Study of dynamic multi-dimensional temperature and concentration distributions in liquid-sprayed fluidized beds

Abstract

A physically based model was developed for heat and mass transfer processes in liquid-sprayed fluidized beds. Such fluidized beds are used for granulation, coating and agglomeration. The complex correlations of a number of microprocesses, spraying, wetting, drop deposition, heat transfer, drying and mass transfer were studied, and transient three-dimensional distributions of air humidity, air temperature, particle wetting efficiency, liquid film temperature, particle temperature, local liquid loading and local evaporation rate were calculated. For the evaluation of the model, the stationary spatial air temperature distributions were measured at a fluidized bed pilot plant of the institute. The fluidized bed of monodisperse wood- or glass beads was sprayed with clear water. Conclusions are drawn on the relevance of particle dispersion, spraying and drying to simulating temperature and concentrations distributions.