由转盘塔内连续相溶质浓度轴向分布 估算传质系数和轴向混合系数的研究

根据转盘萃取塔内连续相溶质浓度的轴向分布进行了参数估算.在估算中应用液滴尺寸分布,将带轴向混合的柱塞流模型应用于塔内连续相,将前混模型应用于分散相.参数估算结果表明:应用d_(32)所获得的连续相轴向混合系数E_c和传质系数k_c的估算值比应用液滴尺寸分布所得的E_c、k_c的估算值偏高;如果忽略液滴生成过程传质的影响,k_c的估算值略有增加,而E_c的估算值则明显偏高.

Evaluation of Mass Transfer Coefficient and Axial Mixing Coefficient in Rotating Disc Solvent Extraction Column (RDC)

Mass transfer coefficient and axial mixing coefficient in RDC were evaluated from the axial concentration profiles of the continuous phase. Drop size distributions instead of d32 were used in the evaluation of parameters. Axial mixing of the continuous phase and forward mixing of the dispersed phase were considered. Experiments were carried out in a RDC of 76 mm in diameter. Water and n-butanol were used as continuous phase and dispersed phase respectively. Succinic acid as the solute was transferred from water to butanol drops. Mass transfer coefficient kc and axial mixing coefficient Ec were simultaneously determined by matching the calculated concentration profile with the experimental data. The predicted values of kc and Ec with drop size distribution taken into consideration were shown to be lower than those obtained by using d32 only and the estimated Ec will be much higher if the contribution of mass transfer during drop formation was not considered.