Safety in EXpanded Metal Type ExpIOSion Proof Construction

Abstract

As a expanded metal is a kind of gauze made of steel plate with meshes expanded by means of press machine, the multigap explosion proof panel made of expanded metal has a special merit which excels in mechanical strength. Experiments on explosion proof apparatus have generally been carried out under stationary gas conditions. However, multigap explosion proof apparatus may be structurally affected by the gas flow velocity in a gallery, and then the experiment must be carried out under fiowing gas conditions. The purpose of the work is to examine the influence of the gas flow velocity of the explosive concentration on multigap explosion proof constructlon performance and to consider how to cope with this influence. The summary af the experimental results is as follows : ( i ) In case of using a multigap panel made up of 10 sheets of expanded metal in 9. 5 10 vol. per cent methane air mixture, the multigap panel is capable of preventing gas explosion in the apparatus from propagating to flowing gas at the gas flow velocity under 3 meters per second. ( ii ) In case of using the expanded metal type multigap panel with a grating of crossed steel plate which disturbs continued existence of holdover fiame after ga~_ explosion, they are capable of preventing propagation of gas explosion at the gas flow velocity under 9 meters per second