Abstract: In order to study the classification process of particles in the classifier SLK5500，CFD numerical simulations for eddy current classifier under both steady and unsteady states were conducted. The simulations were based on theoretical analysis for the granules of force. Particle trajectory and classification efficiency were investigated in the steady state simulation. Particle real-time motion law was investigated in the unsteady state simulation. Results showed that the particles classification processes are random events. Smaller particles were more possible to go fine powdered state than into the coarse particle state，vice versa.

Key words: classifier, hierarchical process, numerical simulation, unsteady

摘要： 为研究颗粒在选粉机内的分级过程，在对颗粒受力进行理论分析的基础上，对涡流空气选粉机SLK5500分级室平面进行了稳态和非稳态的CFD数值模拟，在稳态模拟中考察了颗粒运动轨迹和分级效率，在非稳态模拟中考察了颗粒的实时运动规律。最后得出，颗粒在选粉机内的分级过程是一个概率事件，粒径较小的颗粒进入细粉的概率大，进入粗粉的概率小，而粒径较大的颗粒进入细粉的概率小，进入粗粉的概率大。通过数值模拟对颗粒的实时运动进行了仿真，为选粉机结构改造和操作参数优化提供了模拟方法和数据基础。

关键词: 选粉机, 分级过程, 数值模拟, 非稳态