2017 年 103 巻 6 号 p. 315-324
The motions of particles and gas in the nearly full scale sintering beds were simulated to elucidate the effect of melting volume fraction of magnetite ores on the particle agglomeration and the large scale crack formation by the simultaneous calculation of the Navier-Stokes equations and the Lagrangian DEM equations based on the sintering model in which the phase change of particles and the cohesion forces and the resistance forces due to the liquid films among particles were considered. In this study melting volume fractions of magnetite ores are varied from 60% to 88%. Calculated results show that the large agglomerates and the large scale cracks are not formed when melting volume fractions of magnetite ores become large because the large melting volume fraction of magnetite ores increases the liquid region in which the large viscous interaction forces act among close particles. If the total volume of liquid phase in the melting zone is the same, it is effective to prevent the large scale crack when the liquid phase increases uniformly rather than locally. We also examined the effect of friction forces in the melting zone on large scale cracks under the condition without magnetite ore. Calculated results show that the small friction forces prevent the formations of large scale agglomerates and cracks because the small friction forces become easy to compress the particle layers due to the weight of the particle bed and the drag force caused by air flows passing through the particle beds.
