Chlazení válců za tepla

Cooling of Rolls Used in Hot Rolling of Long Products

zpráva odborná

en

This paper describes the processes of roll cooling design and optimisation. Knowledge of the cooling intensity of a variety of nozzles, and their spray parameters forms the basis for the design of a cooling system. The paper introduces the results of an extensive program of experiments, which provide a knowledge base for provision of cooling optimisation. The influence of pressure and flow rate, type and positioning of nozzle and nozzle spray parameters was measured. The results of experiments using nozzles with flat jet and full cone sprays are compared to results using systems without nozzles. The design of a cooling header starts with the analysis of the contact areas between the roll and the rolled material. Thermal load on the roll is used for computation of stress fields on the roll. This analysis produces critical points in the groove where thermal cracks are likely to originate. The resulting knowledge base of cooling intensity is subsequently used for selection of the best nozzles and their ideal positioning around the cooled roll. The final step in cooling design is the fine adjustment of nozzles in order to provide the best required cooling performance.

Tento příspěvek popisuje postupy návrhu chlazení válců a jeho optimalizaci. Znalost intenzity chlazení různých typů trysek a jejich ostřikových parametrů tvoří základ pro návrh systému chlazení. Příspěvekpředstavuje výsledky rozsáhlého experimentálního programu, který poskytuje základní znalost pro optimalizaci chlazení.

This paper describes the processes of roll cooling design and optimisation. Knowledge of the cooling intensity of a variety of nozzles, and their spray parameters forms the basis for the design of a cooling system. The paper introduces the results of an extensive program of experiments, which provide a knowledge base for provision of cooling optimisation. The influence of pressure and flow rate, type and positioning of nozzle and nozzle spray parameters was measured. The results of experiments using nozzles with flat jet and full cone sprays are compared to results using systems without nozzles. The design of a cooling header starts with the analysis of the contact areas between the roll and the rolled material. Thermal load on the roll is used for computation of stress fields on the roll. This analysis produces critical points in the groove where thermal cracks are likely to originate. The resulting knowledge base of cooling intensity is subsequently used for selection of the best nozzles and their ideal positioning around the cooled roll. The final step in cooling design is the fine adjustment of nozzles in order to provide the best required cooling performance.

chlazení ostřikem, válce, válcování za tepla, intenzita chlazení

spray cooling, rolls, long products, hot rolling, measurement of cooling intensity

16.03.2007

IOM Communications

Birmingham

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