Intelligent control system for the lime kiln

Under strong price competition, the pulp and paper industry is aiming higher profitability through increased productivity and reduction of expenses. In addition, the industry meets increasing market demands for improved product quality and environmental protection. Consequently, extensive research is being conducted to determine how to improve existing processes. One alternative among the others, which is gaining increasing concern, is improved control of the existing processes by using intelligent systems. In this paper the results of a field survey made at a modern Finnish pulp mill are presented. In the field survey, the lime kiln operation was studied in order to develop an intelligent kiln control system for maximizing production capacity, minimizing the degree of variation in lime quality, and reducing energy consumption and flue gas emissions. This paper also describes the structure and functions of the implemented intelligent kiln control system, as well as the results achieved during the long-term testing period at the plant.