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

ABSTRACT

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.

KEYWORDS:

• Flour explosion
• flame propagation behavior
• flame morphology and structure
• flame propagation velocity
• suppression mechanism

Disclosure statement

No potential conflict of interest was reported by the author(s).

Submission declaration

This work has not been published previously and it is not under consideration for publication elsewhere. Its publication is approved by all authors and that, if accepted, it will not be published elsewhere including electronically in the same form, in English or in any other language, without the written consent of the copyright-holder

Additional information

Funding

This work was supported by the National Natural Science Foundation of China [52074174]; Special Project for Benefiting The People of Qingdao West Coast New Area [2020-31]; Qingdao science and technology plan project [19-3-2-6-zhc].