A new model for the drying of droplets containing suspended solids after shell formation

The novel droplet drying model introduced by the authors in a previous paper [Handscomb, C.S., Kraft, M., Bayly, A.E., 2008. A new model for the drying of droplets containing suspended solids. Chemical Engineering Science, in press, doi:10.1016/j.ces.2008.04.051] is extended to droplets drying in the presence of a surface shell. The model now incorporates shell thickening, along with a description of wet and dry shell drying. Structural properties of the shell are included in the model and influence the predicted dried particle morphology. Comparisons between model predictions and experimental data from the literature are presented for two systems of interest: detergent crutcher mix and colloidal silica. These simulations demonstrate the model is capable of predicting dried particle morphology together with other properties of interest such as moisture profiles and moments of the solids particle-size distribution.