(116a) Continuum Modeling of Granular Segregation in Hopper Discharge Flows

Authors: 
Fan, Y., The Dow Chemical Company
Xiao, H., Northwestern University
Jacob, K., The Dow Chemical Company
Umbanhowar, P. B., Northwestern University
Kodam, M., The Dow Chemical Company
Koch, J. F., The Dow Chemical Company
Lueptow, R. M., Northwestern University
Predicting segregation during hopper discharge is important for bulk solids handling as segregation of particles with different sizes can result in severe consequences in product quality. However, due to the complexity of the flow kinematics in the hopper and the nature of granular segregation, little progress has been made in modeling segregation in hopper discharge. In this work, GPU (Graphics Processing Unit) based DEM (Discrete Element Methods) simulations are performed to understand the segregation mechanism and to develop a description of hopper flow kinematics. Then, a continuum model based on a modified transport equation is developed to capture the material transport and segregation within the hopper. Using a hopper filling model to provide the initial particle size distributions after filling, this model is capable of predicting the particle size distribution within the hopper and in the discharged materials during the discharge process. The model is solved using a Finite Element Method algorithm, and the predictions agree well with the DEM results. The model is potentially capable of predicting hopper discharge segregation at the industrial scale and its implications can help with hopper design for minimizing segregation.