Research Of Bubble Enhanced Cyclonic Technology For The Pretreatment Of Desalting Wastewater

Desalting water is a kind of oily wastewater produced during the crude oil electric desalting process,and the separation of the oil is an important procedure.With the oil quality has been heavier and worse that bring great pressure to the pretreatment of desalting wastewater.The normal separation techniques have been unable to cope with treatment requirements.Therefore,it is important for the treatment of desalting wastewater to develop a compact,efficient and energy saving separation technology.In connection with the disadvantage of static cyclone centrifugal separation technology,this thesis proposed that air injection into desalting wastewater could enhance the separation performance.Through comparative analysis a tubular microporous media micro bubble generator was selected as the bubble generating apparatus in the follow-up experiment.The diameter distribution of microbubble generated by the generator was measured as a basis for numerical simulation research.With computational fluid dynamics software ANSYS Fluent,the simulation was performed to analyze the flow characteristics.By means of CFD,bubble's enhancement to the performance of a normal hydrocyclone has been verified.A method of simulating oil-gas-water flow field has been established,and the method could be theoretical support to designing a bubble enhanced hydrocyclone.In order to improve the disadvantage of conventional hydrocyclone such as smaller monomer throughput and more structural constraints,a cylindrical hydrocyclone has been designed and optimized by means of response surface methodology for the first time.In order to verify the feasibility of bubble enhanced hydrocyclone,an indoor experimental prototype has been manufactured and a laboratory experiment platform has been built up.The separation efficiency of hydrocyclone after bubble-injection was compared with conventional hydrocyclone with different operating parameters.The experimental result showed that the oil removal efficiency of normal hydrocyclone after bubble-injection could be 5%to 10%higher than that before bubble-injection.The experimental prototype could maintain high oil removal efficiency with a flowrate of 1.6m~3/h,a spilit ratio of 14%,and a gas-liquid ratio of 20%.The oil removal efficiency of cylindrical hydrocyclone after bubble-injection couled be 10%to 20%higher than that before bubble-injection.The experimental prototype could maintain high oil removal efficiency with a flowrate of 2m~3/h,a spilit ratio of 20%,and a gas-liquid ratio of 20%.Theoretical and experimental research in this paper could provide technical reference for the design and optimization of bubble enhanced hydrocyclone,and would lay the foundation for product engineering.