Thanks for the prompt reply Tom, I appreciate it. I'm getting ready to do a batch this weekend & will be giving it a try! Best Regards To All, Jon
On Thu, Dec 26, 2013 at 9:46 AM, Thomas Reed <[email protected]> wrote: > Jon and All > > I don't have any exact knowledge of the thickness of paper required to > quench a pile of Autochar, but I think a saturated New York Times Sunday > Edition should have enough water to put out any fire burning above it. > > After all, after the fire has passed through a layer, no more oxygen can > reach it because the next layer gobbles up all the O2. AND the upper > layers are all cooling by BLACK BODY RADIATION, which increases as the > fourth power of temperature even though they are still heated from below. > <><><> > > The BB radiation is,according to the Stefan Boltzmann law, > > Stefan–Boltzmann lawThe Stefan–Boltzmann > law<http://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_law> > states that the power emitted per unit area of the surface of a black > body is directly proportional to the fourth power of its absolute > temperature:[image: j^{\star} = \sigma T^4,] > > where *j**is the total power radiated per unit area, *T* is the absolute > temperature <http://en.wikipedia.org/wiki/Absolute_temperature> and *σ* > = 5.67×10−8 W m−2 K−4 is the Stefan–Boltzmann > constant<http://en.wikipedia.org/wiki/Stefan%E2%80%93Boltzmann_constant> > . > For us (Surviving) mortals, this says that a black body (like charcoal) > emits 5.67 T^4 Watts/cm2 > but be sure to add 273 to the centigrade temperature, since T is the > absolute temperature, in degrees Kelvin. > For charcoal at 500 C it would be > > Radiated Power = 5.67X 10^-12x(500+273)^4 = 2.02 Watts/cm2 > > Not a lot, but there are a lot of cm2! , so don't stand too close. > (Assuming I calculated correctly.)(I divide the 773 by 1000, raise 0.773 > ^4 and multiply by 5.67, and avoid the 10^-12 this way. A square meter > surface at this temperature would radiate 20 kW! Toasty! > > In case you haven't guessed it, my degree is in Physical Chemistry, which > deals extensively and intensively in this stuff. > > Comments? > > Tom Reed > > (In case this were not a black body, it would have an emisivity in the SB > equation, the power emitted by the body compared to that of a true black > body. Charcoal is the only substance which comes close to having an > emisivity of 1.00. ) > Dr. Thomas B Reed > 280 Hardwick Rd > Barre, Ma 01005 > 508-353-7841 > > On Dec 24, 2013, at 5:59 PM, Jon <[email protected]> wrote: > > Heya Tom Reed, > Thanks so much for the newspaper idea. I'm using a toplit updraft (55 > gallon barrel), and was wondering how much newspaper are we talking about? > I assume that it would be kept in sheet form & not balled up? > Thanks in advance for the advice. > Merry Christmas To All, > Jon > > > On 12/24/2013 2:02 PM, Tom Reed wrote: > > Toplit updraft > > > > _______________________________________________ > Gasification mailing list > > to Send a Message to the list, use the email address > [email protected] > > to UNSUBSCRIBE or Change your List Settings use the web page > > http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org > > for more Gasifiers, News and Information see our web site: > http://gasifiers.bioenergylists.org/ > > > _______________________________________________ > Gasification mailing list > > to Send a Message to the list, use the email address > [email protected] > > to UNSUBSCRIBE or Change your List Settings use the web page > > http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org > > for more Gasifiers, News and Information see our web site: > http://gasifiers.bioenergylists.org/ > >
_______________________________________________ Gasification mailing list to Send a Message to the list, use the email address [email protected] to UNSUBSCRIBE or Change your List Settings use the web page http://lists.bioenergylists.org/mailman/listinfo/gasification_lists.bioenergylists.org for more Gasifiers, News and Information see our web site: http://gasifiers.bioenergylists.org/
