hi...

we have bottom fired boiler and in every boiler 2 scanner is installed, (fireye make flame scanner. the scanner model 85phonexIR)
we used F.O.(Furnace Oil)as fuel.

the problem is, being bottom fired some parts of furnace oil are snagged in scanner head (as the oil through with a high pressure and it reflect from the roof of the furnace) and also on the head of orifice (as we used orifice for control the flame intensity) for that matter we won't be able to operate the scanner for a long time.

* the air pressure in the boiler is 6kg,

* we used T connector in the sight pipe of flame scanner.

* we won't have any swivel mount.

* the pipe 4inch long in the inner side of the boiler.

* the purging air to the flame scanner (the valve is installed in between T connector and the air pipe joint) is passed though 1/2" NPT valve.

anyone can suggest the way to remove this problem?

 

Responding to Danesh's 11-Dec-09 query... can you provide the Model Number of the Flame-Eye Scanner?

Regards, Phil Corso

 

Hi danesh,

I believe u have a balanced draft boiler. Try decreasing the furnace setting pressure. Your ID fan will somehow work harder with bigger percentage scoop opening.

TQ

 

we are used the model- 85 IR F3-1 EX

Regards, Danesh

 

Danesh, during my ESD/SIS/BMS life I supplied quite a few flame-safeguard systems for bottom-fired HPI Plant process-heaters. Unfortunately flame-loss detector (FLD) failure-rates (regardess of vendor) are quite high... and can't be modeled using the often quoted "bathtube" reliability curve.

However, their performance against unwarranted (false) trips can be materially improved using techniques developed and experience gained during my aforementioned SIS/ESD years.

Please forward additional information to me off or on-list:

1) Are FLDs equipped with flame-proving shutters?

2) Are FLDs equipped with flame-intensity meters?

3) Are the burners equipped with single or dual- FLDs?

4) Can you send sketch or photo of sight-tube alignment with respect to the ignition flame (if used) and the main flame, including refractory penetration, and cooling details?

Regards, Phil Corso (cepsicon [at] aol [dot] com)

 

Hi,
we also face high failure rate for our flame scanner. our boiler is front firing and using oil for main flame.

Suspected problem:
-very hot area
-flame lens easy to get dirty. once cleaned, the detector failed to function

 

Jong... you have not mentioned whether or not a cooling/clearing medium is used?

Regards, Phil Corso

 

Jon... I further to my earlier post: Is the flame-eye setup to "look" at the main-flame, or simultaneously "look" at both the pilot-flame and main-flame?

Regards, Phil Corso

 

flame Scanner air (flow) pressure should be much more than than pressure in boiler

 

Phil,

we are using scanner cooling fan to purge the air to windbox.pressure is 65mBar at the fan. we have 3 dedicated scanners to monitor pilot flame, UV flame and IR/oil flame.

we are using C9707 fireye scanner for oil.

 

Jong...

1) I also forgot to ask... how many burners?

2) If it is your intent to reduce the frequency of unwarranted (false) trips, then what is your present trip-logic?

3) For example, does iginition and trip logic conform to NFPA 8501 (single burner) or 8502 (multiple burner?

4) Is pilot flame continuously monitored?

5) Have you read Control.Com Thread http://www.control.com/thread/1250417026?

Regards, Phil