Theoretical and practical aspects of pneumatic powder injection into liquid alloys with a non-submerged lance

The method of powder injection into molten metal has been widely known since tens of years and successfully utilized in various metallurgical processes. The most common is a solution with injection lance submerged under the liquid alloy surface, because it is easier apart from some of disadvantages of this approach. In this paper the authors' complex experiments on the pneumatic injection process with non-submerged lance have been presented. The new approach on jet cone angle importance and its influence on the efficiency of the injection process has been shown. The issue of the effective jet radius that was proposed by former scientists as well as computer modelling and injection experiments recorded with high speed camera have been presented. The final comparison of the typical injection lance and developed by authors new lance with flange was presented, too. The benefits of use of a new one for the treatment of small liquid alloy volume (e.g. inoculation or alloys addition introduction) have been pointed.