泡沫陶瓷填料旋转填充床微观混合性能

摘要

Two kinds of ceramic foam packing with different apertures were used in a rotating packed bed (RPB). Micromixing efficiency in the RPB was experimentally studied by a parallel competing iodide-iodate reaction system, and segregation index (XS) was used to represent the efficiency. Effects of volumetric flow rate, concentration of H+, rotational speed, and volumetric flow ratio on the micromixing efficiency were investigated. Experimental results show that the ceramic foam packing with smaller aperture is better for micromixing. As concentration of H+and volumetric flow ratio increase, XS increases, while it decreases with the increase of rotational speed and fluid flow rate. The micromixing time tm is calculated using incorporation model based on experimental results and the range of tm of ceramic foam packing is from 0.385 ms to 8.55 ms. Compared with traditional stainless steel mesh packing, the minimum value of tm of ceramic foam packing (0.385 ms) is much less than that of stainless steel mesh packing (1.6 ms). It means that ceramic foam packing presents better micromixing performance.%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，实验考察了物料体积流量、H+浓度、旋转填充床转速、物料体积流量比等对两种不同孔径的新型整体泡沫陶瓷填料旋转填充床的微观混合性能的影响。结果表明，孔径较小的泡沫陶瓷填料更利于微观混合；H+浓度、进料体积流量比的增加会导致XS增加；而旋转填充床转速、进料流量的增大都可使 XS下降。在实验研究的基础上，利用团聚模型计算泡沫陶瓷填料旋转填充床微观混合时间（tm），得到tm范围为0.385～8.55 ms。与传统不锈钢丝网填料对比，泡沫陶瓷填料tm最小值（0.385 ms）低于不锈钢丝网填料的tm最小值（1.6 ms），表明泡沫陶瓷填料的微观混合性能优于传统不锈钢丝网填料。