Emissivity at elevated temperature 2

[pdt1041]

I am looking for some data on emissivity of anodized aluminum at elevated temperature. Specifically of 6061-T0 with a 64 micro-in finish and hard annodized but not dyed and opperating at 500 deg c. If anyone could provide a resource for this type of data I would really appreciate it.

 

[oxilume]

pdt1041,

What wavelength?

Todd

http://www.oxilume.com

 

[pdt1041]

Total normal or hemispherical emissivity for radiant heat transfer calculations.

 

[oxilume]

pdt1041,

Are you using the anodized aluminum as an IR reflector, IR emitter, what, with respect to radiant heat transfer?

I have the information or source of information you need, but please be more specific without disclosing confidential information.

Todd

http://www.oxilume.com

 

[pdt1041]

This product is a heater and would for this analysis be acting as the emitter. The heater functions in a vacuum chamber and is used to heat thin sheet of glass. I need to know the total heat loss so I can determine how much power I need to maintain the surface temp. I have information on my conductive losses and my convective losses are zero (due to vacuum) but the variation in emissivity data is limiting my ability to determine radiant heat loss. At this temperature I expect radiation to be a significant component.


Thanks

Derek

 

[oxilume]

Derek,

Try this link;

http://www.coleparmer.com/techinfo/...=IR:+Emissivity+of+Specific+Materials#anchor2

Todd

http://www.oxilume.com

 

[davefitz]

oxilume:
the data you referenced is not for anodized aluminum. Anodizing will raise the emmissivity to over 0.85 at long wavelengths.

 

[oxilume]

Thanks Davefitz.

Todd

http://www.oxilume.com

 

[electricpete]

http://electro-optical.com/bb_rad/emissivity/matlemisivty.htm#Anodized Aluminum Samples

Gives emissivity values for various types of anodized aluminum - no mention of temperature at which the measurements were made:
Anodized Aluminum
Black0.82
Black (2nd Sample)0.86
Blue0.87
Blue (2nd Sample)0.82
Brown0.86
Chromic0.56
Clear0.76
Clear (2nd Sample)0.84
Green0.88
Gold0.82
Plain0.04
Red0.88
Sulphuric0.87
Yellow0.87

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