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.
