FLOW OF FOAM THROUGH PROCESSING EQUIPMENT

Foams are structured two-phase fluids in which gas bubbles are separated by interconnecting thin liquid films and Plateau borders which denote the regions of intersection of the thin films. They represent an important class of structured fluids possessing a complex rheology and flow behaviour strongly dependent upon local structure and chemical composition. The nature of the foam, i.e. its texture, foamability, stability, and its overall rheological and flow properties can determine both the economic and technical successes of the industrial process concerned.

Foam flow through processing equipment usually affects the structure of the foam and its properties. In many industrial processes foams are forced to flow through narrow intricate passages such as contractions, expansions and orifices. These flows generate complex phenomena that can have important effects on foam structure and can lead to dramatic instabilities and morphological transformations with serious practical implications for foam sustainability during flow and processing. The flow characteristics of the foam at bubble scale are important, but the topological changes incurred and their effects on the rheology and flow of the foam are poorly understood. This project seeks to address this lack of understanding by studying aspects related to the flow, stability and behaviour of foams through channels containing complex geometries.