The numerical simulation of flow field was performed with Fluent

in order to indicate the effect of rotor cage rotary speed on classification accuracy in turbo air classifier.With the same wind speed and different rotary speeds of rotor cage

airflow velocity distribution in the rotor classifier was analyzed and compared， and a reasonable rotor cage rotary speed was obtained

which made a small velocity gradient both in the annular zone and between the neighboring blades

and a stable flow field.Moreover

the pressure distributions between the neighboring blades were analyzed.In this reasonable range of rotor cage rotary speed，the pressure between onward surface and regression surface of rotor blades was evenly distributed

and the formed vortex was weak

which helped to improve the accuracy of classification.Pulvis talci and quartz sand material experiments showed that when wind speed was 8 m·s-1

rotating speed was 600—800 r·min-1

the accuracy of turbo air classifier was high.These actual experimental results confirmed the simulation results using Fluent.Through this simulation

the corresponding reasonable range of the rotor cage speeds with different wind speeds could be obtained.For example

when wind speed was 20 m·s-1

reasonable rotating speed was 1000—1400 r·min-1 and when the wind speed was 30 m·s-1

reasonable rotating speed was 1500—2000 r·min-1.This provides a method to obtain suitable operating parameters of turbo air classifier.