Behavior of gas jet and plume in liquid metal.

Abstract

Measurement of the distribution of gas holdup in nitrogen injection into mercury was made by means of the electroresistivity probe technique with the aid of high speed data processing system. On the basis of the measurement near an orifice or a nozzle, two regimes of gas flow are distinguished; bubbling and jetting. In the jetting regime, the gas jet issuing from the tuyere into mercury becomes very thin and rises rapidly. The radial distribution of gas holdup expands with increasing vertical distance due to entrainment of the surrounding liquid. The vertical distance at which transition of flow behavior from jet to plume occurs is about 30-40mm above the tuyere under the present experimental conditions. The effect of bath depth on the gas holdup is discussed.The upward flow of gas-liquid mixture in the plume zone is analyzed on the basis of macroscopic mass and momentum balances. The calculated results of plume radius and gas holdup are compared with the experimental results. It is presumed that the circulating flow in the bath affects the dispersion of nitrogen.