Fully-3D DEM simulation of fluidised bed spray granulation using an exploratory surface energy-based spray zone concept

An exploratory spray-zone modelling concept which uses energy of adhesion at the contact of particles has been incorporated in a fully-3D Discrete Element Method (DEM)-based granular dynamics fluidised bed model and applied to fluidised bed spray granulation. In this ‘proof-of-concept’ spray model, simple functional relationships are used to notionally model surface energy pick-up by particles traversing the spray zone and an increase in energy of adhesion at drying interparticle bonds. The formation and breakage of interparticle bonds is thus governed by theoretical contact mechanics. Early-stage granulation simulation results provide qualitatively realistic granule size evolution trends.