Optimization of Physical Parameters of Discrete Element Method for Blast Furnace and Its Application to the Analysis on Solid Motion around Raceway

Analysis of solid motion in the vicinity of raceway of the blast furnace has been carried out by discrete element method (DEM). The physical properties of particle for DEM calculation are important factors to simulate precisely the solid motion in the blast furnace. In order to represent the feature of burden such as coke in the lower part of the blast furnace, the rolling friction was cautiously determined. Through the simulation results, it was found in the result of simulation that the contact friction and the rolling friction have a great influence on the solid motion especially in the lower part of blast furnace. In the present study, the contact friction of actual coke used for blast furnace was experimentally measured. The optimum combinations of contact and rolling friction coefficients were derived from the angle of repose obtained from the DEM. On the basis of the physical parameters optimized for blast furnace, the solid motion around the raceway where the ununiformity was remarkable in blast furnace was analyzed. The influence of variation of raceway is examined to clarify the motion of coke in the lower part of blast furnace. According to the results, it was found that the height of deadman varied with changing the depth of raceway. The interval of tuyeres seriously influences on the ununiformity of solid motion in the direction of circumference. Owing to DEM based on the optimized physical parameters, three dimensional analysis of solid motion containing the ununiform region became possible.