Kon - Tiki Kiln

[TRADITIONAL LOGGERS]

I think this idea developed in the Swiss Alps is fantastic and I am going to source one.

 

Looks like it will allow a use for brash/pallets/saw mill waste and making charcoal at the same time. So simple and cook lunch on it.

 

Folks on here have them and experience?

 

There are some videos on You Tube.

[Beardie]

I had a look. It's basically a conical vessel filled with wood, lit, then doused with water when the wood has carbonised. The cone is open-topped, but it seems the lack of updraught inhibits complete combustion. It seems a bit hit-and-miss to me, and appears to be promoted more as a biochar producer than for good barbeque charcoal.

[TRADITIONAL LOGGERS]

I am told from the Aussies complete combustion with no "brands". Fines can be used as well as large charcoal pieces as cooking charcoal. No dust!

[openspaceman]

I think this idea developed in the Swiss Alps is fantastic and I am going to source one.

 

Looks like it will allow a use for brash/pallets/saw mill waste and making charcoal at the same time. So simple and cook lunch on it.

 

Folks on here have them and experience?

 

There are some videos on You Tube.

 

It's a flame curtain device. Evelyn described the technique in his book Sylva in the 1700s.

[Beardie]

I am told from the Aussies complete combustion with no "brands". Fines can be used as well as large charcoal pieces as cooking charcoal. No dust!

 

If it's 'complete combustion', then you don't get charcoal, you get ash. Maybe they meant complete conversion.

 

Thanks to openspaceman for giving me yet another reason to get hold of a copy of 'Sylva'.

[openspaceman]

If it's 'complete combustion', then you don't get charcoal, you get ash. Maybe they meant complete conversion.

 

Thanks to openspaceman for giving me yet another reason to get hold of a copy of 'Sylva'.

 

It's online as freebie pdf somewhere.

 

The scouts used to use something similar by cutting a 205 litre barrel in half along its axis. Light a small fire in the bottom and add dry twigs so the fire is established over the whole length. Keep it blazing so no air can reach the bottom and gradually build up the char layer by adding dry twigs, increasing their size up to about 2". You can see when to add more if the char starts to show grey, this is the ash forming on the outside which shows air is getting past the flame to burn the newly formed char. The essence is the wood has to be small enough and dry enough for the pyrolysis offgas to evolve and burn, using up all of the air before it gets to the char, radiant energy from the flame and conduction keeping the wood under the flame cooking.

 

Once the char has built up to the top leave the flames to die out and start cooking.

 

This technique on a larger scale was used in Africa, a trench was formed by dozing it out with a drott in a clay soil until it was about 6ft deep in the middle, the fire was lit and dry brushwood thrown in, once the pit was filled corrugated iron sheets were laid across the top and the soil then pushed back over it to stop air getting in.

 

I have some pictures of my efforts on a lop and top burn site filling a standard 2 ring kiln with the county and grab. I was able to fill the kiln to the top with charcoal in a morning but there was no way I could seal the kiln properly, so in the absence of any water it burned away over the next few days.

[agg221]

This is exactly the process I am using. Trench in the ground about 6' long, 2' wide and 2' deep with steeply sloping sides. Takes about 2hrs to make 200 to 250litres.

 

There is a bit of an art to timing the layers if your material is not uniform but works well. I normally cover it in steel sheet for around 45mins afterwards and then put it out. Only the top couple of inches are glowing so a combination of 4gals of water and some stamping is all it takes. I am aiming for biochar so the crushing isn't a problem. I try to put it out at night so I can see any glowing bits and then dig out the next morning to catch anything that may still be going before it burns away.

 

Alec

[wills-mill]

[trigger_andy]

What would you use Biochar for?

[openspaceman]

What would you use Biochar for?

 

Modifying the property of a soil to benefit crop growing, although results are variable or indifferent in many cases, and removing carbon from the atmosphere by mixing it into the soil in a recalcitrant and non respirable form.