Paper Title
Study of Cavity Size in Multiphase Flow in a Packed Bed

Abstract
In many solid-gas systems of industrial importance such as catalyst reformer and ironmaking blast furnace, a cavity is formed near the gas injection inlet. The performance of these reactors depends significantly on the cavity size and shape which dictates the fluid flow behaviour in these systems. In the current work, ironmaking blast furnace has been considered as an example, the size of cavity or raceway formation, as it is known as in the blast furnace terminology, has been studied under various conditions. In the blast furnace, gas and pulverised coal are injected through a tuyere/nozzle into a coke bed where liquid slag and iron trickle down. Therefore, the effect of fines (plastic), liquid (water) and gas (air) on the raceway size has been studied. Results are reported here. As such, it is found that the presence of fines and liquid increase the raceway size. The effect of variation of these variables on the raceway size is also presented. Keywords - Raceway size, packed bed, blast furnace, multiphase flow, ironmaking