Study On The Structure Of Oily Sludge Separator Based On Twin-swirl Flow

In the petroleum industry,oily sludge will be produced and gradually accumulated in the refined oil tank.The oily sludge has the characteristics of large oil content,moderate moisture content and less content of other solid impurities,so it has great recovery value.At present,the treatment of oily sludge is still in the exploratory stage.In this study,according to the properties of oil-bearing sludge after pretreatment in the oil product tank,four types of cyclone separation devices with different structures were selected and designed.The appropriate numerical simulation mathematical model was selected and the numerical solution method was determined.Fluent software was used to conduct numerical simulation research.On the basis of verifying the correctness of the model,the characteristics of the flow field in the simulation of four kinds of hydrocyclone multiphase flow were studied,and the influence of the change of the hydrocyclone structure on the flow field variation and its reasons were studied.It is found that the conventional hydrocyclone and the bicone hydrocyclone have a good separation effect on the oil and water in the fluid,and the oil content of the fluid in the overflow outlet reaches 95%,but the separation rate of the sludge particles is very low,only about 70%.The preliminary design of the double-layer cyclone has a good separation effect on the sludge particles,the particle separation rate reaches 96%,but due to the influence of short-circuit flow,the oil-water separation rate is only about 80%.Based on the comprehensive consideration of the advantages and disadvantages of the first three types of hydrocyclone,a new type of double-layer hydrocyclone with baffle structure is designed,which is divided into inner and outer double-layer hydrocyclone,and the length of the baffle is simulated.It can not only effectively recover the oil phase components in the oily sludge mixture,but also effectively separate the sludge particles.After structural improvement,the flow field of the new double-layer cyclone structure is stable,and the separation rate of oil and water and sludge particles reaches more than 96%,which effectively realizes the recovery and utilization of oil phase components in oily sludge.By the research on the cyclone separation of the sludge in the refined oil tank,a novel way as well as the process combination scheme for oil industry has been discovered,which would make certain contribution to the oil industry in the field of saving the energy and improving the economic benefit.