斗式提升机物料卸载流动的离散元模拟

Discrete Element Simulation of Material Unloading Flow of Bucket Elevator

利用离散单元法(DEM)对斗式提升机内物料卸载过程进行数值模拟,计算得到颗粒的运动轨迹与速度分布特征,统计分析颗粒流动的空间位置分布与生产率特性。结果表明:卸料包络域由多个颗粒运动轨迹决定,深斗的卸料包络域较浅斗的更大;料堆表面上,颗粒速度分层均匀,在Z轴方向高度为20 mm位置处,颗粒角速度最小且分布集中;颗粒流动的位置与速度分布对称性良好;选择速度为1.5 m/s的深斗用于卸料,可同时满足生产率高和颗粒与机壳碰撞作用弱的要求。

The material unloading process in bucket elevator was numerically simulated and calculated under the different working conditions using the discrete element method(DEM).The trajectory and velocity distribution characteristics of the particles were obtained,and the spatial position distribution and productivity characteristics of the particle flow were statistically described.The results show that the unloading envelope is determined by the trajectory of multiple particles,and the unloading envelope of the deep bucket is larger than that of the shallow bucket.On the surface of the pile,the particle velocity is evenly layered.At the position of Z=20 mm,the angular velocity of the particle is the smallest and the distribution is concentrated.The symmetry of the particle flow position and velocity distribution is good.The deep bucket with a speed of 1.5 m/s is selected for material unloading,which can meet the requirements of high productivity and weak impact between particles and the house.