Packed bed heat transfer

The use of various published correlations to determine apparent thermal conductivities was found to give results of differing ma; magnitudes. For this reason when these values were utilized in the theoretical relationships proposed by McAdams: tw-t2/tw-t1 = 0.692e-23.14X + 0.1312e-121.9X + 0.0535e-299.6X in which X is defined as X = (KaL/CpGoD2t) For packed bed systems the results were found to be inconsistent. In this investigation a dimensionless equation: Ka/kg = 0.00105 (DpGo/εpμ)1.32 has been developed which permits the prediction of apparent thermal conductivities to air flowing through a 1 inch tube picked with glass beads. The equation gives satisfactory results for ratios of Dp/Dt from 0.15 to 0.22 and a modified Reynolds number of 526 to 3990. The effect of voids in the packing material was studied and a porosity was included in the modified Reynolds number used in correlating the data