Development of Measuring Method and a Fixed Quantity for Wetted Area between Liquid and Particles in a Packed Bed for Ironmaking

Evaluation of wetted area between liquid and particles in a packed bed for ironmaking is quite important for an analysis of transport phenomena, however, measurement of wetted area in the metallurgical packed bed process has never been reported in the literature. Therefore, we have studied a novel method for the measurement of the wetted area under the same wettability conditions as an ironmaking process. In this experiment the contact angle between liquid and particles in the packed bed was controlled to be from 103° to 121°, and a sheet of regularly arranged, hemispherical convexity was lined in the inner wall of the packed bed for eliminating wall effect. Liquid with dye was uniformly supplied to the packed bed, then the particles were dried after being reached steady state, to estimate the dyed area on the surface of all the particles. Wetted area was measured at various conditions of contact angle and liquid flow rate, and then a new empirical formula for the wetted area was related to dimensionless groups of Reynolds number, Froud number, Weber number and non dimensional surface tension.