| 摘要 |
PURPOSE:To improve the yield of a steel strip by providing a partitioned reduction chamber in the communication part between a direct firing nonoxidizing furnace and a reduction furnace thereby preventing the pickup of oxide scale to hearth rolls and decreasing flawing. CONSTITUTION:A horizontal partition wall 20 is provided below the communicating part 14 between a direct firing nonoxidizing furnace and a reduction furnace 4 to form a partitioned reduction chamber 26 and seal rolls 24 for a steel strip 12 to be passed through apertures 22 provided to the wall 20 are provided therein. Gaseous HN or the like is fed to the chamber 26 by adjusting devices such as an atmosphere gas piping 28, a fan 30, a flow rate regulating valve 32, etc. to maintain the chamber 26 in a reducing atmosphere of a high degree then the steel sheet is passed through said chamber. The steel strip 12 on which oxide scale is formed in the direct firing nonoxidizing furnace 2 is reduced in the chamber 26 and is further reduced by heating in the reduction furnace 4 isolated by the wall 20. The pickup of the oxide scale to hearth rolls 18 is thus decreased and the flaws on the strip 12 are reduced as well. |
