气液固三相外环流反应器相含率分布与气液流动结构

结合电阻层析成像和差压法，以粒径3 mm的聚氨酯(密度1110 kg/m3)和粒径0.5, 1, 3 mm的玻璃珠(密度2460 kg/m3)为固相、空气为气相、水为液相，在直径0.09 m、高3.1 m的气液固三相气升式外环流反应器中考察了固相颗粒密度、粒径、固相含率对上升管和下降管中气含率的影响. 结果表明，当玻璃珠粒径为0.5和1 mm、表观气速ug>0.10 m/s时环流反应器可达到充分发展段. 以玻璃珠为固相时，气含率随固相含量和粒径增大而增大，从层析图像可见，在r/R=0~0.2处出现非导电相的极大值，且加入大颗粒的下降管中气固含率明显大于加入小颗粒的. 根据电阻层析成像的虚拟像，给出了时间序列的气固混合相的流动特征.

Distribution Characteristics of Phase Holdups and Flow Structure of Gas-Liquid in a Three-phase External Loop Airlift Reactor

Distributions of gas and solid holdups in a f90 mm three-phase external loop airlift reactor were investigated using the coupled technique of electrical resistance tomography with pressure transducers, and water as continuous and conductive phase, while glass beads and polyurethane and air were non-conductive solid and gas phases, respectively. The effects of concentration of particle, particle size, and particle density on the gas holdups in riser and downer were studied, and the relationship between solid holdups and operating gas superficial velocity was presented. The solid holdups first increases with increasing superficial gas velocity, and have a certain value when ug>0.10 m/s and dp=0.5 and 1 mm. The gas holdups increases with the increase of superficial gas velocity and concentration of solid using glass beads as solid. Gas and solid mixture phase holdups in downer with larger size of particle are larger than one in downer with smaller size of particle. According to the virtual image of 400 frames, flow structures of gas and solid mixture phase with time series were obtained.