EXPERIMENTAL-STUDY ON THE HYDRODYNAMICS O F AN ISOTHERMAL LIQUID-FILMFLOWING ALONG THE CORRUGATED WALL OF A TUBULAR COLUMN

The aim of this work was to study the enhancement of transfer between phases produced by forming a liquid film flowing down a corrugated wal l. The back-mixing phenomenon inside the film was studied using a glob al approach based on experimental measurements of the distribution of residence times. We note, in particular, the importance of the quality of the experimental system and that the Peclet number was strongly de pendent on the position of measurement with respect to the periodicity of the wall. The effect of the wavy wall state on the hydrodynamics o f the liquid films was studied in two zones with differing now rates. Firstly, a zone of weak flow rates in which there is a net improvement in hydrodynamics of the Liquid film flowing down the corrugated wall compared with a smooth wall, a result which is already known for the c ase of flow in a full pipe. Secondly, a zone of higher now rates where a harmful effect is observed; the curvature of the wall affects the s tability of the film and there is no improvement in the hydrodynamics of the film with respect to a smooth wall.