滚筒冷渣机中的颗粒径向扩散运动研究

Study of the Radial Diffusion Movement of Particles in a Roller Type Slag Cooler

在滚筒冷渣机灰渣回转冷却运动中引入扩散系数的概念并探讨了颗粒物料扩散的规律及径向扩散对传热的影响。采用DEM(离散元法)建立颗粒运动模型,对扩散运动进行研究得出以下结论:颗粒在主动层滑落过程中相互碰撞、相互作用导致进入被动层后相对位置的重新组合是径向扩散的根本原因;不同料层区域颗粒的径向扩散强度不同;颗粒扩散可以加速料床内部传热,扩散系数大的部位内部温差小,扩散系数小的地方内部温差较大。

During the rotating and cooling movement of ash and slag in a roller type slag cooler,introduced was a concept of the diffusion coefficient,investigated were the law governing the diffusion of granular materials and the influence of the radial diffusion on the heat transfer. By using the discrete element method,a model for the movement of particles was established and the diffusion movement was studied. The authors had arrived at the conclusion as follows: the mutual collision and action of particles during the process of their sliding down from the active layer result in a recombination of their relative positions after entering into the inactive layer are regarded as the root cause for radial diffusion. The radial diffusion intensities in various material layer zones are different. The diffusion of particles can speed up the heat transfer inside the material bed and the locations,where the diffusion coefficient is bigger,have a smaller inner temperature difference and vice versa.