Numerical modelling and experimental validation of the pneumatic powder injection into liquid alloys

The pneumatic powder injection is well-known and widely used with injection lances submerged into metal bath. However, sometimes better is to not introduce the lance below the liquid metal surface because of the metal splashing and introducing of gases into metal volume. In such a case non-submerged lance is used but the problem with particles jet penetration into the metal volume appears. This paper presents the results of the studies on the pneumatic powder injection with non-submerged lance. The high-speed camera recording of the model diphase jet leaving the lance is carried out. Then image analysis is performed to estimate real particles motion parameters. Furthermore, the jet cone is analysed to check its character of development and compared with the reported results in the literature. The results are obtained that the particles real velocity is smaller than calculated from typically used formulas. The same with cone angles - it seems to be different than quoted in the literature. Next stage is numerical modelling using AnSys software. The results were compared with the experiments and the model is adjusted. The next stage is ferroalloy "cold" injection and again the computer modelling. The last stage is FeSi injection into grey iron experiments. The analysis of the results is combined both with the laboratory results and modelling then compared with previous data. As a consequence the validated numerical model is obtained which can be helpful for the injection process planning in industrial conditions.