Inerting of methane-air mixtures by compositions based on carbon dioxide and nitrogen with addition of halocarbons

Conditions of inerting of methane-air mixtures by carbon dioxide and nitrogen with addition of CF$_3$Br, C$_2$F$_4$Br$_2$, and CF$_3$I are examined. The value of the minimum inerting concentration of the inerting substance is significantly reduced by introduction of these substances [up to 15% (vol.)] to N$_2$ and CO$_2$. A further increase in CF$_3$Br and C$_2$F$_4$Br$_2$ concentrations does not reduce the minimum inerting concentration, and an increase in the concentration of CF$_3$I above 15%(vol.) drastically increases the latter to values higher than the minimum inerting concentration of pure nitrogen. CF$_3$I is found to be a combustible gas, and its addition to a methane-air mixture substantially expands the flammability limits. The flammability limits of CF$_3$I in air under standard conditions are determined, and the explosion parameters are measured.