Liq. film mass transfer coeffs. in packed beds and strings of spheres were calcd. theor. using a penetration model for the mass transfer combined with the hydrodynamics of a laminar spherical falling film. The predictions were tested with packed beds varying in packing size from 0.006-0.058 m, bed height from 0.35-1.20 m, column diam. from 0.08-0.50 m; d. of liq. from 996-1152 kg m-3 and viscosity from 2.88-34.66 kgm-1h-1. Strings of spheres tested varied in diam. from 0.0189-0.0381 m, no. of strings from 1-3 and no. of spheres per string from 1-20. The values of mass transfer coeff. obtained theor. were in close agreement with the exptl. obsd. values. [on SciFinder (R)]