Inhibition of Premixed and Non-Premixed Flames With Fine Droplets of Water and Solutions.
Inhibition of Premixed and Non-Premixed Flames With Fine
Droplets of Water and Solutions.
(177 K)
Chelliah, H. K.; Lazzarini, A. K.; Wanigarathne, P. C.;
Linteris, G. T.
Combustion Institute, Symposium (International) on
Combustion, 29th. Volume 29. Part 1. Proceedings.
July 21-26, 2002, Sapporo, Japan, Combustion Institute,
Pittsburgh, PA, Chen, J. H.; Colket, M. D.,
Editor(s)(s), 369-376 pp, 2002.
Keywords:
fire suppresion; water mist; halon alternatives; flame
inhibition; alkalai metals
Abstract:
Inhibition/extinction of premixed and non-premixed
methane-air flames with fine-droplets of water and
solutions containing several chemical agents are
investigated experimentally. While solutions allow
delivery of much higher concentrations of chemical agent
to the flame front than otherwise possible, the
non-premixed flame extinction results indicate
saturation (or condensation) of the agent at some
effective temperature below the flame temperature. Based
on the chemical additives considered, on a molar basis,
the following order of effectiveness is observed: KOH >
NaCl > NaOH. The inhibition of premixed flames by
similar size droplets indicates insensitivity to NaOH
mass fraction in the water. This insensitivity was
related to the shorter residence time of the droplets
through the premixed flame structure, for the droplet
size used in experiments (13 {mu}m median diameter).
Detailed comparison of the premixed and non-premixed
flame inhibition/extinction with pure water droplets
supports the importance of droplet residence time and
optimum droplet size in controlling the interaction of
droplets with the flame front.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899