双轴桨叶式混合机内椭球颗粒混合特性模拟

摘要

To investigate random motion and mixing characteristics of ellipsoid particles in twin-shaft paddle mixer, mixing process of particles is simulated using discrete element method in this research .Particles mixing law and mixing characteristics are analysed with the view of a single particle random motion trajectories and streamline motion trajectories diagram of particles swarm .And the mathematic relation between mixability and revolutions of agitating blades is de-scribed quantitatively .Results show that random motion of ellipsoid particles is acute , mixing performance is favorable in radial direction and axial direction .Convective mixing , shear mixing and diffusive mixing control the mixing homogeneity process of segregation particles .Mixability of segregation particles has direct correlation with revolutions .The relation be-tween mixability and revolutions conforms to the exponential growth model .%为探讨双轴桨叶式混合机内椭球颗粒的随机运动和混合特性，采用离散元法对颗粒混合过程进行了模拟研究。从单颗粒的随机运动轨迹、颗粒群的流线运动轨迹的角度分析了颗粒运动规律及混合特征，定量描述了混合程度与转子旋转圈数的数学关系。结果表明：混合机内椭球颗粒的随机运动剧烈，径向和轴向上的混合效果良好；分层颗粒的混合均匀是在对流混合，剪切混合和扩散混合共同作用下实现的；分层颗粒的混合度与转子旋转圈数直接相关，混合度与圈数的关系符合指数增长模型。