Agglomerate properties

Abstract

Modelling of wet granulation requires the rate of agglomerate coalescence to be estimated. Coalescence is dependent on the frequency of collisions that occur, and the fraction of collisions which result in coalescence. The collision rate is a function of granulator kinetics and powder properties, while the coalescence success rate is dependent on factors including the Stokes number and particle geometry. This work investigates an aspect of the geometry by examining the distribution of liquid on the surface of agglomerates in the capillary state. Agglomerates are created by adding particles, one at a time, about a central tetrahedral arrangement of four primary particles. For a given agglomerate, the wetted fraction of surface area, defined as the wetness, is evaluated using an approximate fluid surface. Packing density and binder saturation parameters are incorporated into the model. Given a number of primary particles and the volume of binder in a particle, the agglomerate wetness is able to be estimated using computational geometry.