Ideas wanted on building a charcoal retort.

[Bodidly]

Hi all. Wondering if any of you have any bright ideas on how to build a retort. My current one is steel and works great but the steel is not going to last long with the temperatures involved. I have looked into fireproof bricks but they are too expensive for something as unprofitable as making charcoal.

This is my current set up to give you an idea as to what is needed.


The barrels work fine and are cheap enough to replace but the outer chamber takes a hammering with each burn and is buckling more and more. I do need to put a front on during the burn but some old corrugated sheets would probably suffice. Be intrested in any lattaral ideas you all might have.


Thanks  

[garethpuk]

Looks like it's an old water tank? Was it fairly thin to start with? I'm no expert on making charcoal but something makes me think the retorts are usually quite thick steel and round? (just been watching grand designs and Ben law was making charcoal)

How about finding a local engineering firm who could roll some say 4 or 5mm plate into a tube and weld the seam

Is stainless more heat resistant? Maybe some sort of scrap stainless tank with the ends cut off to leave an open bottom and to use as a removable lid, an ex dairy tank any good?

Possibly more random thoughts to follow!

[Bodidly]

I like random thoughts Gareth 

You are quite right about it being an old water tank but is a fairly heavy plate. Yes steel is the convention but does fail over time round or square. There is a production retort in heavy round steel that I know needs beating back into shape after a few hundred burns. Not sure on stainless and had considered looking for some sort of scrap dairy tank but most of the local scrap boys have pretty clear yards and leave little to pick through.

[renewablejohn]

Your ideal solution would be a thermal oil rotary plate dryer but there soooo expensive even 2nd hand.

[Bodidly]

Yes can't spend too much John. This is not really a serious business if you look at the hours involved more a hobby that makes a few quid.

Had wondered about building a brick kiln like a giant pizza oven. Fire bricks are very expensive but apparently some clay bricks cope with fairly serious heat due to the way they are made. Any comments on that?

[smegal]

Yes can't spend too much John. This is not really a serious business if you look at the hours involved more a hobby that makes a few quid.

Had wondered about building a brick kiln like a giant pizza oven. Fire bricks are very expensive but apparently some clay bricks cope with fairly serious heat due to the way they are made. Any comments on that?

What about using cob instead of bricks? (minus the straw) maybe reinforced with something like this.

http://www.ebay.co.uk/itm/230867481610

[Bodidly]

Off to look up cob now. Thanks smegal

[desperate]

Howsabout build a kiln out of ordinary thermalite blocks and have a cast iron pipe going right through it so timber could be fed through the pipes and the charcoal would drop out the other end. If you rendered up the inside of the thermalites with a fire cement render that would be good for at least 1200 degC. Not quite sure how you would stop the charcoal burning inside the pipes though, maybe a batch system with loose fitting plugs at each end?

Sounds like a good fun project to me

Desp

[smegal]

Off to look up cob now. Thanks smegal

I have no idea what temperatures it can take, but may be worth a look. People seem to make pizza ovens from it.

[mr_magicfingers]

was just contemplating a charcoal retort today as I walked through our wood and looked at the old coppice. Was wondering if a rocket stove would work, built around a barrel

[Philip R]

If you are travellingnear the Scottish borders take a couple of hours and visit the gas works museum in Biggar. Very interesting.

BTW why make charcoal, does not sound very environmentally friendly!! Just burn the wood cleanly..

Philip R

[Bodidly]

If you are travellingnear the Scottish borders take a couple of hours and visit the gas works museum in Biggar. Very interesting.

BTW why make charcoal, does not sound very environmentally friendly!! Just burn the wood cleanly..

Philip R

I get your point but we use the small branch wood that in the past we would have been burnt up in a brash pile in the field. A retort is much cleaner than a traditional ring kiln and imported charcoal well don't get me started on that 

Thanks for the tip on the Biggar museum.

[Greenbeast]

i was going to suggest fire cement, or a castable refractory lining
Still might be pricey though for that size (would need a few inches thick i would think)

[Warble]

Why not dig a pit then you would only need to cover the top.

[roys]

Not sure but do you not need combustion air feeding into the base ?