Journal of Loss Prevention in The Process Industries, Vol.8, No.2, 61-70, 1995
THE INFLUENCE OF WATER SPRAYS ON GAS-EXPLOSIONS .2. MITIGATION
Two papers have been prepared, reporting on experimental investigations into the influence of water sprays on gas explosions. The water sprays that were used in these experiments were produced by nozzles that are very commonly used on offshore facilities. The experiments addressed the influence of turbulence generated by these systems on the course of gas explosions and the mitigating effect that water sprays may have on gas explosions under certain circumstances. The first paper reports on the influence of turbulence produced by water spray, investigated in a 1.5 m(3) rectangular box. The present paper reports on mitigation of gas explosions by water-spray systems. For mitigation of gas explosions to be possible using water spray produced by nozzles which are commonly used offshore, droplets need to be broken up. Analysis of experiments performed in a 50 m(3) representation of an offshore module showed that a minimum rate of flame acceleration is necessary to cause the droplets to break-up. This rate of flame acceleration is dependent on the droplet size. The larger the droplets are, the easier it will be to cause droplet break-up and hence mitigate gas explosions.