This study aimed to propose a method for measurement and estimation of the liquid distribution efficiency of a pilot-scale packed tower, filled with 1" Pall rings (plastic and ceramic). The study was carried out analyzing three major conditions: water feed flow (1, 2 and 3 m3/h), feeding position (center, 7.5 and 15 cm from the center) and packed height (30, 60 and 90 cm). The liquid distribution was assessed as water columns in tubes coupled to the bottom of the column. Non-uniform distributions were obtained from the experiments, and therefore the distribution efficiencies were estimated using a 5 parameter model which correlates the efficiency to the tubes water columns. Two efficiency factors were defined (global and dispersion efficiencies). The efficiency of two spray-nozzle distributors were also analyzed with 1" Pall ceramic rings. A sensible improvement in water distribution was obtained, i e, an increase in the efficiency factors was verified. Copyright © 1997 Society of Automotive Engineers, Inc. Bonilla, J.A., Don't neglect liquid distributors (1993) Chemical Engineering Progress, 89, pp. 47-61Chen, G.K., Packed column internals (1984) Chemical Engineering, pp. 40-51Gunn, D.J., Al-Saffar, H.B.S., Liquid distribution in packed columns (1993) Chemical Engineering Science, 48, pp. 3845-3854Haure, P.M., Hudgins, R.R., Silveston, P.L., Investigation of SO2 oxidation rates in trickle-bed reactors operating at low liquid flow rates (1992) The Canadian Journal of Chemical Engineering, 70, pp. 600-603Killat, G.R., Key, T.D., Properly assess maldistribution in packed towers (1996) Chemical Engineering Progress, 92 (5), pp. 69-73Kister, H.Z., (1992) Distillation Design, , McGraw-Hill Inc. New YorkKlemas, L., Bonilla, J.A., Accurately assess packed-column efficiency (1995) Chemical Engineering Progress, 91, pp. 27-44Kouri, R.J., Sohlo, J., Liquid and gas flow patterns in random packings (1996) Chemical Engineering Journal, 61, pp. 95-105Leva, M., (1953) Tower Packings and Packed Tower Design, , The United States Stoneware Company, AkronMetzinger, J., Hasokowati, W., Hudgins, R.R., Silveston, P.L., Gangwal, S., Application of a periodically operated trickle bed to sulfur removal from stack gas (1992) Chemical Engineering Science, 47 (13-14), pp. 3723-3727. , DOI 10.1016/0009-2509(92)85090-XTreybal, R.E., (1980) Mass-Transfer Operations, , McGraw-Hill Inc. NYZuiderweg, F.J., Kunesh, J.G., King, D.W., A model for the calculation of the effect of maldistribution on the efficiency of a packed column (1993) Chemical Engineering Research & Design, 71, pp. 38-44