Experimental investigation on the suppression of aluminum dust explosion by sodium carbonate powder

To prevent the potential explosion accidents in industries involving aluminum powder, the effectiveness of Na2CO3 in inhibiting aluminum dust explosions was investigated using thermal methods and explosion tests. Furthermore, the surface morphologies and chemical compositions of the resultant explosion products were characterized to illustrate the inhibition mechanism of Na2CO3 powder. The results revealed a marginal increase in ignition temperatures and a decrease in combustion peak temperature as the proportion of Na2CO3 increased. Notably, within the range of 0-450%, a notable reduction was observed in both the maximum explosion pressure (from 0.68 to 0.06 MPa) and the maximum pressure rising rate (from 91.93 to 2.87 MPa/s). In particular, as the percentage of Na2CO3 increased, a gradual decrease in flame brightness and average flame velocity was observed. Moreover, a negative relationship was observed between ignition temperature and apparent activation energy with maximum explosion pressure and maximum pressure rising rate. An analysis of the explosion residues indicated the presence of Na2CO3, NaOH, Al2O3, Al(OH)3, Na(AlO)2, Na2O and unburned aluminum. The inhibition mechanisms of Na2CO3 involved heat absorption, isolation, and the consumption of free radicals. These results offer valuable insights that can aid in mitigating the risks associated with aluminum dust explosion.