Citation

Wu D, Song Z, Schmidt M, Zhang Q, Qian X. J. Hazard. Mater. 2019; 368: 156-162.

Affiliation

State Key Laboratory of Explosion Science and Technology, Beijing Institute of Technology, Beijing 100081, China.

Copyright

(Copyright © 2019, Elsevier Publishing)

DOI

10.1016/j.jhazmat.2019.01.032

PMID

30673621

Abstract

Industrial fires and explosions initiating from self-ignition of combustible porous dust deposits represent a serious hazard for human beings, environment and industry. Understanding the fundamental basis of combustible dust ignition behaviours at different geometries is of importance to prevent and mitigate the accidental risks. A correlation of self-ignition temperatures (SITs) measured by hot-oven tests and minimum ignition temperatures of dust layers (MITLs) determined by hot-plate tests has been established previously. However, this analogy approach based on Frank-Kamenetzkii model is limited by ignoring the influence of oxygen diffusion. In this work, an improved method is developed by implementing a correction factor for the pre-exponential factor caused by the boundary geometry. This method is testified by comparing with experimental data, previous analogy method and numerical simulation.

RESULTS show that our proposed method performs a better predictability of MITLs and simplicity. The improved analogy method indicates that the different boundary geometries of a dust deposit significantly impact the apparent pre-exponential factor, while have an ignorable influence on the activation energy, which is also verified by numerical investigations. Furthermore, the numerical model with the corrected kinetic parameters provides a satisfactory explanation compared with experimental observations regarding to temperature and concentration evolutions of dust layers.

Copyright © 2019 Elsevier B.V. All rights reserved.

Language: en

Keywords

Analogy method; Dust layer; Kinetic parameters; Minimum ignition temperature; Numerical simulation