BUBBLE FORMATION FROM SINGLE NOZZLES IN LIQUID METALS.

Abstract

Formation of bubbles, as in steelmaking, copper converting, etc, was studied in mercury and in liquid silver by using a single silica nozzle facing upward. Nozzle sizes were 0. 22 to 0. 82 cm od and 0. 10 to 0. 30 cm ID. The gas-chamber volume and the gas-flow rate were varied from 0. 15 to 200 cc and from 0. 0167 to 77 cc/sec, respectively. The size of bubbles was determined from the frequency of bubble formation and the gas-flow rate. The observed bubble size is compared with that calculated from theoretical or experimental equations obtained for wetted nozzles. The experimental values of bubble size do not agree with the values calculated using the inner diameter of the nozzle. On the other hand, when the nonwettability of the nozzle in liquid metals is taken into account and the outer diameters are adopted as the nozzle diameters in the equations, close agreement between the experimental and calculated results is obtained. Thus, it is shown that the quantitative estimation of the size of bubbles formed from a single nozzle in liquid metals is possible.