Suppression of Ignition Over a Heated Metal Surface.
Suppression of Ignition Over a Heated Metal Surface.
(283 K)
Hamins, A.; Borthwick, P.; Presser, C.
National Institute of Standards and Technology (NIST)
and Society of Fire Protection Engineers (SFPE).
International Conference on Fire Research and
Engineering (ICFRE). Proceedings. September 10-15,
1995, Orlando, FL, SFPE, Boston, MA, Lund, D. P.;
Angell, E. A., Editor(s)(s), 77-81 pp, 1995.
Keywords:
fire research; halogenated compounds; ignition; ignition
suppression; ignition temperature
Abstract:
The objective of this work is to investigate the
effectiveness of various agents in suppressing flame
ignition. Experiments were conducted to determine the
amount of agent needed to suppress the ignition of a
gaseous propane flow over a heated metal disk. The disk
was 14 mm in diameter and was a wound ribbon composed
primarily of nickel. The metal surface was heated by a
regulated power supply which provided up to 200 W. An
optical pyrometer was used to measure the surface
temperature of the heated disk. With power applied to
the metal disk, a fairly uniform temperature (+30 deg C)
was measured in an annular section of the disk. A
coflowing mixture of air and gaseous fire suppressant
flowed through a 78 mm tube about the fuel flow. With
the fuel and oxidizer flowing, flame ignition occurred
in a repeatable fashion by increasing the power through
the metal disk. Various amounts of agent were added to
the air flow and the temperature of the heated metal
disk was measured at flame ignition using an optical
pyrometer. The effectiveness of N2, HFC-125, HFC-227
and CF3I were compared in suppressing the ignition
event.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899