Investigation of the Distribution Nucleation in a Fluidised Bed Using the Particle Coating Number

In wet granulation, controlling binder distribution is essential to manage particle growth. Distribution nucleation occurs when droplets wet larger powder particles, forming nuclei through liquid bridges. The particle coating number (PCN), developed by Kariuki (2013), predicts the surface coverage of solids by liquid, using parameters like liquid-solid fraction, specific surface area, and droplet size. This study, conducted in a lab fluidised bed, validated PCN's predictive accuracy across various conditions, such as liquid mass, viscosity, and atomisation pressure, using HPMC solutions and powders like glass beads and capsulac 60. PCN effectively predicted nucleation outcomes, with capsulac 60 achieving greater liquid coverage than glass beads due to its contact angle and droplet footprint. Changes in atomisation pressure significantly improved granulation by enhancing liquid dispersion, while mixing time and fluidisation velocity didn't impact PCN. The study confirmed that PCN is a powerful tool for assessing particle-liquid interactions, with potential applications in the scale-up and design of fluidised bed granulators.