线性变气速下的下行床内轴向流动结构分析

Axial Flow Pattern in a Concurrent Downflow Fluidized Bed (Downer) with Linearly Variable Superficial Gas Velocity

在气固两相连续方程和动量方程的基础上,考虑到下行床内表观气速的变化,建立了适用于变气速条件下的一维轴向流动模型,并着重考察了气固速度和空隙率的轴向分布情况.计算结果表明,线性变气速条件下的轴向流动情况与常气速下有明显的不同,也更接近于热态反应器的实际情况.

A one-dimensional model is established to simulate the axial flow patterns in a downer reactor. Based on the gassolid continuity equation and the momentum equation, the model takes the variation of superficial gas velocity in the downer into account. The gas and solid velocity and the voidage distribution is emphatically studied.The simulation results show that there exists a remarkable disparity of axial flow pattern between variable superficial gas velocity and fixed gas velocity conditions. The linearly variable superficial velocity condition is more close to a downer reactor in practical operation.