CONTINUOUS MEASUREMENTS OF BUBBLE CHARACTERISTICS IN A MOLTEN IRON BATH WITH AR GAS INJECTION

Present authours developed a new electro-resistivity probe being able to continuously measure bubble characteristics in a molten iron bath a gitated by gas injection. The life of the probe was about two hours at a bath temperature of 1 250 degrees C. The axial and radial distribut ions of gas holdup alpha, bubble frequency f(B), mean bubble rising ve locity (u) over bar(B) and mean bubble diameter (d) over bar(B) were d etermined for the Ar gas flow rates of 50 and 100 cm(3)/s (at 1 250 de grees C). The Ar gas was preheated up to 1 250 degrees C and then inje cted through a single-hole centric bottom nozzle. The results were com pared with empirical correlations derived from cold and hot model expe riments. The measured values of alpha, f(B) and (u) over bar(B) in the upper part of the bath were approximated satisfactorily by correlatio ns proposed by the present authors, but they did not agree with the ex perimental results of Kawakami et al. The measured values of (d) over bar(B) were a little smaller than predicted values by Sano et al. and Irons et al.