Measurement of Radial Transport in Slug Flow Using Enzyme Tubes

Abstract

Work supported by a du Pont Young Faculty Grant.

Radial mass-transfer enhancement in bubble-train flow

“…The term "bubble-train flow" is used by Thulasidas et al [18,19], while other authors refer to the same pattern as "slug-flow" [8,20], "plug-flow" [21] or simply as intermittent flow [22]. All terms imply a flow pattern characterised by a sequence of capsule-shaped bubbles which almost completely fill the cross section of the duct and are separated from the wall by a thin liquid film ( Fig.…”

“…The additional dimensionless groups required to describe bubble-train flow are dimensionless lengths and are therefore straightforward. Using the nomenclature suggested by Horvath et al [8] as far as applicable, the complete set of dimensionless groups describing radial transport in bubble-train flow is as follows:…”

“…1.39, we obtain a Sherwood-number Sh plug that describes the rate of mass transfer from an individual plug. As Horvath et al [8] point out, Sh plug thus conveys information about the relative magnitude of convective and diffusive transport in the liquid. On the other hand, using equ.…”

“…The results from heat transfer studies can thus only be applied to mass transfer by a speculative extrapolation. Furthermore, heat can be transported between wall and liquid via the gas bubbles, while a solute generally cannot, resulting in an over-prediction of mass transfer by heat transfer correlations [8].…”

“…It was conducted by Horvath et al [8], who used a tubular reactor to measure mass transfer. Although limited in scope, the study supplies some valuable reference data and allows the general conclusion that the rate of radial mass transfer in bubble-train flow lies between the values for single-phase laminar and turbulent flow.…”