Imbert Dimensions

Chris Saenz's picture
imbertdimensionsweb.pdf89.86 KB


Stationary Gasifier

I am interested in a stationary gasifier to run a generator to produce electricity for a lathe and mill in my shop. Will a gasifier work with an engine designed for natural gas or LP gas? What is the best size wood chunks to use and what is the smallest usable size chunks?

Steve Unruh's picture

Answers are yes, yes and yes.

Answers are yes, yes and yes.
Natural gas and LP internal combustion engines are the best to woodhgas convert. Eg; Ford/Onans, Kubota DG972 3 cylinders and 4 cylinder GM industrials versus the earlier gasoline B &S's, Honda, Kohlers and Generacs at both of the All Power Labs and Victory Gasworks shops.
Wood chunk size is best matched to the gasifier internal sizing. Gasifier size best matched to the actual horsepower you are asking the engine to produce. Horsepower size range of engine matched to your genhead demanded electrical avarge and peak demand needs. And that in turn will be limited in how much wood supply you Actually Can produced chunked up usable, the deepness of your pocket book to set up or purchase a system. And especially your patience and persistence in learning how to daily operate a system. Means you WILL have to work at it daily for fuel prepping, fuel stoking, condensates, soots and ash cleaning out. Actually much simpler and safer than old steam power . . . but after 60-70 years of being spoiled by easy turn key refined Dino fuels, and switched flip electrical grid most cannot make the transition back to personal daily energy production responsibility. Eg: cord wood bulk heating folk versus pour from a bag/flip a switch commercial wood pellet heating folk; and fuel oil furnace folk knowing/learning they NEED annual soot/burner head/nozzle and filter service versus the clueless "What? I Need any service, ever?!" electric Grid heating folk.
Your specific DYI answers to a useable woodgas fueled stationary system start here: read the MicroGasifer PDF for fuel matched sizing, ect.
Some decent YouTube videos seeded in the chatter/clutter out there too. Look for the posted up work of "foxridgecamping".
Smallest wood chunks I have ran were 1/2"x1/2". TOO SMALL. Right angle flat sided blocks suck. They face to face stack blocking gases flows pathways. Was much better as 1"x 2-3" sawn strips with at least two sides irregular hatchet chopped. Softwood better bigger. Hard woods better smaller.

Washington State Steve Unruh

Gerald Wyatt's picture

New modular modifiable gasifier.

I have started my gasifier and needed these dimension. I don't think I can use most of them because of my design but they give me what I need. My gasifier will be modifiable at the air intake and throat just below the reaction area. I have given it much thought and I think it would be nice to be able to change parts out for two reasons. Smaller throat for smaller motors and or in the hottest zone, one may need to change out the throat plate and screen. This info is helpful and I hope to have a few more details worked out so I can finish my layout. I will be posting photos and plans here in the blog area at some point. Still welding on the basics for now but I am getting near the final design.

Turbocharging to add power

Hi all,

It concerns me that one loses around 30 - 40% power using a traditional 'Imbert' set-up due to the dilution of the produced fuel gas with Nitrogen from the first burn - especially combined with effects of carrying with the weight of the gasifier equipment, and I was idly wondering whether this could be offset by adding a turbo or supercharger to what would have previously been a normally aspirated engine setup?

I know that positively pressuring the toxic fuel gas would present potential leakage risks with subsequent threat to the driver, but if this could be adequately mitigated then surely the power increase form turbocharging would be worthwhile?

Is anyone known to have attempted this?

Any comments gratefully received.



Wayne Keith's picture

Good Morning Mr. Pickles and

Good Morning Mr. Pickles and welcome to the site sir.

Yes the imberts might be just a little short on power but with the right gasifier vehicle combination there should be very few times one would need more power and if so it is much easier , cheaper and safer just to blend in a littler gasoline.

There have been a lot of discussion on the power boost and I think this one is in the general section.



Steve Unruh's picture

Hello and Welcome to the D-O

Hello and Welcome to the D-O-W StefP.
I read your bio so I can see you are willing to read. Good.
The "Imbert" 30-40% power derating was much more due to unoptimized for woodgas fuel engines and fuel gas quantity supply problems imposed by the narrow mim/max good tar free gas quantity capable "Imberts" than by any nitrogen dilution. This is an old now discredited "assumption".
Modern open flowing gasoline fuel injected engines with higher compression ratios, automatic spark advance and wider turn down ratio capable gasifiers are losing only an average of 15% power. But This power IS in a different power band shape!! This shape greatly favors lower than current darling highly developed smallest petrol engine speeds and is best untilized with a lower numerical transmision gearing.
Yes. Yes. Forced induction of air and fuel gases has been done by exhaust turbochargers and belt and electric driven supercharging now and discussed and documented. The power in the smaller installed engines is the Pro's. The Con's are complexity, expense and more damage with inevitable woodgas backfire Ka-Booms.
Let me give you some links to read to support my "outrageous" statements
The best single source documented explainations with many pictures for forced woodgas induction is in Mr Vesa MIkonens book "Wood Gas for Mobile Applications". Search the web for listings. $121 euro's for mine. A Must Get if you are really vehicle serious IMHO. Especially relevent for EU conditions.
Another different Finn vehicle driving fellow here a member named Vesa Makinen put up much actual user information and advice on small vehicle engine turbocharger woodgas boosting. Go up to the LH top search box and search here "turbocharging woodgas". Look for the messages with his name on them.

Also read Chris Senez topic, "Nitrogen IS Not the Problem" still up in the "Forums" -> "General Dicussion" queues.
Then download and read this pdf member KoenVK loaded up;
It will clearly explain that nitrogen is not the problem for engine power. Hydrogen gas tweekiness IS. And just getting enough of this part of the woodgas componet into the cylinder along with enough air (with the best valve timing), (with optimal spark ignition), (ptimum combustion chamber shaping) are ALL factors more important than gasifier passed through nitrogen could ever possibly be.

I've avioded sending you on inaccessible chases to the Premium members side. The using info there on the WK systems show that if the gasifier system itself will produce the fuel gas in the best of current engine configerations you will get back the "lost" power without having to force induction boost.
If you are serious about actual DOing then you should join up to read and participate in the content here also.

Ha! Hope I haven't scared you away on your first message/questions!
Steve Unruh