SYSTEM FOR CONTROLLING COMBUSTIBLES AND O2 IN THE FLUE GASES FROM COMBUSTION PROCESSES

A control system for controlling the fuel/air ratio of a fuel/air mixture for a combustion process which produces flue gases having a combustible content and an oxygen content, comprises selecting desired combustible and oxygen contents for the flue gases which correspond to efficient combustion, simultaneously sensing both actual combustion and actual oxygen content in the flue gases, and controlling the fuel/air ratio in accordance only with the sensed combustible and oxygen content to adjust the ratio until the selected set points are reached. The combustible content can be utilized to regulate the oxygen content set point.