In order to obtain fine powder with narrow particle size distribution and improve classification precision

the full blades in conventional rotor cages were improved to splitter style.The effect of the structure of the rotor cage with full blades and with splitter blades on the inner flow field of a turbo air classifier was investigated with the software Fluent.The result from numerical simulation indicates that air velocity fluctuations on outer cylinder of the improved rotor cage are decreased in the height direction

while

the radial velocity is decreased and the tangential velocity is increased compared with the conventional rotor cage

so the cut size of classified particles is smaller.The deviation of tangential velocity and radial velocity distribution on outer circle of horizontal section of the rotor cage is greatly improved

compared with the conventional rotor cage.When the ratio of the short blade length to the long blade length is 0.77

the flow field between blades is stable

and the velocity distribution on outer circle of the rotor cage is uniform.The experiment results on material classification demonstrate that the rotor cage with splitter blades is helpful to improving the classification precision and decreasing the cut size.The experimental result presents qualitative evidence for the CFD simulation and the feasibility in engineering applications.