TLUD

[Donkey]

I love my TLUD!!
Use it to make charcoal for my forge meanwhile I can stir-fry on it with a BIG wok..

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[independentenergy]

beautiful

[ronyon]

How about putting a heat riser on that thing? Or exhausting it into a barrel/bell?
How long does it burn?
Is it a5 gallon bucket? How is it holding up to the heat?

[Donkey]

It's a 30 gallon barrel. With the chimney that's on it, one full load burns about an hour and a half.

I've thought about building an whole kitchen setup (for a restaurant) that these could plug into.. Imagine an oven that you can plug these into the bottom of.. Wok cookers with slightly smaller chimneys for longer burn times.. The barrels would need good long handles so they could be tipped, dumping the hot coals directly into a BBQ pit.

[ronyon]

The burn time and the left over char, plus potential ability to have Tluds as plugs one could remove and replace makes this very intriguing.

[Donkey]

Right??
My thought is that there would need to be a dolly designed to move them into place. Once set, push the lever to raise the stove into position or lower it to disengage. Another setting to set the thing down on the ground to put it out and store the charcoal for later.

[Daryl]

So the fire is in the barrel and the top part is a riser? Do you have any pictures of how it is put together?

[kddid]

Curious too... Are there air inlets in the bottom of the barrel, or would that cause runaway combustion? I built a small one of these for camping/tea billy heater, but am thinking of upgrading my old two-barrel charcoal retort.

[Donkey]

The bottom of the barrel is has a lot of small, nail holes spaced a couple inches apart, all over it. Just enough air comes in the bottom to pyrolyze the wood load in the barrel, not enough air to create a raging flame. The stove needs to be elevated off the ground for those air holes to work, I set it on bricks.
There is a riser of sorts (no insulation) on top of the barrel that has secondary air holes in it. When this secondary air mixes with the smoke coming out from below, it ignites, making for a BIG flame. The secondary air sizing is really important to get right. I experimented a lot with it, made a few too many holes at first, then made a sleeve that could slide up and down the pipe, selectively covering holes till it burned properly (you can sort of see the sleeve in the image). Once I figured out the setting, I flipped the pipe over, made the RIGHT holes below and cut the test holes open to use as a pot-stand..

The stove is a gassifier and like most of them, it is filled with wood completely before lighting. It's pretty fuel sensitive, it needs all the same type of wood (in any given load); the wood needs to be VERY dry and all rather small, similarly sized pieces or it won't burn properly. When all of the woodgas has burnt off, the flame will go out; at that point, the stove is taken off of the bricks (I've welded on handles), placed on the ground, the chimney comes off and a cap is placed on top of the barrel. I'll kick a little dirt around the bottom to make sure it's close to air-tight. After the barrel cools down completely, the charcoal is ready to take out.. One full load of wood will make about one half a barrel of charcoal, hardwoods a little more, softwoods a little less.

I think I need to take more detailed pictures of the stove and post them here.. The one that I posted above is pretty poor..

[Daryl]

Yes, please do post those pictures.

[Donkey]

Ok.. I had a little forge project that needed charcoal. The images that I promised:

Bottom air.


The stove loaded, kindling at top. I'm burning redwood scrap roughly of all the same size (the pieces setting on the stove).


The chimney (I think of it as a riser, though it's not insulated. Secondary air at the bottom, castellated at the top to hold a wok (or pot) for cooking.


Notice the band welded on. This holds up the chimney, so it can be socketed in. It felt more secure this way than just sitting on top.




Assembled, up on bricks and ready to light.




Just been lit and the wind break has been put on.
img]http://www.sundogbuilders.net/rocket/TLUD/tlud08.JPG[/img]

Jammin'! It burns like that for about an hour and a half, more or less depending.


The wood-gas has been burned off, the fire dies down and it's time to suffocate the coals.




The barrel sets down on the ground, a little dirt gets kicked all around the bottom and a cap is set on top.
All the hot stuff goes back on top, keeps all the dangerous parts together.


The finished product (from a different burn).


Into the forge it goes!

[Donkey]

A short video of it running:

[kddid]

Kind of what I imagined from your description. Earlier you stressed having a consistent size and type of fuel, and I am wanting to try this with the outer barrel that I use for making charcoal currently. I typically work hardwood chunks down to about the size of a hens egg, which isn't hard with all the straight grained ash standing dead in the Midwest. I like the idea of using the combustion for a purpose like cooking.

[Daryl]

Thank you for posting the pictures. Now I get it.

I built my first gasifier and lit it up. Burned great. A lot of fun. Will be doing more in the future. Thanks again!

[ronyon]

I have several cloths dryer drums around the yard. They have always seemed potentially useful but no project involving them has quite worked out

But they do have a lid, a regular pattern of perforations in the bottom, and proven heat resistance.

With a chimney they might be rather tall to cook over, but a pit might fix that.

I will probably be building this before I build a rocket.