轴向移动床内气体扩散规律的研究

STUDY ON GAS DIFFUSION LAW IN AXIAL-MOVING BED

在直径为Φ186mm的轴向移动床中填充国产连续重整 386 1型催化剂担体 ,以氢气为示踪气体 ,采用稳态有限源示踪技术 ,测定了不同操作气速下床层内部不同截面上示踪气体的浓度分布实验数据 ,通过求解移动床二维扩散模型 ,获得了不同操作气速下的轴、径向扩散系数。结果表明 ,表观操作气速是影响轴、径向扩散系数的主要因素。随着Re数增加 ,轴、径向扩散系数均逐渐增大。根据实验求得了表征径向贝克来数。

Using the steady state limited source tracer technique and hydrogen as the tracing gas,the concentration distribution of the tracing gas at different cross sections of a moving bed were measured in a column with a diameter of 186mm and packed with the domestic continuous reforming catalyst 3861.Both radial and axial diffusivities of the tracing gas were obtained by solving a two dimensional diffusion model. The results showed that superficial gas velocity is the main factor affecting both axial and radial diffusivities. Either of them increased with the increase of Reynolds.Correlations between radial Peclet numbers,axial Peclet numbers and Reynolds numbers were established.