Running a DLN 1 Frame 9E mchine with no flame scanners


Thread Starter


Lets assume if you experience a deterioration in flame detectors intensity (4 total) due to different reasons like humidification or dirt accumulation of lens...

What is the likelihood that a healthy machine can be run with very low of no flame detector intensity for all the the installed one? I mean can the 3oo4 trip logic of flame scanners intensity going below a threshold ...can be by passed in any situation?

I know it is being very naive to ask this..but viewing 14 can with 4 detectors leads one to think about other mitigation present in the protection system. one of them is Exhaust temperature spread.


Personally, I don't like to ass-u-me anything if I can avoid it, and I recommend others do the same whenever possible.

There is a move to eliminate combustion turbine flame detectors and just use a sudden change in axial compressor discharge pressure along with a sudden change in exhaust temperature and/or load to indicate loss of flame. However, just as with eliminating mechanical overspeed devices ("bolts") the insurance industry still needs a little convincing.

Before you do something you--and others--would regret, be sure to check with management and the company that insures the equipment at your site. While many sites do experience low flame intensity for many reasons such as you described it's not a good idea to do away with flame detection without understanding--and explaining to all concerned parties, including the insurance company--the details of what you might be implementing in its place.

And, if the unit is still under warranty or some kind of contractual agreement for warrant services you should discuss your plans with them as well.

I would think you would require redundant axial compressor discharge pressure sensors and load feedback transducers, and ensure the axial compressor discharge pressure sensors are very fast-acting (able to detect and transmit sudden pressure drops; many so-called "SMART" transmitters are not capable of such fast response times).

Best to find a way to solve the root cause of the problem (excessive flame detector cooling; excessive evaporative cooling/fogging water flows; poor inlet air filtration; etc.) than to bypass flame detection.