On the Development and Characterization of a Firebrand Generator.
On the Development and Characterization of a Firebrand
Generator.
(539 K)
Manzello, S. L.; Shields, J. R.; Cleary, T. G.;
Maranghides, A.; Mell, W. E.; Yang, J. C.; Hayashi, Y.;
Nii, D.; Kurita, T.
Fire Safety Journal, Vol. 43, No. 4, 258-268, May 2008.
Keywords:
fire brands; size distribution; mass distribution;
experiments; burners; equipment; wind velocity
Abstract:
A unique experimental apparatus has been constructed in
order to generate a controlled and repeatable size and
mass distribution of glowing firebrands. The present
study reports on a series of experiments conducted in
order to characterize the performance of this firebrand
generator. Firebrand generator characterization
experiments were performed at the Fire Research Wind
Tunnel Facility (FRWTF) at the Building Research
Institute (BRI) in Tsukuba, Japan. The firebrand
generator was fed with three different initial firebrand
geometries, two different sized cylinders and one size
of disks. Cylinders were used to simulate firebrand
fluxes from vegetation, such as trees, while disks were
used to simulate a firebrand flux from burning
structures. Samples of these geometries were constructed
from wood dowels, fed into the firebrand generator,
ignited, and the glowing firebrands generated were
collected using an array of water filled pans. The pans
were filled with water in order to quench combustion.
The collected firebrands were subsequently dried and the
size and mass distribution was measured. These
experiments were performed over a range of wind tunnel
speeds, with no wind speed present to 9 m/s, to
determine the lofting distance of the firebrands
generated. Finally, the size and mass distribution
produced from the firebrand generator are compared to
those produced from burning trees. Results of the study
are presented and discussed.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899