Mesoscale Modelling of Fluidised Bed Binder Granulation

Fluidised bed granulation is a unit operation commonly employed for particle size enlargement during the manufacture of various chemical products such as fertilizers, pigments, detergents, pharmaceuticals, ''instant'' food, and others. The internal structure of granules -- characterised e.g. by porosity and pore-size distribution -- is a key parameter which determines product properties such as mechanical strength or the rate of disolution. I will present methodology and some results of our recent efforts to predict the structure of granules from ''first principles'', i.e. from known properties of the primary constituents (powder particles and liquid binder droplets) and process parameters. I will also point out some physical and physico-chemical problems underlying granulation.