Granulation of wet granular medium in rotating drum
Résumé
In this work, we study the agglomeration process of wet granular materials in rotating drum. Agglomeration of fine particles is used in many industrial processes such as powder metallurgy, iron-making industry, food and pharmaceutical industries. Fine granular materials are prepared and mixed in required proportions, compacted into a granule or tablet and finally sintered to acquire sufficient mechanical strength and toughness needed for subsequent operations. We present a numerical model for the agglomeration of wet particles in rotating drum [1, 2]. The particles interact through capillary liquid bridges, which are modeled by accounting for the cohesive and viscous forces expressed analytically as a function of different parameters such as the distance between primary particles, liquid volume and viscosity, surface tension and particle sizes. The model also assumes that the liquid is transported by the primary particles modeled as agglomerates of fine particles. We find that this model is able to simulate the granulation of particles in a rotating drum in which a given amount of liquid is homogeneously re-distributed. Our simulations show that the granule size increases exponentially with the number of drum rotations and in proportion to the amount of liquid. We investigate the effects of process and material parameters such as particle size distribution, mean particle size, friction coefficient between the primary particles and liquid viscosity in each agglomeration process.