TWO-DIMENSIONAL AXISYMMETRIC MODELING OF COMBUSTION IN AN IRON ORE SINTERING BED

摘要

A twodimensional model, based on conservation of mass, momentum and energy equations, is represented in this paper in which the coke combustion process, for iron ore sintering in a packed bed, is simulated numerically. The aforementioned packed bed consists of iron ore, coke, limestone and moisture. The main objective of iron ore sintering is producing resistant agglomerates which can be used in blast furnaces. For this purpose, the sinter mixture is partially melted in high temperature and finally molten is allowed to cool. The molten production and subsequently, the solidification process are totally dependent on composition and components of mixture. Changes in bed porosity, caused by fuel combustion, calcinations and moisture evaporation which directly affect bed permeability and gas diffusion, are also considered in the modeling procedure. Mass, momentum, and energy transfer equations of species are solved numerically by using a computational fluid dynamics code in a discrete solving domain. Modeling of iron ore sintering has complex and various features like coke combustion, complicated physical changes of solid phase particles and different modes of heat transfer, for example convection, conduction and radiation. Here in this twodimensional modeling, various reactions are considered to be involved in this process, e.g. distillation, coke combustion and limestone decomposition. Computational results have been analyzed and compared with lab test data of sintering bed. The achieved temperature distribution diagrams in this investigation are truly an apparent indicator of good consistency between our computational results and the experimental data.