Behaviour of Bubbles at Gas Blowing into Liquid Wood's Metal

Abstract

Experimental studies on the bubble behaviour in submerged gas blowing were carried out with liquid Wood's metal. About 440 kg of Wood's metal at 100°C was contained in a ladle-shaped glass vessel with an inner diameter of 40 cm. The liquid metal was stirred by nitrogen, argon or helium respectively through a nozzle positioned centrically or eccentrically at the bottom. The bubble plumes were investigated under different gas flow rates and nozzle diameters by determination of local gas fraction, bubble frequency, size distribution and rising velocity of bubbles.
The measurements show that the radial distribution of gas fraction and bubble frequency can be described by a Gaussian function and the bubble size distribution obeys a log-normal function. Except for the region near the nozzle the mean rising velocity of bubbles is nearly constant over the radius. The influence of blowing conditions on these variables was estimated.