Chapter 1 Mass transfer in axial flows through randomly packed fiber bundles

Abstract

1. ABSTRACT The literature contains numerous correlations of mass transfer coefficients for axial flows through randomly packed fiber bundles. The predictions of these correlations can differ by an order of magnitude. This large variation severely limits the usefulness of the correlations for design purposes and confounds an understanding of the underlying physics. While the literature suggests randomness in fiber packing may contribute to the variation, a rigorous analysis of mass transfer in randomly packed bundles has not been reported. The results of such analyses are summarized here for uniform wall concentration and uniform wall mass flux boundary conditions. The results indicate that channeling through randomly packed bundles can dramatically reduce mass transfer coefficients relative to regularly packed bundles, especially in the well-developed limit. However, experimental mass transfer coefficients are significantly different from predicted values for regularly and randomly packed bundles; the literature contains correlations that predict much higher and much lower values. This suggests that other factors can control performance such as cross-flow regions that exist near shell ports or poor fluid distribution from the shell inlet port.