Abstract: A resident time model is proposed to evaluate the performance of agitated extraction columns. In this model, the resident time of dispersed drops is simulated with the discrete phase modeling, where the continuous phase and the dispersed phase （drops） are described by the single-phase Navier-Stokes（turbulence） model and Lagrangian model, respectively. The interaction of dispersed phase and continuous phase is neglected for the low concentrationn of drop in the cases studied. The statistical parameters of drops （the average resident time and standard deviation） under different operation condiitions are computed for four columns. The relation of the above statistical parameters with the performance of columns is discussed and the criterions for an optimal compartment are outlined. Our results indicate that the resident time model is useful to evaluate the performance and optimize the design of extraction columns.

Key words: resident time, stirred extraction column, discrete phase modeling, computational fluid dynamics

摘要：

A resident time model is proposed to evaluate the performance of agitated extraction columns. In this model, the resident time of dispersed drops is simulated with the discrete phase modeling, where the continuous phase and the dispersed phase （drops） are described by the single-phase Navier-Stokes（turbulence） model and Lagrangian model, respectively. The interaction of dispersed phase and continuous phase is neglected for the low concentrationn of drop in the cases studied. The statistical parameters of drops （the average resident time and standard deviation） under different operation condiitions are computed for four columns. The relation of the above statistical parameters with the performance of columns is discussed and the criterions for an optimal compartment are outlined. Our results indicate that the resident time model is useful to evaluate the performance and optimize the design of extraction columns.

关键词: 散相液滴;搅拌萃取塔;停留时间分布;离散模型;流体动力学