Risks and limitations of steam curtains protection in case of flammable gases leakage

Abstract

AbstractRefinery and petrochemical production facilities process and produce gaseous and liquid hydrocarbons. In case of any failure, improper design, or human error, flammable or toxic substances can be released into the environment. In such cases, vapor barriers of steam curtains are used in the chemical industry to primarily dilute the released gases as well as to divert the gases to the safe area away from a potential source of ignition. When steam is ejected from a nozzle in the pipe wall, the medium rubs against the edge of the nozzle, liquid water impinges on the wall of the nozzle, and an electrostatic charge can therefore be expected. From the above description, it can be deduced that if the operation of the steam curtains is associated with the generation of electrostatic charge and the possibility of its discharge and the generation of electrostatic sparks, the activation of the steam curtains during the discharge of flammable gases paradoxically represents a certain risk. From the point of view of assessing the potential risks in the operation of vapor barriers, the magnitude of the electric charge energy generated is a crucial issue. Measuring the electric charge on the flowing steam from the nozzles is complicated with a large scatter of measured values. However, with reference to the experience gained from repeated measurements, the experimentally measured values and the obtained results can at least be seen as an expert estimate. This paper focuses on the evaluation of experimental measurements of the magnitude of the generated electrostatic charge on real steam curtains of an ethylene plant. Based on the measured results, risks are defined and appropriate measures are taken.