Characterization of liquid phase mixing in turbulent bed contactor through RTD studies

Abstract

Liquid phase mixing in a turbulent bed contactor (TBC) is experimentally characterized through residence time distribution (RTD) studies. A novel technique is employed to obtain the true exit tracer concentration and to increase the average residence time of the liquid. In this technique, an ideal mixed flow tank (MFT) is included in series with TBC. The RTD of the ideal MFT is deconvoluted from the RTD of the entire system to obtain the RTD of TBC alone. Using this method, the effect of gas and liquid velocities, static bed height, particle size and density, and number of stages on mixing of the liquid phase is studied. The experimental RTD curves are satisfactorily compared with axial dispersion model. Correlations are developed for predicting the Peclet number and the axial dispersion coefficient. It is observed in the present study that conditions close to plug flow of liquid phase can be achieved in multistage TBC.