装填不同填料的管式反应器的微观混合性能

摘要

The micromixing characteristics of a tubular reactor packed with different packings were investigated by adopting the competitive parallel reaction, namely, the Villermaux-Dushman reaction. Experimental results showed that the tube packed with rhombus mesh frame packing (RMFP) presented better micromixing efficiency, compared to the tube with mini ring or empty tube. It could be found that the segregation index (XS) decreased as Reynolds number increased while it increased with increasing volumetric flow ratio. Moreover, the micromixing time (tm) was calculated using an incorporation model based on the experimental data. The minimum tm value of the tube packed with RMFP (tm=2.27 ms) was less than that of the tube with mini ring (tm=2.73 ms) or empty tube (tm=3.79 ms).%采用碘化物-碘酸盐平行竞争反应为工作体系，以离集指数（XS）表征微观混合性能，实验考察了Reynolds数Re、物料体积流量比对装填扁环填料和网架填料的管式反应器的微观混合性能的影响及离集指数在管式反应器轴向、径向的分布。结果表明，XS随着Re的增大而下降，而物料体积流量比的增加会导致XS增加，相同条件下网架填料的XS小于扁环填料，离集指数在轴向上呈现先明显降低后基本不变的趋势。在实验研究的基础上，利用团聚模型计算装填网架填料的管式反应器的微观混合时间（tm）为4.82～2.27 ms。与扁环填料对比，网架填料最小值（2.27 ms）低于扁环填料的最小值（2.73 ms），同时二者均小于空管的最小值(3.79 ms)，表明装填填料可以改善管式反应器的微观混合性能，网架填料的微观混合性能略优于扁环填料。