变转速回转筒内二元颗粒混合特性数值分析

Numerical Simulation Study on the Mixing Characteristics of the Binary Particle in a Variable Speed Rotating Device

采用离散单元法,在前期实验基础上研究圆形和椭圆滚筒转速的连续变化对相同颗粒数量二元颗粒体系混合的影响.从颗粒群运动速度分区图、宏观颗粒运动矢量图的角度分析颗粒在不同转速下的运动混合规律,运用Lacey指数定量评价二元颗粒的混合度.结果表明:在颗粒数一定的情况下,滚筒筒形对二元颗粒的混合具有一定的影响,但转速的影响占主导;最佳混合工况时颗粒在滚筒内处于抛落的运动模式;一定速度范围内筒体转速的变化可增强混合.研究可为颗粒物料增混设备的改进及操作控制提供依据和参考.

In order to understand the characteristic of motion of particles in rotary mixers,the effects of angular speeds of circle and ellipse mixers on mixing are studied by the discrete element method. Macroscopic mixing law and partial mixing characteristics in particle mixing process are analyzed in the view of velocity and motion vector diagram.The mixing was described quantitatively by using the Lacey index.Results show that the shape of drum has a certain effect on the mixing of the binary particle.However,the influence of rotating speed is the dominant factor.The motion of particles on optimum mixing conditions is in the dropping mode.The variability of rotating speed within a certain range can enhance the mixing.The research can provide the basis and reference for the improvement and operation control of the mixing equipment of granular materials.