Experimental evaluation and analysis of methane fire and explosion mitigation using isolation valves integrated with a vent system

Mohammed J Ajrash; Jafar Zanganeh; Behdad Moghtaderi

doi:10.1016/j.jhazmat.2017.06.012

Experimental evaluation and analysis of methane fire and explosion mitigation using isolation valves integrated with a vent system

J Hazard Mater. 2017 Oct 5:339:301-309. doi: 10.1016/j.jhazmat.2017.06.012. Epub 2017 Jun 20.

Authors

Mohammed J Ajrash¹, Jafar Zanganeh², Behdad Moghtaderi¹

Affiliations

¹ The Frontier Energy Technologies Centre, Chemical Engineering, School of Engineering, Faculty of Engineering & Built Environment, The University of Newcastle, Callaghan, NSW 2308, Australia.
² The Frontier Energy Technologies Centre, Chemical Engineering, School of Engineering, Faculty of Engineering & Built Environment, The University of Newcastle, Callaghan, NSW 2308, Australia. Electronic address: jafar.zanganeh@newcastle.edu.au.

PMID: 28658639
DOI: 10.1016/j.jhazmat.2017.06.012

Abstract

There has been a surge of interest from the extractive industries in the application of mechanical means to the mitigation of flame deflagration. To verify the implementation and performance of passive and active mitigation protection, a comprehensive experimental investigation has been conducted on a large scale detonation tube, 30m long and 0.5m in diameter, with two mitigation valves (passive and active) and a burst panel venting system. The valves were used alternately to mitigate the flame deflagration of methane in concentrations ranging from 1.25% to 7.5%. The experimental work revealed that locating the passive mitigation valve at 22m distance from the ignition source mitigates the flame by fully isolating the tube. However, closing the valve structure in the axial direction generated another pressure wave upstream, which was approximately the same value as for the original pressure wave upstream. In the case of the active mitigation system, the system perfectly isolated upstream from downstream with no further pressure wave generation. When the vent was located at 6.5m from the ignition source, the total pressure was reduced by 0.48bar. Due to the counter flow of the reflected pressure wave the flame was extinguished at 12.5m from the ignition source.

Keywords: Detonation tube; Explosion isolation; Explosion vent; Fire mitigation; Flame deflagration.