Molten metal taphole design to improve yield and cleanliness

Abstract From the Canadian patent

A tap hole structure for BOF vessels that will prevent slag entrapment through vortexing and allow most of the metal to be tapped free of slag This is accomplished through the use of a refractory member of generally tubular configuration which extends through the side wall of the BOF vessel and has a closed end portion extending into the vessel. The side wall openings are provided in the tubular refractory member closely adjacent its closed end such that the molten metal will not flow directly into the end of the tubular refractory member but rather will flow into the refractory member through the side wall openings, thereby creating an irrotational flow of metal into the tubular structure …