Inhibition And Numerical Simulation Of Carbonate And Phosphate On Aluminum Powder Explosion

In recent years,dust explosions have occurred frequently,causing serious loss to life and property.Therefore,dust explosions have caused great concern.It has become very important and urgent to study the related mechanism and means of suppressing dust explosion,which can provide some guidance for the research of suppressing dust explosion.In this paper,the effects of carbonates and phosphates on the suppression of aluminum powder explosion are explored through experimental analysis and numerical simulation.The standard 20 L spherical explosive device and dust device of minimum ignition energy are used to test the inhibitory activity of different types of carbonates（KHCO₃and NaHCO₃）and phosphates（NaH₂PO₄,（NH₄）₂HPO₄,NH₄H₂PO₄）on aluminum powder.And the minimum ignition energy（MIE）,the maximum explosive pressure(P_max),the minimum significant inert concentration and the minimum complete inert concentration were used to characterize its inhibitory ability.Experimental analysis was performed by SEM,DSC,TGA and CHEMKIN.The results show that with the increasing amount of inert dust,the explosion pressure of the mixture gradually weakens,the MIE value of aluminum powder gradually increases,and the explosion sensitivity gradually decreases.Phosphate has a good effect on suppressing the explosion strength and sensitivity of aluminum powder.Adding 40%NaH₂PO₄ can completely inhibit the explosion of aluminum powder.（NH₄）₂HPO₄ has the most obvious inhibitory effect on MIE.When adding 10%and40%of inert dust,the inhibition of aluminum powder MIE is not obvious.Only at a higher addition of 60%,its inhibition is obvious.In summary,its inhibitory capacity is as follows:phosphate is superior to carbonate,sodium dihydrogen phosphate is superior to ammonium phosphate,and potassium bicarbonate is superior to sodium bicarbonate.Through the analysis of CHEMKIN software,NaHCO₃ mainly realizes the conversion of high active oxygen to low active oxygen through the"NaO（?）Na"cycle,thereby reducing the activity of the aluminum powder combustion reaction.NH₄H₂PO₄ uses the combination of the intermediate HPO₃ and O atoms and H atoms to reduce the concentration of O atoms in the reaction space,or to convert H atoms into H₂O vapor to reduce the temperature in the reaction space,thereby playing a role in suppression.