Message Board Thread - "Boiler Burner Flame Temperature Measurement"

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Boiler Burner Flame Temperature Measurement Maureen Zack 6/8/2006
My efforts to measure the boiler burner flame temperature using infrared thermography have not been successful so far. The engineer who made the request thinks the flame temperature should be approx. 1649C (3000F) (is he wrong?). The highest temperature recorded so far has been 1311C (2391F). (Settings: Emissivity = 1.00, Ambient Temp = 1200C, Relative Humidity = 6%, Distance = 15 feet). Our infrared camera's highest existing temperature range goes to 1500C (2732F), so the fact that the camera has not been enhanced to an optional temperature range which goes up to 2000C (3632F) has NOT been a limiting factor so far.
I am still looking into how to get our infrared camera to measure the temperature somewhat correctly (within the extrapolated range, perhaps) or to indicate that the flame temperature is entirely out of range (which would show a need for a higher temperature range camera). Maybe one of my settings is wrong, or some tricky technique is required to measure boiler burner flame temperatures. The spectral range of our camera is 7.5 - 13 micrometers.
I welcome any suggestions you might have.
 
Re:Boiler Burner Flame Temperature Measurement Maureen Zack 6/8/2006
Additional info per the author of the request (Maureen Zack): This is a large power plant boiler belonging to an electric utility. It burns pulverized coal.
 
Re:Boiler Burner Flame Temperature Measurement Sugi 6/30/2006
I don't know if it's help or not but try to see with Short Wave IR Camera 3-5 Micrometers.

I've tried to see pipe inside the burner with my LongWave Camera, and Camera read far below the thermocouple mounted at the pipe. And When ShortWave see, it read approx the thermocouple.

Maybe what I'd done is different application but you should try...and I'd like to hear from you what the result will be. In this forum of course.

Best regards,

Sugi
 
Re:Boiler Burner Flame Temperature Measurement JKEngineer 7/1/2006
Some thoughts on what you are doing and seeing, not necessarily definitive.

If you are setting the emissivity to 1.0, the background setting for T in the camera will not matter. However, there are two environmental temperatures which will impact your measurements. One is the background in terms of reflected energy from the surroundings, the other is probably the same value, but is the energy coming through the measured area to the extent that the flame is transparent. These values, again depending on the physical arrangement, are likely to be the wall temperatures of the firebox of the boiler. The value will be something higher than the water temperature in the boiler at that point. It is likely that the water temperature in your measurement region is close to the boiling point of the water for the condition of the boiler. The background and "foreground" temperatures will be higher than this by the temperature difference through the boiler tube wall and through and deposits, dirt, or scale on the tubes, either fireside or waterside. I would be surprised if those temperatures are as high as the 1200C you are using, although, as I point out above, the number is meaningless if you are using e=1.

You may be dealing with an opaque area of the furnace, esp. since it is a PC boiler. At the burners, there will be a lot of suspended particulate which may make the flame opaque, even if your camera and filter set up are not set up for the wavelengths of the gaseous combustion products.

HTH,
Jack
Jack M. Kleinfeld, P.E.
Kleinfeld Technical Services, Inc.
Infrared Thermography, Finite Element Analysis, Process Engineering

Bronx, NY 10463

718-884-6644
866-884-6644 toll free
212-214-0919 fax and voice mail
Skype: JKEngineer

JKEngineer@aol.com or JKEngineer@KleinfeldTechnical.com
come see what we can do for you: http://www.KleinfeldTechnical.com

 
Re:Boiler Burner Flame Temperature Measurement raffar 9/22/2006
Flame temperatures are problematic for pyrometry. The mathematics that lead to Planck's law come from quantum theory of solids. Solids and liquids are OK, but gases are not (gases at low temperature radiate at discrete lines; gases at higher pressure exhibit pressure-broadened lines). To be successful measuring 'flame' temp there needs to be solid or liquid species entrained, as in a luminous flame.

Ralph Felice
FAR Associates
www.pyrometry.com
 
Re:Boiler Burner Flame Temperature Measurement Maureen Zack 9/22/2006
I am the person who originally posted this question. Thank you, everyone, for taking the time to provide answers and suggestions for me. Unfortunately, the attempt at burner flame measurement came to a halt because, due to right-sizing in our company, the engineer heading up this effort took a buyout and I have been transferred to a different department. I apologize because I took so long to get back to all of you. Thanks, again!
 


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