Microscopic evaluation of binderless granulation in a pressure swing granulation fluidized bed

• Plastic deformation of binderless granules using MPIA.
• Realistic values for DEM spring constant and coefficient of restitution using MPIA.
• DEM simulation of granules to estimate collision force and collision frequency.
• Densification phenomena in PSG fluidized bed.

To develop a microscopic understanding of the role of cyclic fluidization and compaction in making spherical and dense granules by Pressure Swing Granulation, numerical simulation was conducted with our private code (SAFIRE21) using realistic parameter values determined by a micro-particle interaction analyzer. The values of the spring constant and coefficient restitution obtained from this experimental measurement were 300–790 N/m and 0.9 respectively. The results obtained by the discrete element method simulation showed that collision frequency and collision force in a fluidized bed were insufficient to cause deformation of the granules but were significant in shaping the granules spherically.