Experimental Study on Coal Dust Explosion Suppression with Dihydrogen Phosphate Salts and SiO_2 Powders

Coal dust explosion inhibiting effects of dihydrogen phosphate salts were studied,with a 20 L explosion test device.Explosion characteristic parameters,such as pressure,of coal dust with one or without all,of the powders of(NH4)H2PO4,KH2PO4,Ca(H2PO4)2 and SiO2 were measured.Influences of the concentration of powder,powder particle size and the ignition energy on the explosion inhibition were studied.The results show that these powders can suppress significantly the maximum pressure and the pressure rise rate of the coal dust explosion,that there is a suppression ability sequence:(NH4)H2PO4KH2PO4Ca(H2PO4)2SiO2,that the powder particle size has little or no effect on the ability,and that with the increase in the strength of coal dust explosion,the influence of the concentration of powder on the inhibitory effect of the powders is weakened.