Discrete element investigation of flow patterns and segregation in a spheronizer
Discrete element investigation of flow patterns and segregation in a spheronizer
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滚圆机中流动模式和偏析的离散元研究
DOI：
10.1016/j.compchemeng.2012.09.023
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发表时间：
2013
期刊：
影响因子：
--
通讯作者：
H. Dumont
中科院分区：
文献类型：
--
作者：
J. Bouffard;F. Bertrand;J. Chaouki;H. Dumont
球形机中的粉末流动的特征在于环形运动，并且流型取决于圆盘速度和填充水平，但也取决于颗粒性质。本文采用离散元法（DEM）数值模拟研究了这些参数对双分散颗粒尺寸分布的分离模式和流动动力学的影响。偏析的表征，通过混合指数和与剪切应力的关系，在环形域，提出。讨论了混合曲线、浓度分布和方位速度相关等特征。对数表达式已被开发来解释颗粒床内的方位角速度的演变上的剪切应力。混合指数和浓度曲线的组合用于量化当填充水平和滚圆机盘的旋转速率变化时在分离上观察到的变化。
Powder flow in a spheronizer is characterized by a toroidal motion and the flow patterns depend on the disc velocity and the fill level, but also on the particle properties. This work investigates numerically, with a discrete element method (DEM), the impact of these parameters on segregation patterns and the flow dynamics for bidisperse particle size distributions. Characterization of the segregation, by means of a mixing index and the relation with the shear stress in the toroidal domain, is presented. Characteristics, such as mixing curves, concentration profiles and azimuthal velocity correlations, are discussed. A logarithmic expression has been developed to account for the shear stress on the evolution of the azimuthal velocity inside the particulate bed. The combination of the mixing indexes and the concentration profiles is used to quantify the changes observed on the segregation when the fill level and the rotational rate of the spheronizer disk are varied.