Abstract: An acoustically operated burner control system for optimally controlling a flow of air and fuel into a flame producing combustion burner throughout a range of firing rates is disclosed. The system includes separate valve assemblies for modulating the flow of air and fuel into a burner, a microphone for generating an electrical signal indicative of the intensity of all sounds generated by the combustion flame having a frequency in excess of about 10 Khz, and a controller including a programmable microprocessor electrically connected to both the air and fuel valve assemblies and the microphone. The system further includes a wave guide for remotely acoustically coupling the microphone to the combustion flame in order to isolate the microphone from both heat and corrosive combustion products. Prior to the operation of the system, empirically-derived sound intensities associated with optimum stoichiometric combustion and minimum pollution are entered into the memory of the microprocessor.

Abstract: A flow controller system for optimally controlling the flow of air and fuel to a burner in a plurality of operating modes throughout the firing range of the burner is disclosed herein. The system includes a pair of differential pressure sensors connected across the air conduit and the burner, and the fuel conduit and the burner, as well as a pair of electrically operated air and fuel valves for controlling the pressure of the air and fuel destined for the burner. The system further includes a microprocessor control means electrically connected to both the pressure sensors and the air and fuel pressure regulating valves. Optimal air-to-fuel pressure ratios are empirically derived at each point along the firing range of the burner by means of detachably connectable flowmeters, oxygen sensors and thermocouples, and this information is stored within the memory of the microprocessor control means.