The bag filter will only work if you mix charcoal with the wood to keep the moisture down. Pure woodgas will plug things up.
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Good to know, thank you for preventing that snafu
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I intend to design this to run raw wood, in the event I don’t have any meaningful amount of charcoal to add just in case.
I don’t really want to trade one special prepped fuel for another one, haha.
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Success! I found another 20 gallon drum at the scrapyard. This one was in the best shape. Very pleased to see how little rust it has on the inside. Lid as well. The locking ring is very tight but I’m replacing the gasket with high temp RTV because it’s some kind of neoprene stuff. I can take that dent out just fine and it’ll be great for the lower half.
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If I use the car rim and the two barrels stacked up as a guide for how tall this unit will be it will get just a bit taller than a 55 gallon drum. Not too bad, it’ll give the hopper some direct cooling while going down the road.
I’m going to see if the drum from a washing machine will fit inside the hopper to give some dead space for condensate to run down.
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Got the worst of the dent taken out of the bottom drum. I don’t have any body hammers so I’m working with a 2lb mallet. It’s good enough for me since its just gotta hold ash. Lid seals up fine.
Still just doing eyeball measurements for my air jacket and whatnot.
I think I’ll only need one 20lb tank for the jacket. I’ll split it at the original weld seam so I have a straight line to go off of for re welding.
Cut holes in the ends to fit the compressor tank and go from there. Not sure if i want to leave a little extra of compressor tank sticking at the top to give more of a tar fence. I don’t think it’ll need it since it’ll be venturi ejected. The propane tank air jacket will sit somewhat inside the car rim hopper extension and I think that will give enough room to let liquids collect and eject out the tube.
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So for the time being cutting down wood chunks I’m going to be using my old mitre saw. Have a spare sawhorse I never use so I’ll attach a surface to it set at an angle and bolt down the mitre saw. That way when the piece gets cut it’ll fall down hopefully into a bucket or small barrel. First fuel size I’ll try out will be quarter of a cigarette pack, or if from branches like golf ball sized chunks. Being a 10" burn tube I’ll have to keep pieces small and I don’t necessarily mind that. This size will be my reference point/benchmark for whether to go smaller or bigger pieces.
Since I now have a lower barrel I can combine the air intake and gas exit to another area for heat exchanging. I’ve got a fire extinguisher laying around that I can use for the gas exit and give room to have 2" pipe with heat sink fins welded on for the intake. I’ll either use two floor flanges at the air intake side or just use a pipe union if those seal good enough so I can take it apart for serious cleaning or repairs/tweaking. Drop box is another vector for heat exchanging so I should have plenty of opportunity to get the incoming air nice and hot. I’d like to find a skinny drum like a 16 gallon but they’re extinct or being used to hold used motor oil by mechanics. I’ll figure something out with what I’ve got laying around.
The scrapyard has gobs and gobs of really strong 55 gallon drums, stronger than the ones I have right now. Very good news for me except for the price for them. 50 cents per pound and I paid nearly 25 dollars just for that 20 gallon drum.
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Another very rough sketch. I’m better on the fly than on paper or at least that’s what I tell myself
I will probably use a longer part of the compressor tank to hold in the Hearth to give me more room for a char reserve in the burn tube. Also might have some extra hanging off the top end as well to make sure condensate doesn’t build up and just flood the tube. I might not have much room for heat sink and a baffle. Not sure which of the two I should choose. Just heat sink fins I would place the air inlet at the bottom of the burn tube to pull heat from the Hearth are and go up to the nozzles. I think I’ll want fins more than a baffle. I would lose one point of Heat exchanging but that also makes the build less complex for me.
If she tests good once mostly built I might go for a muffler heat exchanger to make up for that.
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I have not seen any real good reason to do this. When the gases are converting as they pass the restiction opening you want the charcoal to be starving for oxygen not have a abundance of oxygen this what causes over pulling the gasifer and burning the good gases you have made. Move the nozzles up to 2" to top of the firetube. From the nozzles down to the restriction opening 9" , making adjustable to move down to 14" . There should be a expansion area below the restriction plate. A brake rotor disc works great for this. A small brake drum to hold the restrection plate cut the larger. Now you have a expansion area. Also you can put ashes around the brake drum and firetube for insulation This expansion area causes the gases to change velocities or a frequency change and starts a cooling affect, this area should be about 5" to the grate or so.
Put in a WK grate. It can handle different sizes of charcoal and also allow charcoal to slip if needed. It is very important you can tune your fire tube by moving these parts up and down and change the opening size of the restriction. You have a 10" firetube so it will be different then a 12 firetube like mine. When I rebuilt my firetube I went from 8 nozzles to 12 nozzles my distance from the old firetube setting of the restriction plate and grate changed. You do not want to make tar and mess up your engine. It is better to make less but good quality gases then making more poor tary gases.
The thing is you want to be able to run your gasifer hard and not over pull it . I have accomplish this goal by fine tuning my gasifer and limiting it to over pull. The WK grate to me is the way to go and it can be shook from the top of the hopper open with a grate shaker if need. You do not need a electrical grate shaker, even though I do have one a use it once in a while.
And I agree with what the others a saying too. This is just my suggestions.
Cody you are one of the active members on this site. Good job on what you are doing.
Bob
Edit: just saw your new drawing, point the nozzles up can have some add vantage but it can cause them to plug up. The glowing charcoal has radiant heat coming off of it reflecting up. Air velocity is level or below this so it is very hot just above the glowing white hot charcoal and heat rises anyways. The hopper evacuation line I think that runs off the exhaust pipe is important too.
I all see you are putting in extra ash area below the grate. I am doing this also on my new WK build.
Bob
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The grate idea I’m going for is using one of the rings that are on the bottom of a propane tank. It’s a little bit smaller in diameter than the bottom of the reduction zone so it’ll slip around the edges. I’m going with suspended chain so I can add links to make longer or shorter. I’ll try to use as long of a burn tube as I can to have a good char reserve for pulling. I need to measure just how much tank length I have to work with. In this drawing it’s only 12" long, the length of a 20lb propane tank for a flush weld, but I can just hang off the Hearth zone just outside the propane tank jacket to waste less space, that area will be ash insulated so it shouldn’t need much air heat exchanging.
So should I just use straight across jets? Some guys say upwards jets, some show downwards and WKs use just an open hole or little shorty nozzle.
I know that one guy with the MEN reactor has his jet caps drilled with two holes.
I’m welding in 1/2" NPT couplers in the burn tube so I can tune in the sizes of my nozzles. Just sticking out by a hair. The 1/2" couplers will be flush to the inside walls of the burntube and the inserts will stick out a little bit, I’m probably just going to use NPT reducers as my jets. That or take 1/2" nipples and weld sleeves inside to bring the diameter down, I’ll see what works best further down the road. I’m thinking of using 7 nozzles but might go to 9 and can always just reduce my nozzle size if 9 is too much. Who knows, with all the heat exchanging it might just be open 1/2" couplers.
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Once I get this rough idea put together and see how well it bench tests, I might be confident enough to actually cut holes in the bed for this reactor. Tired of ratchet straps and worrying about barrels tipping over. If I cut holes in the bed I could put in a bigger 55 gallon drum trimmed down as a hopper and get more storage and more of a monorator hopper for more effective condensate removal.
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I only know of one person who has built 14 plus gasifer and ran them successfully on vehicles in America and his name is Wayne Keith and his wood burning design, WK or Keith Gasifer with his nozzles, they work. Do I need to say more?
Bob
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Do you have the “Have Wood Will book yet? If you do turn to page 127,128, and 129. Note this is for a 12” firetube.
Bob
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Oh yeah I’ve got HWWT
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Hi guys, I want to insert a few notes on these sketches. So, as can be seen from the figure, the place for collecting condensate from the bunker is in close proximity to the air nozzles, which means in the high temperature zone. Based on my experience, I would not do this and took measures to move the condensate collection system at least 25 cm from the plane of the tuyeres to the top.
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I was worried that the temperatures would be too high.
I might redesign the hopper to add a shortened 55 gallon drum to make a more true monorator shape. Like here I just modified in Paint. The slope I added is a perforated funnel. Deleting the former condensate exit and moving it up to the true hopper area.
I’ll cut the 20 gallon hopper to make part into a condensate barrier and use the top end as my hopper fill so I won’t have to wrestle with a big 55 gallon drum lid all the time.
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Oh, this is better, but we are losing a lot of firewood space in the bunker! In my opinion, instead of white stripes in the figure, I would leave an annular collar about 2-4 cm high, it will perfectly prevent condensate from flowing into the combustion zone and will not take up much space, it will be convenient and easy to clean it with a poker through the bunker lid, although the capacity to collect condensate, you will have to take it outside.
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The white stripes are where I will cut the 20 gallon barrel, it will be empty space. I will leave probably a 2" annular collar like you said. The ramps I drew bridging the hopper extension to the former hopper is a diamond grate sheet metal. Perforated steel.
That is the problem of editing a drawn on paper image in a computer program
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Have you concider WK condensation tubes? In many ways its the most foulproof solition thats well understood and prooven by dozzens of builders… And you dont loose any hopper space
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I haven’t ruled them out, and I’ll leave room as it sits to add more.
At least then it would give a low spot for condensate to collect and be ejected by venturi.
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