Supervisory control applied to a cement kiln incinerating recovered solvent

The National Cement Company of California has kept pace with developments in the industry with a combination of fuel selection and other capital improvements. In 1982, the plant began burning industrial-waste solvents in addition to petroleum coke. In 1988, a LINKman supervisory control system was added which, in addition to the normal high-level control functions, provided additional facilities to manage their multiple fuels. A major consideration is the balancing of different fuels of varying heat content while maintaining an ideal mix from economic, legal, and chemical standpoints. The LINKman high-level control system has proven effective in enabling the plant operations personnel to deal effectively with these challenges. It has been instrumental in their efforts to obtain a modified permit, allowing them to double their use of recovered solvent fuel. The control strategy is continually reviewed and modified in order to adapt to changing plant conditions and economic considerations