Effect of dust explosion suppression by sodium bicarbonate with different granulometric distribution

Abstract

The inert powder of sodium bicarbonate with different particle size distribution in certain proportion was employed to study its suppressing effect on dust explosion and flame propagation. A certain proportion of combustible aluminum dust was mixed with different granular sodium bicarbonate powder with single-diameter particle or different granulometric distribution. The explosion experiment was performed in a vertical pipe experimental platform. The ionic current and flame propagation behavior and flame temperature were obtained to evaluate the inhibitory effects of inert powder on dust explosion flame. The experimental results showed that the sodium bicarbonate with different granulomertic distribution made suppression effect on the flame of aluminum dust explosion. The inert inhibition powder with different granulomertic distribution led to flame structure change and reduced the thickness of the preheat zone during flame propagation. Meanwhile, the flame propagation velocity and flame temperature were reduced. Furthermore, an optimum proportion of sodium bicarbonate was obtained for the best inhibition effect on the aluminum dust explosion. Results show that the suppression effect on the flame combustion reaction zone was the critical factor for dust explosion mitigation.