AN IMPROVED ROLE COOLING SYSTEM WITH IMPROVED HEAT TRANSFER COEFFICIENT AND A METHOD OF ACHIEVING IMPROVED ROLL COOLING FOR MULTISTAND COLD MILL

摘要

This invention relates to an improved roll cooling system and an improved method of roll cooling for enhancing roll life by improved heat transfer for Multi-Stand cold Mill. The improved roll cooling system with improved heat transfer coefficient comprises selective nozzle means ; means for regulated spray conditions ; means for regulated coolant flow distribution to thereby achieve maintaining substantially constant heat transfer coefficient at impact area during cooling operation. The system is directed to meet increasing requirements on the geometric quality parameters like strip thickness, width, profile and flatness of CR Strips for superior strip profile and flatness for trouble free downstream processing such as cold rolling, coating and press forming. The system would provide for improved roll cooling system which would facilitate enhancing roll life especially for multi-stand cold mills. In particular the system achieves the following advantageous feature/characteristics : I) Achieving optimum impact density of the coolant spray-impingement onto the roll for maximised heat transfer effect. Versatility of thermal control in relation to coolant quantity, flow and placement, to cater all present and future possible rolling conditions. II) To achieve optimum Heat Transfer Coefficient (HTC) and reduce the roll surface temperature as well as premature roll thermal failure. III) Optimum utilisation of coolant for effective roll cooling. The invention is also related to an improved method of roll cooling using the improved system of the present invention.