Flare monitoring apparatus

Claim 1

A flare monitoring apparatus comprising: a means for measuring a first emissive power of infrared radiation emitted from a flare at a first wave length which a peak of emissive power due to a resonance infrared radiation from a specified gas contained in a flue gas in the flare exists and a second emissive power of infrared radiation emitted from the flare at a second wave length at which no peak of emissive power due to a resonance infrared radiation exists; a means, responsive to said measuring means, for calculating the ratio or difference between said first and second emissive powers and for producing signals corresponding respectively to said ratio and difference and representing a burning state of the flare including the generation of black smoke in the flare, excessiveness of the flare and the extinguishment of the flare; a means for detecting the burning state of the flare including a comparator which receives said signals from said calculating means for producing an output signal when said signals exceed or fall below predetermined reference levels; and an alarm for receiving said output signal from said detecting means and producing an alarm; wherein the generation of black smoke in the flare is detected based on said ratio, and the excessiveness of the flare and the extinguishment of the flare are detected based on said difference.