颗粒物料输送过程运动特性的离散元模拟

Discrete Element Simulation of Movement Characteristics for Particle Material on Transportation Process

为揭示颗粒物料输送过程中的运动规律以及卸料轨迹的影响因素,采用离散单元法建立胶带输送机运输模型,对颗粒物料的输送和抛射行为进行模拟。通过颗粒物料输送过程的运动速度和抛射轨迹分析发现:颗粒在胶带输送机上的运动分为加速、抛射和碰撞3个阶段,颗粒在碰撞阶段与挡板和其他颗粒发生多次碰撞,使其速度和方向不断改变,是影响颗粒卸料落点的主要因素;颗粒物料按照入料顺序分为入料初期颗粒、入料中间颗粒和入料末期颗粒,入料中间颗粒在抛射和碰撞反弹阶段都会受到其他颗粒的干扰,其卸料轨迹和落点存在较大差异,碰撞过程中能量损失较大,是影响输送效率的重要原因。

In order to reveal the movement rule and influence factors of unloading trajectory for particle material on transportation process, the transportation model of belt conveyor is built using discrete element method. The transportation and projection behaviors of particle material are simulated, and the analysis of the movement velocity and projection trajectory is finished. The analysis results show that there are three phases including accumulation, projection and impact when particles are transported on the belt conveyor. In the impact phase, the velocity and direction of particles are changed continuously because of the impact between particle and dam-board or particle and other particles. The change of velocity and direction is the main influence factor for particle locations after falling to ground. According to the feeding sequence, particle materials are divided into the initial feeding particles, the middle feeding particles and the last feeding particles. The middle feeding particles are disturbed by other particles both in the projection and impact phases. Therefore, there are large differences among the unloading trajectories of the middle feeding particles as well as the locations after falling to ground. The important reason influencing transportation efficiency is the large energy loss caused by impact.