Study on the explosion mechanism of two-phase organic dust — Based on polypropylene/propylene hybrid explosions as an example

A two-phase organic dust explosion is more complex than a single dust or gas explosion and poses a more significant threat to industrial safety production. To elucidate the explosion mechanism of two-phase organic dust, this study investigated the characteristics of flame propagation in PP/propylene hybrid explosions and revealed the flame propagation mechanism. The research findings indicate that adding propylene makes the flame brighter and more continuous, and velocity and temperature increase significantly. The introduction of propylene shifts the control of flame propagation from a process dominated by pyrolysis explosion kinetics to one governed by premixed gas explosion kinetics. Dimensionless characteristic numbers Bi and Da were introduced further to analyze the control mechanism of the dust explosion process. It was found that the explosion process was mainly diffusion flame combustion and premixed gas phase combustion.