Dynamic foam test apparatus

A measure of the persistence of a foam (the time an average bubble exists before bursting). Ideally independent of the apparatus and procedure used, and characteristic of the foaming solution being tested. See also Dynamic Foam Test. 

Figure 2.17 Illustration of a dynamic foam stability test apparatus in which foam is generated by flowing gas through a porous diffuser. Not drawn to scale.

Apparatus and Procedure. It was necessary to design more definitive tests to further evaluate the better candidate surfactants. This was accomplished by means of a multi-phase dynamic-fiow test that consists of a small packed bed through which surfactant solution can be passed followed by gas to produce in situ foam. The pressure drop through the column is measured as the fiuid is drawn through the column at a constant volumetric fiow rate. From the recorded data, relative mobilities of the liquid and gas phases may be calculated. The change in gas mobility due to the presence of the surfactant is very closely related to the effectiveness of that surfactant for mobility control in oil core studies. A schematic drawing of the apparatus is shown in Figure 2. 

Figure 2.9. The Bikerman method for measuring both the dynamic and equilibrium foam stabilities by using a cylindrical container (a) Schematic of the apparatus (b) dynamic testing from foam volume as a function of gas flow (c) equilibrium testing from foam volume as a function of decay time (note that wall effects may cause scatter in the results obtained)...

---