Flame Extinction by Sodium Bicarbonate Powder in a Cup Burner.
Flame Extinction by Sodium Bicarbonate Powder in a Cup
Combustion Institute, Symposium (International) on
Combustion, 27th. Proceedings. Volume 2. August 2-7,
1998, Boulder, CO, Combustion Institute, Pittsburgh, PA,
2857-2864 pp, 1998.
combustion; flame extinguishment; sodium bicarbonate
An apparatus was developed for testing the extinction
efficiency of a solid powder in a coflowing non-premixed
flame. Extinction measurements were performed by adding
agent quasistatically to the oxidizer stream until flame
extinction was observed. The concentration of powder
agent was monitored by laser transmission. Extinction
measurements were performed on flames burning both
liquids and gases using sodium bicarbonate (NaHCO3)
powder as the extinguishing agent. For comparison,
extinction measurements were also conducted using the
gaseous agents, CF3Br (halon 1301) and N2 tests were
conducted using a number of fuels including heptane, two
jet fuels (JP-8 and JP-5), two hydraulic fluids (83282
and 5606), as well as propane. The agent extinction
requirements for the two small particle sizes tested
here were highly similar. The results showed that on
average, NaHCO3 was three times more effective than
CF3Br and five times more effective than N2 on a mass
basis in extinguishing flames burning the various fuels.
An estimate of agent behavior based on the effectiveness
of inert N2 showed that whereas CF3Br acted primarily
through chemical kinetic effects, only half of the
effectiveness of NaHCO3 could be attributed to kinetics.