Development Of Two-stage Vertical Cyclonic Flotation Unit And Research Of Realated On

As a kind of high efficiency and compact oil treatment equipment,the vertical cyclonic flotation unit achieves oil water separation process by using the method of cyclone separation and flotation separation.On the basis of summarizing the structure of some typical domestic and foreign vertical cyclonic flotation unit,a two-stage vertical cyclonic flotation unit and a swirl type micro bubble generator are designed independently to optimize the compactness and separation efficiency of the vertical cyclonic flotation unit starting from the stage of micro bubble generation.The design and optimization of the structure of the swirl type micro bubble generator are achieved by means of theoretical calculation and CFD numerical simulation and the structural parameters are determined finally.The minimum bubble size determined by swirl type micro bubble generator is 148?m after the laboratory experiment and the bubble size distribution is affected by water flow rate and gas injection ratio.The minimum bubble size decided on microporous tube typed micro bubble generator is about 45?m.The bubble size distribution is affected by water flow,gas injection ratio and the difference of injection pressure.The microporous tube typed micro bubble generator is optimized to provide micro bubble for the laboratory experiment of vertical cyclonic flotation unit.The preliminary structure of two-stage vertical cyclonic flotation unit is designed referring to the rated capacity and other parameters.The final structure of two-stage vertical cyclonic flotation unit is determined by CFD numerical simulation combined with Plackett-Burman screening experiment and response surface optimization method.The single-stage vertical cyclonic flotation unit which removes the second swirling part is compared with the two-stage vertical cyclonic flotation unit.Numerical simulation results show that the swirl flow field inside the two-stage vertical cyclonic flotation unit is more stable and uniform.Laboratory experiment results show that the efficiency of the two-stage structure removing oil from water is increased by 54%on the basis of the single-stage structure.The two-stage structure has lower operating costs.The water content in the oil drainage decreases,which is beneficial to the post-processing of oil drainage.