A review on hybrid mixture explosions: Safety parameters, explosion regimes and criteria, flame characteristics. (April 2023)

• Record Type: Journal Article
• Authors: Wu, Dejian; Zhao, Peng; Spitzer, Stefan H.; Krietsch, Arne; Amyotte, Paul; Krause, Ulrich
• Is Part Of: Journal of loss prevention in the process industries. Volume 82(2023)
• Publication Date: 2023-04
• Subjects: Hybrid mixture -- Explosion regime -- Safety parameter -- Flame characteristic -- Test standard -- Explosion criterion; Chemical industries -- Safety measures -- Periodicals; 660.2804
• DOI: 10.1016/j.jlp.2022.104969
• Languages: English
• ISSNs: 0950-4230

Abstract

Abstract: The hybrid mixture of combustible dusts and flammable gases/vapours widely exist in various industries, including mining, petrochemical, metallurgical, textile and pharmaceutical. It may pose a higher explosion risk than gas/vapor or dust/mist explosions since the hybrid explosions can still be initiated even though both the gas and the dust concentration are lower than their lower explosion limit (LEL) values. Understanding the explosion threat of hybrid mixtures not only contributes to the inherent safety and sustainability of industrial process design, but promotes the efficiency of loss prevention and mitigation. To date, however, there is no test standard with reliable explosion criteria available to determine the safety parameters of all types of hybrid mixture explosions, nor the flame propagation and quenching mechanism or theoretical explanation behind these parameters. This review presents a state-of-the-art overview of the comprehensive understanding of hybrid mixture explosions mainly in an experimental study level; thereby, the main limitations and challenges to be faced are explored. The discussed main contents include the experimental measurement for the safety parameters of hybrid mixtures (i.e., explosion sensitivity and severity parameters) via typical test apparatuses, explosion regime and criterion of hybrid mixtures, the detailed flame propagation/quenching characteristics behind the explosion severities/sensitivities of hybrid mixtures. This work aims to summarize the essential basics of experimental studies, and to provide the perspectives based on the current research gaps to understand the explosion hazards of hybrid mixtures in-depth. Highlights: Hybrid explosions from the perspective of industrial safety are thoroughly reviewed. Available experimental techniques are reviewed for the determination of safety parameters and flame behaviours. No universal method exists to measure the explosion characteristics of all types of hybrid mixtures. The work on developing novel explosion standards with reliable criteria must be continued. Theoretical and numerical studies on the explosion regimes, evolutions and mitigations of hybrid mixtures are lagged.