FLAMSEKERT, LUFTTETT HOLJE FOR ELEKTRISK UTRUSTNING

摘要

The invention provides for flameproof, weatherproof enclosures for electrical equipment for use in hazardous areas where flammable gases or other substances are or may be present in quantities sufficient to produce explosive or ignitable mixtures during normal operation of the electrical equipment. The enclosure which is of sufficient thickness and mechanical strength to withstand the internal ignition of explosive gases is sealed for weathertightness and is provided with a metallic flametrap having a replaceable filter element therein of metallic foil or mesh structure to provide for cooling and deionizing products of combustion as they pass from within the enclosure to atmosphere through the flametrap. The outer end of the flametrap is sealed by a bursting disc of predetermined burating strength which seals the flametrap against the weather. A translucent portion may be formed in the enclosure. The filter element may be in the form of alternate planar strips of metallic foil and crimped strips of metallic foil in face-to ace relation and either folded, stacked or coiled and held together by an annular clamping member.