Transport and mixing in gas-liquid and gas-liquid-solid flows in bubble columns

A research program to study the transport and mixing in slurry bubble columns (SBC) and a jet bubble column has been carried out. The main thrust of the research program was the development of computational fluid dynamic (CFD) models based on the fundamental governing equations of fluid motion for predicting the flow structures of cocurrent upward two-phase (air-water) and three-phase (air-water-glass beads) flows through slurry bubble and a jet bubble columns and mixing characteristics in a jet bubble column.; The fundamental models developed were applied to predict the flow structure in air-water and air-water-glass bead flows through SBC for a wide range of flow conditions. The importance of various modes of interfacial momentum transfer in two-phase flows, under different flow conditions, was also examined. It was found that an accurate estimation of the interfacial forces must be made in order for the models to predict the flow structures well. In order to extend the use of these models to predict the flow structure in three-phase flows, the present study also proposed new correlations to modify the interfacial forces between the phases (gas-liquid and solid-liquid) to account for the effect of the bubbles on the motion of the solid particles and the effect of the solid particles on the bubble motion. Use of fundamental models to predict the flow structures in three-phase flows has not been reported in the literature.; The model was also applied to study the flow structure and mixing characteristics in a jet bubble column. The phenomenon of bubble breakup in the jet bubble column was incorporated in the model. The model predicted the experimental data of axial variation of the gas volume fraction well. In the study of the mixing behavior of two phase air-water turbulent flow in a jet bubble, measured residence time distributions (RTD) of a liquid tracer within the cone agree well with the predicted values given by the model. Use of fundamental models to study the flow characteristics in a jet bubble column has also not been reported in the literature.; The complimentary experimental program focused on the setup of an experimental facility and diagnostic tools for the measurement of phase holdups in a SBC (for both air-water and air-water-glass beads flows). Both the radial variation of the gas holdup and the axial variations of the solid and gas holdup were obtained for different flow conditions. The experimental data obtained were compared to existing correlations for the average phase volume fractions in the bubble columns. (Abstract shortened by UMI.)...