That is fantastic and so simple.
Bob
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Yes, that is so simple and even if a burp or hiccup occurs (emptying the tube),
it will begin to refill and reseal on its own!
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Very cool idea. simple is so much better. But it needs to be a pretty small tube right? If it empties due to a puff or something, it will need to refill rather quickly.
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Also, we have to consider the vacuum the gasifier will be under while running. This will determine how many inches the p-trap will need to be. I was informed of this on my first gasifier when I installed an actual p-trap.
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If you make a really deep one, then it should help with the puff problem too maybe. It can’t really be too deep can it?. Water will find it’s own level. As long as the pressure differential is not greater than the depth of the trap can handle without vacating right>?
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The one I saw on the anaerobic digester biogas system used a 1/4" ID clear plastic tube. I asked him if it ever got plugged with debris of anything. He just said no, and went on talking about other things without a hitch. I have thought since that it could have been made even more cheaply by using a street Tee in place of the lower elbow.
Rindert
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A long enough trap to prevent the water from being blown out might be kind of unweildy, but if it was a problem you could put some sort of jar or bulb at the end so that the water would just be puffed up into an expansion space and then drain back down into the tube.
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Over nozzled… and I’d use a 2" restriction.
A lot of the machines I’ve ran, around 300cc I used 4 1/8inch nozzles
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Reply to KristijanL and Bobmac - Well I finally got around to implementing your suggestions. I made the gap as wide as possible, which is about 4 inches, up from 2.5 inches. (It can be wider, but if I make it more than 4 inches, I need to change the reduction tube) I also made sure there was 15% water added to the charcoal by weight, and I made the lumps of charcoal bigger, average 7/8 inch, which I figured more suitable for downdraft.
I was really amazed what a difference it made! The generator started up after about 25 minutes and ran for 90 minutes. It sounded just as good as when running on propane, and had no trouble with normal loads. I plugged it into the battery bank for my house and it didn’t work at first. But as soon as I increased the tolerance of the frequency on the AC in of the charger, it accepted the current from the generator no problem. It felt so good to have all that power coming from the trees growing all around. Anyway, thanks a lot to all you guys who helped, as I now feel a genuine grain of confidence that I can actually do this process.
https://www.youtube.com/watch?v=wUPD-UH2l0c
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This smile is wery familiar 
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Greg,
Congratulations on your success. Nice to hear that generator running up to speed with a load.
Steve
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Congrats Greg , i had been wondering only a few weeks ago how you were getting on and now we know 
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Thanks! Yes, the little 3500 watt generator ran most of the time supplying only about 600 watts, because that is what the charger was drawing. The batteries were about 89% charged already, so the charger works in absorption charge mode, where the maximum current draw to the batteries is about 10 amps. At the 56 volt charging voltage, this accounts for the 560 (about 600) watts that it was drawing from the generator.
The battery manufacturer says the absorption current should only be 10 amps, but I’m wondering if I should set the charger to give 15 amps absorption current, to increase the efficiency of the generator, and if that could be done without hurting the batteries? It would be nice to use the full power of the generator most efficiently.
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Yes, and I’ll always remember that tip about using my drill to start the generator, instead of hand pulling the rope. What an incredibly easy way to do the job. Though if my gasifier is working properly now, I might be able to just rely on hand pulling again.
I read that using a generator of any kind to charge batteries above 80% state of charge is very wasteful. Generators should only be used below 80% state of charge. That seems to make sense to me. Is that your experience?
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Yes, I actually had a bit of insomnia because I was so happy! But don’t worry, I’m getting used to it. I’m starting to think about getting my car running on wood. Just thinking though. . . . Is there a page where you describe your charcoal making method?
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I tend to run my generator when the solar panels are not getting enough sunlight , and because all my batteries come from the scrap pile i tend to run them right down and then start generator to charge back up during low sunlight hours, and while the batteries are taking a charge i will use the the generator on my drop saw as well to cut fire wood for the house fires and pump water up to my rain water tank .
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I agree with this, and what Dave said. Only fire up the generator when the batteries get low, and then while you are at it, do some other work while it is going. My old battery charger would put in about 20 amps during bulk, and then slowly drop down, so once it got to like 16, i would just shut it all down.
I just actually switched over from my old lead acids to lithium house batteries. The voltage was starting to sag quite a bit, so I decided to get them replaced before they just up and quit on me. If the warranted lifespan (10,000 cycles at 80% DoD) is true, they should end up being a pretty good deal, although the up-front cost is obviously still pretty big.
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January 2023 Update: I have run the unit several times using freshly made charcoal with 15% water by weight added. It was only because of this group that I was able to get it working - Thanks so much. Now, I’m using the wood gas to run a 3500 watt propane generator, which is charging a battery bank, but the generator will only give a max of 1134 watts.
When the charger is set to Maximum Charge Rate and turned on, the charger shuts off immediately. It’s like it draws too much current and the generator can’t supply it. So I dialed down the charger’s Maximum Charging Rate to 13% and it stayed on, supplying 833 watts constantly to the batteries. I slowly increased the Max Charging Rate and the highest it would go was 18% where it produced 1134 watts for a short while. At 19%, it shut off immediately.
On one trial, I noticed, that while running, when I hit the retort with a rubber mallet to settle the charcoal, the charger shut off, though the generator kept going.
I have tried the same propane generator with propane, and it produces the appropriate 3200 watts. So how can I get the gasifier to produce a higher quality gas, to sustain the power needed for the higher current draw when I increase the Max Charging Rate? I expected to get more than 1134 watts, using wood gas on a 3500 (rated) watt propane generator. Any ideas?
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It sounds about correct in terms of power output on charcoal gas, even with the moisture adding some hydrogen.
With my Mazda B2000, the engine brand new was rated at 80 Horsepower and it was probably fairly reduced after 200,000 miles when I bought it.
On charcoal gas it had the acceleration of a VW Beetle with one of the smaller engines. 5th gear Overdrive was out of the question it simply didn’t have the power to maintain speed in that gear. My best guess was maybe 40 or 50 horsepower on charcoal. It was fairly zippy on gasoline.
Does this generator only have hookups for propane or did it also run on gasoline? Some propane/NG only engines have higher compression to compensate power loss.
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This generator has a hookup only for propane. It has no carb made to handle gasoline. Thanks for your experience. I didn’t realize the energy density of wood gas was so much lower than propane. I guess the solution is to get a bigger generator.
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