| 摘要 |
PURPOSE:To heat a degassing device for a blow-up type vacuum refining method with a simple installation without the wasteful loss of energy by using a burner provided to a degassing vessel and the waste combustion gas thereof to heat the above-mentioned vacuum degassing device. CONSTITUTION:A molten steel in a ladle 1 is lifted into the degassing vessel 4 above said ladle from an immersion pipe 2 in the lower part of the vessel and the molten steel is degassed under the reduced pressure. Fuel is supplied through a piping 6 to the burner 5 in the upper part of the vessel 4 and the O2-enriched air mixed with air and O2 from pipings 14, 15 is supplied into the burner so as to be burned by the burner prior to the above-mentioned treatment. The supply rates of the fuel, air and O2 are controlled by an O2 enriching control device 21, air to fuel ratio setter 10, a thermometer 3, arithmetic controller 22, etc., in accordance with the flow rates of the pipes 6, 14, 15 or the concn. of O2 in the pipe 20 or the temp. in the vessel 4. The inside of the pipe 20 or the temp. in the vessel 4. The inside of the vessel 4 is heated to a target temp. The waste combustion gas is discharged from the top end of the pipe 2 and therefore the need for heating from the pipe 2 is eliminated. |
