The inflammation of alkyl nitrate vapours and the effect of inert diluents

Abstract

An investigation has been made of the inflammation of methyl nitrate, ethyl nitrate and nitroglycerin vapours, and of the influence of different diluents, over the temperature range 240 to 500° C. The explosion of methyl nitrate is facilitated by both argon and nitrogen. With oxygen as diluent, explosive conbustion occurs. The results show that the explosion is not thermal as has been suggested, but is due to chain branching. A glow region has been observed with methyl nitrate, ethyl nitrate and nitroglycerin, and this region lies below that of explosion on the pressure-temperature graph. These nitrates even when diluted from a thousand to a million times with inert gases glow on admission to a hot quartz vessel; oxygen and air are less efficient than nitrogen or argon in facilitating the glow. It is suggested that the glow is associated with the production of excited formaldehyde molecules.