LOCAL PARTICLE CONVECTIVE HEAT-TRANSFER ALONG SURFACES IN CIRCULATINGFLUIDIZED-BEDS

The relationship between heat dissipation of individual clusters and l ocal heat transfer to a surface in a circulating fluidized bed has bee n established based on a probabilistic cluster renewal model. Variatio ns of local particle convective heat transfer coefficient with length are predicted based on the model. A simplified model assuming an ident ical contact distance of clusters leads to explicit expressions for th e local and average particle convective heat transfer coefficients, wh ich approximate the more rigorous model for most cases of practical in terest. Previous experimental data for heat transfer to a membrane wal l are in good agreement with model predictions. Information on the wal l contact resistance and mean cluster contact distance is also obtaine d from the model in combination with the experimental data.