Inthedirectfiredfurnaceofacontinuousannealingline,sealrollsaresusceptibletodeformationthatleadstosurfacedefectsofsteelstrips.Accordingtofailureanalysis,thereasonsincludeimproperstructuraldesignandheatimbalance.Animproveddesignhasbeenproposedtoreducestressconcentrationandthermalradiation.Aheattransfermodelhasbeenemployedtodeterminetheproperwaterflowrateforrollcooling.Industrialapplicationprovesthatsealrollswiththenewdesignhaslessdeformationandlongerservicelife.