Carl, I’m so glad that you will try the single 9mm hole. That seems very small compared to Gary G’s 1" or even Koen’s (5/8"?). I would love to find out how that one tiny vertical hole works. I hope we can capture some of your results and add them under the “nozzles for charcoal gasifiers part 2” topic.
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I agree, a single smaller nozzle hole will produce a higher velocity intense air jet, should be interesting to see how it may change reactions. It will tend to raise the reaction zone if aimed vertically.
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When i get a chance i will go out side and collect some charcoal from my gasifier that has been sat outside and not run now for nearly 4 weeks , its just a 55 gallon drum with no insulation over it and open to the elements and so would have gone through hot and cold and 1 engine run since last filled , i shall weigh and then dry a 100 grams and see what i get .
Carl what is the height of your new reactor ? from what i could make out on the photo its about 9 inched dia right ?
Dave
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The new reactor tub is only about 10" tall and its about 9.5" in diameter. My thinking is that I am going to put a flange on it, and it will then be able to be bolted to the bottom of a pail or drum. I figure that the height is going to be a compromise between run time and ease of cleaning/slag removal from the top of the hopper.
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If you can flange it so that you can increase the hight with a hopper then you will get a better run time , just make the hopper so it lifts on and off the flange or hinges in a quick release way , for cleaning out the nozzle .
cant wait to see the finished unit working .
Dave
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Yeah, that was exactly my thinking, and by making it a bolt-on unit the plan is that it could migrate to a bigger drum at some point. Here is what I came up with:
The top is just some 1/2" angle iron with little slits to make it bend, which I drilled and tapped some holes in. I nipped out the bottom of my old reactor to serve as the hopper. Also, i welded on a curved flange to the massive Leitinger nozzle. I drilled an 11/32" (8.7mm) hole, and will test that to see how it fairs. The hole is reamed out on the inlet side, and its super easy to poke a welding rod in there to break up slag. I am just blown away by how easy MIG welding is even with such a massive piece of steel.
Here is the Mark II model with everything RTVed and bolted together. I think I am going to fire up my charcoal retort soon here, and my plan is to make half a drum of hot coals, then dump on 15 gallons or so of engine grade charcoal that I suspect is too wet. Ill let that bake for a while, then seal it up.
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I cant wait for you to fire that up , nozzle tube looks great too .
Dave
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Now thats what I call a nozzle Carl, with all that mass of steel it should last for a long long time. It will be easy to clean the nozzle hole out with a poke rod. If you could make it so water could lay in the bottom half of the pipe it would heat up and the vapor would go up through the nozzle and produce more Hydrogen.
Bob
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I need to think about how I am going to close this thing down at the end of a run, but the thought had crossed my mind about putting a little lip across the bottom of the tube. A simple water drip from above could fill up a little reservoir, and any extra would dribble out the front. I found that a lot of little burning pieces of char would fall out of my other system, but with the smaller hole I suspect I will have less trouble with that here. Either way, I like that anything that falls out is going to be contained, as it made me nervous when the wind would send little burning embers skittering off into the shop.
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Carl shutting down will not be a problem just make a plug out of some aluminum foil rolled into a ball and placed just inside the tube or even a lump of clay or anything non combustible really .
when i tried out my tube i had the gasifier on a gentle slope so that most of the excess water drip ran straight out the tube and the rest was turning to steam straight away , ass i said before next time i try the thick walled tube i shall go straight through the reactor that way water will flow in one side and whatever isn’t turned to steam will flow out the other side , plus the added advantage of have extra air coming through will also help cool the tube .
Dave
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Okay, I finally got some dry charcoal sifted and ready to go - the sample I tested last night had a 1.3% moisture content. I dried out about 30 gallons by dumping into about a quarter barrel of hot char in my clay retort.
I was still having trouble with no flare, so I suspected I had a leak somewhere between the hopper and the reactor. Half a tube of RTV later, and I was in business.
Once I got the mix dialed in it seemed to run as well as it ever did on gasoline. Seems like once the engine warmed up, it wanted a little bit less air to get a nice nice even idle.
I plugged in a 6amp angle grinder, and loaded it down a little bit - which worked just fine. I didnt have a watt meter with me, but at some point I would like to try and find its maximum available power.
All in all it feels like a good starting point. the temperature inside the nozzle got up to 750 F near the hole, and stayed at about 400 F at the inlet. For not having any EGR or steam, that seems promising, right? The reactor tub did get pretty hot - it was reading about 400 F when I shut it down after about 15 minutes of run time. I am thinking about maybe welding on some fins to dump excess heat, any thoughts on that?
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I do that plus have the air intake bring fresh air past the fins and hot air into the intake.
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Are you trying to use the heat to create more steam? I seems to me that colder intake air would be more desirable, and that re-introducing any of the heat that had already escaped the reactor would only serve to accelerate the heating of the fuel (and eventually diluting the gas to the point of it no longer being able to run an engine).
@KristijanL, you are the expert on this type of nozzle, I wanted to hear what you think about EGR vs Water drip? Also, have you ever taken temperature readings of your nozzle? What do you think about the idea of putting a little lip across the bottom of the tube, thereby making a little water reservoir inside?
Thanks everyone for the input, Its exciting to have something that is actually capable of doing work!
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What is the sizing on the charcoal and what wood species did you use? Could explain the heat.
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The charcoal is mixed, but mostly hardwoods like cherry and maple. Its graded by what will fit through 1/2" hardware cloth, and not pass 1/8". @k_vanlooken, you have made small gasifiers with a small tube on the bottom, like 6" diameter maybe? Did they tend to get hot on the sides?
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Re-introducing lost heat should increase efficiency allowing higher humidified air and less nitrogen. Fingers crossed!
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Hi Carl,
Yes, the tubes are small, 5" standard, 4" smallest.
Depending the load , engine size, i can make it hot on the outside, i have some heat pictures on another threat.
Using the heat to pre heat air or fuel does benefit the gas efficiency or at least the fuel consumption.
For heat transfer and materials there is a logical path to follow… where is the heat flowing to ?
( Logical from hot to cold )
The small size tube is creating a kind of balance between descending (cold) fuel with the ascending (hot) gas
Carbon / charcoal however is also a great insulator…
If your nozzle protrude far enough inside the drum, the outer walls will stay cool.
Practical, i could build a charcoal gasifier from or within a plastic drum… just need to know where as i am going to bring the heat from the nozzle…
To give a number; for each pound of carbon gasified to CO you generate about 4000 BTU of heat
The more heat you get in the fuel (preheating) the more efficient your gasifier will be ( higher CO % in the gas )
Thats why i keep the vertical shape, hot gas passing thru the charcoal, gas exitting cold ( ambient)
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Congradulations on your fun! Wellcome to the black club 
I am no expert althugh l have been useing it for a while
Well they both have advantiges. EGR is simple, self metering and adds to a lot better fuel consumption (up to 30%) but does nothing to gas quality.
Water is a bit trickyer and can lead to problems but the gas is A LOT faster and richer. Once you start adding water you must open the mixer walve some as the gas richens.
Sure, a lip wuld work. If l were you l wuld test the setup well first and if you are happy with the power, go with EGR. If not, start thinking about water.
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Nice one Carl , now drive down to the shops and get some lemons
Dave
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I tested the output of the little generator with a watt meter today, and used a shop-vac as a continuous load. I have a tach on there now, and so at 3500 rpm it is putting out 120v, but as soon as i loaded it with the vacuum it would drop to like 3100rm, and only 90 volts. It was showing it as a 600 watt draw. I might try and round up some resistance loads to play with, as I dont want to burn up my motors with the erratic voltage output on this thing.
Mostly this is just a way to test everything, so I am not too concerned with my actual output for now, but I might play around with water once I get a better feel for how much power I can get on just charcoal.
I feel like I have heard 30% thrown around as an anticipated reduction in power from woodgas - and that it could well be more with these small lawnmower engines? I suspect that the nameplate rating of 2000watts is also fairly ambitious even when it was brand new.
I would like to hear from anyone who has done a generator project - how much derating should one figure on? Ultimately I would like to be able to run 20 amps at 120v with a little bit of cushion for surges and such. I had been thinking that a 5000watt gas unit would be enough, but now I am not so sure.
@kyle, are you still playing around with your generator setup? I would love to hear your input.
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