Model-based state estimation MPC technology builds on existing MPC methods and experience, but improves on the model by being able to interpret information that would not otherwise exist. In other words, it can recreate, through modelling, a process input value that cannot otherwise be measured.
In this context, the estimation of mid-kiln temperature has already been mentioned, but another important example is estimation of the mill load. Here, Expert Optimizer uses a mill mathematical model, together with the history of fresh feed rate, elevator power consumption and return rates, in order to produce a reliable estimate of the amount of material inside the mill at a given point in time. This additional information means that improvements in process stability can reach levels that were previously unattainable.
Running such a stable process allows the Göllheim plant to operate closer to its operating constraints than has previously been possible. This means more stable clinker and cement quality and a need for less fuel and electrical energy, which of course means an improvement in operating costs.