Effect of fluid properties on dispersion in flow through packed beds

Abstract

An experimental study is described on the effect of liquid properties on axial dispersion in packed beds. Working with water between 278 and 373 K, the range 57 < Sc < 1, 930 was covered, and this represents a significant fraction of the domain located between what is traditionally considered "gas behavior" (that is, Sc congruent to 1) and "liquid behavior" (typically, Sc > 600). A representation of Pe(L) vs. Pe(m) reveals the existence of a very flat minimum (typically 10(2) < Pe(m) < 10(4)) for each value of Sc. The value of the minimum is almost insensitive to variations in Sc, for Sc > 700, but it increases significantly with a decrease in Sc, for Sc < 700. The experimental data used to test available correlations for predicting D-L show that they are inaccurate over considerable ranges of the variables.