| 摘要 |
PURPOSE:To improve cooling capacity, uniform cooling property, dewatering property and to prevent the external surface of a roll from being roughened by giving a specified relation among an injection distance of cooling water, a nozzle/orifice diameter and an injection pressure in a nozzle. CONSTITUTION:Immediately after steel material 5 is rolled, a roll 1 is cooled rapidly by cooling water injected from the nozzle 6. At this time, in a cooling device 4, each condition is set so that inequalities 1 are satisfied though the space between the roll 1 and the cooling surface is filled with the cooling water. As a result, since the density of average cooling water volume is large, that is, the momentum of cooling water is large, a large cooling power can be obtained through a water screen. Further, since the cooled water is discharged forcedly, the cooling surface is prevented from expanding though the space between the external surface of the roll 1 and the cooling surface is filled with water and ununiform cooling is free from occurring though the injection distance is increased. |
