催化重整再生器床层内径向扩散规律的研究

STUDY ON RADIAL DIFFUSION REGULARITY IN FIXED AND MOVING BEDS OF REFORMING REGENERATOR

在内径为 186mm的床层中填充国产催化重整 386 1催化剂载体 ,以空气为载气 ,氢气作为示踪气体引入床层中央 ,采用稳态有限源示踪技术 ,测定了不同操作气速、不同催化剂循环强度下床层内不同截面上示踪气体的浓度分布数据 ,通过求解二维扩散模型 ,获得了床层内的径向扩散系数 ,并将无因次的扩散系数与雷诺数 (Re)相关联 ,得到径向Peclet准数 (Per)与Re的关系式。分析表明 ,表观操作气速和催化剂循环强度是影响床层内气体扩散的主要因素。随着催化剂循环强度的增加 ,移动床与固定床在气体扩散规律上的偏离程度增大。

Radial diffusivities were measured in a 186mm column packed with the carrier of domestic catalytic reforming catalyst. The air was used as carrier gas and hydrogen was introduced into the center of the bed as tracer and its concentration distribution data on different cross sections were measured at different gas velocity and different catalyst recycle intensity using the trace technology of stable-state limited source. The bed radial diffusivities were obtained through solving the 2-dimension diffusion model and correlated with Reynolds numbers (Re), the modified Peclet numbers (Pe) were computed from the data and a correlation equation of Pe and Re was obtained. The analysis indicated that the superficial gas velocity and catalyst recycle intensity were two main factors, which influenced the diffusion behavior of gas in the bed. The difference of gas diffusion regularity between moving bed and fixed bed enlarged with the increase of catalyst recycle intensity.