The use of television pyrometry in combustion systems

The use of closed-circuit television (CCTV) for viewing oil flames from full scale burners is discussed. After describing a simple method, using a small amount of air, to keepthe lens system and camera cool and clean, the emphasis is on making more use of CCTV toinvestigate, optimize and control combustion. Two television pyrometry (TV-P) systems havebeen used: the first or ‘colour’ TV-P examines large flame areas for overallintensity changes and the second examines the light intensity from small'spot'regions ofthe flame.

Using the colour TV-P system, changes in flame radiation intensity resulting from oil and/or air flow changes can be readily detected. This establishes that the equipment can be used in the setting-up of oil valves or air dampers on boiler plant so as to improve individual burner stoichiometry and give rise to an improvement in plant efficiency.

The spot system has been used to investigate fluctuations in flame intensity arising from instabilities in the combustion processes. It has been possible, with this recently developed diagnostic technique, to demonstrate coherence of the intensity fluctuations from individual flames with furnace pressure fluctuations. There is also a need; for staff and plant protection, to detect complete flame extinction or failure. The same spot system has been adapted to do this, using the output signals in such a way that the flames arecontinuously and automatically monitored.