This unit drinks water. I tied to shoot as much water into it to see if I could get it to stall out, nope. The idle changed when I stopped shooting water into it after a minute or two. Looked at the fuel ratio meter it was running lean. When shooting water into it , it was reading rich. And this was with water added to the charcoal mix. My temperature probe was reading 600°F plus off scale at the bottom of the gasifer.
I am going to have to insulated the bottom and part way up on this unit.
Bob
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Was this with charcoal that already had some moisture added?
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Yes. After lighting it on dry charcoal I added the moisten charcoal. When I opened the gasifer hopper lid this morning the lid had moisture under it driping water.
Bob
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By the way my nozzles are point from level facing each other down about 20°. I started there because I have 10.5 " to the grate. It is a lot more distance then some of the other builds. But I want to be able to run on a 2.5 L to 5.2 L engines. Not sure on the 5.2 L engines at this point. I know I will not be using the smaller engine grade charcoal in the gasifer if I do. Sizing the charcoal is tricky on a charcoal gasifer. I was hoping to just sift out the fines and ashe and use it. But the heat above the double Flute down draft gasifer nozzles is nonexistent even when I ran it down to the nozzles. So my conclusion is this with this unit. Adding wood chips is not going to happen. You need the heat in the area above the nozzles for raw wood to cook down. You need heat. This is where the 12" diameter area in a WK or other type of gasifer shines. You got to have a area above the nozzles where the wood can cook in a 900°F plus heat.
Getting back to Kristijan idea. I think he has establish a larger area with his flute design that he might get away with some added raw wood chips.
But if I do get some brands in my mix I am not worried about making tar in my unit. It is hotter than hates at the restiction zone and at the grate. I hopping the grate will hold up we will see.
It is about time I replace the vaccum cleaner blower on my truck that Chris S. made with my Kirby vaccum cleaner blower. Follow this on my other thread 92 Dodge Dakota (from the book).
Bob
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HI bobmac how is your charco vehicle working out, i havent had time too follow your build plans yet, Have you tried mixing in 10 percent wood chips in your charco gasifier.
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I ran it on the Dodge Dakota engine. The unit is too small for the 5.2 L it will work on a 2.5 . I still have not mounted it on the 1996 Subaru Outback. I need to build a square mount hitch for the slide in platform. Winter came sooner then I thought it would. Yes I need to get back on that project too. But I did finish my retort last fall makes great charcoal.
Bob
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I know what you mean/ winter kicked down i did not feel much like shop work either, my wood burner is in my shop,and has leaky door that needs new rope seal. Caint wait for warmer sunny weather, get going on some gardon and wood / char gas projects Too . Your chargas unit looks like it works well, and wood have a good travel range before need refill,neat looking design. Happy spring , not too far away anyway.Good luck with your new double flute charco gasifier, hope you can get some good travel range on one hopper full.!
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I need to get this double flute gasifier running a car down the road be sides just running my generator when I need it.
I think it will run my 1996 2.5 L , OBD2 Subaru Out Back just fine.
Under the hood on the intake I found the only place I could tap in a chargas line conection.
The plastic pipe is thick walled I cut out the hole and just force threaded it in. Back threaded it out cut off the threaded connection clean up the hole and treaded it back in tight.
On the in take side of the filter box it looks like I will be able to connect a air regulating supply valve.
I am thinking on not put a valve on the chargas supply side. KISS construction like what some of the others have done on their wood and char gasifiers.
Bob
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Cool tie-in method! I just purchased a 2023 Outback, love it. Not quite ready to be cutting and installing woodgas into it, quite yet …
Say, on my F150 4.9L build, what would you guys say as to diameter and number of nozzles, for a dual flute, for this displacement engine? Also, how close to the reactor sides would you get with the outer nozzles? 4 inches? Thanks!
Martin I’d go with some 2" ID DOM tubing. I bought some 5/8" wall so it would have plenty of mass.
Check out Kristijan’s double flute build as well to get a good idea for making it work in a barrel form factor.
Thanks! Nozzle hole diameters, and number of them, I meant to say/ask. Still don’t have a handle on how to size those.
Thinking that since the double flute lends itself to rectangular form factor, may make a 1" square tubing space frame and weld say 12 gauge or lighter plate to that.
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I think if you went with a square form factor, it might be a great idea to make a square tube air ring. Then you would have a complete surrounding reaction.
But for a double flute style I’d consider for your engine to start with five 1/2" holes per flute for your jets. 10 jets should be plenty, and if it isn’t enough air you could use a carbide or cobalt step drill and hog it out to 3/4", or drill smaller jets in between the evenly spaced 5 per.
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I used heavy pipe and welded steel plate to it to make my nozzle square in shape. Lots of mass. I used 4 holes in each nozzle. The hole size depends of what you are planning on running of the gasifier in engine size. Like a small generator engine or a bidder vehicle engine.
My flute will run a small genset engine 6 hp. , but it will run my 5.2 engine up to 2500 rmps.
Bob
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Thanks, Bobmac. Wow, same gasifier runs 6hp to say 200 hp? That’s some kina turndown! Nicely done, I have seen the pics. What are those hole sizes? Half inch?
My conditions are, what number of holes and diameter for 4.9L at say 2750 rpm max, or say 2000 rpm steady state.
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Oops, didn’t see Cody’s previous reply. Prechate it Cody, looks like a good starting point!
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Okay, important at a idle a bigger engine run. But run it down the road under a load humm, maybe for a short distance, but I would think it would over pull on the gasifier or maybe melt the metals in it from over heating. When I ran it with my 5.2 engine even the long conecting pipe that I connected to my cooling rails on the truck got hot and the cyclone filter was put to the test, it was really hot. Lol. But that was why I tested it on a big engine to see what this little flute gasifier could do. I built the whole thing as a test model gasifier. It is fully adjustable on the nozzles and other parts. It will run my genset engine all day, just keep fulling the hopper up with 10% moisture 1/4" to 3/4" charcoal sizes.
My next test will be running a 2.5 engine and see if the 1996 Subrau Outback will go down the road. If it works I will have the correct nozzle size and dimensions for building on the nozzle and spacing distances on the grate. This is all to build the most compact gasifier like @KristijanL, @Matt and others are doing.
Bob
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Bob just to give you some pointers for that, the Mako S1(2L to 4L)had 4 14mm nozzles with a 14x14 round burn tube if I recall correctly. I think 14" depth is the longest you’d ever need to go for a downdraft charcoal if you set the diameter right. I think smallest I’d go for a 2L or 2.5L would be a 12x12 in a square.
Maybe 6 holes for the flutes total would be good. 1/2" holes. When I did my initial testing on my double flute I did in fact get the Mazda 2L to run and drive on it with 6 3/8" holes. My only issue was I melted the rubber couplers that I had in too soon! I thought the big cyclone I made would keep it cool enough. Unless you’re blending in brands or wood I think you won’t have issues idling with that setup. 1/2" is about 1mm smaller than the Mako’s 14mm nozzles.
Everything I’ve read up on downdraft and Crossdraft charcoal, when the gas is extracted still hot that means there’s less CO combining back into CO2. Fine balance between extracting it hot and still making sure all the oxygen is used up
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Yes I agree that heat is the key. A real balancing act for sure. I am actualy testing stainless steel in side with a ceramic insulation above the grate, and a stainless steel grate. I still might have to have more air insulation on the outside of the gasifier or air spacing around it for protection. I am thinking on putting a old washing mechine housing around the whole thing. Lol, Wouldn’t that be a cool stealth gasifier is to have a washing mechine in the back bed of a truck, that looks like you are just hauling it some where but there is a gasifier inside it? Sorry we are a highly regulated tree hugging state here.
Bob
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You dripping water into that, Bobmac, I forget? That’s how you keep the temp down, H2 up.
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I built it that way so I can use water drip, but I have found the moist charcoal works fine also. I have done some experments on running my genset with charcoal that has about 10 % moisture in the charcoal. With a spray bottle spray some mist into the two intakes. You can tell it is making more hydrogen when doing this. But if you keep doing the spraying with the bottle the reaction stops. It is because the reaction of the hot charcoal lobe has cooled down to much. Kinda like flooding it out. But if you wait a few minutes it goes back to normal.
So I thinking with this unit I will use both with being able to turn on the drip if I need more power momentarily then just shut the extra water drip off if not needed.
Lots of fun expermenting with all these things.
Bob
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