| 摘要 |
PURPOSE:To smoothly advance the making and refining of steel by properly retaining a mushroom above the tuyere of converter bottom by mixing oxygen in CO2 from the tuyere of the converter bottom as needed in a steel-making converter in which oxygen is blown into the top lance and CO2 is blown into the tuyere of converter bottom. CONSTITUTION:Pure oxygen is blown onto molten pig iron 27 inside a converter 26 from the upper lance 25, and also CO2 gas is blown onto the converter 26 from the tuyere 2a of the converter bottom. While stirring molten steel 27, the molten steel is refined with excellent refining speed. In this case, the converter bottom tuyere 2a is made up of a concentric double pipe consisting of an outer pipe 7 and an inner pipe 8, each of which is connected to CO2-supply pipes 70 and 80. An oxygen-supply pipe 14 is connected to the CO2-supply pipe 80. In case where semicoagulated mushroom is formed in molten steel above the converter bottom tuyere 2a and blocks the CO2-passing hole 6, O2 from the O2 supply pipe 14 is mixed in CO2 in the inner pipe 8 to keep the CO2-passing hole 6 open, and thereby gas is properly stirred by CO2 to advance smoothly the refining of steel. |
