| 摘要 |
PURPOSE:To maintain the shape of coils well by placing the coils put on with an inner cover on a carriage, annealing the same continuously at prescribed temps., and cooling the same forcibly with controlling under specific temp. conditions. CONSTITUTION:A cooling zone is constituted of the primary cooling zone and the secondary cooling zone. In the primary cooling zone, air suction holes 11 having air suction control dampers 11' in the lower part of the side of a heat insulation wall 10 of the furnace are provided by leaving intervals, and an air release hole 13 is provided in a ceiling part 12. The refrigerant entering through the holes 11 passes through the spacing between the wall 10 and an inner cover 8 and is released through a duct via the hole 13. At this time, the cooling is controlled with the dampers 11'. In the secondary cooling zone, the refrigerant fed with a blower 15 is divided with refrigerant injectors 17, and are controlled with a refrigerant injection rate control damper 20 to cool the coils forcibly under the controlling in such a way that the cooling effect in the circumferential direction of the coils in the side part of the cover 8 is made uniform. The coils are cooled at <=25 deg.C/hr cooling rates between above 1,000 deg.C and 600 deg.C. |
