Preliminary Backdraft Experiments.
Preliminary Backdraft Experiments.
(686 K)
Fleischmann, C. M.; Pagni, P. J.
U.S./Japan Government Cooperative Program on Natural
Resources (UJNR). Fire Research and Safety. 12th Joint
Panel Meeting. October 27-November 2, 1992, Tsukuba,
Japan, Building Research Inst., Ibaraki, Japan Fire
Research Inst., Tokyo, Japan, 208-215 pp, 1992.
Sponsor:
National Institute of Standards and Technology,
Gaithersburg, MD
Keywords:
fire safety; fire research; experiments; deflagration;
backdraft; gravity current
Abstract:
Backdraft is defined as a rapid deflagration following
the introduction of oxygen into a compartment filled
with accumulated excess pyrolyzates. A scenario
describing the physical and chemical fundamentals
underlying backdraft phenomena is presented. A
half-scale apparatus, designed to avoid dangerous
over-pressures, is used to obtain data from backdraft
experiments. A gas burner supplied a 150 kW natural gas
fire in a 1.2 m high, 1.2 m wide, 2.4 m long compartment
with a small, 2.5 cm high 30 cm wide, vent at floor
level. Significant excess pyrolyzates accumulate in 180
sec, when a hatch covering a 0.4 m high 1.2 m wide vent,
centered on a short wall, is opened. A gravity current
carries a flammable mixed region to a spark located near
the burner on the opposite wall. The rapid deflagration
which results upon ignition of the mixed region is the
backdraft.
Building and Fire Research Laboratory
National Institute of Standards and Technology
Gaithersburg, MD 20899