沸腾态气-液-固搅拌槽内宏观混合时间的研究

在直径为0.476m的椭圆底搅拌槽内，采用电导率法研究了沸腾态气-液-固三相体系内混合时间特性。主要考察分散相(气体、颗粒)和功耗对混合时间的影响。实验结果表明：沸腾态搅拌槽内，同转速条件下，颗粒体积分数对单位质量功大小影响较小；仅转速高于480r/min范围内，表观气速增加，体系单位质量功略有下降。颗粒临界悬浮转速随颗粒体积分数的增加而增加，但不随表观气速的变化而发生变化。沸腾态气-液-固三相体系内，混合时间随表观气速或颗粒体积分数的升高而延长。

The mixing time in a boiling gas-solid-liquid stirred tank

The conductivity technique has been used to investigate the mixing time in a boiling gas-solid-liquid stirred tank with a diameter of 0.476 m. The effects of varying the superficial gas velocity and solid volume fraction on mixing time were investigated. At the same stirring speed, the mean specific energy dissipation rate remains constant with increasing of solid volume fraction, although it decreases with increasing superficial gas velocity in the high range of stirring speed (＞480 r/min). The critical just suspension impeller speed increases with the increasing solid volume fraction but remains constant with increasing superficial gas velocity. The mixing time increases with increasing solid volume fraction or superficial gas velocity.