FLAMEPROOF ENCLOSURES:Maximum Safe Gaps with Hydrogen/Air Mixtures in Various Flanged Vessels

摘要

In the present report extended experiments with hydrogen are described;explo¬sion vessels of different sizes have been used with either 1—inch or ½-inch flanges, and either "side" or "central" ignition. The effect of shortening the gap has also been studied, with or without an external obstacle.nA safe gap with a 2½-litre vessel was 0.005 inch, but was wider as the vessel size or the flange length was decreased. The danger from the presence of obstacles was realised, and a paragraph was stated to have been included in the U.S.S.B. Regulations for electrical installations in hydrogen (or acetylene) to the effect that enclosures should not be installed nearer than 4 inches to any obstructing surface.