Richard M. Lueptow

Sr Associate Dean of Operations & Research, McCormick, Northwestern University


Predicting Particle Segregation in Industrial Granular Flows

Richard M. Lueptow
Northwestern University, Evanston, IL
A common problem in the chemical processing industry is that as granular materials flow they can segregate, or de-mix, due to particle size, density, or shape differences. The degree of segregation depends on the flow conditions and the differences between particles. We have recently developed theoretical and computational tools that are validated by experiments to predict this segregation. The model is based on a continuum advection-diffusion equation for individual particle species with a semi-empirical segregation term. To date, this approach has been successful for several flow geometries including steady quasi-2D and 3D heap flows, steady developing quasi-2D chute flow, transient and developing quasi-2D tumbler flow, and even complex geometries like hopper filling and emptying. In addition, we have applied the approach to several different particle systems including particles that differ in size (two sizes, multiple sizes, or a distribution of sizes), particles that differ in density, and particles that differ in shape. We continue to explore how the theory and simulations can be adapted to more complicated flow geometries and particle systems pertinent to industrial particle handling and processing systems. Funded by The Dow Chemical Company, the Procter & Gamble Company, and NSF Grant No. CBET-1511450.

Richard M. Lueptow is Senior Associate Dean at the McCormick School of Engineering and Applied Science, Co-Founder of the Master of Product Design and Development Program, Professor of Mechanical Engineering, and Charles Deering McCormick Professor of Teaching Excellence at Northwestern University. He received his BS in engineering (1978) from Michigan Technological University and his master’s degree (1980) and doctorate (1986) in mechanical engineering from the Massachusetts Institute of Technology. He has five years of product development experience in the biomedical industry and three decades of academic experience on the faculty at Northwestern University. His research interests and expertise range from fundamental flow physics to water purification on manned spacecraft to planetary acoustics. His current research focuses on filtration processes, nonlinear systems, and granular dynamics. He has published over 150 journal papers and 6 patents, received numerous teaching and research awards, and is a Fellow of both the American Physical Society and the American Society of Mechanical Engineers.