Don's double flute downdraft attempt

Not sure how hot it will get, but I’m thinking it may tried to spread open if the heat is to near the nozzle. Perhaps three small slits with a inch of weld separating them to keep the nozzle from opening larger than the cut?


I had a chance to play with this gasifier a little while this aftenoon so I hooked up a bilge blower out of my junk pile that had bad bearings and only 2 blades left in it (noisy and weak) but it managed to light up and make a little gas.
This is what the inside of the slit nozzle looks like.

And after a couple of minutes I could light this little flare

It worked pretty good for a quick temporary hookup.


Looks like it is lit very thoroughly across the whole cut


Hi Don
I must have missed something but can you explain to me the advantage of a split vs holes in a Letinger nozzle?


Looks good Don! Looks like the nozzle is holding on to the heat.

It seems you may have the same situation as l did. Hint was the hazy gas that doesent quite want to stay lit. Once it seals its self well it will work much better.
Trigaux, l am not sure what Dons reasons were but l put a slit in my first flute to aid to faster ignition, flame passing down the slit faster thain if it has to “jump” across holes. If it helped or not, l dont know.


I don’t always need reasons to do crazy stuff but I thought that a wider, slower heat zone might make just as much gas and maybe run a little cooler and have less “dead” zones. I had to quit when the suction blower took a crap after about 25 minutes but then I took a temp reading at the bottom of the gasifier and the highest temp anywhere on the unit was 325 degrees F. so comparing that with Bob Macks 600 degrees, maybe it does run cooler although he was pulling with a Kirby not a weak 12v blower like I was.


Pretty excited to see how this progresses Don. Looks like a really good design. With all the work you did to weld up the rods on each side of the slit I think I would try and do a larger pipe over the nozzle and weld it so that it sealed around the slit and water cool it. I am currently adapting my 8 inch WK to see if I can run it as a downdraft charcoal unit or I’d try those water cooled slit nozzles myself. The idea of water cooled nozzles has been on my mind.


Hi Tom,
My first run yesterday was with bone dry charcoal and my next try will be with 15 to 20% water wetted charcoal which should run cooler yet. I thought a lot about water cooled nozzles but decided it was not worth all the extra effort. One little leak could really screw things up. I have no idea what the life of the slit nozzles will be so after the next couple of runs I may take a look at them seeing they are easily removable and maybe take Marcus advice and run a couple spots of weld across to keep them from spreading open.


Took some time today to run my fuel refinery.
55 gallon barrel

and 40 gallon barrel

This should be enough to do a lot of testing.


Nice looking charcoal you have there Don.
That looks larger than popcorn size. That is the size I like to burn in my double flute charcoal gasifer.


Getting close to making a video of startup and running my double flute charcoal generator.

I gave up on the slit nozzle and went to the tried and true flute design.