Flow Field Study And Structural Optimization Design Of Oil-water-sand Three-phase Cyclone Separator

Two-phase hydrocyclone, as a centrifugal separation equipment, with the characteristics of high efficient, easy to operate, small footprint, has been widely used in industry. However, with the development of industry, the type of two hydrocyclones connected in tandem cannot meet the requirements of the three-phase separation simultaneously. It prompted evolution of three-phase hydrocyclone. At present, few studies and little references are available to engineering application. Therefore, the structure and size of three-phase hydrocyclone has been optimized by numerical simulation, mathematical model and response surface methodology.According to the numerical simulation of CTP hydrocyclone separator by FLUENT Software, we can conclude that the convergence of RSM Model is poor, and RNG k-? Model is good; the convergence of Coupled Algorithm is poor, and SIMPLE Algorithm is good. Euler Model has better adaptability than Mixture Model, and Second Order Upwind is better than the First Order Upwind. Fluent is low-precision in three-phase simulation with 10% error, and the results of the flow field and pressure field are accord with the actual situation inside the hydrocyclone.Sample was composed of quartz sand, diesel and pure water, and physical parameters of each phase were determined. With the mathematical models of the three-dimensional velocity field, the regulation and formula of flow field has been analyzed and established. The design method of height and the radius of the inlet has been analyzed theoretically. The question that a certain size of particles or oil droplets can be separated or not and the calculation of the separation efficiency has been discussed. This mathematical models is relatively simple to use, which avoid complex calculations of the turbulence without other unknown parameters.The traditional CTP three-phase hydrocyclone was improved by a variety of three-phase hydrocyclone structure of the separation simulation of sample. Double inlet is more stable than single inlet of flow field. The vortex finder of overflow can effectively prevent short circuit flow. The vortex finder of underflow can reduce energy consumption and a certain portion of the particles can be prevented from flowing out from the bottom orifice.There were some unknown parameters of the improved three-phase cyclone. Therefore, these parameters were determined by response surface methodology. Draw a conclusion, the inlet diameter X1=0.325D, the vortex finder of overflow X2= 2.175D, the vortex finder of underflow X3=0.6D. Under these conditions, oil efficiency was 60.78% and solid efficiency was 71.25%, which was higher than the traditional CTP hydrocyclone separation efficiency.