Discrete element modeling for flows of granular material

Abstract

The pneumatic transport of granular material is a common operation frequently employed to transport solid particles from one location to another. It is well established in the literature that different flow regimes can arise in such transportation processes depending on the system geometry and operating conditions used. In this work, the pneumatic transport of solid particles in both vertical and horizontal conveying lines was studied numerically using a discrete element model coupled with computational fluid dynamics. The trajectory of every individual particle was followed by numerical integration of Newton's Law and interphase interactions were accounted for by a fluid-particle drag force model. The simulation outputs corresponded well with reported experimental observations in terms of the different flow regimes obtained at different operating conditions. In the vertical pneumatic conveying simulations, two different flow patterns corresponding to the experimentally observed dispersed flow and plug flow regimes were obtained at different gas velocities and solid mass loadings. Similarly, the homogeneous flow, stratified flow, moving dunes and slug flow regimes previously reported to occur in horizontal pneumatic conveying depending on the operating conditions used were also reproduced computationally in this work.