- Author
-
Saso, Y.
- Title
- Stability of Coaxial-Coflow Diffusion Flame in the Presence of CF3Br.
- Journal
-
Report of Research Institute of Japan,
No. 71,
43-50,
March 1991
- Keywords
-
diffusion flames
|
stability
|
halon 1301
|
fire extinguishing agents
|
flame extinguishment
|
flame liftoff
- Abstract
- [Abstract in English] Development of new fire-extinguishing agents requires that the scale of the test method for evaluating the extinguishing effectiveness should be as small as possible. In this study, we examined the scale effect of coflow diffusion flames of methane, propane, and ethylene on flame stability, liftoff, and quenching when CF3Br was added to the oxidizer side. It was observed that the flame lifted off, attached to the chimney, rotated, or fluctuated before extinction. Varying burner diameter and fuel gas flow rate changed not only the range of stable flame region but also the flame behavior found in unstable flame region. Flame quenching mechanisms such as heat loss to the burner or decrease of burning velocity were discussed to explain the variation of the flame behavior. The flame extinguishing concentration had a plateau region in equivalence ratio [equation] for all 3 fuels when fuel gas flow rate was varied. Varying burner diameter made no change in the order of the flame extinguishing concentrations of 3 fuels, though the concentrations were a little lowered as the burner diameter was decreased.