Hydrodynamic aspects of multi-stage turbulent bed contactor

The hydrodynamic behaviour in each stage of multi-stage Turbulent Bed Contactor operations has been studied for light (Type I) and dense (Type II) particles. The experimental data are collected on dynamic liquid holdup, gas holdup, bed expansion and bed pressure drop across each stage for operating parameters such as superficial gas and liquid velocities, particle characteristics, geometric parameters of the column such as static bed height, free-open area of the supporting grid, distance between the supporting grids, downcomer diameter and weir height. In multi-stage operation, it was experimentally observed that the hydrodynamic behaviour of each stage corresponds to a single-stage behaviour. In single-stage TBC for Type I and Type II operations, liquid holdup increases with increase in velocities of gas and liquid and particle density and with decrease in free-open area, diameter of particle and static bed height. Gas holdup increases with increase in gas velocity and with decrease in free-open area. Correlations for liquid and gas holdups have been proposed based on the experimental data. Bed expansion and bed pressure drop are calculated using gas and liquid holdups.