Proposal of a new injection nozzle to improve the experimental reproducibility of dust explosion tests

• Published in: Powder technology Vol. 328; pp. 54 - 74
• Main Authors: Murillo, Carlos, Amín, Mariangel, Bardin-Monnier, Nathalie, Muñoz, Felipe, Pinilla, Andrés, Ratkovich, Nicolás, Torrado, David, Vizcaya, Daniel, Dufaud, Olivier
• Format: Journal Article
• Language: English
• Published: Elsevier B.V 01-04-2018; Elsevier
• Subjects: Agglomeration; CFD; Dust explosion; Engineering Sciences; Euler-Lagrange; Powder dispersion; CFD; Euler-Lagrange; Powder dispersion; Agglomeration; Dust explosion
• ISSN: 0032-5910; 1873-328X
• DOI: 10.1016/j.powtec.2017.12.096

The influence of the injection nozzle on the dispersion process of a combustible dust in the 20 L sphere is established by developing a descriptive analysis. This study compared the evolution of a dust cloud formed thanks to the standard rebound nozzle with that formed from a new symmetric nozzle. For this purpose, a CFD simulation based on a Euler-Lagrange approach characterized the physical properties of the dust-air mixture in the explosion chamber. The computational results established that the symmetric device enhanced the homogeneity of the mixture as well as the initial turbulence during the initial stage of dispersion. Nevertheless, it also constituted a more rapid turbulence decay due to a wider expansion of the gas. Thus, it constituted different sedimentation and agglomeration periods with regard to the standard device. Thereupon, the computational tools determined the most appropriate ignition delay for the dust cloud for each injection nozzle.
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•A new nozzle is designed to enhance the homogeneity of dust clouds in a 20 L sphere.•A comparative analysis is proposed for the new and the standard rebound nozzles.•The injection nozzle defines the turbulence levels of a dust cloud in the sphere.•The injection nozzle affects the explosibility of a dust cloud in the sphere.