Pollution
Humain
Environnement
Economique

In a furniture factory, an explosion occurred inside a silo of wood chips feeding the boiler. Factory personnel switched off the suction system, cut the electricity supply and deployed a fire hose supplied by a 60 m³/h power pump connected to a fire hydrant. Over 20 fire-fighters set up 2 more hose stations tapping the reserves contained in the sprinkler network (470 m³). The wood chips and sawdust in the silo were moved to another part of the site, and extinction water was routed into the rainwater infiltration basin for ultimate recovery. A surveillance patrol was organised for that night. The factory did not lose any production capacity, only one numerically controlled machine had to be shut down. The ensuing damage led to: changing the silo filter cap; replacing the vents, the ultrasonic level probe and pressure measurement tubes; and repairing both cabling and solenoid valves.

Several hypotheses were developed to explain the cause of this fire: a metal part entering the suction duct, loose sandpaper following a snapped sanding belt, a worn or improperly sharpened tool causing heating of a part awaiting machining, and lastly the machining of a piece of metal inserted into the wood.

A new set of organisational and protective measures were adopted to: keep the silo filled to a predetermined level of wood chips so as to reduce the volume of dust; and install a deluge type automatic sprinkler system as outdoor protection, in particular to avoid structural deformation of the buildings.