A Local Model for Gas-Liquid Mass Transfer in a Gas-Liquid-Solid Circulating Fluidized Bed

Abstract

A local mass transfer model which details the local gas-liquid mass transfer phenomenon in a gas-liquid-solid circulating fluidized bed (GLSCFB) is discussed and tested in this work. It is observed that the local mass transfer model with consideration of the axial liquid dispersion can appropriately address the gas-liquid mass transfer at every radial position in the riser; however, that without consideration of the axial liquid dispersion can only deal with the mass transfer near the wall where the axial liquid dispersion is negligible. The effects of gas flow rates, liquid velocities, particle circulating rates, and particle sizes on gas-liquid mass transfer in GLSCFBs have also been examined systematically. Based on the experimental data, a correlation is obtained to predict the gas-liquid mass transfer coefficients in GLSCFBs for the first time.