Brian,
Thanks so much for sharing this project. Kristijan and Matt adding their insights to your determination makes this a great topic!
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Sounds like this idea is never going to work. I really thought the ammo box was a down draft.
Maybe that’s why most of the small engines use updraft.
I’m going to move it to the corner and just use the simple fire.
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Can you revise it so the exit port is oposing the inlet port? We can still make it work and build it into a cross draft. Keep your nozzle where it is. Just one nozzle is all that is needed just like the simplefire. Then punch a hole for the exit port about 4 inches lower on the oposing side or what ever room you have. Then take that expanded matel you have to place over the exit port that is your grate. Dont build any chambers below unless you can fully seal them. Otherwise gas can bypass the reaction zone and bias to the chamber. Since it is small there is no need for a lower clean out anyways.
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Cody,
Thanks for posting in this topic. Your comments and ideas keep the creative juices flowing. I hope Brian hangs in there. Are there other simple downdraft posts hidden away somewhere here on DOW?
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The few experiments that I did ended up in melting my nozzles. Both times I tried just running moistened charcoal with no water drip. That was with the Diagonal Draft single nozzle. I have no idea why both the 1" and the 2" could run my truck but both wanted to melt.
The silicon carbide nozzle was turning to glass, so I aborted that. The super heavy steel nozzle melted down after just 3 miles of driving.
This is why I say to use pipe nipple for nozzles, that way it’s replaceable without need to re-weld.
As far as downdrafts, the only super simple builds I could think of would be one of Stephen Abbadessa’s downdraft gasifiers. Like his Anastasia or Isabella gasifier. Very simple construction and made for small engines.
But this runs on large wood chips.
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Here’s what I have.
I could cut off the exit pipe closer to the side but it would only give about 13 inches to the nozzle hole and I’d probably want at least a short replaceable nozzle instead of just a hole.
If I move the nozzle up a couple inches I could get closer to 14 inches but that would only give about 5 inches of charcoal over the nozzle.
Looks like when I had blocked off all but one nozzle and got a flare I only had about 9 inches between that nozzle and the grate.
If I hadn’t drilled all the nozzle holes this would have just turned into a small charcoal making barrel. Forced air through the outlet pipe under the grate and plug that pipe and put the lid on when it was burnt to coals. Wouldn’t make a lot at once but looks like it would work. I only used the blower a little bit. I drafted good enough without it.
It could also be turned into a small foundry, a forge, or a grill so the tank will get used even if it can’t be a gasifier.
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Try it will it going to the top. I actually wanted to experiment with reversing the the nozzle and exit ports. This way you can lower the nozzle down and increase the usable fuel per hopper load. When the fuel is consumed it will bias to the front where the nozzle is and not to the back. It actually should work better.
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This was what I originally was hoping to run off this gasifier. Only 5.5 HP so basically the same as my generator and log splitter.
The front deck is plastic so it would need raised up a little but it’s self propelled so the weight wouldn’t be a big problem.
I haven’t checked it out but it was likely carb problems that parked it.
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I hadn’t considered that. Somewhat an updraft with the outlet buried in charcoal with a grate?
Could be worth a try.
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If you are stuck for Hight try what i did i had a 20 gallon drum i placed a nozzle about 10 inches off the bottom then i made the gas outlet underneath at 1/2 inch off the bottom now imagine those nozzles are at the 6 o’clock position ,i placed a thin stainless disk just above the gas outlet pipe between them sealed with ash but the far end ( at the 12 o clock ) position had holes drilled in it to allow dust and gas to be sucked down as far away as possible making the gas travel a fair way through the charcoal and down and along below , it did work and also made generator power very fast from start up , but after 1. 1/2 hours the gas temp was too hot for my liking but that’s no biggie with gas cooling and a outer skin on the barrel to stop anyone burning them selves .if i can find some old photo’s i can show you if u want .
Dave
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Yes, Dave. I like it. Show us your downdraft. How thick was the ash that sealed the stainless disc. Would a thicker layer help with the high gas temp? Would a 30 gallon or 55 gallon drum work better?
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Dave, is this what you mean?
My nozzle hole and outlet pipe are already at opposite sides so I don’t think this would do any good but sounds like it should work if the in and out lines are on the same side.
Waiting for some more stove rope for the lid and figuring out how to hold it down.
I think this was one of Matt’s methods.
I’m probably going to weld up all the drilled holes except the one furthest from my bottom pipe and fit some kind of nozzle. I like Matt’s idea of reversing the in and out to possibly get more charcoal before it needs refilled but that would mean cutting that pipe out and fixing the resulting hole. Might be worth doing (or trying) if the run time isn’t long enough.
I’m not sure either way would make it like a real down draft and able to handle less than perfect charcoal without producing tar. That was a big draw to making a down draft in the first place.
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Brian do you have any old steel fire extinguishers?
You could extend the zone by making that the new gas exit. I’ll try to find the video from a Brazilian gentleman that made one for his car.
He made two cross draft gasifiers. This one is for a generator.
Check out his channel, he has more videos.
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Cody, that’s a nice idea. I have one small fire extinguisher body that I might use as my water tank but it’s aluminum so I can’t weld it.
One thing I thought of (too late for this build) is my connecting ring should have been welded to the lid instead of the body.
This is my filter from the simple fire and rain could get in the way I made it. The seal will stop it from getting inside but something to consider for future builds. Less chance of water laying inside to rust or freeze.
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Just make sure to leave a tarp or piece of sheet metal over it when not using.
Also, you could use just about any larger diameter pipe or tubing, I just mentioned a fire extinguisher because they’re made of sturdy material. If you lived in NC I’d give you some!
Do you have any local scrap yards that you can buy metal from? I tend to find the best stuff there.
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Yeah, there’s a few somewhat local scrapyards around.
I know some people that haul scrap pretty regularly but the ones I asked didn’t have any big pipe. I’m sure the scrapyard would. Just haven’t made a trip there recently. I’ve been holding onto my scrap for building stuff like this.
Used to be a good scrapyard that also sold new and used steel but it’s been gone for years.
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Here Brian is a clear w=example of a cross draft gasifier system for small engines.
The fellow says it is somewhat raw wood use capable. (Early on he looks to be maybe tarring up that engine. Smoke or steam?)
I have doubts on that part of his claim.
But fully believe it would operate just fine on wood charcoal.
He has another video presentation up on his version of a raw wood dozen draft build.
So keep sharp eyes out for any steel pressure painting cans! I’ve collected up two now for future use possibilities
S.U.
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Thanks Steve. I’ve seen that video before and it does have some good ideas. Reminds me of my first attempts at running an engine on woodgas.
A long time of just pouring out large amounts of smoke. I didn’t see any drain for the condensation and it looks like he kept the fan on the whole time.
I never got my first attempt to actually run an engine and gave up on it until I met Gary Gilmore and saw his simple fire CHARCOAL gasifier working. One of my problems before was just not knowing how to get the air/fuel mixture right but I was making flammable gas but it was really smokey and condensed a lot of water/tar mixture and still had tar staining the filter and the hoses. That first gasifier was supposed to use wood pellets just like the video showed. Wouldn’t have been cheaper than gasoline to run. Not saving money, taking a long time to start up, and the massive amounts of smoke and tar just wasn’t worth doing.
I have no doubt that all these youtube gasifiers can run an engine or that my attempt years ago should have been able to run an engine but I question if they could run the engine repeatedly for hours at a time.
I really want to figure out how to run on raw wood or at least less than perfect charcoal or a mixture of wood and charcoal but I’m not sure that’s even possible with the small engines I want to run. I don’t want to have to run a blower continuously.
I made another batch of charcoal today since it is raining and I’ve been using up a lot of the charcoal I had. Takes some time to make the charcoal and get it ready to use in the gasifier but it would take time to cut and split the raw wood and, if it took a half hour to get the gasifier running good enough to start the engine I wouldn’t use it as much as I do the simple fire using charcoal. I’ve started the generator on charcoal and shut it back down after 10 minutes (like to fill the air compressor tank or run a grinder or saw for a quick job) and have started it and run it for a couple hours at a time. Easy enough and quick enough that it isn’t a big deal to use in place of gasoline.
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Ha! Ha! No I wasn’t saying to take his experiences as gospel. He is a one-off man. No weld is so limiting when dealing with metals.
Just observe his materials usages and assembly ideas.
The one air jet down from the top cover fully configurable. Farther up/down/in&out. Cross drafting to a side pocket gas collector.
Small and light enough for the small engines you want to fuel gas.
Those paint pressure pot walls are thicker than propane bottles. Have a grooved flange cover already.
S.U.
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Thanks again Steve. I just watched his other video where he didn’t limit the build to no welding and it looked closer to what I had before except mine was just a couple buckets and no real burn tube. It also didn’t have any nozzles (not counting the ignition port) but drew the air from the top through an opening.
If I’m undestanding you, The one jet (hole in his lid) could be a different nozzle and in a different location. I assume if you did it that way the top would be sealed air tight.
I did like his use of scrap and the cooler (radiator) was different than mine and considerably bigger. I have the hot gas going in at the top and out at the bottom. Reversing that might be better. Of course, his is down draft and my simple fire is updraft plus I’m using charcoal only and his is wood pellets but gives me ideas.
He did mention that it shouldn’t need the blower when running an engine and admitted that the gas should be cleaner than it was.
I’m guessing that’s what you meant by “one-off man”. Built this, made the video and moved on to other stuff. A million and a half or more views for each of the wood gas videos so there must be an interest in this. I didn’t notice any advertisements and he doesn’t post a lot of videos so obviously not making his living from youtube. He could be using wood gas and not making new videos about it or stashed it away somewhere just in case.
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