Suppression Concentration of Clean Agents Exposed to a Continuously Energized Heated Metal Surface.
Suppression Concentration of Clean Agents Exposed to a
Continuously Energized Heated Metal Surface.
Braun, E.; Womeldorf, C. A.; Grosshandler, W. L.
Fire Safety Journal, Vol. 33, No. 2, 141-152, September
cleaning agents; hydrocarbon fuels; autoignition
temperature; NFPA 2001; fire extinguishing agents;
experiments; inert gases; ignition; temperature
An apparatus for the determination of autoignition
temperature of hydrocarbon fuels has been used to
measure the change in ignition temperature of a
stoichiometric mixture ofethene/ air with and without
the addition of a suppressant: N2, IG-542, HFC-23,
HFC-227ea, FC-218 or FC-3-l-10. When exposed to a heated
metal surface of nickel, a fuel/air stream with clean
agent added generally required higher temperatures to
ignite than when no agent was present. For some agents
at low concentrations, it was found that ignition
occurred at temperatures lower than when no agent was
present. As agent concentration was increased, ignition
became harder, i.e., the temperature required for
ignition was higher. For each of these suppressants,
with foil temperatures approaching 100 dec C, the agent
concentration necessary to prevent ignition of the
ethene/air mixture exceeded the total flooding and met
or exceeded the inerting design concentrations
recommended in NFPA 2001, the Standard on Clean Agent
Fire Extinguishing Systems.