Numerical study on ladle baking process of oxy-fuel combustion

Abstract

Ladle baking technology is a widely adopted method in the iron and steel industry. For reducing defects such as centre segregation of billet, it is crucial to minimize the heat loss of molten steel; maintaining a high drawing speed and low superheat during the continuous casting process. Nevertheless, it is well known that the traditional air combustion ladle baking technology suffers from high energy consumption and severe pollution problems. On the other hand, the oxy-fuel combustion technology where fuel combustion is supported by pure oxygen offers many attractive advantages, including high theoretical combustion temperature, low flue gas emission, and enhanced heat transfer of gas radiation. Unfortunately, up to date, limited researches have been carried to understand the potential of the technology. In the present study, a 3-D mathematical model has been established considering the details of turbulent combustion behaviour and its coupling effects on the heat transfer phenomenon during ladle baking process. Considering the difference between gas radiation in oxygen-enriched combustion and the traditional air-assisted combustion, a modified weighted sum of gray gases model were introduced and compared with the conventional model. Based on the established mathematical model, the operation efficiency of the oxy-fuel combustion and air combustion technologies were studied in details. Numerical results show that the oxy-fuel combustion is more efficient and achieves a potential fuel savings of 41.6%.