鼓泡流化床内颗粒混合的对流—扩散模型

Modelling for Solids Mixing in Bubbling Fluldized Beds

本文分析了鼓泡流化床内颗粒混合机理，综合了床内颗粒水平方向和垂直方向上的混合，将床内颗粒混合过程分成两部分：一、是向上运动的足迹相和向下运动的乳化相之间的对流交换，二、是乳化相内横向扩散。建立了二维的对流扩散模型，数值计算和实验数据相吻合；研究了给料点的布置和流化速度对床内物料浓度的影响。

In this paper the dynamics of solids mixing in a fluidized bed is investigated, both radial mixing and vertical mixing are considered. Solids mixing is divided into two parts:the exchange betwewn an upward moving wake phase (W) and a downflowing emulsion phase (E),and the diffusion in the E phase land a 2-D convection -diffusion model is developed. The numerical results are in satisfactory agreement with the experimental data.