快速床提升管内颗粒的扩散行为研究

Dispersion of Axial and Lateral Solids in Fast Fluidized Bed

在直径１００ｍ ｍ ×３ｍ 的实验台上，利用热粒子为示踪剂，研究快速床提升管内的颗粒的扩散行为。在不同的径向位置测得反映扩散行为的温度响应曲线，提出二维扩散模型来描述颗粒的轴、径向扩散。通过最小二乘拟和估计轴向扩散系统Ｄａ 和径向扩散系数Ｄｒ。实验发现，Ｄａ 随气体表面风速的增加而增加，Ｄｒ 则基本保持不变。静止床高的增加使Ｄａ、Ｄｒ 略有增加。

Lateral and axial solids mixing are studied experimentally in 100mm×3m fast fluidized bed riser.Using hot particles as tracer,the temperature response curve at different radial position in fast fluidized bed are measured.A proposed two-dimensional dispersion model describes the experimental data very well.The axial dispersion coefficient,D a increases with increasing of superficial gas velocity v g and increases little with increasing bed height(H),while the lateral dispersion coefficient,D r changes little with the increasing of v g and H.