The influence of incombustible vapours on the limits of inflammability of gases and vapours in air

Abstract
The influence of some incombustible vapours upon the upward propagation of flame through mixtures of combustible gases and vapours with air contained in a 1$\frac{7}{8}$ in. glass tube has been examined and some comparisons made with results in a 4 in. tube. From the data obtained with the smaller tube it has been possible to plot diagrams for each of the combustibles with inert vapour and air showing completely the compositions of inflammable and non-inflammable mixtures. From these, the limiting 'safe' composition of mixtures of inert vapour with air and with the combustible respectively have been derived. The combinations studied were hydrogen, methane, ethylene, carbon monoxide, n-hexane, cyclohexane and benzene with methyl bromide; hydrogen and n-hexane with difluorodichloromethane, and methane with carbon tetrachloride. A sample of coal gas, the composition of which was determined, has also been examined with methyl bromide as the inert vapour, and it is shown that the limit curve agrees fairly well with that calculated by Le Chatelier's rule from the curves for its constituents.