Liquid contents in foams formed from solutions of n-pentanol, n-hexanol, n-pentanoic and n-hexanoic acids

摘要

Phase composition of foams formed from solutions of n-pentanoic acid, n-hexanoic acid, n-pentanol and n-hexanol was studied under steady state conditions. Effect of the solution concentration and gas flow rate on the liquid contents in the top layers and the whole foam columns formed was determined by a direct method consisting in cutting-off a foam layer and weighing the solution obtained after rupture of the cut-off layer. For a chosen gas velocity and solution concentration a distribution of the solution alongside height of the foam layer formed was studied as well. The frothers studied formed foams showing average solution contents up to 35% in the case of n-pentanol and n-pentanoic acid, and 30% in the case of n-hexanol and n-hexanoic acid. The solution contents in the top layers of these foams were much smaller (of an order of 4-8%). On a basis of the solution distribution within foam column the average thickness of foam lamellae in the upmost foam layer was found to be of an order of 3-5 #mu#m. Analysis of the liquid distribution showed that for a given frother the solution contents were practically identical at the same relative height levels of the foam columns, despite differences in the total heights of the foams formed at different gas velocities.