METHOD FOR CONTROLLING IN-MOLD MOLTEN STEEL SURFACE LEVEL

摘要

The objective of the present invention is to achieve high-precision control of the level of molten steel surface, by using one level gauge to extract and remove a primary, a secondary, and a tertiary standing wave component, and thus to extract only the variation in the bulging molten steel surface, which variation is to be controlled, and to use this in controlling the level of the molten steel surface. In this method, models (12, 14) are expressed with secondary vibration systems, with these models being models of the variation in the molten steel surface level due to standing waves that oscillate with a specific cycle corresponding to the mold width. In addition, the deviation between a measured level value measured with a surface level gauge and the output from the models (12, 14), and/or the differential value thereof, is fed back as an input to the models (12, 14), thereby exciting the models (12, 14), and the surface level variation component due to the standing waves is estimated by means of the obtained output from the models (12, 14), and the standing wave component is removed using the deviation between the measured level value measured with the surface level gauge and the output from the models (12, 14), thereby producing a level signal. In addition, an actuator that adjusts the flow volume of the molten steel flowing into the mold is operated by means of feedback control using this level signal.