Method and equipment for cooling on a reversing hot rolling mill

Hot reversing mill comprising two work rolls, a top work roll (21) and a bottom work roll (22), and at least one cooling system intended to cool a blank (11), said blank (11) moving on reels (23) and passing through the hot reversing mill between the two work rolls (21) and (22), said cooling system consisting of two cooling devices:

• a top cooling device of the blank (11) and a bottom cooling device of the blank (11) wherein:
• the top cooling device comprises at least one bar (30) of nozzles (35) disposed substantially parallel with the axis of the top work roll (21), the nozzles (35) spraying with jets of cooling fluid (36) the top face of the blank (11),
• the bottom cooling device comprises at least one bar (40) of nozzles (45) disposed between the reels (23) or between the bottom work roll (22) and the nearest reel (23), substantially parallel with the axis of the bottom work roll (22), the nozzles (45) spraying with jets of cooling fluid (46) the bottom face of the blank (11), the axis of the jets of cooling fluid (46) being oriented substantially perpendicularly to the bottom surface of the blank (11),
• the top sprayed convex envelope (52) and the bottom sprayed convex envelope (62) are in the vicinity of the rolls of the mill;
• the maximum distances D55 and D65, D55 being the maximum of the distance from any point of the convex envelope (52) with the line C1 which is the projection of the axis of the roll (21) on the top surface of the blank (11), less the radius R1 of the roll (21), D65 being the maximum of the distance from any point of the convex envelope (62) with the line C2 which is the projection of the axis of the roll (22) on the bottom surface of the blank (11), less the radius R2 of the roll (22), are less than 3 times the largest of the diameters of the work rolls (21) and (22).