Analysis of Drag on Non-Spherical Particles in Fluidized Beds

Abstract

Fluidized bed gasifiers are useful for processes where fuels form highly corrosive ash. Most common particles in this type of chemical process are non-spherical. The modeling of these particles can be determined only through the understanding of flow characteristics such as drag coefficient and terminal velocity. In this paper the calculation of drag coefficient of a solid non-spherical particle moving at the terminal velocity is being studied. The numerical approximations are done using the solver FLUENT on a collocated grid. The non-spherical particle shape simulated in this study was elliptical. Experimental drag results are compared to experimental data for validation. The experimental setup was comprised of an elliptical rice particle and a high-speed camera system to record particle movement in the free falling stream to determine the drag coefficient of the non-spherical particle. A 2% error was found between numerical results compared with those found by the theoretical calculation. Results from the drag model varied by 14% from those obtained experimentally.