"found flames coming from a vent duct on the roof ....."

The accumulation of aluminium fines/dust is common occurrence in our plants. Around or on top of machinery, inside duct work, etc. accumulation can occur. Here is a recent story where an accumulation of aluminium fines met an ignition source.

Fire crews responding to the midwest USA just before 11:30 p.m. on evening during the week of October 30, 2016 found flames coming from a vent duct on the roof at an aluminium company.

The vent stack contained aluminum dust, so water could not be used to extinguish it. Firefighters used a collection of portable CO2 and Dry Chemical extinguishers from their rigs and aluminium company to extinguish the fire.

The roof construction was corrugated steel with a thick rubber overlay. Firefighters used large rotary saws to cut away the metal roof so that the rubber overlay would not continue to burn from the heat of the vent stack.

The process of cutting through the metal and thick rubber was labor intensive and created problems for the saws and blades, as the thick rubber turned to tar when heated and clogged up the equipment, according to a press release from the local fire department.

Other news reports state that fire crews took 90 minutes to extinguish. We congratulate the fire department on successfully putting this fire out safely.

Good housekeeping practices on the shopfloor are easier to control than accumulation in exhaust vents. Especially exhaust vents that have horizontal runs where accumulations can occur. Luckily the fire department and aluminium company had enough class d fire extinguishers to put this fire out. All too often the Aluminium Plant Safety Blog will post an incident where not enough class d fire extinguishers were available. Which resulted in small growing into a large fire. We recommend that every plant should rely solely on what special fire extinguishers that they have in stock, versus assuming that the local fire department will have enough. Most cases the local fire department will not have enough. Unfortunately, aluminium plants only realize that after a fire.