Proceedings

This paper reviews the past decade of sewage sludge drying fire and explosion incidents. It by no means covers all the incidents that have occurred in the UK, but provides an overview of the type of incident, their causes, and the mitigation measures subsequently instigated, to enable some general guidelines to be drawn for existing and future plants.

Historically, prior to the early 1990’s the fire and explosion hazards arising from dust and bulk storage of materials liable to self-heat were relatively unknown to the water industry. Many drying plants were supplied, installed and commissioned without sufficient thought to the possible fire and explosion risks posed by the production of fine dry dust and final granular/pellet product. As a result a number of fires and explosion incidents occurred not only in the UK but throughout the world.

These incidents, involving different types of dryer, provide conclusive evidence that safety improvements were and still are essential for the safe operation of these plants.

KEY WORDS Dryers, Dust, Explosion, Fire, Inerting, Selfheating, Sewage sludge, Suppression, Venting