Method of arranging and setting spray cooling nozzles and hot steel plate cooling apparatus

A method of arranging and setting spray nozzles of a processing and cooling apparatus provided with a plurality of pairs of constraining rolls for constraining and processing hot steel plate and a plurality of lines of spray nozzles, able to control the amounts of cooling water sprayed, between pairs of constraining rolls in the processing direction and/or direction perpendicular to processing for cooling the hot steel plate uniformly in the direction perpendicular to the processing direction, said method characterized by arranging and setting the spray nozzles so that a distribution of values of n power of the impact pressure P of the cooling water on the cooling surface, P″, integrated in the processing direction between pairs of constraining rolls becomes within −20% of the highest value in the direction perpendicular to processing,

• where, 0.05≦n≦0.2,
• and characterized by using a plurality of types of nozzles differing in amounts of water or spray regions of cooling water for each line of nozzles between pairs of constraining rolls.