| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the damage of a sealing device and to improve the productivity of a refining furnace by separating an exhaust gas treating system and a first reaction vessel after completing a decarburizing treatment at a first time while holding the pressure in the vessel during decarburize-refining in specified range, connecting the exhaust gas treating system and a second reaction vessel and repeating the decarburize- refining. SOLUTION: The pressure in a vessel is pressurized at 1.2-5.0 atm. during decarburize-refining. A reaction vessel 2 separated from an exhaust gas treating system 1 is laid on a crawler carriage to charge molten iron 8. The carriage is shifted to below the exhaust gas treating system 1 and bottom-blow Ar is raised to a regulated flow rate, and CaO and scrap are added from the upper part and the blow-refining is started. After confirming the ignition, the exhaust gas treating system 1 is lowered and sealed with the vessel and a pressure valve is adjusted. After the pressure in the vessel is made to be the atmospheric pressure by confirming the molten steel to near the target component at blow-stopping, the exhaust gas treating system 1 is raised and the oxygen-blowing is stopped to complete the decarburizing treatment. The non-operating time is shortened by executing the charge of the molten iron 8 and the tapping of the molten steel in separate places.</p> |
