AN EXPERT SYSTEM FOR CEMENT KILNS ANALYSIS AN EXPERT SYSTEM FOR CEMENT KILNS ANALYSIS USING A GENERAL FRAMEWORK FOR A PROCESS FLOWSHEET DESCRIPTION

This paper describes the prototype of an expert system for the technical analysis of cement kilns. Technical analyses are complex tasks performed by an expert to diagnose malfunctions, to evaluate the effects of recent modifications on the plant, or simply to strike a detailed balance of normal plant operation. The expert system is composed of three modules. The first module deals with flowsheet description through the SPI interface. SPI is a general package which can be used in applications to graphically describe a flowsheet and to automatically generate an internal object-based representation of the flowsheet from its graphical description. Moreover, procedures for automatic deductions can be implemented within SPI, in order to help the user provide the application with relevant data in an economic way and to ensure flowsheet consistency. The goal of the second module is to plan the measurements campaign according to the plant structure and the purpose of the analysis. The third module performs the measurements processing by analysing the process parameter's trend and normality. After the module's contents have been described, the knowledge representation is discussed. The first module relies extensively on object oriented programming while the two others use production rules. Taxonomies for process elements and diagnosis concepts are described, and abstracts of sessions giving examples of rules used in the knowledge bases are provided. Synergy between objects and rules is highlighted. The importance of flowsheet representation and input is highlighted. Finally, it is pointed out that knowledge acquisition has been enhanced by the competence of the expert system designer both in computers sciences and in chemical engineering. The programme presented here is a prototype which takes into account the diversity and the variety of the analysis task, although it does not envisage all the possible cases. It has proved the suitability of the expert system approach for tackling the technical analysis of cement kilns.