COOLING ROLL

PURPOSE:To reduce the equipment cost and the running cost by bringing a steel strip into close contact with a roll at the time of cooling the steel strip by winding around the roll and improving cooling efficiency without using power for suction to improve the heat efficiency, related to the cooling roll applied to a continuous heat treatment apparatus for steel strip. CONSTITUTION:The roll body 21 is constituted of a roll barrel part 22 composed of a roll outer cylinder 23 and inner cylinder 24, roll shafts 29a, 29b and an inner hollow part. Many cooling grooves 25 are arranged in the axial direction on the roll barrel part 22 and coolant is flowed to cool the strip 6 wound around the roll barrel part 22. Further, many through holes 26 are arranged in the radial direction independently of the cooling grooves 25 so as not to cross with the grooves and gas entrapped into gap between the strip 6 and the surface of the roll barrel part 22 is flowed into the hollow part in the inner part of the roll from these through holes 26 and flowed out from the other holes 26 to the outer part. By this method, the strip 6 is made to be brought into close contact with the surface of the roll barrel part 22 and heat conduction for cooling is improved.