External pressures generated by vented gas and dust explosions

Escalation thresholds in the assessment of domino accidental events

“…Considering again a conservative value of A v equal to V 2/3 , the maximum overpressure of the external blast wave is always lower than 16 kPa at distances higher than 20 m for a vessel of about 100 m 3 and a maximum reduced pressure of 100 kPa. The experimental data reported by Forcier and Zalosh [59] support these results. Therefore, a safety distance of 20 m may be assumed to prevent escalation caused by venting of confined explosions.…”

“…External explosions due to the combustion of unburnt gases released after the vent opening were also observed to produce blast waves. A review on the subject, including some recent experimental data, is available in the literature [59]. More specifically, Forcier and Zalosh [59], starting from the work of Whitham [60], proposed the following equations for the pressure of the blast wave propagating outward vented vessels as function of distance:…”

Prevention of domino effect: From active and passive strategies to inherently safer design

“…Blast waves from confined explosions, i.e. gas, vapour and dust explosions or runaway reactions within equipment, producing blast waves propagating in the external atmosphere through vents and openings (even formed for the partial failure of shell) were not included in the discussion due to low distances run by low-energy blast waves (see Forcier and Zalosh analysis [33] and [11] for further details) and considering the more severe damage usually associated to the contemporary fragment projection and/or jet fire formation.…”

Current status and expected future trends in dust explosion research

“…Venting implies that both blast waves and flames are emitted into the surroundings, and this may present a hazard, depending on the size of the emitted flame and the magnitude of the blast wave. Several workers, including Forcier and Zalosh (2001); Harmanny (2001) ;Holbrow, Hawksworth, and Tyldesley (2000), investigated various aspect of this. Various methods have been developed for eliminating hazardous effects of flames from vent openings.…”