Advanced Process Control of a cement plant grate cooler

The present work describes an Advanced Process Control solution applied to a cement plant grate cooler. The grate cooler is located downstream of a clinker rotary kiln with the purpose of suitably cooling the clinker. Clinker is cooled through the action of multiple cold air fan units as it is transported by the clinker rotary kiln. A Model Predictive Control strategy was designed in order to minimize the electrical energy consumption of the cold air fan units while guaranteeing the necessary heat recovery for the kiln and the preheater. At the same time, clinker quality constraints are taken into account. The designed controller has been installed on the real plant, obtaining satisfactory results in terms of kiln tertiary air increase and of kiln combustion improvement. In particular, a major process stabilization has been achieved, proven by a significant reduction of the standard deviation related to the pressure of cooler grate.