EFFECTIVE THERMAL-CONDUCTIVITY OF BINARY-MIXTURES AT HIGH SOLID TO GAS CONDUCTIVITY RATIOS

The effective thermal conductivity of single size and binary mixtures of packed particle beds with stagnant gas at high solid/gas conductivi ty ratios is determined by a deterministic, unit cell approach. The mo del results are shown to be in good agreement with experimental data f or various gas pressures and solid to gas thermal conductivity ratios up to 1300. A set of correlations for effective conductivity of binary mixtures as a function of gas pressure and particle size is derived. The effect of particle swelling on the effective conductivity of binar y mixtures is studied by performing a parametric study of the contact area between the particles.