Pollution
Humain
Environnement
Economique

An explosion occurred at around 10:15 am, in a wooden furniture factory, at the exit of a dryer in the cyclone. The explosion spread via the conveyors and the screens to a 60 m³ silo used to store dry wood chips. The employees began extinguishing with RIA before help arrived. Two firefighters were exposed to a blast and smoke from a second explosion while they were opening a roof panel on the silo (thermal flash). A total of 3 firefighters were injured, and an employee was injured in a fall. The fire that had engulfed the equipment was contained at 12:45 p.m., but the fire on the silo was put out at 2:15 p.m. The production area had not been threatened by the fire.

The accident occurred when the dryer was in the process of being restarted after a series of maintenance operations. The first explosion occurred at the outlet of the dryer’s cyclone and was linked to:

  • the probable presence of a crack in the cyclone’s lower cone;
  • damage to the conical structure of the cyclone resulting in an accumulation of embers in the bottom of the dryer.

The explosion spread to the silo via the conveyors when production was resumed, with the vertical auger in production mode. As the site’s restart procedure did not integrate placing of the auger in discharge mode, operators were not sufficiently trained, and the practice of performing a discharge operation at start-up had been forgotten over time. The watertightness of the ATEX lock was also questioned. It was not coupled to a spark detector. It should also be noted that emptying the silo of large chips during combustion, combined with spraying down the inside of the silo from above caused the surface crust to collapse and generated an explosion inside the silo.

The site had also experienced another fire in June 2016 (ARIA 39506).