| dc.description.abstract | In this study, a scaled-down cold model of the hopper, proportionally designed based on the actual blast furnace hopper, is constructed for parameter measurement and charging/discharging experiments using soybean particles. The parameters are calibrated and simulated in EDEM, and experimental measurements are compared with simulation results to verify the accuracy of the simulations.
Also, the Discrete Element Method (DEM) is used to model the blast furnace and burden materials (sinter, lump ore, and iron-bearing materials). Various charging modes, burden ratios, and gate opening angles are used to simulate the stacking and movement behaviors of different burden materials during the charging and discharging processes in the blast furnace hopper. The impact of adding Hot Briquetted Iron (HBI) on the burden in the blast furnace hopper is investigated to find the optimal operating parameters. The analysis includes the distribution of burden materials such as particle size segregation, volume fraction, discharge mass flow rate, and arching phenomena.
The study results indicate that the results of the scaled-down cold model experiments using soybean particles show only slight deviations within a reasonable range from the cold model simulation results. The agreement between experimental and simulation results validates the accuracy of the EDEM simulations. Moreover, adding HBI using the layer charging method results in thorough mixing of HBI and sinter. After charging, HBI is distributed in the upper layer of the burden pile and shows an almost symmetrical distribution along the X-axis of the analysis region. Along the Y-axis, the distribution is discontinuous due to the location of the stone box in the hopper. For discharging, the optimal gate operating parameter is a 37.5-degree opening angle. Under this condition, the discharge duration for various HBI concentration ratios are close to ideal total discharge time, allowing for smooth coordination with the lower rotating chute distribution operation.
As the HBI concentration ratio increases, the discharge flow behavior becomes relatively unstable. However, the total mass flow rate remains within a fixed range of oscillation, and no arching of HBI occurs during the discharge process. Therefore, the layer charging method for adding HBI and a 37.5-degree gate opening angle are identified as suitable operating parameters. Under these conditions, even with an HBI addition concentration as high as 150 kg/THM, the blast furnace can operate smoothly. | en_US |