Effects of water vapor content on the inflammable limits of ammonia‐oxygen‐nitrogen mixtures

Abstract

AbstractA study was undertaken to confirm and extend available information on the inflammable limits of ammonia in air or oxygen‐nitrogen mixtures, and particularly the effects of water vapor on these limits. Such information should prove helpful in the prevention of explosion in equipment handling these gas mixtures, for example in the autoclaves for leaching of nickel sulphide concentrate under pressure, with ammonia and compressed air. Flame‐quenching technique was used for determinations at atmospheric pressure, and the dynamic bomb method at ten atmospheres.At atmospheric pressure, the inflammable limits of ammonia in dry air were found to be 17.2 and 30.2% ammonia, but these limits were found to narrow as the water vapor is increased, until at 10.8% H2O and 20.8% NH3 no flame could survive. With a dry oxygen‐ammonia mixture, the lower limit was found to be 15.2% ammonia. At ten atmospheres, the explosive limits of ammonia in dry air were found to be 16.9 and 28%, and these limits were narrowed with addition of water vapor until, above 9% water, no explosion occurred.