In November 2015, an operator at an explosives manufacturing plant was tasked with transferring aluminium grit atomised powder (aluminium powder) from a flexible intermediate bulk container (IBC) outside the plant to the hopper inside the plant. Using a pneumatically-driven vacuum suction pump and transfer pipe work (which incorporated five metres of PVC piping) the operator successfully transferred part of the powder from the IBC. When the hopper began to empty the operator resumed transferring product. Just after repositioning the suction pipe inside the IBC, he heard a loud explosion that sounded like a cartridge of explosives detonating, and felt the pipe shake violently in his hand. The operator ran inside the plant to find that the vacuum pump and chamber were on fire and had been blown off the hopper. There were spot fires of burning product. The operator used an extinguisher to put out the fires. There were no injuries. There was charring on the inside of both the vacuum chamber and transfer pipe work but not inside the hopper. It appears a dust explosion was triggered by a static discharge inside the vacuum chamber creating a flash-back through the transfer piping.
Dust Explosion during transfer of Aluminum Powder (Static Electricity)
