EVALUATION OF BLEVE IMPACTS FROM LPG SPHERICAL TANK

Major Hazard Installations (MHIs) such as refineries are producing Liquefied Petroleum Gas (LPG). LPG is characterized by an atmospheric boiling point below ambient temperature and therefore stored under pressure in a sphere or a bullet type of vessels. If the LPG tanks are subjected to a fire of sufficient duration and intensity, it can undergo a Boiling Liquid Expanding Vapor Explosion (BLEVE). A BLEVE is an extremely violent explosion that can occur when a vessel containing a pressurized liquid is ruptured. The BLEVE gives rise to the following effects: (1) blast wave, (2) fireball, and (3) fragments. This study aims to evaluate the BLEVE impacts from 1000 m^3 LPG spherical tank. The blast wave has been estimated by Trinitrotoluene (TNT) equivalency, Specific Volume, Entropy and Enthalpy (SVEE) and Prugh models. The BLEVE fireball thermal radiation has been estimated through point source model. Mathematical calculations as well as an EXCEL program have been used for the evaluation of the BLEVE impacts. It has been found that the plant facilities as well as the neighboring community buildings will be exposed to blast wave effects up to 400m from the tank. The workers and the residents who live about 400m from the tank will be at risk from thermal radiation if they are outside of their shelters during the incident. 80% of fragments range reaches up to 700m. The BLEVE impacts increases with the increasing of the material released. Keywords: Liquefied Petroleum Gas, Boiling Liquid Expanding Vapor Explosion, Blast wave, Fireball, Fragments.