Modelling and analysis of blast furnace performance for efficient utilization of energy

A simple model is presented to assess thermal performance of blast furnace (BF) for efficient utilization of energy with an integrated view to improving the productivity of the plant. The model is developed using the mass, energy and availability balance equations and is applied to an existing Iron and Steel industry in India. A comparison of the actual operation of the BF is made with that of the model prediction. The model provides a reasonable agreement with the real time (on-site) data of the BF operation. The predicted values of BF coke rate and blast rate are 8.6% and 5.11% higher than that of the actual values, respectively. The First and Second law efficiencies of the BF operating system were found to be 77.3% and 39.13%, respectively. Irreversibility of the actual operation of BF was found to be 18.9%, which included the irreversibility due to the transformation of chemical energy and promotion of reduction reactions. The main cause of the irreversibility in the process was the conversion of chemical energy of the fuel (coke) to thermal energy. The effect of the changing operating parameters on the plant productivity is also investigated. This study suggests that the plant productivity can be improved by increasing the hot air blast temperature, reducing hot metal silicon level, reducing coke ash level and increasing sinte rvolume in the charge.