I like that idea. I’m planning to use 3/4" threaded nipples with piston wrist pins welded inside. I could use washers as a shoulder to clamp down the plates.
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Because I am fickle minded and want to build one of his designs I’ve decided to go for Joni’s specs for the core of my reactor combined with the form factor of Wayne’s reactors.
On this side for the non-premium members I’ll show how I build the burn tube but on the premium side I’ll show everything else since it relies heavily on Wayne’s design.
It isn’t exactly how Joni builds his but I submitted the idea to him to approve the dimensions. It also sadly isn’t stainless steel. I wish I could source stainless and I may be able to in the future, who knows.
The most important factors to Joni’s design I think is the engine exhaust vacuum ejected gutter and his nozzles, combined with the lack of a recovery/reduction zone. Just a choke plate leading to a grate. It’ll be fixed with a short chain with angle iron V grate.
I’ll try to draw it up without the rest of the gasifier so you guys can picture it more easily.
I have most of the components to start my build so it will be very soon.
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I think my drawing is abstract enough that it doesn’t reveal Wayne’s trade secrets, if someone thinks otherwise let me know and I’ll edit the image. I don’t like stepping on other’s toes.
The burn tube is a 20lb propane tank with the top and bottom cut off and a 12" steel trailer rim welded in. The rim I ordered will hopefully be a little oversized so I can make it a tap and weld fit. Rim is inserted to the propane tank after nozzles are added.
For the time being I’m going to make it with cold air just like Joni uses. If there’s any preheating its coming from the burn tube being part of the air jacket.
Using my scrounged piston wrist pins as the nozzles, they have a good length to them. Joni advised I add material to the tips of the nozzles to bring down diameter for increased air velocity.
I’m hoping to make a brake drum fit as my choke plate to take advantage of the cast iron’s ability to take heat at the restriction area. Still thinking of either a 3" or maybe 3.5" restriction using a bearing race.
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One funny thing I noticed is in the MEN gasifier they also used an exhaust venturi for water. I think that because they used a hot hopper imbert style it probably wouldn’t work as well as Joni’s use of it seeing how he leaves the hopper area uninsulated to get some monorator action.
Trailer rim arrived today, I’m going to try to prep that when I get home and buy the couplers so I’ll have removable for tuning nozzles.
I’m thinking either 5 or 7 nozzles. If I have too many I can just reduce internal diameter.
Going to buy the round plain steel conduit female to female couplers and try to cut them in half, only need threads from one side and it will bring cost down.
I’m still thinking of a way to get the fresh air in through the side of the bottom barrel without it being permanent. There isn’t much use of having a barrel as the bottom if it’ll be welded permanently down. I guess I could make a flange curved to match the barrel’s curvature. Use carriage bolts or weld studs to the flange so it’ll only require removing a nut from outside.
Or I could use threaded pipe, weld a flange, and use a pipe nut to tighten down
Other solution is to just weld in the top and air intake.
I’ll have to see if I could weld a drum lid upside down to a barrel and it still be able to use a clamp.
Glad I went with a trailer wheel, pretty thick stuff!
It’s a little oversized but that just means I can trim it down to fit. I’ll have to cut open one of the tanks this weekend to see just how much.
It luckily is stepped in shape so I’ll still have plenty of room for air.
It looks like I’ll just have to cut off the bead seat area, I’m hoping that’s the case that’ll be easy with the plasma cutter to hog that out.
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Cody, is that your “thinking chair”? I think I’d fall asleep in that one.
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The Lazyboy is one of my thinking chairs. Other one is made of porcelain 
Sometimes I’ll put HWWT and Ben’s book under my pillow to sleep on an idea.
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After looking more and more from JOs build I see so many universal merits to it. I have a spare air compressor tank and I think I will make that my drop box area. The tank is roughly 2 feet long just by eyeball measurement, and I could weld it to the side of the gasifier to give me a massive expansion zone to bring soot turbulence down.
I am still going to use cold air like Joni’s system uses. After looking at his measurements from the 8.0 I noticed my char bed will be deeper than his but seeing how my engine is slightly bigger than the one in his Opel I don’t see cause for concern. If I feel I have a need for pre heating I can re engineer it using the massive drop box. I’m wondering if the countercurrent forces of cold air entering the heat exchanger against the hot gas exiting has a role to play, even though they’re separated. Either way it gives me more gas storage to assist in any long idles.
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Got the air ring cut to size. Not much of a car rim left but it luckily was at a convenient spot to follow with the plasma cutter. The second bend after the bead seat area. From the center of where the nozzles will go to the bottom of this tank I have 10 inches, but nozzles will point up at a 20 degree angle so I may have 11 inches of room. I’m leaving the residual of the spokes from the wheel to give me a tar fence to prevent tar from slipping past the nozzles.
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Joni prescribed I narrow the very tip of the nozzles to incite higher velocity of air. I’m deciding on 7 nozzles. These wrist pins are 11mm bore but I added a bead of weld to the tips to narrow them.
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Blasted the holes for the nozzles out of the air jacket with the plasma cutter. Need go buy a die grinder to finish the job.
I have the nozzles tacked in place. Will try to seal them up before I head to work.
I tried to get them all as close to 20 degrees upwards as possible. Will try to remember to take photos in the morning.
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I like it Cody, nice workmanship.
Bob
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Looks great Cody. It would be nice if there was some way to pressure test that ring.
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Just plug the nozzles and put water in it. If no water leaks out your welds are good.
Bob
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I can try to test it by spraying soapy water and using my air gun to blow air through the welds. I need to go over the welds with a wire brush to make sure slag isn’t temporarily covering any leaks.
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I have two different pairs of bearing races. The tightest portions measure one with 80mm and the other with 91mm. I think I will go on the more conservative side and use the 80mm bearing races as my restriction. Weld the two matching races together to act as an ash retainer to insulate the bottom of the burn tube.
I will weld them together like so and as done in the Mini Joni. When welded they form an internal hourglass figure, almost looks like a venturi area of a carburetor. I wonder what this would do inside the gasifier?
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Since my grate will be on a short chain, I’ve wanted to think of a manual way to shake it. What’s a good way to seal a rod to prevent a hot leak? I’ve seen some use a bronze bushing, is it just the precise fit and grease that prevents the leak?
I know others use an internal motor but I just want some redundancy.
The motion I was thinking of would just be a rotating motion, horizontal bar with a finger loosely attached to the grate.
Should I even worry about using a grate shaker and instead just use a poker 9 times out of 10?
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