Suppression effects and mechanisms of three typical solid suppressants on titanium hydride dust explosions

Abstract

The suppression effects of melamine polyphosphate, titanium dioxide and melamine cyanurate powders on titanium hydride dust explosions were studied using a 1.2 L standard Hartmann tube system, a 20-L spherical vessel testing system, a simultaneous thermal analyzer and a field emission scanning electron microscope. The experimental results showed that the three solid suppressants could effectively decrease the explosion parameters such as flame luminescence intensity, flame propagation velocity and maximum explosion pressure, et al. Because of the different suppression characteristics of the suppressants, their suppression effects on the particles combustion temperatures were significantly different. To completely suppress the dust explosion of titanium hydride, the inerting ratio of the melamine polyphosphate powders was the smallest when compared with those of the titanium dioxide and melamine cyanurate powders. In addition, the field emission scanning electron microscope was used to analyze the residues of a dust explosion. The testing results showed that the thermal decomposition residues of melamine polyphosphate powders were coating on the surface of the unburned titanium hydride particles to make them lose reactivity, that was why the suppression effect of melamine polyphosphate powders was the most effective when compared with titanium dioxide and melamine cyanurate powders.