Dear Bruce, (And List).
You are touching on a well debated subject (IR vs. conductive). This is what I know to understand about these. Conductive heat is the band of light that runs "full spectrum" (high order wavelength) Radiant heat is low order IR and below Because we (We) are, for the most part, carbon and water, radiant heat follows the same as "dull red" iron or steel (it contains carbon also). Think of singing in the shower, and that one note, that appears to "vibrate the entire room", that is the F-res (Free air resonate note) the one that excites the largest drum in the room, the bathtub or shower, the same rules that apply to sound and speaker design also apply to the wavelengths of light in a fire. Since the low order red spectrum "excites us" (warms us to the core) this is the carbon portion of us. On the other hand, ultraviolet (microwaves) border the gamma and x-ray area, and thus excite different media (namely water content) other than IR. A classic version of this is washing ones hands in hot water, we feel it right away, BUT, the heat does NOT "stay with us" the way low order IR does. A fireplace or stove has that "heating to the core" because of the IR portion, exactly opposite of the water heating of ultra-violet. methane (blue) heat is great at heating water (gas stove) however, as you say "I can pass my hand through it" (I know the feeling, it's a cool heat), it's actually not that cool, BUT because it's more appt to heat water, than carbon (at a faster rate) that is why it feels cool to us, where as the coals (red end of the spectrum), feel very hot. Does this make sense ?? Greg Manning -----Original Message----- From: [email protected] [mailto:[email protected]]on Behalf Of Bruce Jackson Sent: Wednesday, December 15, 2010 8:36 PM To: Discussion of biomass pyrolysis and gasification Subject: [Gasification] heat transfer properties.... Before I forget this yet again... Is it possible that the zone that produces heat, needs a catalyst like iron? My uninformed opinon (without reviewing my heat transfer tomes) would be that the gas is invisible to the infrared component. I suspect the gas is only picking up heat from conduction. I don't know the percentages of which components are domainant (thats the home work part), but if the IR component is significant, then its being lost on the gas. This especially if the ash is what the gas impinges on. This idea occurs to me from watching the fires. I can hold my hand in the flames but I can't hold it near the coals because I am picking up too much IR. BPJ _______________________________________________ The Gasification list has moved to [email protected] - please update your email contacts to reflect the change. Please visit http://info.bioenergylists.org for more news on the list move. Thank you, Gasification Administrator ----- No virus found in this message. Checked by AVG - www.avg.com Version: 10.0.1170 / Virus Database: 426/3318 - Release Date: 12/15/10 _______________________________________________ The Gasification list has moved to [email protected] - please update your email contacts to reflect the change. Please visit http://info.bioenergylists.org for more news on the list move. Thank you, Gasification Administrator
