(83e) Capillary Interaction in DEM Simulations of Wet Particulate Materials

Processing stages such as granulation, encapsulation, coating, drying, particle melting are present in a variety of industries, including the manufacture of food, pharmaceuticals, catalyst, mechanical part products. The presence of some liquid between the particles determines forces and complex particle formation or breakage whose understanding and characterization is far from complete. Discrete Element Method (DEM) simulations possess the ability to carry out analysis of dense particulate material under actual industrial processing conditions, being able to include interaction contributions at the individual particle level.

In the present work, microscopic models of particle-particle capillary interaction for inclusion in advanced DEM simulations are investigated. Liquid bridge formation, interaction force, stability and rupture are investigated as a function of the liquid volume, liquid wetting properties (e.g. contact angle), particle separation distance, particle size ratio. The extensive set of results are obtained adopting a rigorous computation of the equilibrium bridge shape and characteristics. Comparison with existing approaches, such as the toroidal approximation, will be finally presented.