STUDY ON THE TURBULENCE IN PULSED STAGEWISE EXTRACTION COLUMNS: TURBULENT MACROSCALE

Abstract

The authors studied a particular turbulent parameter – turbulent macroscale, which characterizes the size of large energy containing eddies, and it is one of the basic parameters with essential role in the concept of turbulent motion. Pulsed turbulent liquid flow in stagewise column type apparatuses with internals of disks and rings is considered. The distribution of turbulent macroscale L over the stage is determined as depending on stage geometry and Re number. Insignificant changes of L are registered in the course of pulsation cycle. Similarly, the dynamic flow parameters, expressed by the value of Re number, pulse amplitude and frequency, demonstrate slight and not pronounced influence on the size of turbulent macroscale. Most important effect on L has the stage geometry with pronounced influence of interplate distance and lesser dependence on plate free area. It was found that the zones of large L-values correspond to zones of intensive drop breakage, located experimentally. A correlation is proposed for determination of the mean value of turbulent macroscale as a function of stage geometry parameters. Comparison with other correlations is made along with discussion on their advantages and inconveniences.