NOx modelling of a travelling-grate process

Environmental awareness has proliferated in the last couple of years. A consequence of this is that governments are making stringent legislations on pollution control. This implies that industrial companies will face increased costs if they do not reduce the amount of pollution. Hence, there is a great need to study and diminish the pollution that originates from different combustion applications. LKAB has very special circumstances regarding the combustion in a traveling- grate indurating machine. Due to the requirements of the sintering process, an immense amount of extra air has to be utilized in order to facilitate the sintering. As a result of the extra air, the thermal NO generation will be augmented. In order to scrutinize the thermal NO process, the airflow and the combustion process in the pertinent furnace have to be studied. The commercial CFD code CFX is employed to analyze the flow and the combustion. Furthermore, a parameter study of the burner nozzle was performed in order to minimize the thermal NO production. The results show that the airflow in the furnace is not optimum for minimizing NO or achieving a homogenous bed temperature due to the construction of the geometry. Moreover, the thermal NO can be minimized by adjusting the burner nozzle settings. It was also found that the temperature in the bed is influenced by the burner nozzle configuration.<p>Validerat; 20101217 (root)