Effective Use of Water Curtains in Dispersing LNG Vapor Cloud

The need for increased LNG storage facilities in the US to meet the demand for natural gas has increased the attention on LNG safety issues. Because of its high flammability, LNG poses significant hazards to the surrounding communities. One of the major hazards is the formation of a flammable vapor cloud from an inadvertent LNG release, which may lead to a massive fire. Therefore, the mitigation of accidental release consequences of LNG is a serious concern. Federal safety regulations and standards require a “dispersion exclusion zone” for LNG facilities so that vapor generated during releases of LNG will not propagate beyond the plant boundaries. This exclusion zone begins at the LNG spill site and extends to the predicted distance at which the average vapor concentration in air is 2.5% volume. An effective technical approach to create this safety zone is forced dispersion of LNG vapor through control and mitigation measures.Water curtain is recognized as an efficient engineering method to mitigate various types of hazards in the petrochemical and gas industries because of its availability, simplicity of use, efficiency, and adaptability for various hazards such as gas dispersion, absorption, and fire inhibition. Today, water curtain is recognized as a promising technique to suppress LNG vapor clouds.

Even though extensive theoretical and experimental research has been carried out to determine the effectiveness of water curtain in dispersing LNG vapor, there is no comprehensive and substantiated engineering guideline for water curtain design. The aim of this research is to provide comprehensive guidance towards the development of engineering design criteria of an effective water curtains to disperse LNG vapor and establish an effective safety zone for LNG storage facilities. The proposed research will determine the effectiveness of water curtain through comprehensive theoretical and experimental analysis of its LNG dispersal mechanisms. Finally, the results from water curtain model calculations and experimental measurements as well as industrial water curtain information will be analyzed.