An influence of oxygen content in an oxidizing atmosphere on inhibitive action of fluorinated agents on a hydrogen flame

Abstract An experimental investigation of the influence of inhibitors of various chemical natures on flammability limits in mixtures H 2 +oxidizer (O 2 +N 2 )–suppressant (C 2 HF 5 ; CHF 3 ; C 4 F 10 ; inhibitor AKM, which is a mixture of olefins) was carried out. Compositions of N 2 and O 2 with elevated (25 vol%) and reduced (15 vol%) oxygen concentrations and air were used as oxidizing atmospheres. Experiments were done at room temperature and atmospheric pressure. Flammability limits were determined in a closed vessel of volume of 4.2 dm 3 (internal diameter 20 cm). Mixtures were prepared immediately in the preliminary evacuated reaction vessel by partial pressures. The mixtures were ignited by an electrical spark of energy near 1 J in the center of the reaction vessel. A flame propagation was detected by a pressure transducer. Twelve flammability curves were measured, which allowed to compare effectiveness of the inhibitors at various oxygen contents in the atmosphere. A qualitative analysis of the obtained results was done, which showed an important role of an inhibitor regeneration.