Aurélia Dandrieux

Small scale field experiments of chlorine dispersion

Abstract The objective of this paper is to increase current knowledge on the dispersion of a small plume of chlorine using medium scale field experiments. An experiment using a peacock tail spray was undertaken to study the mitigation of the chlorine cloud.

The DVS model: a new concept for heavy gas dispersion by water curtain

Abstract Numerous accidents involving dangerous substances may unfortunately occur, namely because of the importance of the transport of dangerous materials, of the storage and use of dangerous products on industrial sites. Several kinds of barriers can be used to protect or reduce the consequences of these accidents, such as the water curtains which mitigate the atmospheric dispersion of toxic clouds. Nevertheless, few studies assessing their effectiveness exist and models predicting the concentrations downstream of water curtains are scarce. In this context, a new concept, based on the representation of the water curtain as a Discontinuous Virtual Source is proposed. From this concept, the DVS model aims to predict on one hand the influence of the ‘peacock tail hose’ (vertical and upwards water curtain) on the dispersion of a toxic cloud, on the other hand, to predict the concentrations downwind of the water barrier. The bases of the model are set out and the results of the simulation, are presented and compared with experimental values of an ammonia plume dispersion in presence of the peacock tail spray.

Effectiveness of water curtains to protect firemen in case of an accidental release of ammonia: comparison of the effectiveness for two different release rates of ammonia

Abstract This paper presents the results of some dispersion experiments of liquefied ammonia in the presence of peacock tail water curtains. The aim of this paper is to evaluate the effectiveness of water barriers to counteract a weak release of ammonia under pressure (0.25 kg/s). The dissolution of ammonia in the water curtain is rather poor (about 15%), but at 10 m behind the curtain the effectiveness can reach levels as high as 90%. The results of the effectiveness obtained with ammonia releases of 0.25 kg/s are compared with results from those obtained from a release of ammonia half the size.

Vulnerability of the Environment in the Proximity of an Industrial Site

This work is carried out in the framework of the ARAMIS project, which aims at developing a comprehensive procedure for assessing the risk level associated to an industrial site with respect to the surrounding environment. To this end, an index is defined which consists of the contribution of three terms, expressing the scenario consequence severity, the safety management efficiency and the vulnerability of the surrounding environment. The present work focuses on this last aspect by determining the vulnerability of the area in the proximity of an industrial site from the contribution of classes of elements belonging to the categories of human, environmental and material targets. The applied methodology consists in identifying and quantifying the targets by means of a geographical information system (GIS) and in assessing the contribution of each target on the basis of a multicriteria decision approach (Saaty method). The result is an operational tool allowing competent authorities, industrialists and risk experts to assess the vulnerability of the area surrounding an industrial site.