脉冲筛板萃取柱中传质过程的研究

在内径40mm实验脉冲筛板柱中,用30%磷酸三丁酯-硝酸-水体系测定了各种操作条件下两相稳态传质浓度剖面、液滴直径分布和分散相体积分数.根据多级返流模型拟合实际浓度剖面推算得到真实的体积传质系数K_(oDa)和两相返混参数,并进而计算出相际传质系数K_(oD).对标准板和分散-聚合型板两种柱结构内的传质过程进行了分析和讨论.研究结果表明,在本实验范围内,脉冲筛板柱内相际传质系数可按单液滴湍流内循环传质模型来预测.

Mass Transfer in Pulsed Sieve Plate Extraction Column

Mass transfer experiments have been carried out in a 40mm diameter pulsed extraction column equipped with standard and "dispersion-coalescence" type cartridges; respectively. A system with 30% TBP (kerosene as diluent)/ HNO3/H2O was used. "True" volumetric mass transfer coefficient and back- m ixing parameters in continuous and dispersed phases were simultaneously evaluated from the steady state concentration profiles in both phases using a computer program based on the backflow model. Drop sizes and dispersed phase hold-up in the column were measured at the same time. Overall mass transfer coefficients were then calculated. It was shown that the mass transfer charicteristics of the extraction column can be predicted by the single turbulent circulating drop mass transfer mechanism.