Study On The Stochastic Characteristics Of The Separation Process In Hydrocyclones

The optimum design of structure of hydrocyclones need deeply and exactly understanding the essential of fluid flow dynamics and the separation mechanism of hydrocyclones. However, the previous investigations only considered determinate factors, and ignored the stochastic factors. So the conclusions were inaccurate and unsatisfied. In this study, comprehensively considered factors effecting on the separation process, the stochastic characteristics of the separation process inside hydrocyclones was investigated systemically using numerical simulation and validated by experiment.Flow field, flow structure and movement of particles inside hydrocyclones were simulated systemically by a high-precise software named FLUENT 6.1. The velocity distribution, pressure distribution, flow structure, air core, movement tracks of particles, effect of location of particle entrance on separation process and influence of particles size on separation efficiency were analyzed. The results showed that the flow field inside hydrocyclones was asymmetric. The factors that caused this asymmetry were asymmetric feeding location, strong turbulence of fluid flow, irregular form and radial fluctuating violently of air core. Eddies with different forms and sizes which distribute randomly within hydrocyclones have affected the stability of flow field. Therefore, the flow field had stochastic characteristics; The results of numerical simulation indicated that the diameter of air core depended not only on diameters of overflow and underflow orifices, cone angle and pressure, but also on its axial position; Movement track of single particle inside hydrocyclones was randomly. For single particle, forces acting on it are very complex, the determinate and stochastic effects were both important. The effects of location of particle entrance on separation process were also analyzed systematically.The moving process of particles inside hydrocyclones were observed using advanced KODAK EKTAPRO HS Motion Analyzer for the first time. The moving traces of partices were obtained and the motion behavior were further analyzed.The results testified that movement track of single particle inside hydrocyclones was stochastic.From above investigations,we discovered that the moving forms of...