Control of the flow of a casting admixture into a molten metal involves optical detection of the effective passage of the admixture in a selected region downstream of the admixture feeder

摘要

Control of the flow of a casting admixture into a molten metal involves supplying the admixture from a feeder (12) above a casting bowl (4), selecting a region (Z) downstream of the feeder for the theoretical passage of the admixture, optically detecting effective passage of the admixture through the region, and generating an alarm signal in the absence of the admixture in the region. Detection of the effective passage of the admixture into the selected region (Z) can be achieved by detecting the contrast formed by the admixture in the selected region (Z) against the bright background of the molten metal stream (6) and, optionally, a supplementary light source. A momentary value representing the flow rate of the admixture into the selected region (Z) is measured and compared with a reference value corresponding to a reference flow rate, and the momentary flow rate is adjusted. An independent claim is given for an apparatus for controlling the flow of a casting admixture from a tubular feeder into a molten metal stream during casting of the molten metal in a casting bowl.