The Flow Of Foam: I. Rheology And Streaming Potential

This, paper presents an experimental study of the flow behavior of foam through capillary tubes as well as a theoretical and experimental study of the streaming potentials generated during the flow. Important parameters such as the pressure differential, the quality of foam, the electrochemical nature of the surface active agent and the dimensions of the capillary tube have been investigated and a physical model describing the experimental results is presented. Foams were produced from aqueous solutions of various surface active agents in a foam generator of novel design. The flow media studied were:capillary tubes of several diameters,a capillary tube packed with glass beads slightly smaller in diameter than the capillary tube, anda capillary tube filled with crushed pyrex glass. The quantities measured were foam flow rate, foam quality (ratio of gas volume to total volume of foam), streaming potential and streaming current. As indicated by the general overall shape of the pressure differential versus flow rate plots, the flow of foam in capillary tubes is quite similar to that of pseudo-plastic substances.