The difference in extinguishing effectiveness of an inhibitor introduced on the two sidesof the reaction zone of diffusion flames has been measured as a function of oxygenconcentration in the O -N mixture supplied to the flames. Six fuelsand two inhibitors were used. It was found that when the inhibitor was added to the fuel,the volume percentage required for extinguishment was much greater than when added to theoxygen side of the reaction zone, with the single exception of CO flames inhibited bytrifluoromethyl bromide. In all cases except the latter, the amount required forextinction increased with increase of the oxygen concentration, being relatively lessdependent on oxygen concentration above a certain threshold in the neighborhood of 21percent when the inhibitor was added to the fuel. Above oxygen concentrations on the orderof 25 percent, methyl bromide was completely ineffective when added to the oxygen side ofthe reaction zone, and above about 32 percent oxygen it was ineffective when added to thefuel, since at this oxygen concentration it burns without additional fuel.
展开▼
