Drop Size Distribution Spectra in Mixing Vessel for Extraction of Fuel

在核燃料后处理中，由于分散液滴向混合液的传质行为在很大程度上取决于液滴的大小，因此，为了优化铀或钚的提取，必须从液滴的粒度分布谱来分析混合沉降器或脉动塔的性能。在混合容器中，液滴的大小取决于容器中微观和宏观尺度的湍流运动和流型。掺气改变了混合槽内的流型和湍流运动，从而改变了液滴的粒径分布。实验结果表明，随着掺气的增加，液滴的粒径分布增大，中等粒径的液滴比例减少。液滴的体积粒径分布曲线由三个参数的组合表示搅拌能耗率和分散相体积分数对Sauter液滴平均粒径的影响表明，在有通气的混合容器中，聚并现象占主导地位。

In nuclear fuel reprocessing,the performance of mixer-settlers or pulsation columns should be analyzed from the spectra of drop size distribution for optimization of uranium or plutonium extraction because mass transfer behavior from dispersed drops to mixing liquid is largely dependent on the drop size.The drop size in a mixing vessel is dependent on the micro-and macro-scale turblent motions and flow patterns in the vessel.Accordingly,introduction of aeration can change the drop size distribution because the aeration changes the flow patterns and the turblent motions in the mixing vessel.Experimental results in this study show that both small and large size drops in distribution increase with aeration to decrease the fraction of the intermediate size drops.The volumetric drop size distribution curve is represented by a combination of three normal distribution curves though the number distribution curve is represented by a combination of two log-normal distribution curves.Effect of energy dissipation rate by agitation or that of volume fraction of dispersed phase on the Sauter mean drop size shows that coalescence phenomena are dominating in the mixing vessel with aeration.