Thank you Don i can see it more clearly in my mind now , do we know why this stands up to the extreme temps of charcoal ? is it because the air is around a central movable piece that helps break up the slag formation or the mass of it all or is there another reason why the steel tube isn’t being oxidized away ?
I guess by now you have many many miles on it now and will have a good idea how well its standing up .
Impressed by it all anyway
Dave
When Gary Gilmore came up with this idea, he was thinking about his blacksmith forge and how the massive air inlet lasted a very long time without deterioration. That I think is the secret to this design.
Hi Dave
I think it’s for the same reason that Kristijan’s nozzle resists heat well!
The massive nozzle radiates heat at the same rate as the coal overheats the nozzle.
The large mass of the nozzle offers a large heat transfer capacity to its environment (primary air, water, egr …)
This is the explanation that seems most plausible to me!
THIERRY
Thierry , i am sure you are correct due to the mass , i watched Dons video a few times and silly me only noticed that the tube that the central shaker is in although it only looks to be about 2mm thick walled it was then welded onto the base plate that is of course a much thicker piece of steel and so helping to dissipate a lot of the extra heat , it will be interesting to see how much has oxidized away ( if any ) when its cleaned down for a service , so many different ways to build and to explore i wish i could have the time and the workshop to play at them all , summer would be my perfect time right now if it was not for life getting in the way right now .
Dave
I think Kristijan’s nozzle just didn’t get as hot, because he mixed EGR in with the combustion air and didn’t allow the reaction zone to get as hot. Just my two cents.
Rindert
My thods are with Thierry. Plus the fine lair of slag on the nozzles reflects the worst of heat.
Rindert, actualy the egr was a later adition. Mainly for fuel economy purposes and to soften the slag.
Dave, I just ran across this video and I don’t know if you have seen this before but it might help answer the questions above.
Excellent photo work. Really shows what is going on… I am in no position to build one like yours, but my interest brings up a lot of questions. I’ll be back to ask later. TomC
PS. Please don’t flare IN your garage. After my insolent, I have a lot fear of unconstrained fire.
Don thank you so much for that video it was very interesting to see the nozzle in action while producing burnable gas .
Am i correct in thinking that as the charcoal burns away below the size of the gap between the puck and the outer tube you get small bits of slag and even charcoal dropping through ?
Dave
Dave, It appears to me that the glowing char ball is mostly above the puck and the outer tube and most (90+%) of the slag forms like a 2 inch ring around the perimeter of the outer tube. I think the other 10% falls down to the ash storage box. At least that is what it looks like when I clean it out.
Thanks for the video, Don. If I recall correctly, I think you said once that you have a 1/8” gap around the edge of the “hockey puck” in the center. I was wondering how thick the center puck chunk is.
Robin, the puck started out as a flat belt air compressor pulley
I think it is 1-1/2" thick and 2-1/2 round. That left a 1/4" space between the puck and the 3" and I wanted it to be a bit less so I fastened a stainless pizza cutter blade under it to throttle it down to 1/8th ".
Thanks Don. yours is one of the few “nozzles” that appear to have been an unqualified success and every little bit of design data is useful to reproduce your results.
Don, I believe you posted this video before. It was so interesting I had to watch it again. You’re an amazing fabricator. Thank you
Okay, I have a quick update on my Leitinger style nozzle. Granted, it has only had maybe an hour of run time- but so far it is looking pretty good.
It uses a much smaller orifice - 11/32" (8.7mm), and is currently running a little 204cc Tecumseh engine at like 3600 rpm. I couldnt get a really good view of the nozzle, but it felt like the edge of the hole was still sharp. I can shoot an IR thermometer inside when its running, and I have never gotten a reading of more than 800F, and 600-750 is more typical. None of the metal visible inside is glowing, there is just a brilliant little spotlight of yellow light shining down from the hole. I think the total mass of the nozzle is about 7 lbs.
I am not using any EGR or water at the moment, but I am probably going to add exhaust back in to boost the fuel efficiency.
It seems to be forming a little slag volcano on each run, which I can push out of the way with a welding rod to start it up again.
I found no ash when i cleaned it out, but it did seem like the charcoal was pretty dusty.
So far, this seems like it shows promise - I will post more info once I have some more hours on it.
Very nice! Is the 3600 rpm under any load? Please remind us of the dimensions of the parts we are seeing.
The RPMs drop to closer to 3500 when the generator is loaded down with 500 watts or so, and no amount of fiddling will get them back up. With a smaller load, I think I could keep it pretty steady. The nozzle is about 10" long, and like 3" in diameter with thick walls. In this picture the camera is inside the 5gallon fuel hopper, and the reactor can on the bottom is nearly as big, maybe another 3-4 gallons.
What about hybriding? If a small amount of gasoline is added, how would performance go?
Hi Carl,
You will need either a bigger hole, at least 1/2" or better 14 mm
or drill 2 more holes of same size as you have now…
Your engine is “choking” on all the restrictions…
Best performance is running on 40 mm water vacuum, measured between engine and gasifier
( gas hose vacuum )
Koen,
Your guidance here for Carl is very exciting and timely for me since I am working on a gasifier for a 200 cc cargo trike in Africa that will operate at 1500 meters elevation. I have 11 mm and 15 mm tungsten carbide nozzles to try. I have previously used 25 mm nozzles for small engines, but had been wondering if the smaller 11 mm nozzle might work best based on the suggestions of Troy and Kristijan. Based on your suggestion, the 15 mm would probably be better.
Would you please tell us a bit more about the best performance at 40 mm vacuum? Is this “40 mm vacuum” a “rule of thumb” or starting place that you have observed for all engine sizes, loads and elevations or is this specifically for a 200cc single cylinder engine running at 3600rpm under load at sea level?
Thank you.