Abstract： Fluent software and the method of numerical simulation of liquid -solid two -phase flow were used to analyze the flow of fluid in classification chamber of ultrafine powder wet centrifugal classifier. Under the condition of steady state, renormalization group（RNG） k-ε model, Eulerian multiphase flow model and multiple reference frame method were used to analyze the velocity distribution of the fluid in classification chamber of different shape classification wheel blades, in order to study the influence of different shape classification wheel blades on classification performance. Under the condition of unsteady state, the discrete phase model was used to analyze the rule of particle track in classification chamber, in order to study the influence of different rotate speed of classification wheel on cut size. The results indicate that comparing with straight blades and oblique blades, the classification performance of curved blades is the best. Using curved blades, the cut size is greater than 1 μm when the grading wheel speed is 1 000 r/min, the cut size is close to 1 μm when classification wheel speed is 2 000 r/min , and the cut size is smaller than 1 μm when the classification wheel speed is 3 000 r/min. Improving the classification wheel rotary speed is helpful to reduce the cut size.

Keywords: liquid-solid two-phase; wet centrifugal classification; numerical simulation; cut size