Abstract: The inhibition effect of sodium salt powder NaHCO3, Na₂HPO₄ and NaH2PO4 on the explosion severity and flame propagation characteristics of wheat starch dust was studied by using a 20 L spherical explosion system and a 2 L Hartmann tube device. The pyrolysis behavior of sodium salt and wheat starch and its effect on wheat starch explosion products were studied by thermogravimetric analyzer and Fourier transform infrared spectroscopy, and the inhibition mechanism of different sodium salts on wheat starch dust explosion was revealed. The findings indicated that increasing sodium salt content significantly impacted the explosion pressure, rate of pressure rise, and flame propagation velocity of wheat starch dust. These effects were particularly pronounced at various stages of the explosion process. Under the same mass fraction, NaHCO₃ had a better inhibition effect on wheat starch dust explosion than Na₂HPO₄ and NaH₂PO₄. The results of this study provide a theoretical basis for the prevention and control of explosion and fire accidents in wheat starch processing industry.

Key words: wheat starch, dust explosion, flame propagation, sodium salt powder, inerting suppression