Fire Safety Science Digital Archive

A series of experiments on the formation of roof layers of buoyant flammable gas, using mixtures of natural gas and air and also 100 per cent natural gas, is described in which both vertical and horizontal distributions of gas concentration were determined. Mixing of the introduced flammable gas with air in the explosion chamber has reduced by the adoption of appropriate input conditions. The distribution of gas in horizontal planes in all mixtures was found to be uniform but the vertical distribution of gas indicated the formation of diffuse layers, particularly when introducing 100 per cent natural gas. The effects of filling rate and also the charge of concentration with time in a quiescent layer are described.