Pollution
Humain
Environnement
Economique

During the morning, in a wallpaper manufacturing factory, the firing burner in a printing machine furnace experienced low power problems that required the intervention of a maintenance company. Following this operation, the temperature of the furnace rose abnormally and then stabilised. At around 2 pm, the temperature increased again up to 250°C (working temperature: 180 °C). A few minutes, later a fire broke out in one of the printing machine’s solvent vapour extraction ducts. Staff were evacuated. Fire-fighters controlled the fire which was limited to a section of the extraction duct. The expansion sleeves were replaced and an extractor was taken from another circuit, allowing the installation to be restarted at around 4 pm. According to the operator, the accident could have been caused by the ignition of plasticising agents in the solvent vapour extraction duct (caused by an incorrect alignment of the duct’s sections) or in the extraction turbine casing whose central part forms a basin which promotes the build-up of condensates and prevents them from being flushed out. The triggering event could have been the excessive temperature of the furnace caused by a faulty burner and thermostats or a hot spot generated by the failure or friction of the extractor’s blades. The operator checked the burners, changed the faulty thermostats, realigned the various solvent extractor duct sections and installed bleed holes on the casing of the solvent vapour extraction turbines. The isolation valve at the evaporator inlet had operated correctly, so the fire did not spread to this equipment.