A numerical approach to investigate the maximum permissible nozzle diameter in explosion by hot turbulent jets. (July 2015)

• Record Type: Journal Article
• Authors: Ghorbani, A.; Markus, D.; Steinhilber, G.; Maas, U.
• Is Part Of: Journal of loss prevention in the process industries. Volume 36(2015:Jul.)
• Page Start: 539
• Page End: 543
• Publication Date: 2015-07
• Subjects: Transient jet -- Ignition -- PDF method -- Flameproof enclosure -- Explosion protection; Chemical industries -- Safety measures -- Periodicals; 660.2804
• DOI: 10.1016/j.jlp.2015.03.021
• Languages: English
• ISSNs: 0950-4230

Abstract

Abstract: The ignition of a combustible environment by hot jets is a safety concern in many industries. In explosion protection concepts, for a protection of the type "flameproof enclosures" a maximum permissible gap is of major importance. In this work a numerical framework is described to investigate the ignition processes by a hot turbulent jet which flows out from such gaps. A Probability Density Function (PDF) method in conjunction with a reaction-diffusion manifold (REDIM) technique is used to model the turbulent reactive flow. In this paper the ignition of a stoichiometric mixture of hydrogen/air gas by a hot exhaust turbulent jet is examined. The impact of the nozzle diameter on the ignition delay time is investigated, too. The method is used to explore the maximum nozzle diameter for specific boundary conditions for which there is no ignition. Highlights: In this paper we apply a numerical approach to tackle the problem of explosion by hot turbulent jets in "flameproof enclosure". The simulations are performed using a stand-alone PDF code which incorporates models like PDF methods and REDIM technique. The method is successfully applied to investigate the maximum safe nozzle (in the context of flameproof enclosures).