Fluid flow phenomena in a cylindrical bath agitated by gas injection from a submerged top lance were investigated on the basis of cold model experiments. A swirl motion of liquid, which was similar to rotary sloshing, was observed under a certain blowing condition. The condition was experimentally clarified and subsequently the following experiments were made for cases without swirl motion. The vertical migration distance of gas from the lance exit was measured using an electro-resistivity probe and an empirical correlation of the migration distance was proposed as a function of the modified Froude number. The axial and radial velocity components of liquid phase were measured for a water-air system using a two-dimensional Laser Doppler Velocimeter. Applicability of the previous correlations of axial mean velocity proposed for gas injection through a centric bottom nozzle to the present case was examined. An electrochemical method was used to measure the mass transfer coefficient between a platinum flat plate and aqueous FeSO4 solution. In the axial region below the bubble plume, the so-called dead water region was observed.
