This is what an air nozzle with a grille should look like, which would be pushed through the upper opening into the gasifier, …
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Very artistic there Tone!
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How about hanging the grate plate by four chains like a 1" below the gasifer bottom opening then the grate could be made larger to hold the charcoal bed. Less possibilities of it getting a tight charcoal bed. The grate would just have a hole in the middle and not welded to the intake air pipe. The grate can now be shook through the clean out or from above. If you use a restriction opening It can now be moved up or down for fine tuning the gasifer.
This idea of yours is a super K.I.S.S. design. It has to be light weight by looking at it.
I am thinking a charcoal/10% wood gasifer would work in this design.
Bob
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Allow me to think briefly about the operation, the air enters from below through a tube, which would be a bit larger in diameter (1 "), so the speed is lower and the air has time to preheat against the glowing wall, as the temperature of the welded grille is transferred to the tube. as well as higher, the radiation of burning charcoal.The air is so very preheated and hot supplied to the oxidation zone.Because the gas is sucked down through the grate, I assume that the vacuum is slightly higher at the nozzles than at the top of the gasifier where water vapor is retained , so a water vapor capture is created, which is then mixed with hot air and blown into the “center of events” to form hydrogen and methane.All together it would be good to insulate, possibly with a welding carpet. Bob, even a hammock is a good idea.
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Goran, I hope you won’t be too serious, because I’m stealing your topic with my philosophizing. I would like to greet you Mr. Don Mannes, you always write a short article that says a lot, I feel your support and good energy, thank you.
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Hi BobMac,
I believe Tones intent was to have the whole center assembly rotatable.
This will grate move, the grate.
Rotating the air holes outlets. Maybe for benefits? Re-align to prevent burning channeling? Knock off slagging?
Only way to know is to try.
S.U.
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Hi Tone, no worries, i appreciate all input in this topic, and i like your design of gasifier, interesting idea to scavenge moisture from top of fuel hopper, should work as i see it.
But if charcoal dries out to much, do you think there is risk of air entering hopper and expanding glowing zone upwards?
Just wondering, i really like the idea anyway. 
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I made a sketch of what im thinking about, nothing special, please don’t take this as proportinally correct.
The idea of the steel ring is to guide the hot lobe to the center of the gasifier, to avoid hot channels near the walls.
The pipe going upwards should have a threaded pipe cap, just to open and drop some burning stuff into for light-up.
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That is what I thought at first. But how would you make a rotating pipe up through the bottom of a very hot area of the gasifer and not leak air in on a vaccum system. One tiny leak there and you have a hot furnace affects causing weak gases. I am not saying it can’t be done, just saying it might be very challenging.
Bob
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Hi BobMac
VesaM; Ben Peterson; and the GEK systema all use center UP rotating grate posts or tubes.
Three different ways used to air seal that from rotation. All three work.
Here’s why.
The charcoal stack and ash weight pushing down if far greater than any vacuum pulling up.
And that ash settling-in seals.
Just a machined collar against a machined collar works quite well.
S.U.
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Thats great, the problem was no problem at all. It then can be made into a mechanical shaker from the cab I like that. My electric blower motor vibration shaker quit on me. I didn’t use it very much, thats probably why.
Bob
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Hi all, today i have done some preparations for building the charcoal gasifier.
First of all some history pieces.
Here is an aftermarket, replacement Imbert hearth, from late war-time, there is no air-pipes going to the nozzles, just an air jacket.
Here’s an Imbert copy, made under license by Swedish Ford.
As one can see this is warped/distorted due to uneven gas suction, gas taking the easiest route even with Imbert’s high mounted gas outlet.
This often lead to uneven heat spread at this hearth’s
I cut off the nozzle tips from this.
Seem’s to be good stuff, probably made of Kanthal alloy, very hard to cut, and almost no sparks, (using angle grinder)
Funny thing is, when someone cuts a piece of with angle grinder, and pick them up immediately, burned fingertips is what happens.
Not this time, they felt only warm, must have something to do with heat transfer?
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Hm…even old Imberts had lots of thermal mass down low.
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Yes they had, it’s interesting to see the differenses in these war-time gasifier hearth’s, the ones made early hold up really well, and are Much heavier also, than the ones made later, due to shortage of alloy material.
About the diabol-shaped restriction it probably had some flywheel effect, when needed.
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What I wonder is, everyone used a cone shaped reduction zone during WW2 or at least the most popular ones.
Now the vogue is plain cylindrical shaped reduction zone. Why?
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Easy fabrication I guess
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Today i’ve also separated the hearth from the outer housing. Time to inspect the hearth tomorrow.
Had to cut the nuts and bolts for the airbox.
And i’ve found the problem i was looking for, an air-leak, under the gas-outlet, the close pic shows some light “dot’s” where sun shines through. Really happy to find it
When gasifier was mounted on truck there was no way to reach that point where the leak appeared.
Also find a lot of white ash on the inside, just close to the leak, indicating burning gas.
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I guess it’s also evolved from the experimentation with ash-collecting/insulating hearth’s, which was a big step ahead in life-span of the hearth’s.
During wartime the classical Imbert was known to work very well, no need to improve it, when it became harder to get good material/alloys, and enough of it, the need raised to construct hearth’s made of less and worse quality material, that still hold up pretty well, something that led to, for example, the V-hearth.
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Thanks for the pictures Goran.
Yes, easyer construction, on both sides. Easyer for the manufacturer to cast them that way, but for us DIYers its easyer to make it cylindrical.
Wich is better? Im taking an educated guess here. It depends 
Those mass produced gasifiers were intended for the common man. Most dont want to think about bridgeing, vacuum ratio, plugged charbed etc while driving. For this, this kind of a gasifier is probably better althugh less efficiant! Look at how much metal is exposed to the glowyone and later gets radiated in the gas.
An ashcone gasifier that most of us use nowdays (the non WK gasifiers) will be more efficiant with added insulation but require some feeling. For instance, you cant just poke in with a poking rod like mad like we see in war time films, this will damage the ashcone. No problem with a cast hourglass hearth…
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I have seen that and have always wonder why they could do that. I have always been careful about where I am poking my rod. “Okay Tom H. check that dirty mind of yours”. Lol. But yes even in the WK Gasifier I’m being careful not to damage the little ash cone that is in there.
Bob
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