TOWARDS A GENERALIZED-MODEL FOR VERTICAL WALLS TO GAS-SOLID FLUIDIZED-BEDS HEAT-TRANSFER .1. PARTICLE CONVECTION AND GAS CONVECTION

A generalized theoretical model describing heat transfer in gas-solid bubbling fluidized beds with heat exchange walls is presented in this paper. With use of heterogeneous theory and the concept of variable pr operty boundary layer for the emulsion phase, both particle and gas co ntributions are considered. The effect of controlling parameters, such as particle size, contact time, porosity profile, etc. is investigate d and detailed information is obtained to analyze the heat transfer me chanism in fluidized beds. The comparison of predicted results with ex perimental data from literature indicates the validity of present mode l for fluidized beds of small and large particles (groups B and D).