Hi Kristijan,
I built an imbert and am really satisfied with its gas output. It’s a bit bulky,
but I could have downsized some of it (not the critical areas sized by
horsepower need). I was a bit limited by using what I had on hand.
Hopper could have been smaller, as could the cleanout area, but
it operates great. After running it, I also feel I could have built a smaller cooling
tube unit as well as a smaller condensate tank. However, it produces a voluminous
amount of gas. I think knowing your exact HP needs is critical to sizing the
components of the unit. Check out my site (My first small engine run) in the
small engines section.
Pepe
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Hi Kristijan, with that thick wall pipe it would only need some lug nuts welded on the inside for nozzles, I vote a WK. If someone is going to make a WK gasifier that run on wood chips with a inverted V it would be you. This is going to run on charcoal mix too to get more hydrogen I expect.
On your last WK design you used more of a Imbert style nozzles because of the square box fire tube and with ceramic blanket. The round fire tube will keep the wood, wood chips, pellets, charcoal flowing to the grate. In your last design I liked how you had your gases move through the grate and then move across the bottom moving the ash out of the way to the clean out door hatch keeping the low profile. Also cooling the gases.
If you could build a preheated air off the exhaust pipe that could improve efficiency.
Looking forward to this new and more improved build. Just using the round fire tube it is already going to be smaller than the last build.
Bob
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Wow!! One time you said you always have several projects going at one time – you haven’t finished the saw mill and your off again. Dutch John made and Imbert small enough to run his push type power lawn mower. Can you make a WK small enough to go on your garden tractor that will be running the sawmill, and doing garden work? TomC
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Tom, l got half way trugh your post when it dissapeared??
Oh, the mill is finished as far as it can be for now. For further progress l need to wait a litle bit. The log wagoon design allso needs some use of the thinking chair
Yep, thats the plan. Not sure yet what kind of design it will be on the cultivator thugh, probably charcoal or a charcoal/wood mixture.
I see its a tie 
l think l will do both. A wk firetube with ability to accept smaller nozzles and a lmbert restriction. This way l can do both.
Not sure about the grate thugh. I am thinking WK hanging grate, but there is litle space under the firetube and l am afraid of it locking tight with sliped char…
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Yesterday I skimmed through @madflower69 's Tom Reed pdf in @Matt 's thread, about increasing the proportion of H2. The English used was a little over my head but I picked up the main message: Extending the hot zone by using extra rows of nozzles and adding char. Sounds familiar?
I see no reason why 2 planes of nozzles couldn’t be used in a WK as well. Super short nozzles may require sacrificial plates and/or some beef though.
I think, if I were to try 2 planes of nozzles again I wouldn’t bother having a shut-off valve for the upper plane. I never close the valve on my Mazda gasifier. It seems at low demand the air takes the path of least resistance and enters through the lower sets of nozzles (for the most part).
I think a combination of a WK with the huge lower char reserv extending the hot zone downwards when pulling hard, combined with 2 planes of nozzles to extend it upwards, could be a winner. @Ron_L 's nozzles pointing upwards is another option.
Oh, and then there’s adding char of course, to make more use of the steam created, for making H2.
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Sorry about removing my original post, but as usual I found myself getting to “wordy”. TomC
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Tom, don’t bother the wordiness. I was quick enough to be able to read your post. I already forgot what it was about but I remember it was funny
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Tom, your words are golden. I find that I get to the point of to many words trying to explain someting and then repeating myself. Lol
Bob
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Hi JO, on the WK Gasifier the flow velocity is low compared to the Imbert Gasifier design at the nozzles. With my temperature at the grate reaching as high as 1730 at 70 + mph and still not over pulling on my char bed, I am not sure if the extra set of nozzles would be needed. WK fire tubes have a habit of melting down because of the low velocities of air blast out the nozzles. This is why the fire tube design is now being shielded for extra protection.
I picture in my mind a different type of hot char lobe in this hot zone area, more of a donut shape lobe being cooler by in the middle at lower air velocities of air going through the nozzle, and going down the shielding of the fire tube. But at higher velocities the blast moves more to the center of the fire tube like a Imbert gasifier.
By just adding damp charcoal in the mix of the wood has proven to me is a great way to make extra H2 with no gasifier design change needed.
Mike Gibb, Kristijan, and you have convinced me this is the simplest way to go for more performance out of the gasifier. Dry hard wood, and damp charcoal mix. I think any wood gasifiers would see a performance improvement when mixing wood/charcoal.
I have thought about putting one nozzle pointing straight down over the fire tube, but was also thinking this would cause bridging problems and my grate shaker would no longer would work. The grate shaker won out on this one.
Bob
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Great summation Bobmac.
Especially about the velocities differences and effects.
Sorry KristijanL. I always start with the gasifiers intended use/purpose.
You have too in the past. Then the space/weight/operators-willingness’s that drives everything else.
So this one is more an hearth core systems experimental unit, eh?
No directed put-to-use purpose?
S.U.
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Bob,
Kristijan is aiming to power a vehicle of about the weight and profile of the Dakota with a 7" gasifier. I believe overpulling could become an issue regardless of gasifier design. Anything that will stretch out the high end will be helpful.
Now with his automatic hybriding linkage I guess it’s still doable.
Remember the famous qoute: “Satisfying the low end”
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Steve, l am not sure l understnd your question. Yes, the goal is to make a system for everyday use. Experimntation is only nessesery becouse l am limited on so many factors. Its not my intention to invent the wheel.
What JO sayd. If you look at it from this prospctive it does seem ridiculus but l am planing to use much smaller fuel so that makes a huge effect on the gasifier dimensions.
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I think l will go with a wk with 2 nozzle planes. Reason being burning small tightly packed fuel not all tars might burn on the first nozzle plane, l want to give them a second chance. Afer all l can still plug one plane if it shows unnessesery.
Now for some thinking chair time
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What is this new gasifier going to power??? I was thinking the garden tractor that has so many uses on his farm. Now JO says something similar to a Dakota. TomC
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He was reffering to the Mercedes. Its a big hevy car.
Nope, still stuck with the old Merc 
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Okay Kristijan, I forgot about the size of fuel that you will be using in this gasifier, very small. So the double nozzle plane is going to be used to get a more complete burn of the wood to charcoal surface area of the materials and convert the tars also. Hears a thought, May be staggering the nozzles and not have them over the top of each other will keep valuable charcoal to move on by the second set of nozzles keeping a char bed. The second set of nozzles could also become more of a Charcoalgasifer burn area turning charcoal into a complete burn to ash area like a Charcoalgasifer.
Have you thought more on your idea of adding supper hot moisture vapor through the second set of nozzles would help on additional H2 conversion.
I am sure you are going to have a way to restrict the air flow of incoming air so it will not be able to over pull like on your last gasifier unit.
Bob
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You think like offseting the nozzles? Thats the plan yes. On steam injection, probably, if l use charcoal but using pellets that have around 10% moisture there shuld be a exess anyway.
If you were reffering to hopper steam thugh, there wount be any. The hearth will be sealed from the hopper via gate valve with only a say 2,5x2,5" opening. This is nessesery for 2 reasons. Hopper must be ambient temp at all times and it must not have steam/smoke in it (pellets). The hopper gate valve will be shut off at each engine stop. Hopefully cooldown heat will pirolise the wood in the hearth but stop at the ss gate valve.
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Still time to weld things in the firetube. Plese share your opinion if its nessesery
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I had some heat sinks burn out I hate to think about what that would have done to the nozzles in the tube. I would probably put some heat sinks around the nozzles. They are not very heavy and not hard to instal; rebuilding firetubes is difficult and expensive.
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Hi Kristijan, looking at the nozzle holes. If you could weld some old wheel lug nuts that have been cut in half with rounded nut end out. This would keep the hot air away from the fire tube wall. With the small nozzle holes you are using, I would thing it would be blasting the hot air out of the nozzles like a Imbert gasifier. The small dense wood pellets should help in shielding the fire tube wall as they turn into charcoal and ash cone with the angle to the restriction opening. Also may be filling it with ash to start with. For extra protection on the first start ups.
With the grate just sitting in the bottom like that, how will you keep it from going side ways from use. I would weld small pieces of metal round bar below the grate so it would stay pretty much level in the bottom. This would still aloud the ash to flow by the grate.
Is there any way you can make it, so it can be taken apart for service and repair or for modification if needed?
I like the sliding hatch to isolate the hopper when shuting the unit down.
Bob
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