Experimental study on the effectiveness and safety of cement powder on extinguishing metal magnesium fires based on pneumatic conveying technology

Abstract

A pneumatic conveying powder device was carried out to investigate the fire-extinguishing performance of cement powder against metal magnesium fire. The fire suppression test shows that pneumatic conveying can effectively transport cement powder to the combustion area for suppressing metal magnesium fire, and the fire-extinguishing time increases with the fire load of metal magnesium. The fire suppression effect of cement powder in metal magnesium fire is ascribed to the formation of a thermally insulation layer as physical barrier concomitant with heat absorption during pyrolysis process that effectively weaken the heat transfer and reduces the combustion intensity, as supported by the morphology and DSC analysis. The results of explosion suppression test reveal that cement powder has a significant inhibitory effect on reducing the explosion max-pressure and max-pressure rise rate of methane explosion, exhibiting a high-level security in the fire-extinguishing process. This work provides an effective and safe strategy for extinguishing metal magnesium fires. • A pneumatic conveying device was designed to transport cement powder in fire extinguishing field. • Pneumatic conveying cement has excellent extinguishing effect in metal magnesium fires. • Inhibition effect of cement powder on methane explosion verifies the safety in extinguishing process. • The fire suppression mechanism of cement powder in metal magnesium fires is proposed.