Hey Andy, just came across your video and I think that that is the perfect charcoal retort. I may have a solution for your gasification problem to make it even more efficient. Instead of sealing the top and making new holes on the bottom of the inner chamber, use the same top that you have now with the threaded hole in the center, get a black Iron T and nipple and put in the threaded hole, run out a couple of short pieces from the T just long enough to reach the space between the inner and outer tanks, on the end of the short pieces put a couple of elbows pointing down to the space between the inner and outer tanks. Put on two longer pieces of black iron pipe that will reach from the elbows down near the fire area. I think the weight of the extra pipes will help seal the lid on the top, get your wood gases down to the fire, and still have a blow-off area up on the top lid if the gas pressure gets too high. You'll still be able to easily lift the lid and pipes off of the inner chamber to fill and remove the charcoal. Just a thought...
+Planet Lars That sounds like a good idea. The only problem is getting things like black iron pipe here in the UK is actually quite difficult. Nobody makes much of anything here, so suppliers for stuff like that are a bit few and far between. We certainly don't have big hardware stires that sell anything that useful. :-( I can probably get it online though so that might be the way to go. The difference I think I'd make is to block the small hole in the loose lid and run the pipe from the side of the inner barrel near the top rather than from the lid. I'd then pass it rhrough the outer barrel, run it down the outside and back into the burn chamber at the bottom. Inthink James Hookway did something similar on one of his designs. The difference with his is he packs the wood around the outside and has the flames shooting up the middle rocket stove style. I tried that but found there wasn't enough hot surface area to transfer enough heat into the wood without fitting a fiddly outer layer of insulation. My way the flames insulate the wood inside. I think a few midifications are called for then another test burn!
I didn't realize that black iron pipe was such a scarce commodity there in the UK. I'm from Pennsylvania, every hardware store you walk into in my area has tons of it. I'm going to build a retort exactly like yours when the weather warms up a bit, I think I'll add the black iron pipe thing. I'll report back once I get mine made and how it works. If you get your edition added before me, let me know.
My question is: is there enough oxygen getting in from the top hole of the retort to keep the charcoal ignited during the cooling period? I don’t want to end up with a pile of ashes instead of good charcoal. Did it ever happened to you? Thank you for sharing with us, your retort is by far the best one I’ve seen. I have started my retort today and i will keep you updated on the progress. Best regards -Yves
The idea is to get as little air into the retort containing the charcoal as possible. If air gets in the wood would just burn to Ash. However you do have to leave a hole to allow the expanding gasses to escape. I've never had any problems using the small hole you see, which is the original hole where the gas fitting was before I re-purposed the cylinder. Also the lid is not sealed so gas can escape around the edge of that too. The system could be made more efficient by fitting a sealed lid and running a pipe from the hole in the top back down the outside and into the burn chamber. The gasses ould then ignite there so you wouldn't use quite so much wood as fuel.
@@AndysShed thank you for the information. It's helping me allot. Update: (The outer barrel including the feeding door is done, the inner barrel is almost done, i just need to install the gas exhaust pipe on. I did make the inner barrel lid airtight and the chimney is installed. Almost ready to try the first batch of charcoal) Best regards -Yves
@@yveskc1 Have you run a pipe from near the top of the inner barrel, down the outside and back into the fire chamber? That's something I've been meaning that do. The trouble is you really need to make the inner Barrel air tight to do that but also have some kind of pressure escape valve. That's why a lot of people making gassifiers hold their lids on with springs. It sounds like you're definitely on the right track. I'd be interested to see a video of it in action.
Andy's Shed yes sir, that is exactly what I’ve done to the retort. I ran a pipe from the top of the inner barrel lid to the bottom of the outer barrel. It was a lot of fitting and welding but at the end it worked. I am now waiting for the snow to melt, I need to fire up the retort in the field behind my house and I can’t get there quite yet. We still have 1m of snow on the ground Northeast of New-Brunswick Canada. I will definitely let you know how the first batch of charcoal turned out. Thank you again and best regards -Yves
Welding isn't too hard to do if you don't mind it being ugly as sin (read as; functional) Couple hundred dollars and you'll be able to pick up a welder of one flavour or another, do some research and pick one up or find a welder, give em a call and arrange em to do it for ya. Ain't no problem if it can be solved by $
I think a non-welding version would be very difficult to make. There would be lots of joints that have to be sealed somehow. It's almost certainly easier to buy a cheap welder and give it a try. Provided you use decent quality rods or wire it's a lot easier than you would imagine.
Make sure you plug the top hole and provide an escape route at the bottom for gases to escape. It will ignite and produces the heat necessary for pyrolysis to continue. There is no reason to procrastinate.
I agree with you, but the "plug" doesn't have to be tight, as anything V shaped of metal or even a stone ? (possibly not heavy enough) Would enable the very small amount of pressure to push the "wood gas " out the new bottom holes. It only has to counter the buoyancy of the hot gas so there really isn't any pressure. Once this retort burning starts you won't have to feed the fire as the wood-gas will produce more heat than is required to maintain the process, and when it goes out the process is finished If Andy is worried about the end of the burn when air might enter the bottom and burn up the charcoal as it rises and escapes from the unsealed lid, then a ring of gasket/door sealing "rope" from a slow burn wood stove should prevent that.( A twist of it could even be used to block the threaded hole.) There are lots of videos on inverted 20L paint tins with open 1.5" lid put into drums lid down that show this doesn't have to be sealed to prevent charcoal from burning up. As there is nowhere for the air/combustion gasses to flow too but OUT stopping fresh oxygen/air coming in . Its an easy mod to make a few holes in the bottom and if it doesn't work the holes can be welded up or short bolts dropped through them.
Greenwood I think you hit the nail on the head about the top needing to be totally sealed if you have a hole in the bottom. I don't think sealing the top is practical because it's curved. Also it acts as an emergency pressure valve. However what you could do is drill a hole near the top but not on the lid and fit a pipe that comes out through the side of the retort and back into the fire chamber below. I'm currently trying to further reduce the smoke the unit produces. Once the gasses coming off the charcoal are lit smoke is very little. However the first few minutes while warming up can be very smoky. Returning any gasses burning off to the fire chamber will probably help with this too.
Hey Andy, just came across your video and I think that that is the perfect charcoal retort. I may have a solution for your gasification problem to make it even more efficient. Instead of sealing the top and making new holes on the bottom of the inner chamber, use the same top that you have now with the threaded hole in the center, get a black Iron T and nipple and put in the threaded hole, run out a couple of short pieces from the T just long enough to reach the space between the inner and outer tanks, on the end of the short pieces put a couple of elbows pointing down to the space between the inner and outer tanks. Put on two longer pieces of black iron pipe that will reach from the elbows down near the fire area. I think the weight of the extra pipes will help seal the lid on the top, get your wood gases down to the fire, and still have a blow-off area up on the top lid if the gas pressure gets too high. You'll still be able to easily lift the lid and pipes off of the inner chamber to fill and remove the charcoal. Just a thought...
+Planet Lars That sounds like a good idea. The only problem is getting things like black iron pipe here in the UK is actually quite difficult. Nobody makes much of anything here, so suppliers for stuff like that are a bit few and far between. We certainly don't have big hardware stires that sell anything that useful. :-( I can probably get it online though so that might be the way to go.
The difference I think I'd make is to block the small hole in the loose lid and run the pipe from the side of the inner barrel near the top rather than from the lid. I'd then pass it rhrough the outer barrel, run it down the outside and back into the burn chamber at the bottom. Inthink James Hookway did something similar on one of his designs. The difference with his is he packs the wood around the outside and has the flames shooting up the middle rocket stove style. I tried that but found there wasn't enough hot surface area to transfer enough heat into the wood without fitting a fiddly outer layer of insulation. My way the flames insulate the wood inside.
I think a few midifications are called for then another test burn!
I didn't realize that black iron pipe was such a scarce commodity there in the UK. I'm from Pennsylvania, every hardware store you walk into in my area has tons of it. I'm going to build a retort exactly like yours when the weather warms up a bit, I think I'll add the black iron pipe thing. I'll report back once I get mine made and how it works. If you get your edition added before me, let me know.
I think homayoun Shirazi above has a great Idea and a simple mod and I have also made some potential variations on his idea and explained a few things
My question is: is there enough oxygen getting in from the top hole of the retort to keep the charcoal ignited during the cooling period? I don’t want to end up with a pile of ashes instead of good charcoal. Did it ever happened to you? Thank you for sharing with us, your retort is by far the best one I’ve seen. I have started my retort today and i will keep you updated on the progress. Best regards -Yves
The idea is to get as little air into the retort containing the charcoal as possible. If air gets in the wood would just burn to Ash. However you do have to leave a hole to allow the expanding gasses to escape. I've never had any problems using the small hole you see, which is the original hole where the gas fitting was before I re-purposed the cylinder. Also the lid is not sealed so gas can escape around the edge of that too.
The system could be made more efficient by fitting a sealed lid and running a pipe from the hole in the top back down the outside and into the burn chamber. The gasses ould then ignite there so you wouldn't use quite so much wood as fuel.
@@AndysShed thank you for the information. It's helping me allot. Update: (The outer barrel including the feeding door is done, the inner barrel is almost done, i just need to install the gas exhaust pipe on. I did make the inner barrel lid airtight and the chimney is installed. Almost ready to try the first batch of charcoal) Best regards -Yves
@@yveskc1 Have you run a pipe from near the top of the inner barrel, down the outside and back into the fire chamber? That's something I've been meaning that do. The trouble is you really need to make the inner Barrel air tight to do that but also have some kind of pressure escape valve. That's why a lot of people making gassifiers hold their lids on with springs.
It sounds like you're definitely on the right track. I'd be interested to see a video of it in action.
Andy's Shed yes sir, that is exactly what I’ve done to the retort. I ran a pipe from the top of the inner barrel lid to the bottom of the outer barrel. It was a lot of fitting and welding but at the end it worked. I am now waiting for the snow to melt, I need to fire up the retort in the field behind my house and I can’t get there quite yet. We still have 1m of snow on the ground Northeast of New-Brunswick Canada. I will definitely let you know how the first batch of charcoal turned out. Thank you again and best regards -Yves
Hi Andy I have no problems getting the parts, but finding someone who can weld is the challenge any thoughts on a non welding model?
Welding isn't too hard to do if you don't mind it being ugly as sin (read as; functional) Couple hundred dollars and you'll be able to pick up a welder of one flavour or another, do some research and pick one up or find a welder, give em a call and arrange em to do it for ya.
Ain't no problem if it can be solved by $
I think a non-welding version would be very difficult to make. There would be lots of joints that have to be sealed somehow. It's almost certainly easier to buy a cheap welder and give it a try. Provided you use decent quality rods or wire it's a lot easier than you would imagine.
Make sure you plug the top hole and provide an escape route at the bottom for gases to escape. It will ignite and produces the heat necessary for pyrolysis to continue. There is no reason to procrastinate.
I agree with you, but the "plug" doesn't have to be tight, as anything V shaped of metal or even a stone ? (possibly not heavy enough) Would enable the very small amount of pressure to push the "wood gas " out the new bottom holes. It only has to counter the buoyancy of the hot gas so there really isn't any pressure.
Once this retort burning starts you won't have to feed the fire as the wood-gas will produce more heat than is required to maintain the process, and when it goes out the process is finished
If Andy is worried about the end of the burn when air might enter the bottom and burn up the charcoal as it rises and escapes from the unsealed lid, then a ring of gasket/door sealing "rope" from a slow burn wood stove should prevent that.( A twist of it could even be used to block the threaded hole.)
There are lots of videos on inverted 20L paint tins with open 1.5" lid put into drums lid down that show this doesn't have to be sealed to prevent charcoal from burning up. As there is nowhere for the air/combustion gasses to flow too but OUT stopping fresh oxygen/air coming in .
Its an easy mod to make a few holes in the bottom and if it doesn't work the holes can be welded up or short bolts dropped through them.
Greenwood I think you hit the nail on the head about the top needing to be totally sealed if you have a hole in the bottom. I don't think sealing the top is practical because it's curved. Also it acts as an emergency pressure valve. However what you could do is drill a hole near the top but not on the lid and fit a pipe that comes out through the side of the retort and back into the fire chamber below.
I'm currently trying to further reduce the smoke the unit produces. Once the gasses coming off the charcoal are lit smoke is very little. However the first few minutes while warming up can be very smoky. Returning any gasses burning off to the fire chamber will probably help with this too.