[Stoves] Destroying combustion chambers after TLUD pyrolysis ends Re: Need experts advise on combustion chamber

[Ray Menke]

I use a 10 cm (4") wide replaceable band of old stovepipe material
inserted into the lower section of the stove.  When it burns away, I
just replace it with another one.  (I have no other use for old
stovepipe.)  It also would help to reduce the amount of air coming
from the primary fan to lessen the forge effect.  However, as Paul
stated, Ceramic or cast iron would be a better solution.

On Sun, Feb 10, 2013 at 4:05 AM, Paul Anderson <psanders at ilstu.edu> wrote:
> Dear Stovers,
>
> I received an direct inquiry for assistance.   I think my reply might be
> useful for others, so I have removed identifying information and am sending
> the reply to all and a Blind Copy to him.
>
> Dear (Friend),
>
> I have read your description (below) and viewed the photos (not attached
> here, but similar to a large Ourja stove).
>
> I believe (am quite sure) that you might be starting the stove in it TLUD
> mode with fuel ignited at the top, with fan assistance.   But then you are
> continuing to burn the char that was created, and you are probably adding
> more fuel to get the 3 hour duration.
>
> Once the pyrolysis is finished, and the fire / heat is at the bottom, it is
> no longer operating as a TLUD stove.   Your stove is essentially burning the
> char, with the assistance of forced air.   You have created a forge, with
> air being blown on the hot char.   That will destroy your stove (as you have
> described).  That is NOT a TLUD problem.
>
> Ceramic or cast iron are probably your only materials for a solution.
>
> Note that the Ourja stove (by BP and now by First Energy) is quite similar
> to your design, but smaller for residences.   The Ourja stove has a cast
> iron cup in the bottom.   And it is glowing red hot at the end of the
> cooking because it is a charcoal burning stove (with forced air) that has
> made its own charcoal via the TLUD process, and then produces more charcoal
> when additional biomass fuel is slowly place on top of the hot char bed
> where it will pyrolyze.
>
> Sincerely,
>
> Dr TLUD
>
> Paul S. Anderson, PhD  aka "Dr TLUD"
> Email:  psanders at ilstu.edu   Skype: paultlud  Phone: +1-309-452-7072
> Website:  www.drtlud.com
>
> On 2/10/2013 1:14 AM,  Friend wrote:
>
> Dear Dr Paul Anderson,

> I am from (developing country). i am doing R&D on Biomass smokeless stove
> from last 1 year . i have designed stove for commercial application.
> i have placed few stoves in hotels for testing last month . i am facing lots
> of problem in combustion chamber. within a month the bottom layer of the
> combustion chamber has completely melted.
>
> It is Top lit up draft(TLUD) forced draft biomass cook stove with 2 fans,one
> for primary and another for secondary air. the combustion chamber which we
> have used is SS 304 (3mm thickness). the pellet capacity is 9 KG , which
> burns for 2 hours - 3 hours .
>
>    Please help me in designing better stove . i need your help . will be
 & Regards


-- 
Ray  Menke