Weekend build of a clean burning incinerator for a family member.
Based on an EPA approved design.
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Still documenting it...
Basically creates a vortex by injecting moderate pressure air around the outer edge in a spiral.
Exhaust is at the center, through a spark arrestor. Ashes and smoke are trapped by the vortex and re-burn, producing a clean exhaust.
Once up to operating temperature, produces zero smoke and ash.
Provided you don't overload it (about 2/3rd full), it produces zero sparks. If you do overload it, it looks a lot like an afterburner.. :)
Took a short video today of the vortex in action.
Originally the top cover was designed to swivel on/off. I built the vortex inlets around the edge angled back into, and above the surface of the plate. The center exhaust was just a hole, and nothing extended into the burn area. I even made sure my Northern hemisphere location didn't spin the wrong direction. It was elegant and looked great on paper, right up until I actually tried it.
There were two problems that showed up.
I went looking for a solution. I found a cross-sectional line drawing of the theory of operation for another vortex burner. In addition to the vortex inlets and the exhaust pipe, they had a plate in the center below the exhaust.
So I modified my swivel design to be a lid that hinges at the back. I then could add the needed plate inside the burn area.
I suspended the plate via three strips of steel, which I angled to oppose the vortex spin. This ensured only things which could make the two right angle turns at speed would escape through the middle, aka... gas. That solved the ash problem, but I still got some sparks and it took a long time to get up to temperature.
Then I added three sacrificial layers of expanded steel mesh to the inside of the steel strips above the exhaust plate. That created more turbulence and gave me a nice red hot surface living in the exhaust stream. The combination very effectively countered the sparks. As a bonus it seems to burn fully over a wider temperature range, and will now tolerate opening the top to add more fuel.
Take the 55 gallon drum lid, and cut a whole in the center smaller than the exhaust pipe.
Weld a flange around this hole to fit the inside of the exhaust pipe.
Rinse the smaller barrel out with soap and water, and run a vacuum to swap out the air inside with fresh air. Volatile chemicals explode when mixed with air in the right ratio. We are trapping the volatiles in the soap and water mix, and then taking the air ratio below the ignition point by doing this. Leave the vacuum running while doing the cut to be safer.
Put a wrap of flat tape around the barrel to get a cylindrical mark, then cut along the edge of the tape. Try to be straight to avoid a lot of extra welding later.. It should be 1/3rd as tall now.
Cut a hole in the center of the smaller barrel part to match the outer exhaust pipe diameter. I left the vacuum running while doing this.
Reminds me of my ZipZstove wood burning backpacking stove. It even has a blower fan motor at the base and also burns clean once up to temp. I would like to see how this build turns out :-)
It's done at this point. Burned the motor a bit and had to re-center the bearings as the rubber mounts creeped. Got a few wraps of electrical tape, a sheetmetal fan on the shaft inside the motor, and a few cooling holes. Problem solved.
The build went by kinda fast and without documenting it during... so I still need to go back and do that more.
Love the night shot, very impressive :-) It helps that I like a good fire ;-)
We had snow on the ground here, and I still needed to be 8 feet away to be comfortable when it was running full bore. I have since decided I should be running it about 1/2 throttle. It burns down to the bottom then, and the barrel will last a lot longer if I don't get it glowing red/burn off the paint every time it is used.
Having the additional range on the throttle helps to get it to where it is burning clean though. Cycling between full on and nearly off does a really good job of getting the afterburning of the smoke/ash going. I took a peek and when I reduced the air, the barrel was filled with lingering 'flame' in the air space above the fuel, so that gets the secondary burning going.
The air being injected around the edge also does a reasonably good job of keeping the sides a lot cooler than they would be normally. There is still a load of radiant heating happening there, but better.
Daren Schwenke
mybura
Ronald Jaramillo
Matt Moses
Forgive my sense of humour, but you never said which family member got incinerated... ;-)
Great build, I made a little helical forge using the same principle, gets *really* hot, enough for brass and copper at a pinch.
I need a better lid, your chimney is recessed and works really well. ;-)