Mass transfer and effective interfacial areas in packed columns

Experimental studies on the mass transfer rates were performed for three kinds of operations: vaporization of water into air; absorption of methanol vapor by water; and distillation of three binary mixtures, trichloroethylene‐toluene, ethanol‐water, and acetone‐water, by use of columns of the same diameter packed with 25‐ and 15‐mm. Raschig rings. Correlations are presented for the individual phase height of a transfer unit and also for the effective interfacial areas. The effective areas for a given packing vary depending on the kind of operation as well as on the liquid rate and surface tension. The effective interfacial area for vaporization is significantly larger than that for absorption. The effective area for distillation seems to be roughly the same as that for absorption, if correction is made for the effect of surface tension.