PROCESS MANAGEMENT AT A MELT-SHOP AND CAS TING SHOP BY MEANS OF MODEL-BASED PROCESS-CONTROL

To operate the furnaces economically while maintaining the contractual ly agreed level of power consumption, it was necessary to maximise the throughput capacity of the entire chain of melting and casting facili ties. This required, on the one hand, making full use of the fixed qua rter-hourly peak mean value and, on the other hand, also assuring the quality of the cast products. Among the most important tasks of this o ptimisation project, besides exact adherence to, and precise achieveme nt of the metal tapping temperature, was the control of the ''instanta neous energy consumption''. In particular, bath overheating and waitin g times for the finished heats had to be avoided. Through computer-aid ed monitoring of the process condition for each operated unit, targett ed process predictions and optimum coordination of all the process-rel evant variables, it was possible to achieve these objectives. In the c ourse of two years a 10% increase in capacity and , at the same time, an improvement in the quality of the produced slabs were demonstrated. Operating personnel are no longer necessary to maintain or selectivel y raise the temperature of the furnaces at weekends.