Entrainment from a flat liquid-liquid interface

The entrainment of water into a stream of light mineral oil has been studie d in a laboratory scale cell measuring 40x25x15 cm, Oil is continuously pas sed through the cell in which a stratified oil/water system is maintained. The exit flow of oil is found to entrain a small proportion of water depend ing on the distance z of the interface below the centre of the exit duct. I n most cases the entrainment occurs when the interface is significantly bel ow the bottom of the exit duct. The threshold interface level (z,) for entr ainment has been measured for several exit duct configurations as a functio n of oil flow rate and compared with a hydrodynamic prediction. This thresh old and the rates of entrainment are strongly affected by the configuration of the exit duct. The laboratory scale results have been discussed in rela tion to the entrainment of matte into slag leaving the Inco Flash Furnace. Operating recommendations have been made to reduce the losses of matte by e ntrainment.