[Stoves] Heat to sustain TLUD process

[AJH]

On Fri, 1 Jun 2007 21:23:39 -0400, Alex and Christine English wrote:

>Andrew, Crispin and Paul
>
>Many moons ago I tested the gasses from wood pellets in a TLUD
>before the secondary flame using an IR CO/CO2 sampler. This would be from
>the first "chimney" on my double chimney, or not-so-close coupled tlud. 
>It is in the archives but I remember CO2 being roughly twice CO. Something 
>like 16% and 8% repectively.
>
>I think this fits with Andrew's explainations...?

So do I, thanks Alex, good to see you are still reading and
contributing to the list.

The test would be to run exactly the same set up with the primary air
completely closed and the heat supplied from a small electric element,
such as are used for lighting pellet stoves and see what the CO:CO2
profile is then and the yield of char.
>
>
>As for temperatures; if you go to 
>
>http://www.repp.org/discussiongroups/resources/stoves/English/bigtop2.htm
>
>the yellow line on the graph shows the temperature of a thermocouple burried
>in the pellet fuel of a forced draft tlud as the pyrolysis front passes. It rises from 
>ambient to about 1400F or 760C in about ten minutes and stays within about 50C of 
>that untill the thermocouple becomes exposed.

Again pointing to the fact not too much heat is lost from the char.


Andrew Heggie