Sensor for entry guide gap measurement in hot strip mill

Proper positioning of entry guides before finishing stands in a hot rolling mill are very important to improve product quality. Measuring the entry guide gap and controlling the gap as per the width of the strip at finishing stands, are very important to improve the performance of a hot strip mill. A sensor system has been designed, developed and implemented for crop shear and finishing stands using Incremental encoder and processing the signal by programmable controller. The components in the control system have been designed in a way to improve reliability of the overall system. Suitable interface has been developed to feed the coil width manually or through network. The scheme has been implemented in Hot Strip Mill of Rourkela Steel Plant, India. Implementation of this scheme has resulted in reduction in cobble due to malfunctioning of entry guide system by 72%, and reduction in mill delay by 70%.