Abstract
Experiments were performed to study the stability of cellular foam for the purpose of foam breakage in chemical reactors and bioreactors. The growth and collapse process of cellular foam formed from four kinds of nonionic surfactant aqueous solutions with different Hydrophile-Lipophile-Balance (HLB) values were observed in a standard bubble column. As a result, three types of foam growth process and two types of foam collapse process were found. Furthermore, the critical film thickness at the time of the burst of the cellular foam was obtained by using the thinning equation of liquid film proposed by Hartland and Barber (1974) and Barber and Hartland (1975). The critical film thickness obtained was correlated with surface viscosity and HLB, which are physical properties at gas–liquid interface, in addition to density, viscosity and surface tension of liquid.
