| 摘要 |
PURPOSE:To heat immersion nozzles with a small amt. of fuel and to decrease the variance of a heating temp. by covering the nozzles with heat insulating boxes and providing holes to control the flow of gas to the boxes. CONSTITUTION:The immersion nozzles 12 of a tundish 11 are covered by the heat insulating boxes 13 and caps 19. The holes 14 to control the flow of the gas are formed to the boxes 13. The high-temp. gas is supplied from burners 16, 25 to the nozzles 12 in such constitution. The gas is then passed through the inside of the nozzles and discharged from the lower ejection ports so as to enter the boxes 13. The gas flows backward on the outside of the nozzles 2 and is discharged from the holes 14. Since the nozzles 12 are heated by the high-temp. gas from the inside and outside in the above-mention manner, the nozzles 12 are efficiently heated and the fuel cost is reduced. The variance of the heating temp. between the individual nozzles is decreased. |
