Transport processes in narrow (capillary) channels

Abstract

Rates of mass and momentum transport in narrow flow channels (gaps 0.2–0.5 mm) have been determined over a wide range of flow velocities, 220–7,700 cm/sec (Re 1,300 to 22,000). Existing correlations that apply to smooth channels of much larger hydraulic diameter were found to be valid for the narrow channels as well. However, in the turbulent regime the condition of hydraulic smoothness could be satisfied only when the walls were optically smooth. Transport rates to rough walls were also measured. The ratio of the mass transport to the momentum transport in the form of jD/(f/2)—a measure of the improved mass transfer compared to the increased pressure drop—is given for the smooth and rough‐wall cells over the Re range studied. Copyright © 1985 American Institute of Chemical Engineers