Apparatus for Screening Fire Suppression Efficiency of Dispersed Liquid Agents.
Apparatus for Screening Fire Suppression Efficiency of
Dispersed Liquid Agents.
Yang, J. C.; Donnelly, M. K.; Prive, N. C.;
Grosshandler, W. L.
Fire Safety Journal, Vol. 36, No. 1, 55-72, 2001.
fire suppression; diffusion flames; droplets; water
additives; sprays; equipment
This paper is an abridged version of NISTIR 6319. The
design, construction, demonstration, and operation of a
bench-scale device capable of screening the fire
suppression efficiency of liquid agents are described in
detail in this report. The apparatus is based on a
well-characterized flame, a means to facilitate the
introduction of liquid agents, and a way to generate
liquid droplets. A Tsuji-type burner, a porous cylinder
used in a counterflow diffusion configuration, is used.
Both wake and enveloped flames can be maintained over a
wide range of fuel and oxidizer flows. The flame is
easily observed, and critical stages such as the
blow-off limit (abrupt transition from an enveloped
flame to a wake flame) can be ascertained with ease and
high reproducibility. A small-scale vertical wind
tunnel, which allows for the delivery of a uniform flow
of oxidizer to the burner at a low turbulence intensity
and also assists in the delivery of liquid agent
droplets to the flame, is used for the flow facility.
Two techniques of generating droplets have been
examined: (1) a piezoelectric droplet generator and (2)
a small glass nebulizer. The piezoelectric droplet
generator was found incapable of handling fluids with
high loading of dissolved solid due to frequent clogging
of the orifice opening. The nebulizer is used in the
current liquid screen apparatus.