Can infrared thermagraphy be utilized successfully around ss piping

[micjk]

I work for a synthetic fiber manufacturer and a lot of our piping as well as insulation jacketing is 304 and 316 ss ( @ 80%). Our process is dependent on strictly controlled temperatures, deviations of 2-3 deg. C can throw our product off-spec. We have problems with line pluggage and heat loss and would like to use our recently purchased Flir Thermacam as a detection method. What factors other than reflective energy from other sources and emissisivity would we take into cosideration for this. I am new to thermagraphy and am planning to try for Level 1 certification this year. I would like to incorporate this technology into our predictive program ( we already use vibe and oil analysis.) Roy Gariepy
Maintenance and Reliability Dept.
Bayer Corporation Dorlastan Fibers Div.
Goose Creek, South Carolina USA

 

[JKEngineer]

micjk -

I think you need to separate your issues from each other. Line pluggage is very different than heat loss and temperature control, both in terms of its effects on your process and the methods to detect it.

A plugged line should have a sharp temperature change at the plug. This should be detectable using the IR camera. You will need to be careful about reflections and background temperatures, and may need to work at night if the piping is outdoors. If the SS is too reflective, you will need to alter its surface at least temporarily. You are not, however, trying to measure temperature in this case, only observe significant differences.

To measure heat loss and temperature control issues, you will need to be concerned about the issues that you have identified, emissivity and background temperatures. You could put patches on the pipe as reference points, using a high emissivity material. This will allow you to measure those points. You may have to correct the estimate of the temperature measured this way back to the non-radiative surface condition if the outer surface of the pipe or jacket is sufficiently hot that radiation is a factor in the temperature. That is, if the skin temperature is high, the emissive patch will lose sufficient additional heat via radiation to be cooler than the surrounding surface. This is a correction usually ignored, but not necessarily correctly so.

I hope that this has not been too confusing. You might take a look at my website (below) to see if it helps a little more. Jack M. Kleinfeld, P.E. Kleinfeld Technical Services, Inc.
Infrared Thermography, Finite Element Analysis, Process Engineering

http://www.KleinfeldTechnical.com

 

[micjk]

JKengineer,
After reading my post again, I guess I did jumble the issues together. The line pluggage detection we have already been performing. As far as heat loss and temp control you've given me the answer I understand the concepts of emissivity, background temps, atmospheric conditions and there effect on infrared radiation. Those were good pointers using patches and altering surfaces. I am very new to the field of thermography.
Can you suggest any good training courses. I have looked at the Infraspection Inst., FLIR (which uses ITC I believe), and AIRT. My cohort and I are looking to get enrolled in a training class soon and possibly, dependent on the course, maybe try for Level I certification. If it's no tougher than the Level I course I took with the Vibration Institute I may stand a chance. Roy Gariepy
Maintenance and Reliability Dept.
Bayer Corporation Dorlastan Fibers Div.
Goose Creek, South Carolina USA

 

[JKEngineer]

micjk -
I think that all the sources you cite provide good training. The additional one in the field that you did not mention is Snell Infrared. I am not in a position to comment on one versus another. I know people at at least three of the training companies and respect them.

For the type of work you are describing, you may want to consider completing Level II training as well.

You may also want to consider joining the new International Society of Professional Thermographers, ISPoT. It began forming about a year ago and will be having an organizational meeting next week in conjuction with the IRINFO conference, which is run by the Infraspection Institute. I am currently one of the organizers and the list master for their discussion list which is hosted on topica.com If you want to subscribe to the list, send an e-mail to ISPoT-subscribe@topica.com This will put you on the list and you will be able to exchange email with the other early joiners. Feel free to contact me directly about it if you want more information. See my website for contact information. Jack M. Kleinfeld, P.E. Kleinfeld Technical Services, Inc.
Infrared Thermography, Finite Element Analysis, Process Engineering

http://www.KleinfeldTechnical.com

 

[hotspot]

When deciding on your training, please consider Infraspection Institute. Shop around and talk to others.

Please remember that temperature measurement will be Level II thermography. Your Inframetrics/Flir Thermacam has an accuracy of +/- 2 degrees C or 2% (whichever is greater). Bear in mind that there are ways to refine(make smaller) this accuracy, even in the field. These refinements maintain the calibration traceability and can be implemented within any calculations associated with the process control setpoints.

If you are looking for changes along a stretch of pipe, you will probably see the +/- 2 degrees C as long as the extremely low E and spot size to target size allows it. This would be Level I or your delta T thermography.

 

[IRJohn]

Roy,
You'll have GREAT difficulty seeing a 2-3C difference on stainless.You'll need to increase the emittance of the suface, either temporarily or permenantly. This is usually not hard to do in a way that is compatible with other needs. We have many customers in various industries who have done it with great success in ways that do allow them to see the differences you speak of.

If I can be of further assistance, let me know.

Thermally yours,
John Snell
Snell Infrared

http://www.snellinfrared.com