| 摘要 |
PROBLEM TO BE SOLVED: To keep a molten metal temp. to a fixed value by calculating enriching quantity of necessary pure oxygen based on molten metal tapping temp., controlling the oxygen concn. in a specific range and supplying to a tuyere of a furnace body. SOLUTION: An air flow rate control valve 7 and an oxygen flow rate control valve 7 are controlled with a program controller 10 to adjust the air quantity and the oxygen quantity into a vertical type melting furnace 1. The molten metal in the melting furnace 1 is tapped from a siphon part 16. The molten metal tapping temp. is continuously measured at the siphon part 16 with a molten metal temp. measuring instrument 17 and transported to the controller 10. A theoretical oxygen quantity needed to combustion is calculated in the range of 1-20% of the enriching rate and the opening degree of the oxygen flow rate control valve 12 is adjusted through the controller 10 to supply the oxygen from an oxygen tank 11. The oxygen is mixed with the air and supplied into the melting furnace 1 from the tuyere 2. Since the optimized oxygen enriched quantity is supplied, the operational cost can be reduced. Since the response time to the oxygen enriched quantity is quickened such as five min., the quantity control is facilitated. Further, since the stable melting at high temp. can be executed, component control is facilitated. |
