EXPANSION OF A FREELY BUBBLING FLUIDIZED-BED

The expansion of a freely bubbling fluidized bed is studied over a range of particle properties and gas velocities that applies to fluidized bed boilers. A bed expansion model is derived from a modified two-phase flow model. The results from the model are compared with measurements in both a cold two-dimensional bed and a 16 MW(th) fluidized bed boiler, as well as with data found in the literature. The model represents experimental results for sand particles of a diameter ranging from 0.15 mm to 4.0 mm and with gas velocities up to 3 m s-1.