Experimental characterization of bubbling in submerged lance injection

The bubbling phenomena from a downward facing nozzle immersed in a liquid bath are studied experimentally on a water model facility. The pressure fluctuations in the injection lance are correlated to the bubble growth and detachment thanks to simultaneous visualizations and digital processing of the resulting images. The main control parameters for the bubbling frequency are identified within an important experimental database for submerged injection. The effect of the gas volumetric flow rate, the lance submergence depth in the bath, the tip diameter and the gas properties are characterized in particular. An empirical dimensionless correlation is proposed for the frequency prediction.