A QUANTITATIVE-ANALYSIS OF HEAT-TRANSFER REGIMES IN GAS-SOLID FLUIDIZED-BEDS

On the basis of a new theoretical model recently proposed by the autho rs for heat transfer between walls and fluidized beds, a quantitative analysis on heat transfer regimes is presented in this paper. From the dimensionless, differential equations describing the heat transfer mo des; i.e., conduction, convection, and radiation is mainly determined by the characteristic numbers: Archimedes number, Ar; and Planck numbe r, N. It is found that the convection in laminar regime and conductio n in turbulent regime are still nonnegligible components. A heat trans fer diagram in a Archimedes number versus Planck number is proposed. N ine domains are defined according to the variation of the dominant hea t transfer mechanism.