Fire Safety Science Digital Archive

A small scale vertical tube apparatus and experimental procedure are described for determining the maximum oxygen concentration permissible to exclude the possibility of an explosion in flammable dust dispersions. The results obtained with the small-scale apparatus are in good agreement with those obtained in an apparatus of industrial proportions. The results are also compared with those obtained in the standard furnace test apparatus which is at present used for measuring maximum permissible oxygen concentrations for atmospheres in which explosible dusts are dispersed in clouds. The method of preparing gas mixtures and filling the apparatus has also been used with the standard dust explosion pressure test apparatus. It is concluded that a test based on the small scale vertical tube apparatus can be used for recommendations for the safe working of industrial plant and would be preferable to the standard furnace test.