Nozzles for Charcoal gasifier's

I finaly found the time to document my nozzle setup so here goes my small contribution to a better world of clean fuel:

the lid of the gasifier taken off

the charcoal emptyed. you can see the amount of slag of about 800km

the “slag nest” up close

the nozzles clean of slag

a peace of slag

the nozzles up close. you can see there is absolutly no erosion.

the pipe i made the nozzles out of

lt all runs great. Just clean it once a month and add fuel every day.

Here is allsow an artisticly butyfull peace of charcoal, just for a treet :grinning:


Your result seem very impressive .You need to reach more than 1300 C to melt the ash and yet the nozzel is intact
What is your recipe?

I did not know you’ve changed the brass nozzle for a thick pipe? iron?
for what reason you have drilled several small holes instead of a large nozzel?

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More like 2300 C as l do not use any coolant :grin:


  • the nozzle has a lot of mass (steel)
  • the air cools it from inside out
    : the slag nest protects it from direct contact with superhot coals

l am limited by hight. Thats why l have 4 nozzles not 1


Wow, yes, very impressive! Are the nozzle holes 10mm? Please remind me of your engine size in CCs. It looks like combining a massive tuyere with vertical air blast is a winning combination.


Are the 4 holes drilled completely through the pipe, so air can exit from the top and bottom of each of the 4 holes?


How do the several holes affect lighting?


How have you measured 2300C?

Have you yet croosdraff configuration? (Extraction of gas on the side with heat exchanger?)

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I could not tell from the picture was the pipe cut from a larger casting or just a longer pipe?
Thanks for posting these. You and others make the dark side very tempting. But I have not gone there… YET:smiling_imp:

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This is fantastic! Such a simple solution.
Can you also let us know how long the pipe is and how far apart are the holes? If I remember correctly, you are using cast iron? Have you tried this with the holes closer together? Have you tried it with just regular steel?
I’m guessing the velocity of the air is keeping the temp away from the pipe?
Thanks for sharing this.

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Kristijan , your nozzle results are very impressive indeed .

I didn’t realise when you first mentioned your nozzle that you had a row of 4 holes along the length , another question along with the other questions asked would be , how do you lite your system up or do you have a separate lighting port ?

Congrats on a great designed nozzle /system



Kristijan - Those are fantastic results.

So far as I know, you show less nozzle erosion than anyone.

I wonder if it is the heavy pipe, the vertical jets, or the fact that you are using multiple jets?

Maybe a combination of these factors.

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Another unique thing about your setup is the “slag nest.”

I have not observed anything like that forming in my gasifier.

But it does give me an idea.

I wonder what would happen if I just loosely wrapped the end of my nozzle with kaowool or some other sort of porous ceramic fiber. Maybe that would help start a “slag nest” and protect the nozzle?

I think that stuff is cheap enough that I could treat a small amount of it as a “consumable” each run.

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I think the bottom iron approximately 1500 C .It must “slag nest.”
is an excellent insulator for proterger nozzle

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Thank you all for all the kind words.
The holes only point upworrds.
I think this pipe is a part of an old hydraulic cilinder but im not sure. Just a peace of scrap metal i found :wink:
I use multiple nozzles becouse that way my reaction area per one nozzle is only about 20cm high eaven thugh the engine is 1000cc. I gain a lot of space!
Holes are about 10mm about 10cm apart. But it realy isnt so inportant how many holes and how big they are, as long as they point up. One culd just cut out a wider cut along the lengh and do just the same job or eaven better!
Lightning isnt a problem. I start the engine on gasoline, open the gas valve on full and touch the air intake with a small propane burner for a second and its done. In case not all nozzles light l have a cut in the pipe that goes from nozzle to nozzle so that charcoal starts burning fast and eaven on all holes. Once lit i can stop the engine and the char will last about 8 hours.

I think vertical nozzles are the future of charcoa gasification. I realy hope more people start researching and making it better and most of all i hope they dont get selfish by keeping the inovations for them self.


Hi Kristijan , thanks for answering our questions so quickly .
In your reply back to us you say that vertical nozzles are the future , but isn’t your system horizontal though ?
You see if any system at all can cope with the run times or the mileage that your system does then I would count that as a success , but sure never stop experimenting and trying new things and sharing .


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It was horisontal (crossdraft) but then i reorganized things. Glad i did.

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I suspect the size and number of holes is significant because of the air velocity. In some experiments, tripling the superficial velocity (speed of air against charcoal) increased CO yield by 25%. A narrow saw cut is an interesting option. It looks like your charcoal is screened to about 20 mm?

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I have read a lot about air velocetys but didnt realize it wuld be so significant.

Charcoal is a lot smaller. 3-10mm. Works best


How did you deduce that the temperature inside the reactor reaches 2300C?

what temperature, the exterior walls of the gasifier, reach?

I guess the gas exits the gasifier from above. it is cooled by your copper exchanger?

I think you have designed revolutionary .

I 'd like to better understand

Thank you ,Thierry

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Hi Kristijan,

To give you an idea about your nozzle speed at wot (wide open throttle)

with your 4 nozzles of 10 mm you’l have about 20 to 25 M/sec airspeed at 4000 Rpm

I doubt you have a higher temperature then 1300°C to 1600°C coz all ashes would be vitrified and the metal molten…
The lack of pure oxygen … :wink:

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