An alternative explosion criterion of combustible dusts based on combustion duration time: Applications for minimum explosion concentration and limiting oxygen concentration

Abstract

A novel method based on combustion duration time was newly proposed as an explosion criterion to determine minimum explosion concentration (MEC) and limiting oxygen concentration (LOC) in our recent works. This work further studies the reasonability and reliability of the alternative method experimentally and theoretically. Six different dust samples were tested via a 20-L spherical explosion chamber. The experimental results showed that the data of MEC and LOC determined by using the alternative and the standardized methods are in good agreement. The minimum flame propagation velocity ( S f ) and the corresponding maximum combustion duration time ( t c ) were found at its MEC and LOC, suggesting that the theoretical analysis can well explain all the experimental data. It is the first time to study the theoretical basis of the explosion criterion, thus helping to improve our understandings of dust explosion characteristics, and to amend the explosion criterion in future test standards. • An alternative method based on t c was proposed to determine MEC and LOC. • The alternative method was found to be reliable and feasible. • A theoretical analysis on flame propagation velocity was performed to explain the proposed method. • The alternative method compensates the deficiency of the current standardized explosion criterion.