A Fast Electro-Optical 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 temperature response of a rapidly rotating roll under spray cooling encountered 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, an electro-optical data acquisition system has been developed to provide fast acquiring rate without physical contact to the rotating roll. The system has been implemented on a roll simulator to demonstrate sensor reliability and system feasibility. Also, using the measured temperatures as boundary conditions, a numerical calculation has been performed to provide the temperature distributions of the roll and the corresponding heat transfer coefficients of the spray cooling. Results indicate that the cyclic peak value of the heat transfer coefficient varies from 75 to 100 kW/m² -K directly under the impingement of the spray jet. These values are consistent with the existing literature.