Chemical Engineering Research & Design, Vol.77, No.5, 442-460, 1999
The morphology of spray-dried particles - The effect of process variables upon the morphology of spray-dried particles
Single particles were produced in a convective drying process analogous to spray drying, in which, different solids or mixtures of solids were dried from solutions, slurries or pastes as single suspended droplets. The localized chemical and physical structures were analysed, and in some cases, the retention of volatiles monitored. The results were related to experimental conditions, viz.; air temperature, initial solids concentration and the degree of feed aeration. Morphologies of multicomponent mixtures were found to be complex, with the respective migration rates of the solids being dependent on drying temperature. The results are of relevance to dryer optimization and to the optimization of product characteristics, e.g. particle strength or friability, and essential volatiles retention in convective drying.