Screw systems for supplying slag-forming mixture to the molds of continuous-casting machines

Abstract

The prospects for dosed supply of slag-forming mixture to the molds of continuous-casting machines are considered, and the need for further improvement of such systems is established—in particular, the use of a screw supply system. The parameters of flexible screws with internal diameter 15, 20, and 25 mm for transporting fine-grain materials are studied experimentally; these screws are based on a steel helix (external diameter 11, 16, and 18 mm; screw pitch 5, 10, 15, and 20 mm) rotating at 250–500 rpm. The output of the screw depends linearly on its speed of rotation, for the given geometric parameters. The ratio of the pitch Ss to its external diameter dex has considerable influence on screw performance. The dependence of the supply per screw turn on Ss/dex is nonlinear, with a maximum at Ss/dex = 0.9–1.1. The minimum unit energy of the screw system is observed at Ss/dex = 0.5–0.6. These results are used in the design of a new series of systems for dosed delivery of slag-forming mixture to the molds of continuous-casting machines with different cross sections.