Flow of foam through plain perforated and woven metal screens

The interaction of foam with textile substrates has been investigated, starting with an attempt to describe the flow of foam in textile–like substrates. This was done by separately evaluating rheology and pressure–drop data. The influence of bubble size was found to be particularly important. In a coaxial cylinder viscometer the viscosity was found to be inversely proportional to bubble size. This finding could not be used to describe the pressure drop of foam flow through flat metal screens according to the d'Arcy equation. Equations could not be satisfactorily derived to describe phenomena such as bubble deformation and diminution, but empirical determination of these parameters could be achieved for each combination of foam and substrate.