煤粉通气料仓的优化设计

Optimization Design of Pulverized Coal Discharged from an Aerated Hopper

料仓通气技术具有成本低、噪音小的优势,被广泛应用在黏附性粉体下料过程中。为确定黏附性煤粉下料过程的最优通气条件,在自行搭建的有机玻璃料仓上进行煤粉的通气下料实验。实验结果表明,通气可以显著促进煤粉下料,但通气高度和通气气速对下料过程的影响存在耦合作用。以气泡运动理论为基础,结合气泡与颗粒间的相对运动关系,建立了煤粉通气下料模型。基于实验数据关联气泡尺寸与通气高度及通气气速间的关系,通过模型分别计算了最优相对通气高度H/D=12.25和最优通气气速U_g=2.4U_(mf)。模型计算值与实验值的吻合效果良好,当5.56<H/D<18,U_g>U_(mf)时,下料流率的计算偏差小于±20%。

The silo aeration technology, which has the advantage of low cost and low noise, has been widely used in discharging adhesive powder. The experiment of aerated discharging of pulverized coal was carried out in the self-built plexiglass hopper for determining the optimal aerated condition during the pulverized coal discharging. The result showed that aeration could promote the discharging remarkably, however,the influence of aerated height and velocity existed coupling effect. On the basis of the theory of bubble motion,the model of pulverized coal discharging was built considering the relative motion between bubbles and particles. The relationship between bubble size and aerated condition was associated based on the experiment. The calculated optimal height was H /D = 1 2 . 25 and the optimal velocity was Ug = 2. 4l/mf. There was a good agreement between calculation and experiment. The deviation of calculated discharging rate was less than ±20% while 5. 56〈H / D〈18, Ug〉 Umf.