Mine Fires Prevention
The objective in extinguishing a coal mine fire is to reduce the oxygen content of the combustive gases below the lower limit of explosion (LEL). Specialty foams are sometimes injected with the nitrogen to help seal off air ingress to the fire and help cool the surface of the coal embers after the LEL has been achieved. Continuous injection is required for days, even months in some situations, so on-site nitrogen generation is often more cost effective than hauling liquid nitrogen to the location and vaporizing it at the mine’s surface.