Cold model study of submerged peripheral gas bubbling from a cylindrical dispenser

Abstract

Modeling of the emerging gas flow through the cylindrical dispenser was important and critical where magnesium vapors were generated through chemical reaction between MgO and Al at 1 673 K inside the dispenser and forced out through its perforations along with a carrier gas (Ar) into the liquid iron bath for desulphurization of hot metal. At lower part of the dispenser and 5 mm above from bottom, six equidistant perforations each of 1 mm diameter were drilled along the axis of the dispenser. Cold model study was carried out to assess the flow rate of carrier gas, dispenser clearance and bath height on the rate of ascent of gas bubble through the bath influence and mixing time, when gas emerges from the periphery of a cylindrical dispenser immersed into a liquid bath. Water was used for representing the liquid bath. The diameter of the gas bubbles which were released through the perforations of immerged dispenser increased with increase in gas flow rate and was not significantly influenced by dispenser clearance. The minimum gas flow rate required to escape the gas bubble from dispenser decreased with clearance. The mixing time in the bath due to the agitation caused by the bubbles was found to be a function of the gas flow rate, clearance and the bath height. The rate of ascent and the mixing time could be modeled successfully with mathematical formulations. The data were used for predicting the behavior of gas bubbles in 5 ton liquid iron bath.