Mass- and heat-transfer data obtained by the vaporization of water from porous spheres were used to calculate j-factors. Strict adiabatic conditions were employed for the attainment of solely fluid to particle transfer.
Fixed beds of several void fractions were constructed using short lengths of fine rigid wire to hold the spheres in regular geometrical orientations. In addition, the entrance and exit effects were eliminated by extending the ends of each bed with layers of inactive solid plastic spheres.
The resulting mass- and heat-transfer factors possessed a good correspondence indicating the existence of an analogy for these transfer processes. It was found that for the same Reynolds number the transfer factor,j, increased with the elimination of entrance and exit effects. The j-factors and the void fractions of the several beds, for which end effects were eliminated, produced with the Reynolds number the relationship, e1.19j = 0.539Re0.437 in the range 185 < Re < 8500. This relationship is somewhat higher than that resulting from the data of Gamson, Thodos and Hougen and definitely lower than that proposed in 1963 by Sen Gupta and Thodos. Explanations for these differences are advanced.
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