Gas-liquid dual phase inhibition method for explosion accident of wet Al dust collection system based on KH2PO4

Metal dust has explosion risk in wet dust removal system. In this study, a gas–liquid dual phase explosion hydrogen inhibition method (EHIM) is proposed. The inhibitory effect of KH₂PO₄ on Al dust explosion in a dust removal pipe (gas phase) and Al dust hydrogen generation in a wet dust collector (liquid) is discussed separately and collectively. Adding 70% KH₂PO₄ totally inhibits the formation of Al dust explosion flames while inhibiting Al–water reaction in the wet dust collector at the same time. Inside the dust removal pipe, KH₂PO₄ acts in the initial stage of Al dust combustion and works as a pyrolysis endothermic coolant under 220℃–380℃; inside the aqueous solution of the dust collector, it generates AlPO₄ with water and creates a film over the surface of the Al particles, which isolates water from Al, thus blocking Al–water reaction. Our new method offers a novel way of protecting the safety of wet dust removal systems.