This study models a high shear granulation system, including both dense and dilute regions. The dense region is modeled using an approach in which the system is treated as a visco-plastic fluid and the rheology of such a fluid is evaluated. The dilute regions are modeled by the standard Kinetic Theory of Granular Flow (KTGF). The switching between the models is accounted for by using the dimensionless inertial number, defined as the ratio shear forces/pressure forces. The results compare favorably with experimental data for a disk impeller high shear granulator. Granular temperatures and volume fractions, in particular, are well captured by the aforementioned model. The velocity profiles show better agreement with experimental data as compared to previous studies. (C) 2014 Elsevier B.V. All rights reserved.