| The separation of dispersed solid particles has been applied in many fields, for example, in mineral processing, in food technology and waste water treatment thechnology, in petro-chemical engineering, environment engineering etc.The typical apparatus is hydrocyclone. Although the geometric structure of a hydrocyclone is simple, the fluid flow field in it is very complicated, generally there exist inner and outer helical flows, a circulation and short-circuit flows and an air core. The previous investigations were just concerned with the theoretical and experience model, the available theories are the equilibrium orbit theory, the residence time theory, the turbulent two-phase flow theory and the crowed theory. The typical experience models are Dahltrom and Plitt model, and so on. However, at present, a uniform theory that can fully describe the separation processing has not been formed yet. The reason is that the separation process in hydrocyclones is affected by many factors, such as the three-dimensional flow field, fluid pressure and flow rate, as well as suspension concentration etc. Based on the reason, this dissertation will study problems which include analysis the force and following property of particle, numerical simulation of the flow field and the particle motion trajectory, measuring particle trajectory and air core characteristic by experiment method, discussion the stochastic separation theory, and so on. The stochastic motion characteristic of particles in hydrocyclones was found by the results, and the stochastic separation model theory was established. Those above work provided the evidence for extending application area of hydrocyclones in industry.According to analyze the forces acting on a particle in hydrocyclones, this work put forward that the accurate motion equation of particles can be described using determinative and random factors, Besides, the following property between liquid and solid phase was analyzed in...
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