CFD modeling of Peirce-Smith converter leaks and off-gas flow

摘要

Gas dynamics within and around Peirce-Smith converters was modeled for Chagres smelter, the property of Anglo American Division Fundicion Chagres. The modeled domain is more complex than considered in the literature because it includes the volume within the gas handling system and the space within the building around the converters as well. Both sub domains, the one within the gas handling system (comprising converter, water-cooled hood, drop-out hopper, cyclones and ID fans.) and the building, are connected through some selected areas. Air leaks into the gas handling system through these areas and fugitive gas leaks out from the hood into the building. The air movement in the building is controlled by convection of the hot gas leaking from the converter hood, the dynamic pressure of the wind, the presence of the roof central openings and the presence of a tested air temperature gradient that sets up within the building. The model operation presented special problems due to the very different behavior of the inner and the outer sub domains, since gas velocities are very different. To make the calculations in these sub domains compatible, some simplifications had to be consented. The results achieved are good because they include not only a detailed description of the gas movement within the gas handling system but a better estimate of the leaks. The latter are compatible with tests performed on the air within the building, to measure ambient SO_2 concentrations and temperature.