Don's double flute downdraft attempt

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
https://youtu.be/eD_MPDw6wRI
It worked pretty good for a quick temporary hookup.

16 Likes

Looks like it is lit very thoroughly across the whole cut

5 Likes

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

3 Likes

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.

8 Likes

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.

11 Likes

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.

3 Likes

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.

11 Likes

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.

16 Likes

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.
Bob

7 Likes

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.

21 Likes

I ran the generator this afternoon. Please excuse the shakey video. I had my phone on the end of a selfie stick which amplified every little movement and I couldn’t see what I was pointing at half the time.
My 1/2 inch air adjustment valve is too small. It was wide open and still needed more air. It did run though!

23 Likes

Sounds sweet Don! Man them chargassers sure make the gas quickly. Was this a for fun project or a backup for power outage?

6 Likes

For backup power mainly but for fun too!

9 Likes

Thanks for the video Don.

You sure make it look easy :blush:

8 Likes

Tell you what the double flute really likes a square form factor. I’m just trying to think of a good nozzle hole to engine size ratio.

3 Likes

Don, what Mr Wayne sayd. How does the power feel?

Cody, l belive the goal is to reach around 25m/s of air velocity on any gasifier air jet, cold. You do the math then :grin:

5 Likes

Really enjoyed that Don. Is this with the wetted charcoal? How do you gauge the moisture content of the char? Made me smile to think of you with a selfie stick.

6 Likes

It is a little low on power partly because it needs more air than the little 1/2 inch valve can give but otherwise not bad.

7 Likes

I weigh the charcoal in a cardboard box and then spray water until it weighs between 15% and 20% more. After a couple times like that I sort of get the feel of how much to add.

7 Likes

Cody,
Koen posted a link to a spreadsheet for calculating nozzle size a few years ago on the Nozzles for Charcoal Gasifier’s thread at post 50.

6 Likes