A model experiment on the gas entrainment with pouring liquid steel stream.

Abstract

In order to understand the air oxidation of molten steel during teeming, the model experiments on the gas entrainment of pouring stream were carried out by using water, ethanol, glycerin aqua solution and liquid tin.The breakup length of pouring stream depends on the shape of nozzle, the pouring rate of liquid and the flow of liquid in the tank.It was found that, in the range of the present experiment, the amplitude of disturbance at the nozzle exit, e0, decreases with the decrease of nozzle length and pouring rate as indicated by the following equation. In (a0/e0)=44.3(l0/D0)-0.75(Re)-0.1 The rates of gas entrainment by the pouring stream increase with increasing height of teeming and rate of teeming.It is confirmed that the rate of gas entrainment can be represented by a model assuming that the gas entrainment does not occur under the true cylindrical stream but arises by the cavity produced by the collision between the bath surface and the stream surface protuberances.Consequently, taking the cavity radius Rc into account, the rates of gas entrainment can be described for all kinds of liquid stream as follows; Vg/Vl=0.02{(Rc-a)/a0}3