基于离散元法的番茄秸秆立式螺旋混合机理

对番茄秸秆碎料的本征参数和接触参数进行测定,以物料自然休止角为判断依据,通过正交试验法标定离散元仿真参数组合,并分别进行仿真试验和样机试验,分析发现:桶内物料颗粒宏观上为对流混合过程;物料颗粒与叶片表面法向方向形成一定角度做发散运动,距离叶片越远,颗粒速度越小;上下叶片之间存在很多湍流区域,无明显直径方向上扩散运动过程;叶片转速提高、螺距增大、填充高度降低都有利于物料混合均匀,揭示的高效混合机理为后期设备的开发与优化提供理论基础.

Vertical spiral mixing mechanism of tomato straw particles based on discrete element method

In this paper, the intrinsic and contact parameters of tomato straw particles were determined. Based on the natural angle of repose of the material, the discrete element simulation method parameters were calibrated by orthogonal test. Based on these parameters, a series of experiments were carried out. It is found that the particles form a macroscopic convective mixing process. The particles of that material form a certain angle in the normal direction of the surface of the blade to do divergent motion, and the farther away from the blade, the smaller the particle velocity. There are many turbulent regions between the upper and lower blades. The particle movement shows the process of spiral ascending and spiral descending, and there is no obvious diffusion movement in the diameter direction. The increase of blade rotation speed, the increase of pitch and the decrease of filling height are beneficial to the improvement of material mixing effect. The high-efficiency mixing mechanism is revealed, which provides a theoretical basis for the later equipment development and optimization.