FLAMEPROOF ENCLOSURES. Environmental Effects on the Maximum Safe Gap for 1 inch Flanges with Hydrogen/Air Mixtures

摘要

An external obstacle to the free flow of the gases issuing from the flange gap of an 8-litre spherical vessel in which a hydrogen ex¬plosion occurred, was found to reduce the value of the safe gap unless the obstacle was at least 1¾ inch distant. The reduction was the greater the nearer the obstacle was to the gaps for instance, as com¬pared with a maximum experimental safe gap of 0.011 inch in standard conditions with 1 inch flanges, there was external inflammation with a 0.007 inch gap when the obstacle was less than ¼ inch distant.nSecondary external flanges also had the effect of reducing the safe gap if the width of the channel between such flanges was narrower than about 1½ inch. Also the fitting of a fabric cover to a flanged joint seriously reduced the safe gap (in one instance to 0.002 inch) unless the fabric was of a sufficiently strong nature entirely to contain the explo¬sion.