Stress field and solid flow analysis of coke packed bed in blast furnace based on DEM

Abstract

The stability of blast furnace operation, such as blast pressure, burden descending, liquid holdup and residual amount of slag in hearth, are dominated by the permeability of coke packed bed. The coke degradation in packed bed is caused by abrasion. Then the stress field is calculated by simulation based on discrete element method (DEM) to make clear the abrasion mechanism. Coke free space shape affects on the liquid drainage efficiency and hearth refractory erosion. Then the effects of hearth depth, burden load and coke consumption on the coke free space shape is considered by using the DEM simulation also. The calculated results show that a force network is formed in the whole of BF and supports the load of burden. The stress of particle in the network is much larger than the average, which can be estimated by continuous simulation. A coke in force network is abraded until the contact cross section larger and contact stress is less than the compressive stress. After then another coke particle participates in force network. Coke abrasion is caused by such force network reconstructions. Coke free space shape is dominated by the solid flow caused by coke consumption in hearth. The coke free space shape, hearth refractory erosion and drainage efficiency can be affected by the hearth depth, burden load and coke consumption in hearth. © 2005 ISIJ.