Properties of a good wood gasifier

I believe they are stone cutting drill bits. Typically hollow and made of very high carbon steel.

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Hey Trigaux,
Why don’t you just use a pipe? I’m sure the only reason Tone used a hexagonal piece was just because that’s what he had lying around.
Rindert

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Hi Rinder
what I understand is that these old drill bits had a very high carbon content, which made them very heat resistant.

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Rindert, these drilbiIts are purpously used for this. I use them as nozzles too, for “clasical” gasifiers. They are just the right size and thickness, but most of all, wery high carbon steel. Somehow this has shown to be important for hot, oxidative enviroments.

Thierry, you can use any high carbon steel of good thicknes. Torsion rods, axles
 but you will need to drill them. To do that its best to aneal them first, heat the peace to orange heat and let them cool as slow as possible, in vermiculite or in the dying forge itself.

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Quarry’s or blasting companys use to have them, if its a welded hard metal “edge” and the edge brokes, or is worn beyond sharpening, they often throw them away, even the modern ones, with replacable “crown” can go bad, or bend.

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Thierry may get lucky if he looks for “Tool steel” grade DOM tubing. I’m sure there’s some sort of high carbon hydraulic tubing.

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thank you for the answers guys. What do you think, for a vertical nozzle, to use a simple piece of pipe topped with an engine valve (the valve stem threaded into the pipe)


excuse the quality of the drawing. Sketchpad is a first for me today
air enters at the bottom and exits at the top of the pipe into the hot coal. The valve acts as a baffle and heat shield
Thierry

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If it’s not clear, don’t hesitate to ask me questions.

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Trigaux, very good idea, I just sat down in my thinking chair when I turned off Fergi, who has been driving me to work during the day
 hauling wood, driving a circular saw and a screw chopper,
 when you have fire, it is necessary to work.
The valve from the engine, especially from some Japanese vehicle (Subaru, Honda,
) is very temperature resistant, it is cooled by fresh air below, and above it will be coated with ash, this should bear all thermal loads. If you used a used ball bearing for the tip of the nozzle, it would be a great product. The essential thing about this blowing of air is that the heat spreads to the side, where the flow of gases is towards the engine and a wide area of glowing coal is formed, which can produce gas for a fairly large engine.

The valve in the picture could be bigger, or the bearing could be smaller.

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Tone I’m glad to have your support.
I imagine that the air passage surface could be easily modified by moving the valve up and down. :wink:

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Thanks for that. I learned something today. Now I see why Tone showed us a picture of his masonry bits.
Anyway, this is a piece of an axle shaft from a 1998 Bronco. I heated it orange and then let it cool slowly in an old coffee can surrounded by charcoal with the lid on so the charcoal wouldn’t burn up. It is soft. I can use regular metal cutting tools on it.
Rindert

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Tone I know you are looking for any heat loss in your gasifier. so I was wondering if you knew the “pyrocoil” from the company All power labs?
http://wiki.gekgasifier.com/w/page/6123805/PyroCoil

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Thierry, this is a excelent idea!

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Beware of excellent ideas that add fabrications complexity. Add mainteneces points. Add failure points.
Engine heats inputs are better applied by reducing down the raw fuel wood moisture and pre-warming the raw wood just before adding into the hopper. Then the gasifier system can be single wall simple, not condensating.
To better heat boost the tar ring section Ben Petersons’ original Woodie model gasifier and then his later book system route the hot produced gasses first past a simple inlet air loop. Then around the tar ring zone; as an “pyrolysis accelerator” before exiting the gasifier hearth. Removing some of the heat from the gas and internal slowing it he had to enlarge the the drop out pocket and cleaning out trap.

Tones proposal is to preserve the core reactions heat in a charcoal system by temperature energy wrapping the core with still hot produced gas. Let the hot gas lose the external heat. Not the core reaction area.

Way back Australia Kurt Johanasson did this with his triple shell raw wood gasifier system.

So not a matter of who copied who. They were/are all realizing better uses for all made heat energys will give better overall boosted performances.
Heat energy is only wasted, if you waste it. Do not attempt put it to some useful work.
Max gasman was always saying to stop heating the crows.
S.U.

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Thinking about very high carbon material. I have heard many times that cast iron is very corrosion resistant. It has higher carbon content than any steel. Perhaps cast iron would make durable nozzles.
Rindert

P.S. But of course Silicone Carbide (Hexaloy) would be the ultimate.

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It does have a wery low melting point thugh
 and bad thermal conductivity. But the good thing is it culd be cast in any form so thats good. Easy to machine too.

Speaking of wich, l tryed throwing a bit of cast iron in the forge a while back and l was surprised how easy it melts. Im thinking of giveing casting a try someday. I love cast iron cookwere but here you can only buy enamel coated ones wich are crap, and they cost a kidney


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I realy like the charcoal cooling method. Will use for sure.

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If you do it maybe you can make money that way. It used to be a “cottage industry”, meaning one person could do it in a shed behind the house. The hard part is making patterns.
In modern times most patterns are made by CNC. So then, if you have a CNC machine and really know about the metal casting industry in your area you can maybe make a living as a pattern maker. But you have to be very good, because now people expect everything to look perfect.
Rindert

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In the topic about the tractor, we nicely developed the thinking about the production of caloric wood gas, Goran and Bob state that when the fuel starts to run out, a very strong gas appears, how would one explain this? Obviously, the temperature in the hot zone with charcoal rises a lot, thus the steam and pyrolysis gases are completely decomposed and strong gas is produced, and in all probability the entry of fresh air is also minimal, because the expansion of gases at elevated temperature is large. I notice this situation with my gasifier when I put more load on the tractor for a while
 What did I do differently in the gasifier than what is done at WK? The biggest difference is in the size of the air nozzles, and I think this is essential. If we make an experiment and blow compressed air into the embers through a small hole, we can see that this method ignites the charcoal much more than a gentle breeze, and I also believe that in the first case, much less air is introduced. I think that the narrow and fast jet of air also drags and swirls the pyrolysis gases, which penetrate deep between the glowing coals and thus the conversion of gases takes place at a high temperature. I will mention the lower nozzle again, where the negative pressure is the deepest and thus the air velocity is the highest, there is an area of fine coal, coal dust and ash that collapses from above, probably a “bubble” of coal plasma is formed here, which transforms the remaining superheated steam into flammable gas. Some time ago, we said that this air supply can be done with a valve from the engine and a ring from the bearing, well, it would make sense to cut notches in the ring from the bearing, similar to how a gas burner is made on a stove, it is possible to make the notches at a slight angle, in order for gas circulation to occur.

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Yes Tone, I see that the Imbert design uses a much smaller nozzle holes which causes a higher velocities of air blasting into the firetube area and have a different shape firetube, and lower velocities air blasting in the firetube in a WK Gasifier with much larger nozzle holes. The common things they both have is time, frequency of light and sound, heat or temperature, vaccum, air, moisture in the fuel but not the type of wood fuel, hard, soft, mixed or moisture content. You said at the end of the fuel run when the fuel was fully pyrolysis and moisture was removed from the wood that is now Charcoal, thus event happens. After pulling hard on your tracker engine going up hill. In my experience it is a high vacuum pull maybe caused by the charbed not necessary a hard pull or load on the engine, but it can be from going up hill.
So narrowing down, it sounds like at this point the wood fueled gasifier does a conversion changing over and becomes more like a Charcoal Gasifier in its operation. We know Charcoal gasifiers are lacking water/moisture so we add it. A wood gasifier has to much so we try to remove it. We also know this is a balancing act of being way to hot or to cold in making good gases out of a gasifier, what ever design type we are using. It seems there is this almost perfect zone to operate in with many variations. We just need to find it and operate in it when we can. Conclusion is if we can build a gasifier that can make and operate in this super good zone for long periods of time that would be the wining combination. You seem to be on the right track with upper/ lower nozzles.

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