Great work!
Some questions, do you use a monorator hopper on this build or what is the double Wall for?
I guess it’s made like a FEMA with a nozzle and lid correct?
Can you maybe make a simple sketch of the design?
What problems did you have with it and how did you solve them?
Just be thankful you do not have to deal with the the cold freezing weather. If you pick up a tool and try to use it in your bare hand your hand will get really cold fast. Frost bite, it hurts. I have gotten my hands to cold to many times in my life, now I’m paying for it.
Great to hear there is a new and better design that will be making it day view in the future. I love the simplicity of the design and the light weight of it.
Do you have any pictures of the new design might you want to share?, feel free. A sneek preview teaser of what is coming up in the world of gasification.
Bob
There are pictures of the new one in the first part of my 93 dakota build. but I will post them again here. The main improvement was a stainless heat shield around the nozzle Because the barrels were getting cooked. The ammo can we used on the prototype for the ash cleanout always leaked because we only could silicone it in if we welded it the inner barrel is not removable. I also shrunk a 55 gal drum to fit inside of another 55 gal drum instead of using the 40 gal drum for the inner barrel. that gave us more room for wood and a larger Diameter for around the nozzle theoretically so the barrels won’t get as hot as quickly. orange outer barrel 55gal. black, inner barrel 55gal shrunk to fit inside outer barrel with 1/2 inch clearance all the way around. maroon, 2 inch pipe. green, fire brick. purple, grate. yellow circles valves. light blue in stainless heat shield. brown, ash cleanout. We are using the two barrels for condensing hopper juice the inner barrel has slits in it down till almost the stainless heat shield so It will condense water and tar on the inside of the outer barrel and they collect in a sump at the bottom. and are drained off the same as a wk. also our air inlet at the top has the ability to pull some of the condensate and tar down into the nozzle with the incoming air to be burnt so instead of putting exhaust or water drip into the nozzle It pulls tar and condensate into the nozzle out of the hopper.
Hi guys
I have been thinking on this design again these days. My neighbor gave me a 96 Toyota Rav-4 with a 2.0 4 cyl. It is not in the bet shape and it is a Yankee car so the lower part of the body is rusted out pretty bad But it is mostly functional. I retimed it and rebuild some other things on it already.
I think this will make a good test vehicle for this gasifier. I am quite certain this gasifier won’t run a v8 or other high volume engines. That seems to be our issue a gasifier that will run a small vehicle and be light enough to be carried by the cars.
I wil post some more sketches later once i have more time to draw them.
On the subject of nozzles if anyone knows what this one looks like you will understand this better. The nozzle i have been using is made out of fire brick and pipe flanges the fire brick is supposed to handle the heat and protect the steel. it works pretty well but after a few runs the firebrick gets brittle and breaks apart.
Do y’all think stainless steel would handle the heat. If i were to build an octagon out of square tubing that was 4-6 inches in diameter and on every side of the octagon drill the right size nozzle (to be figured out depending on engine size) and put a stainless heat sink around it, would it work like a Letinger nozzle or just burn out?
I will post pics and some sketches later to help explain my ideas better.
Hi Jakob, this design originally had brake rotor in the middle for nozzles and now you are using fire brick.
I see a heat problem here. You have your nozzles in the middle of the hot, hot lobe of heat, it is like a forge and the nozzles are in it. Is there any way to make the nozzles blast downward like a Kalley Gasifier. Some of the members have been using tungsten carbide nozzles.
On my cross flow I put my fire brick nozzle inside of steel pipe. And it still cracked, but it is hold up well. Check out " The Gasifier That Wanted To Be" thread. My nozzle is not exposed to that kind of heat though.
Bob
Hi Jakob, as I see you are building a gasifier with a center nozzle, I have a similar design in mind, except that the holes in the nozzle would be directed slightly downwards, so the nozzle itself would be slightly higher and less exposed to high temperatures. I will make the nozzle out of steel for improvement, I have already tested this on a charcoal gasifier and it works. This construction system makes it possible to compensate for lifting and lowering the nozzle, as well as easily demolishing the bridge by moving it.
You are a cute family, you work hard and diligently.
Hi Jakob,
I can’t picture your design, but I know that silicon carbide material can survive high temperatures for a long time. It is used for melting pots (crucibles) for molten metals, and grinding wheels and a lot of other things. Here’s a shape that might be useful.
Rindert
https://www.alibaba.com/product-detail/2020-low-price-silicon-carbide-ceramicThermocouple_1600176472937.html?spm=a2700.7724857.0.0.2ef967c4x56Cug
I have been busy with other stuff that Woodgas these last couple weeks but on the trip i had lots of time to think. I finally got enough time and energy to make a drawing of my idea for the LBJ Gasifier. Larry was convinced of using fire brick for the nozzle. i have run tests with several different types of brick I can’t get more that a few hours of run time before the firebrick gets really brittle and just crumbles. I am thinking of using a stainless manifold nozzle with the air blowing down so that the nozzle isn’t sitting in hot char.
@Bobmac had the idea for the heat skirt for the fire tube area i like the idea. Two things I’m not sure of are the restriction and the grate. Do I need one or either. Also the heat exchanger can be larger. On the two prototypes i have they don’t have one at all just two big cyclones. Some people I know don’t like cyclones but they seen to cool the gas a lot. Most of this piping is probably oversized seeing as how this gasifier I think is about the size for a four cylinder. Pink = Regular mild steel barrel. Cut a section out of it and add in a piece of stainless sheet metal (blue). The hopper area is the same design hopper we all use (WK). Orange is air inlet. Yellow is gas out. I am looking for feedback and ideas. The goal is to make a light weight WOOD gasifier if possible. I am not trying to replace what works I just like more tools in the tool box. Every Square is 2 Inches. (about 5 cm)
So is it a singular central nozzle acting like a showerhead, or is there a perimeter of nozzles in the wall as well?
Would be really interesting to figure out nozzle ID to a ballpark displacement. I guess use Imbert nozzle dimensions but combined total area of those to imagine a singular?
Nope different process. My guess is 3/4 to 1 inch pr 1 lite of displacement. Charcoal is much more tolerant as well wit a huge turndown ratio. This is where building a team I think would benefit a vehicle. Build a box not a cylinder that will make better use of the square bed box.
You guys want to something cool put a small engine carb on your intake take jet and use that for your water flow. It will need to be linked to your accelerator. Mash down the go peddle it adds more water to boost your water intake. That would be cool.
I think you are making it too complicated just use a side nozzle. Shield that nozzle and keep it wet you will not have any issues if you do this. Dont let it go dry of water.
Bridging above the nozzle.
I’m not sure of nozzle size yet. The idea is just a showerhead style nozzle.
I have always been concerned about bridging above the nozzle but in all the test runs it never has, even sitting still.
I am hoping for this to be a wood gasifier i think it will work.
Do you guys think i need a restriction or a grate? @Matt @Dualfuel @KristijanL
Restriction or reduction? Wouldn’t you want a restriction/choke-plate for raw wood? Joni has done fine without a reduction though.
Jakob,
Earlier posts said this design made good gas. It was just wet.
A restriction is to force the heat lobes to pass through the center band of incandescent charcoal. Seeing as the center tuyere is already doing that, I would try it with no reduction tube or restriction.
My assumption is that from the tuyere out to the hopper wall will be a heat gradiant. Hottest at the tuyere and coolest at the wall. I think the trick is keeping it hot enough somewhere below the tuyere and by the wall, that the wood gets cooked to charcoal.
If the gas always passes through hot carbon…then the CO2 will always get reduced to CO.
Is the output really wet? I have trouble with that, seeing as you have kiln dried maple. It should burn hot enough to reduce water. You should not have a big moisture load being sent through the reaction. So where is the steam passing by the carbon? Or is it an air leak down below somewhere?
Anyhow, it’s the best kind of fun, working on a new reactor.
I want to redesign it so it doesn’t have the double wall hopper and just use a standard WK hopper. I think that will held a lot with moisture. Also some cooling systems will help a lot.
That is what is making me wonder if I need a reduction zone because Moisture/ tar could be slipping through. No leaks that i know of in the one prototype that we used the most.
Oh I was thinking this was for a charcoal gasifier. The light weight / simple through me way off. lol.
Ok your center tier design is a good idea then for direct fuel system and Ive always thought this made better sense. I don’t think bridging will be an issue and having that jet in the center will push and direct heat from the center of the raw fuel above so it can not fuse and bind. This actually will solve bridging problems. For the jet, just use a single straight jet. Focus that heat to the center at (high velocity) as much as you can and using a single jet is the only way to do that. It will form insulation naturally around your oxidation zone. I think you should try it without a restriction fist but may need an (hour glass shaped hearth) and your grate should have a solid center this will prevent center channeling. I can see that coming without this. So to visualize you gas flows; Primary air comes out from a single point at your jet and then fans out like a cone and then to the grate. Adding the center core to the grate ensures this happens. On the outside of this flow cone natural and regenerating char insulation will form.
Yes you need a grate with a chamber under to equalize the pressure. Otherwise pulling out the side will make the unit lopsided and the gas flow will be to the one side where you are pulling out instead of evenly from jet center to grate center.
What you will have is a Central Nozzle High Velocity Down Draft Gasifier.
Hello Jakob, don’t be offended if I express my opinion in your topic.
I was also thinking about the center nozzle from the top down, but I decided to make the air supply from the bottom up, because that way the temperature of fresh air and exhaust gas is exchanged more, the air is preheated and the gas cools down. The second reason is that there is no obstacle in the upper part. Sealing through the bottom is easily solvable, easily also with ART.821 SPOJKA, PREFABRIKAT – Livarna Titan. For easy construction, I would use a brake drum as a fire hose side-sealed and insulated with ash, and for air supply a thick-walled hose with side bores and closed at the top, which also allows the hot zone to rise and fall.
I would suggest silicon carbide for nozzle material. Foundry crucibles are commonly made of it. These thermocouple sheaths would seem to a convenient shape.
Also @d100f Dave & Brian seemed to get good results with tungsten carbide
Rindert
Some questions Jacob, I also think about making a new gasifier.
How long does an oil barrels suffice without breaking, like a jumper and protection around fire tube?
Don’t you cool down the area of the reduction with the air to the nozzles?
I had problems with hanging the wood when I had the little fire tube, wonder if you not got problems with it, with the construction of the nozzle?
