Mass transfer in conical spouted beds equipped with internal devices

The gas–solid contact in spouted beds is characterized by a hydrodynamics leading to high heat and mass transfer rates. Several correlations have been proposed for estimating the minimum spouting velocity, and heat and mass transfer coefficients. However, those available for estimating the mass transfer coefficient are not suitable for conical spouted beds equipped with internal devices. Based on drying runs and a drying model already validated, mass transfer coefficients were estimated under different operating conditions and geometries of the internal devices. The features of the bed materials are those of greatest impact, followed by the air inlet temperature and velocity. Although the influence of the dimensions of the internals is less significant, they are also key parameters for the scaling-up of spouted beds. Therefore, a new correlation has been proposed, which accurately predicts the mass transfer coefficient in both plain spouted beds and those equipped with internal devices.