| 摘要 |
In the continuous casting of metals by means of a water-cooled tubular mold into which the molten metal is fed by means of a refractory pouring nozzle which opens in the molten metal bath below a supernatant protective layer of fusible slag, automatic control of the molten bath level is obtained by forming an image of the upper portion of the mold with the pouring nozzle and the slag layer by means of an optical instrument, by disposing a plurality of photo-electric cells on this image along a line substantially coincident with the axis of the nozzle on the said image, some of said cells being on the image of said nozzle and others on the image of the slag layer, by determining the radiation gradient between the successive cells along said line, by taking as the analog of the level of the molten metal bath within the mold the zone of said line where said gradient reverses and by deducing a controlling signal from the position of said zone along said line. The successive cells may be connected two by two to comparators which emit an output in correspondence with the sign of the difference between the responses of the cells of each pair, these outputs being totalized algebraically to deduce the controlling signal. |
