Bubbling fluidized-bed combustors are being built as a means of burning high-sulfur coals in an environmentally acceptable manner. Although this technology has reached a commercial status, understanding of solids motion and its effect on erosion of heat exchanger tubes immersed in fluidized beds remains inadequate. To understand the mechanics of solids motion in fluidized beds with internal heat exchangers, a two-dimensional fluidized bed is simulated using hydrodynamic models. Predicted instantaneous and time-averaged porosities at different locations in the bed are compared with experimentally measured values. Power spectral analyses of both computed and experimental transient porosities are made to validate the presently used hydrodynamic model of fluidization. This study further extends the validation of such models used in earlier studies to compare experimental and predicted bubble sizes
