Experimental Study on Suppression of NH4H2PO4 on Cassava Starch Dust Explosion

Abstract

In order to study the inhibition effect of inert powder NH4H2PO4 on the cassava starch dust explosion. Using the 20L spherical explosion experimental device and the Hartmann tube experimental device to test the effects of NH4H2PO4 on the dust explosion parameters and flame propagation characteristics of cassava starch. The results show that NH4H2PO4 can effectively reduce the maximum explosion pressure, maximum explosion index, maximum flame propagation height and maximum velocity of cassava starch. What's more, the inhibition effect increases with the increase of NH4H2PO4 mass fraction and the decrease of particle size. According to the analysis of the explosion suppression mechanism of NH4H2PO4, water vapor and free ammonia will be produced during the decomposition of NH4H2PO4. The water vapor will absorb heat in the surrounding environment and reduce Oxygen content, and the free ammonia can capture free radical •OH and terminate the chain reaction. Therefore, NH4H2PO4 inhibits the explosion of cassava starch dust through both physical and chemical effects.