Hi, do anyone knows how important the size for the housing dia of the hearth is?
It’s marked with dr on the chart in the library.
Will ash not fill out the extra space if a bigger diameter is used?
What both KristijanL. and J.O. have said. Along with Pepe’s still unanswered question.
The woodgasifier system certainly must be able to tar-free fuel gas supply from that engines Idle/minimum fuel usage RPM.
For an synchronous IC engine AC generator system this minimum use RPM can be 1500/1800. Or directly into 3000/3600. BIG fuelgas volume needs difference between IF those minimum RPM’s are at electrical loadings or not!!
Vehicles. You bet has to be able to intersections idle. 500-700 RPM. Forcing 1200-1700 RPM “standing” idles just to keep the woodgasifier system flowing Hot. And on an internal velocity dependent INBERT still be internal velocity ash clearing . . .
that’s just asking for auto transmission overheating; or lots of manual clutch slippages vehicle movements movement starting out. Then, Brakes riding coming up to intersections stops overriding that forced up “idles” RPM.
A woodgasifier systems ability to cleanly safely produce MORE (and just how much MORE) than engine minimum basement needs IS called it’s turndown ratio capability.
Our modern overhead valved, 8.5-1 compression ratio’ed, and far above 3000 RPM capable, IC engines have a can-use-more-fuels capability then woodgasifiers and charcoal gasifiers systems can supply. Face this reality.
Then even though this/these questions are asked on a General Topics area, do realize many&most here on the DOW are operating by WK systems experiences. Wide range internal velosity, Large Internal Volumes systems. Same temperatures. Bigger dimensions to get those space volumns bias.
So you want the direct short effective answers JimH and JanA.?
KristijanL, MattR, J.O., TomC, WayneK are saying just take a best guess swing at building, and using something. Anything. Then carve it up and down from there. This had been their routes.
Guaran-damn-tee-you. Your first guess-quest build-up will be sub-optimal.
Your second DOing Build modification will be closer to your wanted results.
Your third modification DOing/trying should be even better yet. (or be a fall back step from your own overthinking/overreaching. Mirror, mirror on the wall - you are always your own biggest problem of all)
There are just too many variables in turning wood into useable powers to ever think any guru-god can more that just steer you into a general direction.
All of the books. All of the studies. All of the exchanges. And still it remains.
Your system. Your usage for You and Yours with this many variables, “organic” process is the only route now after 150 years that actually ever leads to real world using successes.
So my question will always be: for-Who; and for-Why, are you pusueing this Hard-Way versus just easy fuels buying out your energies?
The answers to these will predict your success’s or failures.
Steve unruh
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Dr is not important. Biger is even beter, more insulation.
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This is just my experience, I have built several gasifiers 2 are WK(1 for a 5.8, 1 for 2.5) others were Imbert, all for mobile use. The WK worked flawlessly right out of the gate, using Wayne’s recommendations, Imberts not so much. Not too much to think about, just build. I am going to build a Ben P. gasifier at some point for a 2.3l generator, I think his dimensions are really close.
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Hi Jim,
I respectfully disagree that Dr is not important. These are proven dimensions. In my mind, if
you have a constant draw (load) (x cubic feet per second for example), and if
you make Dr 1 1/2 times bigger, the VOLUME OF THE BURNER enlarges dramatically with that
same constant draw. Thusly, the VOLUME OF GAS (under constant load will decrease (slow down)
with that “constant draw”.
This will have a significant effect on the core temperature and gas production ( slow down or stop blowing on your starting campfire, what happens???). My gasifier has an
insulating shell around the hearth to help keep that “core” temperature as high and
as constant as possible.
Jim, these are proven numbers since WW2, stick with them, use them, they work!
Check out “My first small engine run” in the" Small engines section" on this site. You’ll
see that my unit ran very good right from the start. Yeah, a lot of work, but you want
a first time success, right! Then you can experiment with designs!
But I could be wrong, Pepe
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The most common reason for disagreement is misunderstanding.
Correct me if I’m wrong, but I think @KristijanL was reading @Jim_H’s post and is refering to the gasifier housing. @pepe2000, you looked at the drawing and you’re taking about the firetube diameter, right?
For some reason I find the Alabama terminology easier to follow 
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What JO sayd. Pepe, look at the picture again. Dr is not the “nozzle circle”. I agree, that one is important and usualy follows a 60° slope to the restriction. I belive Max sayd the volume of the frustum shuld be in the 5-10% of gas that is sucked in the engine every second (so called sekundgas).
But, the outer space beond the nozzles (Dr) will fill with charcoal and ash anyway, so is not important in the design.
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It appears I may have misunderstood the question, y’all.
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Me too.
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I’m sorry Kristijan, but I have spent a lot of time in my notes and in the library here to find the equation you gave.
That constant of “3” is throwing me. You have RPM-rev/min x displacement- l x constant- 3 equals gas volume-l/s
My understanding of the value of “3” could come from 1/60 for sec/min; and 1/2 for a 4 stroke engine only taking in air every other stroke, then their could be .70 for volumetric efficiency … Then I suppose we could have another 1/2 in there because we are talking about air going into the gasifier and gas coming out which we eventually mix 1:1 for engine fuel.
I started my work by calculating the “theoretical” air/gas then going to the "inverted V dimensions and finding the Max Range of Gas Output which met my calculation. So i think this formula, not being exact, but close is important.
After this discussion, I’m not sure I would really know where to start, First off I will probably never build an Imbert style again. If I did I would want to start with know numbers, such as Pepe and Jan A. have posted, but I DON’T believe in working with HP so here I am back to some form of the formula you posted. TomC
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Exactly what you sayd on the constante.
Well the buty of the lmbert is that it can be made adustible. Nozzles can all be screw-in, restriction and grate can be changeable, like l used to make them.
But like l sayd, get the dimensions in a rough ballpark and it will work as long as the RESTRICTION is the right dimension.
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On the other hand it can be stored in charcoal for at least a thousand years. Gasoline is unsafe, so easy for it spill and start a fire. It evaporates. Starts wars! Can only be bought. If I spill charcoal on the ground it can be picked up or left to help the soil. I have never noticed a turn down ratio issue with charcoal. Seems to keep the engine combustion area clean. Engine sound so nice on it, happy. I could go on.
Of course the modern people would hate it. Just as well.
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Well said Jeff, some more things, you and eat it, and it purify water to drink. Try that with gasoline. Lol
Bob
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I like the idea of “charcoal” for all these thing you have sayd. But; I think you give way too much credit to raw charcoal as a fertilizer. It is good at holding moisture, and minerals IF it is inoculated with the minerals. TomC
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I have added switch grass charcoal to the soil and never have seen a difference in how the grass grows in that area. When I scuff up that area I can see nice black soil just no apparent benefit. At least no harm. Others report massive benefits. Compost has always amazed me.
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I have a “muck” farm close by. Is “muck” black from the carbon in years of material decaying in a moderate wet area. Muck is hight in minerals also. TomC
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Tom, I had to google that one, Sapric soil. Looks like this soil can catch fire and burn for a long time. Always learning. Thanks!
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Is that the same as a peat soil? Becomes more common in colder climate zones in wet areas. There are peat soils near my parent’s farm dated roughly 9,000 years old. They can burn like a coal seam. No peat being formed in the area in recent millennia.
" I have added switch grass charcoal to the soil and never have seen a difference in how the grass grows in that area. When I scuff up that area I can see nice black soil just no apparent benefit. At least no harm. Others report massive benefits. Compost has always amazed me."
I also question some of the claims of benefits. In good quality soils I think it’s less influential. In poorer soils it might be increasing nutrient availability? It will improve soil aeration, and should improve moisture retention in certain kinds of soils, which could be beneficial. But it’s definitely carbon out of the atmospheric cycle long term.
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Yes Jeff, these muck areas , if they are drained of water, which farmers do to get equipment in there, will catch fire and they just have to let the fire go. It some how gets enough O2 under ground to continue burning. Eventually they burn themselves out. Muck farms grow mostly vegetables for a much higher profit than corn, soybeans and other profit crops.
Garry, I think “muck” has the characteristics of soil where “Peat” has a lot of vegetation in it where to harvest it, they cut slabs out of it.
That switch grass- back to what I understand about charcoal for fertilizer, it has to be inoculated in minerals. In a field that has a lagoon plated at the time of putting charcoal, the charcoal would pick up nitrogen and future crops will benefit from that nitrogen. I’m not a soil expert. This is just impressions I have gotten from conversations here on DOW. TomC
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This is after about 10 years in the soil. I think it would till better. How the charcoal is made and what it is made of are all part of the equation. What I am saying is that at worst case, everything wrong, I see no harm.
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