Next is your filter system. A good system will have very good cooling. The cooler your gas the more energy potential pr volume it will have along with better moisture dropping. This is not a steam injection system and steam injection does not work by simply introducing moisture into the intake air steam. Wet fuel equals wet fouled spark plug, resulting in weak engine performance followed by the entire system crashing and angry operator
Next is gas scrubbing if the gas is not clean enough add more filters. Easy enough.
Run time, a good system will meet the desired run time simply put. Pellet fuels are the best option to meet long run times. They are three as energy dense pr volume as most other fuels and you dont need an auger feed. They can simply be gravity fed via a huge hopper and are the only fuel capable of flowing through a reducer to the hearth. Someone mentioned this fuel is energy intensive to produce. In the bigger picture it is no more energy intensive than any other fuel and it is far more viable. First thing I want to address is auger systems, to bulk feed chips; you need a minimum 3 HP motor and it will still jam I guarantee it. Every time this auger runs its 2.2 kW of energy input to bulk feed chip fuels. This a big loss in energy some forget to factor. Chipping fuel with the smaller chippers will generate waste. 25 to 50 % of what you chip will not be usable. The energy you used to chip that fuel is wasted, the energy potential of that fuel is wasted and your time is wasted. Pellet fuels only require a cheap wood chipper / mulcher and you only need to process the amount you need;; all of it will be used. Chip fuel sorting is not fast or fun, it takes time and your energy. You will have less time into feeding a hammer mill that can process 100 lbs of fuel in minutes. Then a 3 kW pellet mill can produce 150 lbs of fuel in an hour. This can run directly from the gasifier so basically its fueling itself as you can get them electrically driven. As for the other equipment you can run that on charpellets using a small charcoal unit. The charpellets from the wood gasifier are perfect fuel for this, with very little screening effort. So zero gasoline input here. Keep in mind I am talking about bulk feed systems here. If an hour run time is satisfactory then chunk fuel is probably the best way to go. But for me; my clients want these machines to run 8 to 16 hours a day with zero intervention. Turn it on and forget about it for the next 8 to 16 hours. I have achieved this with these machines they will run until they are out of fuel and its easy to do, as you do forget they are even running. Those that have experience know what runtime anxiety is; where you are constantly listening to your machine so that you can intervene to keep it running. A good wood Gasifier does not have this issue.
Only issue with pellets, is they will not work in a traditional down draft gasifier. You need to control combustion moisture so it can not migrate into the hopper and foul the fuel. Otherwise it will soak it up and turn to mush!. The Drizzler or my system are the only systems I know that will work. I will open source my tech but you will need to sign an NDA.
Matt, l have run pellets on a more or less traditional downdraft. The trick is simple. Keep the heat in the hopper above boiling point of water. My insulated hopper on my Chevy got up to 250 c, estimate, enough that the wood on top of the hopper started turning brown. No chance of moisture here HOWEVER l only filled in pellets for long highway drives. The goal was l burn a whole hopper of chunks after the pellets were gone, so that the gasifier cools down on chunks.
Well, except in case the pellet level was low enough that the pellets were allredy partialy torrefied by heat. But it was a risky buisness, stoped doing that after a few times l had sawdust to clear out…
Oh, by the way, since we are at it… there is allso a fuel that flows good, doesent turn to mush when moist, requires litle to no energy imput to make (even emits it!), doesent contain tar… can anyone guess what that is? Hint: its black, begins on C…
Well Tone as you read there is a big divide in the wood-for-power endevor world on a number of issues.
Train-make smarter Operators? Versus making systems dumb-dumb, push buttons useable.
Use actual trees wood as an input fuel? Versus gasifing everything else; “bio-mass”.
Develop and promote designs DYI capable? Or: solutioneer a patent design to be sold to anyone able to come up with the money to buy it. Or; have Gov’mint agencies buy your design. Become the next Winchester, Edison, Elon Musk.
Anyhow from your topics title I must assume you intend to use actual tree wood. So on your proposed design any experienced wood gas operator could make what you’ve proposed work.
With then later cursing difficulties within hours of useage.
Your below grate ash bin is too volumn small. Gas velocity down through the grate will be contioualy floating the ash to be drawn up. with the gas. Never allowed to settle in-place for collection and removal. Matt Ryders system picture above shows a huge below the grate area. He learned.
Some actually design for for intentional removing the ash with the gas and then outside the hearth system ash/soot removing immediately in a hot cyclone. Then they take out gas-ash-soots down low. Not bothering with the tall double walled system.
You propose a lower fuel hopper shaking ring? Why? This will cause fuel bits hanging up. Yet would use a non-active grate.? You lose me here. I will only bother anymore with a active capable, gas by-pass, grates. And no cyclones. Settlement areas. Simpler. With a wider good gas-use range. Example. The V-8 engines supplying WK’s able to for hours supply a small single cylinder electrical generator.
No cyclones. Large settlement/separation areas.
Actually hard using wood gasifiers and what strikes person is the severe temperate gradient differences between the different system zones. You must design to accommodate systems materials temperature driven expansion and contractions.
Then the inner system ALL hanging down factory Inbert systems begin to make sense.
These only had one lower system connection point at the air-in/lighting point. Then the whole inner could heat expansion/contraction float in three directions.
Your will have much problems with cracking and then leaking at the back side air nozzles area.
The GEK and MENS use long flexible capable individual air tubes. Works for both the temperatures expansion/contration. And intended air-in preheating. Too complex for me. There are much simpler systems.
And I think you will run into much fuel chunks hanging up at your above the air nozzles slope. Tars run down and collect here gluing.
Trick designs use the rising oxidization zone heat on the under side of a metal slope-cone here. Heats the tars to runny. And lighter fraction vaporizing to be gas flows drawn down. The heavy tars fraction then drip down right onto the air nozzle faces for final destruction.
Ha! Ha! I do not wish to be too critical.
I am strongly in the make something,; anything to get into using, learning. as soon as possible.
Then modify, improve that to your own particular circumstances.
Only got a declared no-no oak wood? Experience learn to use that.
Only got super high ash wood like cottonwood/aspen? Use learn to operate with that.
Only got 20-25%, even 30% moisture wet wood instead of “ideal” 10% moisture wood? Learn to operated with that.
Live where water is a solid for 6 months of the year? Ha! you will not be using water washing and condensing systems!! Hint. Hot produced gas bypassing in large passages ways clears them of ice blockages.
Mistake to across the world, do one-world desgns. Even the great Inbert Company ran into problems with their systems proven on European woods when deployed into South America. Required in-country modification for the different woods and hot humid climates.
Thanks Mr Steve, very constructive. I think Tone and me are after the same thing: a small gasifier to run a small generator.
I am thinking of the gasifier plans from Ben. He delivers cad files. Cut it out, weld, assemble and put it on fire. I don’t have time to shop for used material. Cut it from new plates and off you go, sorry.
JO had some interesting plan, could deliver some plates…
Hello All,
Winter slow time now. Time to deep think.
Tone I want to introduce a new approach system that I am trying to evolve.
Inputs + Outputs = fulfills Goals
So to work this Logic system would have to be expressed:
Goal to achieve = the sum of Inputs +/x the Outputs generated.
I have re-read and reviewed this whole topic again.
Except for JoepK.'s last post there is no pre-stated Goal/woodgas use.
To not have this then wood gasifier developing is:
Inputs + Outputs = Whatever occurs. ??? What? Blue flare gas? Woodgas as a further chemical input for molecules building? Woodgas to burn off for heating? Cooking? Direct combustion illumination? Woodgas for IC engine fuel powering?
And this approach without a fixed driving Goal is the Lab-rat/White-coat exploratory, inputs subsidized way. And the subsidizing supporters interests fades, they move on and leave.
If for direct IC engine fueling; then what is the working purpose for the IC engine?
Mobile different from stationary.
And size does matter.
Your recent posts on your home life with your long chunks wood chipping for your home heating gives many hints.
In this time of winter slowness thinking. Read here on the DOW of the different charcoal gasifiers working.
Approach a wood gasifier as a charcoal gasifer that makes all of it’s own charcoal internally.
Or not.
Kristijan’s more flexible hybrid fueled system has much merit.
And Joni systems do make blue flare clean gas and IC engine run.
So a challenge.
Is your Goal-to-be-achieved important enough to use someone else system.
Or is Made-By-Me the actual Goal.
I read this description that Til showed, and have a question. http://www.gengas.nu/byggbeskrivningar/smp/kapitel_2.shtml
Why is the distance between the restrictor and the bottom of the fire tube reduced, according to the size of the restrictor?
I saw that @Joni, has a very small distance between the restriction and the bottom?
Hello colleagues,
today is the day that can really show whether your car is good on the wood. in the morning my thermometer read “-15C” and it made me think about whether I could start up and leave for work … Fortunately, my system did not let me down and I am already at work …
I think this was interesting, if it is true and I interpret it correctly.
It looks like the calorific value increases a bit if the wood is not really dry, I can understand this completely wrong as well.
Also looks like it would be better if the charcoal to go up on the outside of the firepipe, due to the insulation, that should be right? http://runeberg.org/tektid/1945/0333.html
Jan,
The fact is that when wood (cellulose) burns, chemical water “Dulong water” is released and this water is enough for gasification of even absolutely dry wood. Proceeding from this, I dare to declare that any moisture in the wood only interferes with us and does not lead to the addition of the power of the wood gas generator. As far as charcoal is concerned, yes, the addition of moisture increases the hydrogen concentration in the gas produced, but everything is within reasonable limits.
Joni, I agree woodgas and cold temps seem to work very well together. It’s my experience cranking up on woodgas works even better than on gasoline when it’s really cold
My main problems are condensates. We’ve had a moderate -10C here lately, but I have only 15 km to work and it’s not enough to melt anything. I will have to make a longer trip really soon. BBB
Thanks to everyone who shares their experience and knowledge, I tried to draw another sketch, a system with a center nozzle with side holes and the possibility of shaking. I intend to use the system as a stationary unit to drive cogeneration. What is your opinion?
Mr. Tone; I don’t know if you have read it before, but anyone who has and uses a gasifier, has said at sometime or another, “the secret to running a gasifier is 75% operator knowledge and 25% gasifier design and construction.” I suggest you take the most simple proven design (as much as any are proven for universal use) and construct it using the BEST of your talents. Then, go through learning as much of the 75% that can be learned, until you have reached a sufficient ability. And then, think about building something of your own design. I mean no disrespect. Just trying to point out the importance of the operator over the designer. TomC
I must say l agree with Tom here. It is good to start by making a good clasical lmbert first, to establish a baseline. Then, by trying out new ideas one at a time, make it better! Afterall, if you dont know how a “clasical” gasifier performs you can never know if your design works better, or worse…
I think l remember counting l built 11 gasifiers for my 3 woodgas cars and only now l am starting to get a feeling of how a good woodgas system looks like and thats not counting the litle differences like hopper designs, coolers, filters etc…
