Anti Foamers act in one of two ways; they either displace stabilizers from the bubble wall or locally rupture them.
- Displacement of foam stabilizers occurs after a thin defoamer layer is spread over the bubble surface.
- Bursting occurs when a defoamer, with a lower surface tension than the oil, causes localized surface-tension depression.
Category
- There are several generic types of Anti Foamers, but silicones are the most commonly used for crude oil systems.
- The most commonly used silicones are the polydimethylsiloxanes, with various viscosities, depending on the molecular weights of the polymers. However, the most effective Silicones in crude processing systems are the fluorinated silicones. They are insoluble in oil and are there-fore very efficient. The advantage of using fluorine instead of other halogens is the small size of the atom which will allow penetration into very thin foam films.
