Fire Fighting Foam
Fire-fighting foam is a foam used for fire suppression. Its role is to cool the fire and to coat the fuel, preventing its contact with oxygen, resulting in suppression of the combustion. Fire-fighting foam was invented by the Russian engineer and chemist Aleksandr Loran in 1902.
The surfactants used must produce foam in concentration of less than 1%. Other components of fire-retardant foams are organic solvents (e.g., trimethyltrimethylene glycol and hexylene glycol), foam stabilizers (e.g., lauryl alcohol), and corrosion inhibitors.
Low-expansion foams have an expansion rate less than 20 times. Foams with expansion ratio between 20 and 200 are medium-expansion. Low-expansion foams such as AFFF are low-viscosity, mobile, and able to quickly cover large areas.
High-expansion foams have an expansion ratio over 200. They are suitable for enclosed spaces such as hangars, where quick filling is needed.
Alcohol-resistant foams contain a polymer that forms a protective layer between the burning surface and the foam, preventing foam breakdown by alcohols in the burning fuel. Alcohol-resistant foams should be used in fighting fires of fuels containing oxygenates, e.g. MTBE, or fires of liquids based on or containing polar solvents.
Read more about Fire Fighting Foam: Class A Foams, Class B Foams, Applications, History of Fire Fighting Foams
Famous quotes containing the words fire, fighting and/or foam:
“Do they know they’re old,
These two who are my father and my mother
Whose fire from which I came, has now grown cold?”
—Elizabeth Jennings (b. 1926)
“So that’s our new flag. The thing we’ve been fighting for—thirteen stripes for the colonies and thirteen stars in a circle for the union.”
—Lamar Trotti (1898–1952)
“Yet ere I can say where—the chariot hath
Passed over them—nor other trace I find
But as of foam after the ocean’s wrath”
—Percy Bysshe Shelley (1792–1822)