Reply #70: A coal fire is a good approximation of a blackbody. A blackbody

[stickdog]

is a body that absorbs all the radiation that falls on it. Most bodies are NOT good approximations of blackbodies and therefore reflect a portion of the radiation that falls on them. Non-blackbodies (basically everything that burns other than coal) emit 10% - 90% of the energy that a coal fire emits.

Coal fires generate almost no UV radiation and lots of IR radiation, resulting in hotter fires.

In addition, 1700 C is an outrageously high temperature for even a coal fire. Nobody has ever experimentally measured a coal fire at even nearly this temperature. The 1700 C value you guys are throwing around was arrived at indirectly by examining geological artifacts that may have been the result of any of a number of geological phenomena.

From:

http://www.ears.nl/EARShome/projects/txtco.htm



From:

http://pub-geo.tuwien.ac.at/showentry.php3?ID=500&lang=2

The surface radiant temperatures of a coal fire range from 300 to 900ºC.