Simulation of Reacting, Moving Granular Assemblies of Thermally Thick Particles by Discrete Element Method/Computational Fluid Dynamics

Abstract

The potential and limitations of the discrete element method (DEM) coupled with computational fluid mechanics (CFD) to simulate chemically reacting, moving granular material interacting with a fluid flow are summarized. A special focus is set on thermally thick particles, which requires to resolve the intraparticle transport and reaction processes. The aspect of complex particle shape is addressed, as shape may dominate the particle behavior in densely packed granular assemblies even more than the details of contact force laws. The fluid flow in the granular assembly is assumed to be a gas. The potential of DEM/CFD will be highlighted presenting three illustrative examples: a large-scale lime shaft kiln with intermittent operation, an industrial-size grate firing system for the incineration of municipal waste, and a small-scale straw pellet stove.