hi all

i need to select the right flame eye for my packaged boiler. i noticed that most of the sensors are either IR or UV based. can someone share the "rule of thumb" when selecting a good and reliable flame scanner?

maybe some OEM recommendation?

 

Selection of flame scanner depends on which type of fuel your boiler is burning, for example if you use Gas/oil then you should use UV flame scanner. For coal fired boilers you should use IR scanners. Basically it is the type of rays which are emmitted during combustion process.

 

ok now i understand. i'm on gas.

the next question would be, is there any general tips on selecting a good UV flame scanner?

 

In the US, code (NFPA, I believe) states that burners that run continuously for 24 hours or longer use UV detectors that 'self check', which involves a mechanical shutter mechanism that blocks the flame path temporarily so that an internal check can be made to determine whether the UV sensor has 'burned in' in the "ON" state. Any sensor doing so can not detect a flame failure, which is what the shutter mechanism is simulating.

Obviously self-check sensor mechanism are multiples the cost of ordinary UV sensors.

Part of the engineering task is to ensure that the flame sensor has a clear site path to flame of interest and that it is mounted where it will not overheat.

David

In the US, Honeywell is big supplier of UV sensors.

 

Dear sir
UV Sensors are having the characteristic of self firing in nature and the shutter coil mechanism is provided for self check where the module keeps the previous stage of the sensor pick up.

The problem in the shutter coil mechanisim is if the cooling air for scanner is more than the adequate pressure it will not allow the shutter to close where the will be problem in the pick up of signal while the self check cycle is going on. So due to this fault signal is stimulated and the scanner trips the burner.

So UV scanner with shutter coil mechanism with proper cooling air will function properly.

Shall i know where is the Project & boiler to this scanner is to be mounted

 

Dear sir

UVis good for oil
IR is good for coal