Physical And Numerical Simulation On Auxiliary Desulfurating And Deslaggling Process By Pouring N₂ In Hot Metal Ladle

There is a serious resulfurization in convertor after using Mg grain as desulfurizer in a specific steel plan. The main reason is that the stirring time after desulfurization is short, and the reaction can not be completed thoroughly. It is easy for workers to leave the false impression of desulfurizing at low level; the slag is quite rare and thin and therefore it is hard to be removed, which leads to high sulfureous slag entering the hot iron again. Against this problem, physical and numerical simulation on strengthening mixing after desulfurization and auxiliary deslagging process by pouring air in hot metal ladle was done in this subject.Physical simulation is based on the similarity theory. Through reblowing experiment, the RTD curves are mensurated under the different gas-flow rates and positions of injection gun. Meanwhile the effects on the mixing time under the different parameters are analyzed. Through side blowing experiment, the effects on deslagging areas under the different positions of porous bricks and gas-flow rates are mensurated and analyzed.Numerical simulation is based on physical simulation. Applying PHOENICS software to simulate the flow fields in different gas-flow rates of reblowing, positions of injection gun and side-blown gas-flow rates. The flow field features on reblowing and side blowing have been achieved. Through analysing, the reasonable technical parameters on stirring and auxiliary deslagging by pouring air have been fixed.The results showed that in reblowing process, the lower injection gun, the more gas-flow rates is, the shorter the mixing time is. So the mixing effect is the better; In auxiliary deslagging process, with increasing of the gas-flow rates, the deslagging area becomes bigger. On the same gas-flow rates, the position of porous bricks is departing from axis of ladle spout, The deslagging conditions has been improved. Conclusions from the experiment with the situation considered, the reasonable parameters in reblowing and side blowing process in hot metal ladle are: the position of injection gun is 275 mm, the gas-flow rates is 170 m~3 / h～230 m~3 / h; the gas-flow rates of side blowing is 34 m~3 / h～45 m~3 / h ,the position of porous brick is Hmm in height and L mm removing from axis of ladle spout in arc length.