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Tlud gassifier with awesome mods by Karl J. Frogner, PhD

biochar tlud gassifier Assembled 200 l TLUD

Tlud gassifier

I love being a charmaster and I love having a website that people are happy to use. So to all you readers check this out…

Introducing the UB 200 l  natural draft Tlud gassifier oven 2 July ‘11

E, Dolph, aloha kaua-
Just came upon your web page and thought you might like to take a look at the modifications we made to John Rogers’ 200 l TLUD based on what little I know from a bit of reading of TLUDs.
I’ll send a set of pictures that should give you the basic idea if your page input allows me to, otherwise send me an email address and I’ll send them.
An extended set of pictures is available that I would be happy to send if you think they would help. We are calling it the UB 200 l  natural draft TLUD oven, or the UB T- oven  or t-oven for short. But please, please, please don’t call it a stove.


Biochar Tlud Gassifier Component parts of 200 l TLUD

Biochar Tlud Gassifier Component parts of 200 l TLUD

1 of 5 Component parts (l to r):

1.Primary air chamber with adjustable slip ring intake ports;
200 l feedstock chamber;
afterburner (also with adjustable slip ring intake ports) with chimney.

Biochar Tlud Gassifier Chimney damper

Biochar Tlud Gassifier Chimney damper

2. Chimney damper
Only a power drill and a power grinder are needed to make the design, although the student who was doing the work had access to a welder and used it to put the handles on the slip rings on the primary air & afterburner air, the male slip coupe for the chimney and the handle for the chimney flue. Easy workarounds could be used if welding is a problem.
I’ve run two trials so far, both with cow manure that was air dried after being shoveled out of the cowshed. Both runs were smokeless. The first, in which hand to 20-30 x 20-30 x 5-10 cm sized on down burned down in 55 min, the second that was filled with fairly uniform 7-10 x 7-10 x 5-10 pieces together with the fins from chopping up the larger pieces burned down in 1 hr 40 min. The charing was compleat throughout the charge, slightly oily on the rub to the hand rub test.
Another run was made (I was absent) using birch branch & twigs segments (2 cm on down) about 10 cm long. They had smoke problems with keeping the afterburner lit in an exposed site on a windy day, but the char came out good. Devising a wind shield should not be much of a problem.
biochar Tlud Gasifier Primary air hole pattern

biochar Tlud Gasifier Primary air hole pattern

3: The circled square pattern of 45 holes, each 13 mm in diameter.
We are very interested in developing these large TLUDs for getting serious amounts of biochar into the ground, leveraging smallholder benefits of biochar in sustainable rural development into timely climate change mitigation. We are thinking of initiating another sib-project based on a virtual community of low-tech biochar producers, TLUD designers and tinkers who would want to test and improve the design. Joining might be a good sub project for your Biochar Project or any of your interested readers.
Me ke aloha-frog
biochar tlud gassifier Assembled 200 l TLUD

biochar tlud gassifier Assembled 200 l TLUD

4. Assembled 200 l TLUD
biochar tlud gassifier Burn line at 20 min

biochar tlud gassifier Burn line at 20 min

5. Burn line 20 min after spreading starting fire coals
and putting afterburner/chimney in place.
(Coals were spread 10 min after igniting starting fire)
Note smokeless burn

Karl J. Frogner, PhD, OZP
President & Project Development Head; UB International (UBI)
Project Development Head; Mongolian Biochar Initiative (MoBI)
Project Development Consultant; Thai Biochar Initiative (ThBI)
Project Development Head; UBI Hawaii (UBI Ha
Member, Advisory Committee, International Biochar Initiative (IBI)
47-481 Ho’opala St.,
Kane’ohe HI 96744 USA
Hawaii:  1-808 234-3486
Ulaanbaatar:   976 9600-3688
Bangkok:   085 328-3731

I am so very happy to see our biochar project family extending to all corners of our planet. Yes I know it is impossible for a round planet to have corners:P.
Thank you Karl and thank you to your assistant(s) for inspiring sustainable biochar, Reusing, Refashioning, Repairing, Reinventing and of course sharing (Y)our Biochar Project with the world.
If you folks are ever in Australia come stay with me for a visit and I will treat you like the royalty you are. On behalf of Biochar Industries, Biochar Project and Biochar enthusiast the world over we salute you.
Charmaster Dolph Cooke
{ 5 comments… add one }
  • Karl Frogner July 4, 2011, 9:19 am

    4 July ‘11
    Aloha kakou-
    The names of those helping me pictured (l to r) are Boldkhuu & Bayarsaikhan Narmandakh. Both are graduate students at Mongolia State University of Agriculture and Nara is also Founder & Exective Director of the Mongolian Biochar Association and Translator and sometimes Liaison Officer for UBI International.

    Me ke aloha-

    Karl J. Frogner, PhD, OZP

  • Scott April 1, 2012, 12:38 am

    Thanks for the detailed info on this gasifier. I am now in the process of making something very similar.

    As a fuel I will be using bamboo offcuts and rices husks. Can you provide information of whether these are suitable fuels and how to best to use them.


  • Richard Whittle March 5, 2013, 9:03 pm

    I am fascinated by your modified T-Lud. I have been experimenting for a few weeks trying to make char out of woodchip. Trouble is that I’m in the UK and it’s almost impossible to dry the chip. But I am having some success with damp chip.

    I am interested that you have a chimney damper. Before I spend time fitting one to the steel drum kilns I am working on, is a damper really helpful? What purpose has it, does it help?

  • Charmaster March 5, 2013, 9:35 pm

    Hello Richard, The modified T-Lud was made by Dr Karl and his gang of students.
    I can help you understand the damper it slows the flow of exhaust gases so that they have a
    residence time long enough for the afterburner to clear out the volatiles if any.

    Usually in start up and shut down. Perhaps Dr Karl might see and give us a expert opinion.

    With your wood chip drying I have a solution for you. I saw it some time ago in some list somewhere
    so chances are I can’t put my hands on it readily so I will try and Texplain it for you.

    Create some kind of a wall with 3 sides out of bessa blocks or something. Say 1 meter square. Make a rocket stove at one end and use a flue pipe to go from the rocket stove top across to the back of the wall then 90degrees up the back wall. So it looks like you have a rocket stove with a long horizontal chimney that goes across the floor then up the wall. Place all wet wood chips on and around the flue pipe pile em up full in the wall area.

    Light the rocket stove up and watch as your chips start to dry quick you will notice the chips directly above the flue dry first and then you will see the rest dry it is fabulos to watch. Dry in about 2 hours make sure you keep an eye on it as the chips could ignite from the heat once all dry.

    Charmaster Dolph Cooke

  • Richard Whittle March 6, 2013, 9:10 pm

    Hi Dolph, thanks for the prompt reply! Never thought of a damper in terms of gas residence times, more as something to control updraft. Makes sense, so probably best that I add one.

    Thanks too for the drying advice. I’ll let you know how things work out.

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