MASS-TRANSFER TO REGULAR PACKINGS AT LOW REYNOLDS-NUMBERS AND UNDER NATURAL-CONVECTION

Mass transfer coefficients for regular packings determined for low flo w velocities show to be influenced by natural convection. In order to apply the coupling rule for forced and natural convection, mass transf er correlations for both pure regimes are required. Since no relations hip for natural convection could be found in the literature, a systema tic study of free convection in regular packings was undertaken. Gener al correlations were developed and it was shown, that they also apply to static mixers. A simple model was formulated which describes natura l convection mass transfer in structured packings by correlations obta ined For inclined surfaces. The mass transfer results measured for low Reynolds numbers could be correlated successfully by the coupling rul e and also by a method using a modified Reynolds number. (C) 1998 Else vier Science Ltd. All rights reserved.