Determinação da extensão de áreas classificadas para liberações bifásicas.

Abstract

Many accidents involve biphasic release of hazardous chemicals into the atmosphere; they are often stored and transported in the form of liquefied gas under its saturated pressure. In these cases, in the contact with the environment, the released product will disperse as a steam jet with small droplets, which evaporate causing changes in temperature and composition of the surrounding gas. The larger droplets may fall on the ground (rainout) forming a pool that will spread and evaporate. Droplets smaller than a critical size will remain on the jet and will be evaporated due to entrained air. In this case, in view of estimate of the behavior of the released material is useful for a hazard assessment, this work aims to determine the extent of the classified area for biphasic releases, using as case studies liquefied gas leakage of butane, in its Saturated state at ambient temperature, and propane at 321 K and 20,64 bar. Used the model proposed by Long for turbulent subsonic jet and model for two-phase jet in Kukkonen to predict this extension. From the analysis of the results it was observed for propane as a release component, a satisfactory result when compared to the one obtained in CFD, presenting approximately 1.3 m extension. The extent to the leakage situation of the butane presented a conservative value (86 m), considering that the pouring hole has a considerable diameter. These results are important since they may help in similar situations in the classification of areas. In view of the lack of extension data available in the literature, this work has a practical innovation and can serve as a basis for standardization of the calculation of extension of classified areas for biphasic releases.