At a plant specialised in making wooden articles, fire broke out at around 2:15 pm at the level of a suction system component. Incandescent elements were found and removed; the entire network was verified. On 19th June around 6 am, the suction system was turned back on as part of the production start-up routine. Smoke was observed emanating from the cyclofilter. The suction system was shut down to perform an inspection. During this step, it was discovered that embers had accumulated in the lower part beneath the sleeves in the middle of the cyclofilter. The staff present onsite stopped the suction system. Fire services and the Classified Facilities Inspectorate were both alerted.

Upon their arrival, fire-fighters entered the cyclofilter wearing self-breathing apparatuses in order to remove all incandescent dust as well as the cyclofilter sleeves penetrated by this dust. The fire response team also inspected the top of the storage silo and found hotspots. They disassembled an ATEX-rated vent and entered the silo via a manhole, at which point they analysed the surface of the storage area using a thermal imaging camera. Their analyses confirmed the presence of embers on the surface. Fire-fighters then sprayed this surface with water and emulsifiers so as to create a foam blanket that extinguished the embers and prevented the dust from becoming airborne.

Once the foam blanket had been formed, fire-fighters requested a complete draining of the silo. An initial dust bin was removed via the silo’s lower part. Since this intervention was taking too long, fire-fighters insisted the drainage step be stopped so they could disassemble the majority of anti-explosion vents to allow fresh air to circulate. They also worked on the upper part of the silo to remove burnt dust over approx. 10 cm of thickness and a 5-m² surface area. A follow-up thermal camera inspection from the top of the silo revealed no other hotspots. The fire crew left the scene at 6 pm and asked that plant personnel continue the drainage operation, which was completed on 21st June at midday.

According to the operator, it seemed that the fire outbreak occurred during the machining of a part. The incandescent chips were partially removed by the “trap” device on the suction system and thus routed to the cyclofilter and silo.