US Patent 7,121,354

This patent discloses a fire extinguishing device and associated methods. The device is adapted to be positioned in proximity to a fire and operable in response to heat output by the fire.

Abstract: A fire extinguishing device and associated methods. The device is adapted to be positioned in proximity to a fire and operable in response to heat output by the fire. The device includes a first reservoir, containing a fluid, adapted to receive the heat from the fire and thereby exert a pressure and a second reservoir, communicating with the first reservoir, containing a fire fighting material. The device further includes a pressure-sensitive membrane, forming a pressure-sensitive barrier between the first reservoir and the second reservoir, adapted to rupture upon a predetermined pressure being attained in the first reservoir and thereby releasing a steam into the second reservoir. The steam expels the fire fighting material onto the fire. Additionally disclosed are methods for using the device to control and extinguish fires.