空气重介质流化床干法分选原理的单颗粒动力学描述

Dynamics of Single Particles of Dry Coal Separating in the Air Dense Medium Fluidized Bed

燃煤已造成了我国严重的大气污染及酸雨 .选煤是煤燃前净化的主要技术 ,对治理煤烟污染发挥着重要作用 .传统的选煤方法是水洗 ,而严重干旱缺水的现实又制约着西北地区洗煤技术的应用与发展 .空气重介质流化床是不用水的干法分选新技术 ,对我国西部煤炭资源的开发利用具有极广阔的应用前景 .因此 ,开展对空气重介质流化床的多相流体动力学研究具有十分重要的理论意义和作用 .本文通过单颗粒动力学模型及数值计算得到不同的密度与粒度的矿粒在空气重介质流化床下沉的深度描述 ,同样粒度下矸石密度大于精煤密度而形成矸石在上精煤在下的分离层 。

Here presents to study the fundamental hydrodynamics of the Air Dense Medium Fluidized Bed (ADMFB),which is a new technique of clean coal technology.In this kind of gas solid fluidized bed there is a pseudo fluid instead of water as the separating medium.By using the dynamical model of single particles and numerical calculations, the researchers obtained some results which show that,for mineral particles of the same size,the higher the density of a mineral particle, the longer the distance of sinking in the fluidized bed; and for mineral particles of the same density, the larger the size is, the longer the distance of sinking will be.That is an answer to the question why coal and waste form different layers on the fluidized bed: the upper is the lighter particles of coal and the lower is the heavier ones of waste. That is the basic principle of particles separating in the ADMFB.