DISCHARGING HOLE FOR MOLTEN METAL IN MOLTEN METAL CONTAINER, METHOD OF OPERATING CONVERTER WITH THE DISCHARGING HOLE, AND SLEEVE EXCHANGING DEVICE AT DISCHARGING HOLE OF MOLTEN METAL CONTAINER

摘要

A discharging hole for a molten metal in a molten metal container for a converter and others, particularly a discharging hole for the molten metal using a sleeve-like refractory, capable of reducing an averaged discharge time to increase the operating efficiency of the converter and others. The discharging hole comprises an upper sleeve (32) fitted to the lined refractory of the converter and a lower sleeve (33) detachably installed on the lower end part of the upper sleeve. The cross sectional area of the inner hole of the lower sleeve (33) obtained after use is set to 60 to 98% of the cross sectional area of the inner hole thereof obtained at its exchange.