Growth and Deposition of Saline Droplets Covered with a Monolayer of Surfactant

Abstract

Experiments and theoretical calculations were carried out to investigate the effects of a surfactant monolayer on the growth and deposition of saline droplets in a horizontal elutriator. Cetyl alcohol was used as the surfactant in the study. In the calculations, the condensation coefficient of water vapor on the surface of a droplet covered with a surfactant monolayer was determined from the specific evaporation resistance data. It was found, in the presence of a surfactant monolayer, the growth of saline droplets is retarded and the deposition efficiency in the elutriator is reduced. The deposition pattern in the elutriator is mainly determined by two time scales: the growth retardation time and the time for gravitational settling. When these two time scales are comparable, the distribution of particle deposits in the elutriator is markedly nonuniform.