Pollution
Humain
Environnement
Economique

A central heating wood-fed boiler exploded in a sawmill after six employees left for their lunch break. The children playing in the vicinity sounded the alert after the accident occurred. The stones comprising the boiler chimney were projected nearby. The rabble was recovered as far as 150 m according to the press. Vehicles parked nearby were damaged. An electric line was damaged and the technical department had to be called in to restore electricity supply in the neighbourhood. The sawmill used a central heating boiler that produced hot water (no steam) between 80 and 90° to heat the wood drying building. High temperature conditions (40 to 50°) are required to prepare the wood before transferring it to the oven. The sawmill recycles the wooden chips and sawdust used as fuel for the boiler. Following the explosion, the on-site operations could not be resumed due to the extent of damage. According to the operator, the explosion occurred due to gas accumulation in the furnace due to poor draught. The manufacturer modified the supply to the boiler to cut off in the event of a fault. A problem on the boiler exhaust valve is also suspected (leak and rapid evaporation of water in the furnace). An inspection of the exhaust valve has been added to the periodical maintenance operations. Site reconstruction operations were to last between six to eight months.