料仓中湿颗粒的卸料流型

摘要

Based on the discrete element method, the model of wet particles discharging from a hopper was constructed, and the relationship between the mass flow index (MFI) of a hopper and wet particle friction characteristics, hopper half angle, hopper outlet size and wall friction characteristics were studied.The results were compared with the predicted results of Jenike theory.The results show that wet particle-wall friction coefficient and hopper half angle have great influence on the flow pattern index MFI of the hopper.With the increase of the wall friction coefficient or the hopper half angle, the MFI value decreases, and the flow pattern can be changed from the mass flow to the funnel flow.The results are in agreement with those predicted by Jenike theory, but hopper outlet size, wet particle friction coefficient, Bonumber and the dimensionless water content have little effect on the MFI.%基于离散单元法, 构建湿颗粒料仓卸料模型, 研究料仓卸料流型量化指标 (MFI) 与湿颗粒摩擦特性、料仓半顶角、料仓开口尺寸以及仓壁摩擦特性之间的相互关系, 并与Jenike理论预测结果进行对比.结果表明:湿颗粒-壁面摩擦系数和料仓半顶角对MFI的影响很大, 随着壁面摩擦系数或半顶角的增加, MFI值减小, 卸料流型可由整体流变为中心流, 该结果与Jenike理论预测结果一致;料仓开口尺寸、湿颗粒-颗粒摩擦系数、颗粒Bond数 (Bo) 和无因次含水量则对MFI的影响较小.