Permeation and Blockage of Fine Particles Transported by Updraft through a Packed Bed (Numerical Approach)

Abstract

As a method for reducing CO₂ in blast furnaces, low-reducing agent ratio and large amount of pulverized coal is being carried out to reduce the amount of coke used and reduce the carbon input to the blast furnace and its operation cost. However, these operating methods increase the deposit amount of coke powder and unburned char generated in the blast furnace and decrease process efficiency. A three-dimensional numerical model is built and observed by the coupling system of DEM-CFD, performed to understand the principal factors that affected fine and gas permeability. Simulation is carried out in, where fine particles are injected simultaneously from the bottom of cylindrical packed bed, mimicking the experimental approach. The fine to packed diameter ration is given by 0.133≤Dp/dp≤0.162. At a larger diameter ratio, fine particles tend to concentrate at the bottom of the packed bed. In the case of lower particle diameter ratio, updraft gas will easy to permeate along with fine particles because of the existing of large open flow channels relative to fine diameter. Furthermore, no significant change in fine fraction transported to the upper area due to the change of gas velocities. In this present study, the effect of continuous fine particles injection and its effect on gas flow can be observed, where the gas flow avoiding the heavily concentrated area.