Controlled cooling apparatus and cooling method of steel plate

Abstract

The present invention provides a steel plate cooling method, in controlled cooling of thick-gauge steel plate, which uniformly cools steel plate over its entire length and eliminates plate warping, that is, a method of conveying and cooling the top and bottom surfaces of steel plate in a high temperature state after hot rolling while constraining the high temperature rolled steel plate by a plurality of sets or top and bottom draining rolls, wherein cooling nozzles having a large number of nozzle openings and individually or simultaneously spraying the two fluids of air and water are used to cool the steel plate, the cooling method of steel plate characterized by giving a stable pattern by driving out air trying to invade the path of flow reaching the front end of the cooling apparatus when the water which is fed is low in amount or low in pressure. Further, the apparatus for working this method is a steel plate cooling apparatus comprised of an outside header having an air feed system, a plurality of air spray nozzles arranged at the air spray surface of this header, an inside header having a cooling water feed system, and a plurality of cooling water spray nozzles arranged at a cooling water spray surface of this header.