A Mathematical Model of Burden Distribution in the Blast Furnace Equipped by a Bell-Less Top Charging System

A mathematical model of burden distribution for the 5800 m³ blast furnace at Jiangsu Shagang Group Co., Ltd. was developed based on the falling trajectory obtained by surveying the falling point of ore and coke at different charging angles (R² > 0.99) and the cold model of burden distribution. Compared with the burden profile laser scanning results, the results from the proposed mathematical model can simulate the burden distribution more accurately, with root mean square error (RMSE) of 0.0179 and hit rate (HR) of 98.86 pct (± 0.04). Using this mathematical model, a quantitative analysis of the burden distribution of 5800 m³ blast furnace was carried out. Based on the key technical theory of minimum coke thickness, an optimized charging matrix was proposed: (1) Increasing the minimum coke thickness; (2) expanding the charging platform width; (3) controlling the width of the central funnel; (4) enhancing blast furnace productivity and reducing fuel consumption. As a result, the minimum coke thickness(The thickness of the thinnest coke layer in the radial distribution) was stabilized to 0.327m, the gas utilization ratio of the blast furnace increased by 0.59 pct, the coke ratio decreased by 17.3 kg/tHM, the heat load decreased by 50-75 GJ/h, the core temperature in the furnace hearth increased by 10 °C, and overall furnace performance significantly improved. This work provides valuable insights for expanding the charging platform width and reducing fuel consumption for (>4000 m³) blast furnace.