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 CF3Br, C2F4Br2, and CF3I 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 N2 and CO2. A further increase in CF3Br and C2F4Br2 concentrations does not reduce the minimum inerting concentration, and an increase in the concentration of CF3I above 15%(vol.) drastically increases the latter to values higher than the minimum inerting concentration of pure nitrogen. CF3I is found to be a combustible gas, and its addition to a methane-air mixture substantially expands the flammability limits. The flammability limits of CF3I in air under standard conditions are determined, and the explosion parameters are measured.