Hydrodynamics of Fluidization: Time-Averaged and Instantaneous Porosity Distributions in a Fluidized Bed with an Immersed Obstacle.

摘要

Erosion in bubbling fluidized-bed combustors is a serious issue that may affect their reliability and economics. Available evidence suggests that the key to understanding this erosion is detailed knowledge of the coupled and complex phenomena of solids circulation and bubble motion. A thin ''two-dimensional'' rectangular fluidized bed with an obstacle served as a rough model for a fluidized-bed combustor. This model was studied experimentally and computationally using two hydrodynamic equation sets. The computed hydrodynamic results agree reasonably well with experimental data. Bubble frequencies compare well with those obtained from a high speed motion picture study. Time-averaged porosities computed from both models agree with time-averaged porosity distributions measured with a gamma-ray densitometer. 46 refs., 13 figs., 2 tabs. (ERA citation 14:019210)