"Modelo multidimensional de avaliação do desgaste de cadinho de alto-forno

Abstract

Blast furnace campaign has been determined by hearth refractory line lifetime, this way, it is very important a systematic follow up of wearing evolution, to plan blast furnace revamp. It is tried with that to avoid to interrupt the campaign prematurely or to extend it until a safe limit.Hearth refractory wear happens due to hot metal and alkalis corrosion. Another important element present in the hearth life is skull, that is over carbon block and it impedes the direct contact with the liquids. It can be formed by iron, slag and coke, and its composition is varied along the hearth height. Its presence is important in the carbon blocks protection and its fall can provoke the wear. The refractory thickness measurement and skull thickness is difficult to be carried out directly during the blastfurnace operation, with that the mathematical heat transfer model is a powerful tool to quantify the wearing based on the evaluation of the 1150 ºC isotherm. In this work, a heat transfer axially symmetrical wear model based on finite element method and the Gauss-Newton interactive method were developed. Using this computational model, the hearth temperature profile was evaluated in way to investigate the maximum wearing present in the carbon blocks. The simulation results based in the model with the purpose to evaluate the Gerdau Açominas blast furnace 1 hearth wearing, were shown quite coherent, evidencing to be a powerful tool to be used