DETECTION OF END POINT OF MOLTEN STEEL POURING

PURPOSE:To improve the quality of a billet by providing a sound collector to a pouring nozzle or a member connecting thereto and deciding the change of the flow in the nozzle from a molten steel to slag. CONSTITUTION:A sound collector 9 is installed to hardware 13 receiving a pouring nozzle 3 to detect the outflow sound of a molten metal. The detection signal is amplified by an amplifier 10 and is compared with a set value by a regulator 11. The detected sound decreases sharply when the flow in the nozzle changes from a molten steel 7 to slag 8. The detected value is therefore compared with the set value by the regulator 11 and when the detected value decreases below the set value, an indication controller 12 outputs a signal for closing a sliding nozzle 2. The end point of the molten metal is early and exactly decided by the above-mentioned method and therefore the intrusion of the slag into a billet is prevented and the quality of the billet is improved.