Charcoal bell nozzle

Hi, Jeff!
1.03.2016
Yes, down in the pocket it is a full-fledged “boiling” fluidized cavity.

Painting it black makes it hard to see if it is empty when it is dark outside…

Max

1 Like

Hi Jim!
1.03.2016
Yes, it will. But the char cannot burn higher upward than the char-surface, or can you make it burn up in the air?

Gas around an air-beam cannot burn, if the air-beam has a higher velocity than the flame front velocity of the gas.
The air-beam surface will cool the contact “skin” with the gas so the “heat maintenance” (needed for a flame) cannot be established.

Max

2 Likes

sorry guy’s, Max, but the kalle does not blow in a cavity, nor has it a “bell” where as the gas floats in…
The Kalle has a defined construct to do exactly as we are supposed to do, blow the gas thru an glowing charcoal bed…
And the tip is always in direct contact with the char…

2 Likes

Koen
Do you think the high air speed (> 25 m / s) helps to cool the nozzle around?
Thierry

1 Like

Hi Thierry,
No, the velocity does increase the temperature but the focal point of the high temperature shifts a bit further away from the tip

1 Like

The coil for steam decreases the temperature of the nozzle?

The diameter narrowing of the tube lights (in generators that you build) helps to reduce the temperature of the nozzle?

@gasman,
What purpose would the funnel serve as opposed to the drawing koen posted?

1 Like

Hi, Koen!
1.03.2016

Torsten Källe’s articles have been available over 60 years.
Joacim Persson’s netversion came about 13 years ago…

I think it is an easy way to show, that when the airstream
downwards comes to an end, the stream upward will also go through processing-hot char.

That is the only aim with giving this example.

Max

Hi Bill!
1.03.2016

The funnel under the bell will avalanche new char into the pocket in the charbed, as the airbeam feeds it down into the pocket.

Max

1 Like

Max,
What would be the angle of slope around a disk or cone above the nozzle, that charcoal would form passing the disk or cone with gravity only. No air movement out the nozzle. My guess 30* slope, may more? Thank you for all your in put.
Keep on Gasifiing.
Bob

1 Like

Then maybe a smaller bell would work as good - maybe better than a larger bell?

2 Likes

Hi Bobmac!
1.03.2016

The natural avalanche angle for piles are ~60 degrees to the horizontal, but here the upstreaming gas from the sides of the pocket may upset things “lifting” the surface… which would flatten out the slope…

The nozzle-tip should be kept slightly above the downsloping, avalanching pile.

Max

1 Like

Hi, Don!
2.03.2016
A smaller bell diameter means smaler area for the rising gas; that means higher velocity and more probable upsetting for the avalanche… as earlier called “dancing” char.

Max

1 Like

Hi Max; As I said along with my “drawing (?)” I don’t remember where or when I got the information to draw it, but I did have your name written on it so I am sure I got it from you. Do you have any idea, when or where you might have originally posted it?

My two cents on this is; I like Gary Gilmore’s ideal that the gas passes back through the char bed rather than the Kala where it flows up a tube. It gets cooled going through the char ( meaning it has been in contact with charcoal all during the cooling process so it has picked up as much carbon as you could expect.) With the cone and pipe, there could be some CO2 still going up the pie/tube. And a point that I will make but I sure am not going to debate, is; you could use a flat plate as I drew instead of a cone and the char would form it’s own angle from the plate to the air / gas cone bottom.

Non of what I say is “statement”. I realize this is your work so, take what I say as questions. Thank you,TomC

PS Is there really an air pocket under your bell or is it filled with char which forms a extremely hot eclipse shaped reaction zone?

1 Like

Max,
That’s good information, now can make my visor plate over my cross fire gasifer the right high and diameter. I’m trying to keep the charcoal out of my fire brick 2" tuyere.
Keep on Gasifiing.
Bob

1 Like

Some information to share.

And I read someplace that the reduction to co from CO2 and H2 and CO from H20 starts around 600F with about a 25% conversion rising to above 90% at 1000F.
The rest of the char is inert bellow 600.

So the real question is how does one calculate the size of the reduction zone?
You could pull the gas all the way to the top as is done in most producers here.
But this is a restriction to flow, and in order to get as much power out of the gas the burden of pulling on the producer has to be reduced as much as possible.

2 Likes





4 Likes

Hi, Tom!
2.03.2016
I do not see any connection to your skizz!

I am not aware of your flat plate; can you make a skizz or still better, a drawing?

Under unlucky (bad design; too small diameter) circumstances, the outgoing gas would suck up char and clog the metal cone.
Compare what a vacuum cleaner (with high suction) does!

It could also be a ~3–4" tube, as Ray has proposed!
Practical man!

The main point is: Exiting gas draft should not interfere with the char avalanche approaching the center blasting hole, which the the nozzle-tip-blast is maintaining!

There is no air under the metal cone IF the airblast is operating with fire or is cut-off!

Max

1 Like

Hi, Bob!
2.03.2016

No comment before seeing a (proportionate) skizz or a real drawing…
Max

2 Likes