 0.82.And the critical Weber number and capillary number during oil droplet breakup were calculated.Furthermore the corresponding relationships between the deformation and breakup laws of oil droplets and the stress components were investigated at three locations—namely the cascade inlet,cascade pressure surface,and cascade suction surface.The results show that,both the critical Weber number and capillary number during oil droplet breakup increase with the increase in oil droplet diameter,with the average critical Weber number being 12.67,which is consistent with Hinze's research results.Under the action of the shear stress components τrθ and τθz,oil droplets undergo irregular deformation followed by multiple breakup into several sub-droplets with different diameters.Under the action of the tensile stress components τθθ and τrr,oil droplets deform into a uniform linear shape and undergo binary breakup.The research results can provide a theoretical basis for the design.