Probabilistic hard-sphere model of binary particle-particle interactions in multiphase flow of spray dryers

► A probabilistic hard-sphere model of binary particle-particle collisions is proposed. ► The model is consistent with spray drying process involving vast amount of particles. ► Predicted zone of heat and mass transfer is located in central core of spray dryer. ► Particle-particle collisions distribute dry particles over periphery of spray dryer. ► Particle-particle collisions affect estimated particle fouling on chamber walls.