Melting Effects of Air-termination Rods in Explosive - Atmosphere due to Lightning

Lightning strikes that occur on air-termination rods situated outside or above explosive areas (Ex-zones) have the potential to cause metal melting and the ejection of hot particles. These phenomena can subsequently lead to the ignition of the explosive atmosphere within the Ex-zones. This study aims to examine the impact of an electric arc force on the molten metal pool and the subsequent dynamics of particles. The research employs theoretical calculations and laboratory experiments to simulate scenarios of lightning strikes and quantify the characteristics of the particles involved. The findings of this study indicate that the laboratory results align with the theoretical values and propose several potential strategies for mitigating the hazard. These include the utilisation of a specialised tip on the rod, elevating the height of the rod above the Ex-zone, and implementing a reduction factor for the electric arc force. This study makes a valuable contribution to the evaluation and mitigation of ignition caused by lightning in Ex-zones.