ANALYSIS OF THE OVERALL PRESSURE BALANCE AROUND A HIGH-DENSITY CIRCULATING FLUIDIZED-BED

A steady-state model is presented for predicting the flow behavior of a novel high-density circulating fluidized-bed coupled dual-loop syste m. The model allows the maximum achievable solids nux for given steady -state operating conditions to be predicted. The effects of superficia l gas velocity, solids inventory, particle diameter and density, and t he diameters of both risers and both downcomers as well as the positio n of the solids control valve are all predicted. Predictions are shown to be in good agreement with experimental values for solids circulati on rates as high as 420 kg/m(2) s for FCC particles in a dual-loop sys tem. Parametric studies illustrate the usefulness of the approach for optimizing the operating conditions of complex gas-solid systems.