EUROPEAN STEEL TECHNOLOGY AND APPLICATION DAYS 2017 - ESTAD 2017

Explosions due to the entrapment of water by molten iron, steel, or slag pose a very serious safety risk in the industry, and can occur during any of the several molten stage processes involved in iron & steel making. Although prevention of these explosions is the primary objective, understanding the overpressure resulting from an explosion is important for worker protection, and to the design of control pulpits, control rooms, crane cabs, and protection of other equipment. A commonly used engineering approach to predict overpressure is to calculate the explosion pulse at the source (overpressure profile with time using a Kingery-Bulmash blast parameter model, for example), and then calculate a decreasing overpressure with radial distance thereafter. This approach, however, neglects the complex interactions of the blast wave with walls and other bodies, which can result in wave amplification leading to overpressures higher than that calculated using the simpler, one-dimensional methods. Compressible, transient, computational fluid dynamics (CFD) modeling overcomes these limitations by solving the problem in three dimensions and inherently accounting for these complex interactions. In addition, CFD also predicts the negative pressure behind the blast wave and the resulting blast wind that can also cause equipment damage and injury to worker personnel. Historically, attempts to solve these problems using CFD have been plagued by excessive simulation times. This paper presents a methodology to predict overpressure due to a molten metal-water explosion using a novel, manycore CFD code – EXN/Aero, developed by Envenio Inc. This code represents a step change in supercomputing of fast transients, rendering problems like this tractable within typical engineering design cycle timelines. This capability is illustrated through a case study, which demonstrates the suitability of the methodology for the design of structures to withstand the overpressure, the design of explosion vents or rupture disks for the relief of overpressure, and for informing best safety practices for personnel.