SUPPRESSANTS FOR THE CONTROL OF INDUSTRIAL EXPLOSIONS

Explosion suppression is now a well established means of mitigation ag ainst the consequences of a gas or dust explosion in industrial proces sing. Such systems were first deployed by Graviner Ltd (Maisey, H.R. C hem. Process Eng., March 1959) in the early 1950s following developmen t of the technology for military purposes. The first industrial explos ion suppression systems used proprietary halons as the explosion suppr essant. By the mid-1970s, dry chemical power suppressants were becomin g established as the preferred suppressant because of their superior s uppression performance. Today water and halon suppressants are only de ployed where they offer specific benefits over the dry chemical powder s. The Montreal Protocol (UNEP, Sept. 1987 amended 1991 & 1992) has im posed controls on the availability of most halons-a production ban cam e into effect in the UK on 1 January 1994-because these agents have a proven ozone-depleting effect in the upper atmosphere. Not surprisingl y, the chemical industry has identified a range of alternative agents that are environmentally friendly and have fire-extinguishing properti es. Some of these agents are now being assessed as options for explosi on suppression. This paper considers the demand on an explosion suppre ssant and contrasts the effectiveness of available suppressant agents against industrial explosions.