Effect and mechanism of Aluminium hydroxide and Magnesium hydroxide powder on flame suppression of flour explosion.

In order to systematically study the suppression effect of Aluminum hydroxide[Al(OH)₃] and Magnesium hydroxide[Mg(OH)₂] on the explosion of flour, Hartmann experiment system was used to carry out the explosion flame propagation experiment, and the influence of adding different proportions of Al(OH)₃ and Mg(OH)₂ powder on the morphology and propagation speed of flour combustion flame was studied. Combined with the thermogravimetric analysis (TG) and differential scanning calorimetry (DSC) curves of Al(OH)₃ and Mg(OH)₂ powder, the inhibition mechanism of Al(OH)₃ and Mg(OH)₂ powder on flour explosion was analyzed. The results showed that with the increase of Al(OH)₃ and Mg(OH)₂, the flame propagation speed gradually decreases. After adding 40%wt Mg(OH)₂, when t = 182 ms, the flame reaches the top of the glass tube. When 60 wt% Mg(OH)₂ and 60 wt% Al(OH)₃ powder were added, the maximum flame propagation velocity of flour decreased from 13.86 m/s to 5.78 m/s and 1.62 m/s, respectively, and Al(OH)₃ was superior to Mg(OH)₂ in inhibiting flame propagation. Both inhibitors can inhibit flour combustion by adsorption of H and OH radicals. [ABSTRACT FROM AUTHOR]