Modelling of Mean Drop Size in a Extraction Spray Column and Developing a New Model

Abstract

Drop size distribution plays a key role in the liquid extraction systems and related hydrodynamic and mass transfer parameters. In current research work, the size of drops in an extraction spray column has been measured by direct photography method, and the Sauter mean diameter has been obtained accordingly. Then, two types of models are assessed based on using dimensionless analysis and appropriate software. The interfacial tension in used chemical system is 1.8-32 dyne/cm. In first type of models, the correlation is established based on dimensionless parameters similar to approaches defined by other researchers. In second types, dimensional parameters have been used and therefore a new model is introduced for multi-drop extraction columns. The results show that the drop size diameter has the most affect on Eotvos number (Eo) in the first type of model and the correlation based on Eo number predicts drop size diameter with 8.1% error. In the second ones, four dimensional parameters (d N, Dr, s, u) have been selected as the most effective variables on drop size diameters and modelling results show prediction of drop size diameters with 5.82% error. In other cases, without using u as a variable, the amount of error has been decreased to 5.73% which shows better fitting.