New Charcoal Kiln project







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Hello all. I’m a South African farmer boy who moved to Sweden 5 years ago. I have been learning to love this new lifestyle,living with wood. It’s a new special relationship this cutting, splitting and storing wood. I have been slowly upgrading my wood processing area and process to be a little more efficient every year.

Currently all my wood processing is taking place in my barn and I want to built a permanent setup space for it outside, next to the barn in its own undercover area.This is where my new charcoal kiln project fits in, and if I may ask you all for some advice first.

I’m wanting to start easy and get something up and running first. So I’m thinking of doing a down draft version similar to the fine “kursk 2.0” model.

However this is where I need some advice. My context is primarily this unit will be for making charcoal then eventually making biochar with woodchips that I will feed into the drum via the top port with a hopper.I would like this set up to eventually in the future run a small motor that would charge a battery bank. But it doesn’t need to, I can also build another one ;). can I fit in the design so that I can pipe off the gas to the power unit when I need to do it eventually? Will this affect the char process or can I just keep feeding the burn chamber longer?

Also when I cut the one side off of this diesel tank I’m thinking of getting some flanges laser cut that I can weld back on the door and tank and seal with a fireproof gasket between. What do you recommend for the thickness of the flange materials. I was thinking around 12mm with M16 nuts & bolts spaced 8 around the circumference(maybe 12?)

I think I have drawn this us a updraught? Is it best to direct the gas back into the front of the burn chamber? Or can it come from the side or under?

Is there a formula for size of the burn chamber relative to the diameter and length of the exhaust? Eg The pipe I would like to use for the exhaust is 100mm wide and I have 3.8m of it. Can the volume of the burn chamber exceed the volume of the pipe? Ie can I make the burn chamber bigger volume than the pipe?

I’m not needing this kiln to be built in a hurry, I like the planning stage as much as the building stage.

Please any and all advice welcome.

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Hello CharlC.
Welcome to the DOW.
Read back the post comments from a real charcoal maker in Sweden.
So very familiar with Swedish woods. And Swedish conditions.
Maybe close to you?
https://forum.driveonwood.com/u/rakkolla
Member Jorgen Schroder

I will let Kristijan (the Kurst developer) chime in on your project questions.

I think you will not want to fuel an engine off of this charcoal making kiln. Too much steam and goo in the outgases.

Regards
Steve Unruh

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Ha! Ha! Well my link did not work. Typical for me.
Here:

His first new member comment.
Click open his big “R” avatar on that opened up comment.
Then click on the even bigger “R” on his members info summary opened up.
That will give you his all Activities listings. Open that up and read away.
You can PM him directly on any of his comments.
S.U.

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Hello Charl,
Welcome.
I learned to make TLUDs (Top Lit Up Draft) out old food cans for camping stoves. Then I made a 50 gallon TLUD out of an old water heater. It works very well and makes 30-35 gallons of charcoal at a time. I live in a very dry climate here in Colorado, USA so it is easy to find dry wood. However, now @Pelletpower in Netherlands seems to like his TLUD to. Netherlands is a very wet climate. So I am beginning to think that a TLUD is the easiest way to make charcoal.
Here you can see that the fire has worked it’s way down about a third of the cylinder. This is only a cylinder with a grate in the bottom, and an after burner on top.
Rindert
DSCN3221

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Welcome Charl, and I hope you are a faster builder then me.

Thanks Rindert, yes I like TLUD best. Tried a hookway but couldnt get it warm enough. Gary Gilmore really explaines it all, from making charcoal to the gasifier. I tried a small Simple Fire and it worked right away. Follow his advice and you will be ok. The only advice I can give , is keep it KISS. Less parts is less chance that there will be trouble. I made the last TLUD very fancy but there must have been some leaks somewhere and the charcoal yield was only 10% by volume. Normally it is about 30%.

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Charl,
Welcome! If you study Kristijan’s “Kursk” material, and other charcoal makers on the forum, you will have all the information you will need to get started. It looks like that might have been a fuel oil tank or something, make sure you clean it out good before welding / cutting / grinding. Remove that bolted cover and wash it out!! :cowboy_hat_face: :thinking:
New charcoal kiln, aka “the Kursk” - General Discussion - Drive On Wood!
Charcoal kiln, Kursk 2.0 - Small Engines / Charcoal Gasification - Drive On Wood!
Charcoal Documentary - Small Engines / Charcoal Gasification - Drive On Wood!
Making Charcoal without Smoke - Small Engines / Charcoal Gasification - Drive On Wood!
Just a few of many… :grin:

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Thanks all for the info. I spent some hours reading through those links thanks Mike. You guys here on DOW really are a great community, great stuff.

Now I need to do some more consideration on what my goals are first to decide which direction to head. I’m still leaning towards the kursk 2.0 style. I think cost wise though a TLUD would be cheaper to make. Unloading it might be a challenge but I could build a A frame for emptying like Bruce S did.

Adding to the collection of stuff lying around for the project.

Thanks again for the support and I’ll keep on reading up here on DOW

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I take the simple approach and use a dull spade to empty the barrels, and toss the shovelful onto my classifying screen. When it’s really full I use a spade missing it’s handle.

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I have only two barrels of charcoal yet. Waiting for a grinder, didnt build that one yet. If you run a TLUD, it is light enough to discharge into a grinder. I would skip the tool to empty a barrel, first try to get if full and grinded.

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I built a burner on the weekend to have a play around. It worked well and I learned lots, I did 3 separate burns with different grades of fuel. One with wood chips that didn’t work too well. I think it was not enough airflow for the wood gas to escape. Second was just dry wood which worked a treat. Third I just tried a TLUD fire with no internal sealed container. Which cranked out some serious heat. To top it off I did it on Saturday night and the northern lights came out. It was the first time I have ever seen them. It was beautiful.


First burn only smoke


Second burn took about 30min before burning on wood gas


Charcoal


3rd burn. Clean and hot

Question? How do you light the gas coming out the top without a blow torch. I didn’t have anything strong enough to keep it going long.

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If the water moisture is to high in the smoke it will not stay burning with out help.
Bob

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Hi Charl,
You are well on your way!
Any how, here are pictures of my afterburner chimney. The idea is to let a lot of air in at the bottom of the chimney so all the smoke gets burned up. A windscreen keeps it from blowing out. And Bobmack is right, the smoke from wet wood just won’t stay lit.
Rindert



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Rindhert; A question considering that you seem to understand “secondary air and after burning”: I built one of those double barrel wood stoves. Over the years, the pipe that connected the top and bottom barrels, burned out. It allowed air in but I didn’t get a burn in the top barrel. I have made charcoal in a TLUD barrels where I put two pieces of rebar across the top of the TLUD barrel and set a second “chimney” barrel on top. That worked really well-- hot and no smoke. So why didn’t I get a secondary burn in the double wood stove? TomC

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Tom it may have only burned halfway up the barrel and not shoot out the very end.

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Tom,
I don’t know enough about those to say anything. Was it making a very rich smoke? Do you have pictures or sketches? Maybe point me to a you tube? Something like that.
I have been looking for a way to heat my garage with a tlud and then use the charcoal to operate a vehicle.
Rindert

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I hope this works. This is a youtube of a double barrel stove/furnace.

TomC

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Well, from what I can see this is not a tlud and would not make a rich, flammable smoke. So adding secondary air would not create a secondary burn. With a tlud all of the primary air is forced to go through the stack of burning fuel. This creates an oxygen starved environment and therefor a rich smoke that will burn when oxygen is added to it.
Rindert

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