Prediction of the Maximum Heat Transfer Coefficient Between a Horizontal Tube and Gas–Solid Fluidized Beds

Abstract

Average heat transfer coefficient between a horizontal tube and fluidized bed reaches a maximum at an optimum superficial gas velocity. Prediction of the optimum superficial gas velocity and maximum heat transfer coefficient in gas–solid fluidized beds was obtained based on a cluster-based mechanistic model that properly takes into account the thermal and fluid dynamic properties of the solids and the fluidizing gas. Experiments were carried out in a 15 cm diameter fluidized bed using 280, 490, and 750 μ m sand particles fluidized by air with an 8 mm diameter horizontal tube immersed in the bed. The predicted values were compared with the experimental data of this work as well as those from the literature under a wide range of operating conditions with good agreement. The model presented in this work for prediction of maximum heat transfer coefficient and optimum superficial gas velocity is considerably more reliable than existing correlations.