Research on suppression effect of different types of inert dust on coking coal dust explosion pressure in a confined space

Abstract To study the suppression effect of inert dust on coking coal dust explosion pressure, NaCl, KCl and NH4H2PO4 are selected for explosion suppression. It is found that as dust cloud mass concentration increases in the range of 300~500 g/m3, both Pmax and (dP/dt)max increase first and then decrease. The coal dust explosion pressure decreases continuously as the mass percentages of inert dust mixed into coal dust increase from 0% to 70%. The explosion no longer occurs when the mass percentage of NH4H2PO4 mixed into coal dust is 70%, indicating that NH4H2PO4 is more effective than that of NaCl and KCl. The smaller the particle size of inert dust NH4H2PO4, the more obvious the suppression effect on dust explosion. The coal dust no longer explodes when the mass percentage of NH4H2PO4 mixed into coal dust is 60% and the particle size of NH4H2PO4 is 25~38 μm, which proves that decreasing the particle size of NH4H2PO4 is important for suppressing explosion.