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NGP Advances in Powder Panel and Propellant Technologies.


pdf icon NGP Advances in Powder Panel and Propellant Technologies. (502 K)
Grosshandler, W. L.; Cyphers, D. C.; Holland, G. F.

HOTWC 2006;

Halon Options Technical Working Conference, 16th Proceedings. HOTWC 2006. May 16-18, 2006, Albuquerque, NM, 1-12 pp, 2006.

Keywords:

halon alternatives; halons; halon 1301; fire suppression; powder panels; solid propellants; test device; dispersion; fire tests; temperature; fire extinguishing agents; gas generators

Abstract:

Halon 1301 has a vapor pressure high enough to propel it from a storage bottle and through distribution piping rapidly enough to suppress even fast growing fires. Nitrogen gas is used to pressurize halon 1301 storage bottles to ensure that even at temperatures as low as -40 DGC, when halon 1301 is a liquid, the pressure is sufficient for rapid discharge of the fire suppressing fluid. Hydrofluorocarbon alternatives to halon 1301 such as HFC 125 are discharged in a similar manner, but because around three times the amount of agent is required to ensure the fire is extinguished, the amount of nitrogen needed to pressurize the fluid is also increased, leading to a system that is considerably bulkier and heavier than the halon 1301 system. Two technologies were explored in the Next Generation Program (NGP) that avoid the need for a high pressure storage vessel to operate effectively. These technologies are (1) powder panels, and (2) solid propellant gas generators. Both of these technologies have the ability to discharge fire fighting agent in less than 100 ms, which makes them suitable for protecting dry bays (enclosed spaces adjacent to a fuel cell). The solid propellant gas generator can be adapted to aircraft engine nacelles, as well. Powder panels consist of powdered fire extinguishing agents sandwiched, unpressurized, between two rigid membranes that, as a unit, can be attached to or used in place of the skin of the aircraft confining a dry bay. The powder is released and dispersed into the dry bay when the panel is pierced by a projectile, forming an aerosol cloud sufficiently dense to prevent ignition or suppress a fire resulting from the rupture of the adjacent fuel tank. The system is entirely passive.