[Stoves] Fwd: RE: Changing rate of pyrolysis front in TLUDs

[AJH]

On Wed, 11 Apr 2007 20:08:51 -0500, psanders at ilstu.edu wrote:

Dale's report:

>As for how the primary air varies as other variables change, I would
>think the height of the air column above the fire doesn't have much
>influence since it doesn't change by that much of a percentage.  As for
>the fuel stack resistance, it could increase or decrease depending on
>how the fuel pellets contracted as they pyrolyzed, or turned to ash and
>just disappeared.  Of of the things about the Anderson TLUD that
>pleasantly surprised me was the the flame seemed nearly constant, at
>least with pellets, for a long time. 

Yes this has been my experience and to my mind it is a simple
consequence of the way a tlud works, the energy being put into the
pyrolysis front is directly related to the primary air and the fact
the hot products immediately rise away from the fresh fuel. If the
primary air supply is constant (and a fan would allow this) this
should always be the case but with natural draught and a long stack I
think the draught would increase as the column of hot gas increased.
Not relevant to a stove but maybe relevant to a simple char making and
flaring device.


Thanks for forwarding Dale's reply.

AJH