The use of water sprays for mitigating chlorine gaseous releases escaping from a storage shed

摘要

Accidental releases of toxic gases in partially confined spaces, like a storage shed, can sometimes be controlled by water sprays. This paper presents the results of experimental field tests during which various water sprays were used to mitigate chlorine gaseous releases. The releases (source strength: 1-4 kg/min) simulated a loss of containment occurring at an industrial chlorine storage installation (5 m{sup}3). The mitigation performances of different water sprays were investigated for diverse configurations, and under various atmospheric conditions. The best chlorine concentration reduction was achieved close to the source by a mobile upward water spray, with a maximum concentration reduction of a factor 10 at a distance of 5 m downstream from the source, and for a release flow rate of about 2 kg/min. The good performances of a fixed downward flat fan water spray were also pointed out (mean concentration reduction of a factor 2-5 for the whole series of experiments carried out), with an optimum of effectiveness at a distance of 10 m downstream from the source. In low wind speed conditions (U{sub}10 < 1 m/s), the downward flat fan water spray was more effective for weak release flow rates. The mitigation effectiveness by absorption remained slight (<3%).