A method and system for controlling the combustion of, for example, coal or bark in a stoker boiler or black, liquor in a recovery boiler to provide operation at maximum efficiency. Control loops are provided for primary or undergrate air and secondary or overfire air. The undergrate air control loop...http://www.google.fr/patents/US4362269?utm_source=gb-gplus-shareBrevet US4362269 - Control system for a boiler and method therefor
