Study on inhibition effect and mechanism of NH4H2PO4 on explosion of titanium powder

Abstract

In order to effectively inhibit the explosion of titanium powder, this study used the Hartmann tube experimental system and the 20 L explosion tank experimental system to carry out flame propagation and explosion overpressure experiments, respectively, and the effect of NH4H2PO4 on the explosion suppression of titanium powder was studied. The results show that when the addition of NH4H2PO4 powder is 50%, the flame propagation velocity and explosion pressure can be reduced to the minimum, and the explosion pressure can be basically suppressed. Finally, the inhibition mechanism of NH4H2PO4 on the explosion of titanium powder was analyzed. The endothermic decomposition of NH4H2PO4 absorbed the energy needed by the explosion of titanium powder. Oxides produced by the decomposition of NH4H2PO4 powder cover the surface of titanium powder, increase the thickness of the oxide film, and play a role of heat insulation; the gaseous water produced by the decomposition of NH4H2PO4 powder reduces the concentration of oxygen in the air and increases the difficulty of the explosion reaction. NH4H2PO4 powder traps the free radicals needed for the explosion to block the chain reaction.