A FAST ELECTROOPTICAL SENSING SYSTEM FOR MEASURING THERMAL RESPONSE OF A ROTATING ROLL WITHOUT GENERATING CONTACT NOISE

A non-contact sensing system has been developed to measure the tempera ture response of a rapidly rotating roll under spray cooling encounter ed in metal rolling processes. A thin-film sensor with a fast response time, on the order of microseconds, has been designed and fabricated to measure the roll surface temperatures. To eliminate contact noise, apt electro-optical data acquisition system has been developed to prov ide fast acquiring rate without physical contact to the rotating roll. The system has been implemented on a roll simulator to demonstrate se nsor reliability and system feasibility. Also, using the measured temp eratures as boundary conditions, a numerical calculation has been perf ormed to provide the temperature distributions of the roll and the cor responding heat transfer coefficients of the spray cooling. Results in dicate that the cyclic peak value of the heat transfer coefficient var ies from 75 to 100 kW/m(2)-K directly under the impingement of the spr ay jet. These values are consistent with the existing literature.