First response re possible way to get low cost, locally made TLUDs. (Message #9) #stoves #tlud

Paul S Anderson



[NOTE:  As a ONE-TIME message, I have included the Stoves and Biochar Listservs to receive this message.  Anyone interested in joining  the special “low cost locally made TLUDs” group should contact Ron Larson.   IMO, if we do  not put messages at least occasionally onto  the 2 Listservs, they will cease to be useful.] My message is in response to Ron’s which is below after my message.


1.  Plancha with heat from TLUD char-making gasifiers is done by Gustavo Pena of El Salvador.   I have added him to receive this message.   But his stoves are strong, welded steel and hefty and therefore costly.  But he has the desired plancha top in several designs.  I ask Gustavo to send a message to this group with links to the many documents he has, including videos.   But it is not inexpensive or locally made by artisan tinsmiths.


2.  The “riser” (4 inches) is crucial for ND-TLUD!!!!!!!!!!!!!!   See it on the Champion TLUD from India.   This is fundamental (IMO) but is frequently overlooked or is present as an evident afterthought.


3.  The pot can be ABOVE the TLUD.  But I was talking about it NOT resting on, touching with its weight, the gasifier canister.   Having a REMOVABLE GASIFIER CANISTER is a big plus.  But it adds cost of somehow supporting the pot separately.   When the gasifier canister is in a hole under a pot, it is troublesome to remove it (exchange with a second one for continual cooking).   Vertical access is problematic:  Remove pot, remove pot support, pull up a hot gasifier (with your hands above the heat), replace the canister (or empty the char and then refill and then replace the gasifier), replace the pot support, replace the pot.    That is a sequence that will discourage most cooks.       My conclusion:  Do not build (construct, assemble, etc.) a TLUD in a hole (closed on all sides, not easily accessible from at least one side).


4.  Using a plancha or any arranged horizontal movement of the hot gases MUST have a chimney.   And a simple hood (with free access to ambient air) will not provide the needed draft.   Hot gases exiting horizontally do not cause a draft (negative pressure) to pull the other gases that are following. 


5.  People, even very poor people, have aspirations.   And the hole in the ground does not (IMO) get their buy-in.  


I leave for India tomorrow (4 Dec) for 2 weeks, so any further comments/responses from  me could be much delayed.   In India I will be in Bhubaneshwar, Odisha, at IMMT.   Multiple projects there include: 


A.  Champion2 TLUD (lower the costs and make some improvements to the original Champion (1) TLUD-ND that is now over 10 years old.  Including how to add forced air.


B.  Fabstove prospects industrial production


C.  4C char-making kilns in barrel size and larger (main topic)


D.  Collaborate about biochar production, especially with non-traditional biomass.


E.  C2P char-gasifiers to fuel internal combustion engines, seeking 10 to 20 kWe.


F.  How to capture and use the heat from 4C kilns.


Tally ho!!




Doc / Dr TLUD / Paul S. Anderson, PhD --- Website:

     Email:  psanders@...       Skype:   paultlud

     Phone:  Office: 309-452-7072    Mobile & WhatsApp: 309-531-4434

Exec. Dir. of Juntos Energy Solutions NFP

     Go to:  to support woodgas (TLUD) projects

     incl. purchase of Woodgas Emission Reduction (WER) carbon credits

     and please tell you friends about these distinctive service efforts.

Author of “A Capitalist Carol” (free digital copies at

     with pages 88 – 94 about  solving the world crisis for clean cookstoves.


From: Ronal Larson <rongretlarson@...>
Sent: Saturday, November 30, 2019 11:37 PM
To: Anderson, Paul <psanders@...>
Cc: Anh Nguyen <ntanh72@...>; Andrew Heggie <ajheggie@...>; nsambahussein2000@...; aabyslo@...; DHAN HURLEY <dhanhurley@...>; Kevin McLean > <info@...>; Gordon West <gordon.west@...>; Bill Knauss <wmknauss@...>; dan weinshenker <danweinshenker@...>; Kirk Harris <gkharris316@...>; Anderson, Paul <psanders@...>; Norman Baker <ntbakerphd@...>; Paul Belanger <pebelanger@...>; bigbird886@...; Anand Karve <adkarve@...>; Francesco Tortorici <francesco@...>; Maurice Onyango <onyangomaurice30@...>; Gilbert Mwangi - Wisdom Stoves <trebligmn@...>; Julien Winter <winter.julien@...>
Subject: Re: First response re possible way to get low cost, locally made TLUDs. (Message #9)


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Hi Paul and all:


Thanks again.  See inserts.  This is #9.


On Nov 29, 2019, at 2:25 PM, Anderson, Paul <psanders@...> wrote:


Dear all,


1.  I do not consider a chimney (after the pot) to be essential.   Nice if available, but adds to the cost.   Instead, a 4 inch tall riser (before the pot, sort of like an internal pre-chimney) is sufficient to get the draft for a TLUD-ND unit at elevations below 2000 meters (6000 feet).  

[RWL1:  I have not been saying anything about a chimney after the pot.   But not opposed to such if one really needs to get the smoke out of the kitchen.   The alternative via hoods seems OK.   


But the geometry I am describing (Horizontal flames) is completely consistent with a chimney after the pot (because we can have multiple cook pot sites above multiple  horizontal flames.


2.  I do not like the placement of the cooking pot directly on the top of the gasifier. 

[RWL2a:   I have been describing a system with multiple cook pot locations - not just one pot.  One of these likely to be “directly on the top of  the gasifier" portion of the system (only a few inches away from the top of the fuel/char “can/pot”.


Are you Ok with stoves like the Phillips and Peko Pe - which do have the cook pot above the gasifier.

Instead, the pot should be on a pot support.  

[RWL2b:  Think of a plancha type stove - very safe and stable.  This for all but the top-most cook pot.  Mostly I agree that these look pretty unstable with TLUDs, but Julien Winter’s Akha stove looks safe enough (on a taller than 4”- 6”-8”  normal TLUD chimney).


This lowers the necessary strength and cost of the gasifier which needs to provide stability. 

[RWL2c:   Same as above.  I am trying to describe a system where stability is a minor issue.  (As in plancha-type stoves.)

  It does add some cost to having a pot-support structure, but that could be as simple as holding the pot on two pieces of rebar that rest on some bricks.   The stove frame (pot support structure) developed earlier this month in Kenya, might add some cost, but it is made to last for many years, and is portable.  See attached photo.   The frame is still missing the 4-inch riser that has telescoping movement as in the Champion TLUD of India.

[RWL2d:  All these are possible in the system I have in mind.   I like your photo with 3 identical fabricated support units.   With the ground as a design element,  I think the pot support could be 3 (not 4) re-bars pounded in the ground (with a vertical also permanent (narrower - less costly?) “stove pipe” sitting between these three rebars.


I don’t have a mental image of your “4 inch riser” - but am imagining in this possible plancha approach a chimney of greater height - to get higher power from the increased draft that comes with chimney height.  (For more dense and greater depth of fuel situations.)


3.  I am questioning if the base (and the 4 legs) are necessary, but the Kenya market might want the base and legs.   To be determined.   Price is not yet known, and is only based on manual artisan labor.

[RWL3:  I look forward to hearing those prices.  In my thinking as much as possible is done by the stove user - especially digging the small pit  and the (small) primary air shaft.  The major expense I assume is the short “plancha” plate (which is slid or lifted out of the way in order to load/unload the fuel char pot (maybe call FCP?)


I hope others will chime in.  Maybe ask can we design a really low cost char-making plancha-type stove - by using the ground (for cost reasons mainly).  Anyone heard of a char-making plancha-type stove (either above or below ground pyrolysis).


Not mentioned above anywhere, but I have no objection to a fan/blower.  Reason - it could save money in reduced height of chimney.  And more sure control of primary air over a larger range.










Subject: RE: First response re possible way to get low cost, locally made TLUDs. (Message #6)


Dear Ron and all,


I like this dedicated group.      And I have added Maurice and  Gilbert in Kenya to this list of interested persons.




[RWL:  This message from Paul responded to in Message #8)


Tom Miles

We have created a subgroup called to facilitate discussion of the low cost tluds. As a member of the biocahr group you can join tlud subgroup.