Performance Analysis And Structure Optimization Of Three-phase Decanter Centrifuge

In the process of petroleum exploitation,refining,processing,transportation and storage,there will be a major waste material-oily sludge,which is generally composed of water,oil and sand,a very stable emulsion.Recovery of crude oil from oily sludge will bring considerable economic and environmental benefits.The three-phase mechanical centrifugal separation technology of oil,water and sand has many advantages such as low energy consumption,low pollution and simple operation,which is suitable for industrial application of sludge resource treatment.First of all,the structure model,principle and separation efficiency of the traditional three-phase decanter centrifuge were analyzed,and the three-dimensional system assembly drawing of the three-phase decanter centrifuge was established to provide theoretical basis for the subsequent numerical simulation and experimental research.In order to continue to improve the working efficiency of three-phase decanter centrifuge,a three-phase decanter centrifuge with oil guide hole is proposed on this basis,this structure can make liquid phase axial flow,shorten the oil phase flow distance,can improve the separation efficiency.Then,the flow and separation performance of three-phase decanter centrifuge were numerically simulated by using the Mixture model of computational fluid dynamics(CFD)software Fluent.The three-dimensional watershed model of three-phase decanter centrifuge was established,and the grid division,boundary conditions and numerical setting were carried out.Through CFD numerical calculation,the separation efficiency of the traditional three-phase decanter centrifuge and the three-phase decanter centrifuge with oil guide hole were compared and analyzed.It was found that the volume fraction of oil produced by the traditional three-phase decanter centrifuge was 69%,and the integral number of solid produced by the former was 71%,and the separation effect of oil phase and solid phase was not good.The volume fraction of the latter is about 90%,the volume fraction of the solid phase is about 86%,and the recovery rate of the oil phase is higher,and the solid phase of the sand is drier.And in the process of changing the operation parameters and physical parameters,the separation effect of the improved centrifuge is improved compared with the traditional centrifuge.Finally,through the oil,water and sand separation experiment of three-phase decanter centrifuge,the influence of operation parameters,physical parameters and structural parameters on the separation performance was studied,which was verified with the numerical simulation study,laying a good foundation for the efficient and stable operation of three-phase decanter centrifuge in the industrial production process.