Lessons Learned from Installing an «At Line» Free Lime Analyzer to Control and Optimize the Cement Kiln Operation

Abstract

Traditional instrumentation and control at a cement manufacturing plant is carried out by taking samples from different processing points and analyzing them in a central laboratory, either manually, or in some cases automatically. For clinker, the samples are typically taken after the cooler on the pan conveyor and analyzed every 2 hours. With this method the clinker free lime result, is not truly representative, is too late and too infrequent to be used to correctly control the kiln burning zone conditions.In 2015, the plant management decided to install ‘At-line fully automatic Free Lime Measurement system’ taking the clinker sample directly at the kiln discharge before the cooler. This solution presents a number of advantages over the traditional methods – notably in terms of more timely controls and of higher frequency, resulting in fuel and power savings and better and more stable product quality. The system was successfully commissioned at the end of 2016This paper will provide a brief description of the control instrument as it was implemented at the cement plant in Arizona, its installation, the teething problems that were faced and resolved, its effectiveness in helping the kiln operators control the process, the substantial improvement in clinker consistency as seen over the last 2 years, as well as the very significant and consistent savings that were achieved and that quickly paid back for the investment.