BOILER COMBUSTION CONTROLLER

PURPOSE:To perform stable combustion even if an air amount is decreased due to a trouble on an air system, by adding a circuit which corrects the output signal of an analogue memory in response to a deviation signal between a fuel flow rate signal and an air flow rate signal. CONSTITUTION:A correcting circuit 21 finds deviation between a fuel flow rate signal 11 and an air flow rate signal 12, and when a fuel amount is increased and the deviation becomes positive, a level switch 22 is turned ON. A control system manual signal 23 is provided during manual operation of a fuel regulating valve, according to an AND between said signal and a signal from the level switch 22, a pulse generator 24 is actuated to output a pulse to an analogue memory 18, and an output signal from the analogue memory analogue memory 18, and an output signal from the analogue memory 18 is decreased to a maximum point, to which air rich can be kept, to throttle the fuel. Simultaneously, the output of a manually-operated increase switch 20 is cut. This permits continuance of stable combustion even if an air amount is decreased due to an air system trouble during manual operation of a fuel regulating valve.