Effect of particle size distribution on segregation in vibrated systems

Segregation, or demixing, of granular mixtures in vertically vibrated systems is a common occurrence that has been an active area of research. In many industrial processes, such demixing often occurs during transportation and handling of granular mixtures and can lead to inferior product quality and undesired product variations. Thus, understanding granular segregation can help resolve potential problems relating to low product yield and thus offer time and cost savings to many industries which use such materials. Our work looks into size segregation in vertically vibrated cylinders with binary, ternary as well as polydisperse mixtures. Experimental results were compared to those obtained from numerical analysis in an effort to better characterize the system segregation. We first introduced a slight particle size distribution to each species in binary and ternary mixtures and then varied the amount of intermediate species in ternary mixtures. Our results suggest that adding a slight size distribution to each species in the binary and ternary mixtures reduces segregation and enhances mixing. We also notice that for a ternary mixture, the amount of segregation is reduced as the mass fraction of intermediate species present in the system is increased. (c) 2013 Elsevier B.V. All rights reserved.