Por: Joao Berganholi (RHI Magnesita), Anderson morais de paula (gerdau ouro branco), eric novaes de almeida (gerdau ouro branco), gabriel mauricio gomes (rhi magnesita), marina braga campos (gerdau ouro branco), neivson josé carvalho (rhi magnesita), paulo vinicius souza da conceição (rhi magnesita), romulo batista baitz (rhi magnesita), Samuel Augusto Martins Oliveira (rhi magnesita), Tito Hugo Nogueira Coelho (gerdau ouro branco)
Resumo:
Gerdau Ouro Branco (GOB) is the biggest plant facility of the Gerdau Group, with an annual production of 3.8 million tons of steel and the only producer of slabs, blooms and billets in the same steel shop in Brazil. A major investment few years ago in a new heavy plate rolling mill facility was done, following the Group vision of providing to the market more added value finished products. More than ever the secondary metallurgy is playing a very important role on the development of this line of products, in special the RH Degasser facility. With oxygen top blow capabilities, this equipment is the only one capable to achieve the very challenging steel specifications, when minimum hydrogen, nitrogen and carbon contents are demanded for the oil and gas industry, wind power, shipbuilding industry, machinery and equipment. Due to intense flow of different phases (gas, liquid slag, liquid steel, solid phases), refractory erosion/corrosion are very high in RH degasser vessels, which decreases productivity consequently increasing the steelmaking costs. On top, the vessel works under very low pressure and its geometry makes any hot inspection in between heats impossible. In alignment with the customers’ needs, RHIM developed an Online Refractory Wear Prediction Model (APO, Automated Process Optimization) for the lower RH degasser vessel. Over the past 2 years, APO helped the process and operational engineers to take data driven decisions when it comes to refractory cost, operational productivity and safety. This paper describes the development of APO on the RH Degasser and shows the results achieved so far, that lead GOB to achieve 330 heats in the vessel, a new historical record in the country
