Abstract
In the steelmaking and refining processes, bottom gas blowing is a widely-used method. In these systems, the gas is blown into liquid from the bottom of the vessel at a temperature lower than liquid temperature. The mechanism of heat transfer between bubbles and liquid and the effect of heat transfer on the formation of bubbles and the rising characteristics of the bubbles were investigated, using air and helium in a water model. The injection temperature of the gases was about –110°C. Heat transfer between bubbles and liquid was almost fully completed near the nozzle. Bubble expansion due to the heat transfer resulted in the increase of gas holdup in the radial direction. In the region far from the nozzle, the bubble characteristics accompanying cold gas injection were the same as those initiated by an ambient temperature gas injection at the same mass flow rate.
