偏心楔形喂料斗卸料过程中颗粒流动特性

采用三维离散单元法，研究了偏心楔形喂料斗中不同粒径颗粒卸料过程的流场分布，建立了适用于偏心楔形喂料斗的整体流系数模型，分析了料斗卸料流型以及卸料流型与卸料质量流率的相关性，并通过实验验证了离散元模型的可靠性。结果表明：偏心楔形喂料斗内颗粒流场分布以靠近喂料管口区域为高速区，并呈辐射状朝远离垂直壁面端的料斗上部低速区过渡，高速区颗粒流场的整体一致性好，低速区颗粒流场呈局部涡流状；颗粒粒径增大，颗粒整体流动性变差，高速区域范围减小，低速区域范围增大，过渡区域变模糊；当颗粒粒径不大于10 mm时，整体流系数与颗粒粒径呈线性负相关，卸料质量流率与整体流系数呈线性正相关。

Flow characteristics of granule discharged from eccentric wedge-shaped feed hopper

Flow field distributions of discharging various sized granular materials from wedge-shaped feed hopper was numerically simulated using three-dimensional discrete element method. A mathematical model of mass flow index (MFI) was proposed for the wedge-shaped feed hopper. The discharge flow pattern and its relationship with discharge mass flow rate was analyzed, and model reliability was verified experimentally. The results show that granular flow field in the hopper has a high velocity region near feed pipe outlet and is radially attenuated towards low velocity region at the upper hopper which is away from vertical wall and feed pipe. The flow direction of particles in high velocity region was well consistent, whereas granular flow in low velocity region exhibited local vortices. With the increase of particle size, overall flowability of particles in the hopper decreased, which high velocity region shrinked, low velocity region enlarged, and transition region became obscure, hence both MFI and discharge mass flow rate were decreased. When particle size was no more than 10 mm, MFI was negatively linearly related to particle size, but was positively linearly to discharge mass flow rate.