Speaker
Description
Metallurgical processes such as the AOD converter generally utilize gas blowing for mixing and refinement of liquid steel. Due to the harsh environment of the complex and opaque system it is common to study the stirring of the process through physical and numerical models. Effective mixing in the bath has an important role for refinement such as decarburization and have been vividly studied before. However, high temperature chemical reactions also play a big part and is sparsely investigated. This project investigates the effect of altering the pressure around the nozzles on the decarburization in the AOD converter. The ferro-static pressure enforced by the liquid steel at the nozzles is practically lowered by lowering the bath height above the nozzles with the means of inclining the vessel or elevating the nozzles. With the help of physical and numerical modelling, a computational fluid dynamics (CFD) model coupled with a thermo dynamics model has been developed allowing the study of both the mixing and chemical reactions in the process. In the current work an investigation regarding the chemical reactions for a single gas bubble in the AOD has been performed. The results have been used as input to the understanding of industrial AOD decarburization mechanisms, especially focusing on where reactions take place, how fast and the role pressure plays during these reactions.