Hi, Bob!
2.2.2018
Much better than Gary Gilmore’s dribbling of the “birdhouse roof”!
You can thwart the back-flow downhill flowing char, assisted by the return-gas flow!
Fulfilling construction principals!
Congratulations!
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Hi Koen, I’ve been looking at your design and based on my experiance with a similar one, it will quickly oxidize away. The charcoal hanging around the small air inlets will radiate so much heat that the metal, even stainless steel will quickly erode away. The SS rod/tube located above the air holes will likewise get so hot that it too will erode. However, circulating water through it will prevent that, but you still have the problem on the bottom pipe where the air/charcoal interface. I have some nozzles of a similar design laying under a bench that show this erosion/destruction, even after a few hours of run time. I’ll try to get a photo up soon.
Gary in PA
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must be a strange feeling that every’s name becomes Koen 
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Wish my name was Koen - if I had your brains to go with it. grin:
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brains come with age… i am getting old
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I’m old and my brains seem to be leaving. I do get more goofy ideas that sometimes turn into fun projects.
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You are still young and on the up-slope of the curve. But by 80 you will realize that the curve turned at some point.TomC
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I’ll take it as a compliment being called Koen.
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Maybe eventually it will become ironic, like Einstein, or Sherlock.
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Here are seveal designs I’ve tried that have not held up to the intense heat of the chargasifier. Some of these are carbon steel and some are stainless steel. All are oxidizing away after just a few hours of use. No engine exhause was used which could have extended their service life. Some of these are a two piece design with a one inch pipe inside a 1 1/4 inch pipe. The idea was to rotate the interior pipe (which had a slot on one side) to break off ash and to shut off air from getting to the charcoal at the end of the run. Both both holes and slots were tried.
Gary in PA
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hi Gary , looks like a good collection of tried and tested and put to one side
nozzles there .
Have you tried Kristijans thick walled steel pipe with horizontal holes drilled along it yet ? or have you settled on the forge type nozzle that you put on your ranger ?
All the best Dave
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Thanks for all of this good work and a photo record. It is hard to tell how much damage from these pictures. They don’t look too bad. The holes still look round.
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Yeah, I need to put some close ups here to show the deterioation. These nozzles were inspired by Kristijan’s design but made from thinner steel. If they could be made from thick cast iron or copper, they may work or at least work better. For now, I am going back to keep using the forge style nozzle.
Gary in PA
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Some observation i made during the last years of fidling around with nozzles;
Thin walled and or red hot glowing nozzle tips tend to “glue” the sticky slack on them
Thick wall or “cold” nozzles, seems to be non sticking and the molten slack ends up further away.
Once the nozzle sticks, the orifice gets smaller, the airspeed increases , temperature rises in the glowing zone, untill complete shut down from the nozzle…
The crazy part is: decreasing the nozzle opening that way, will increase the power content from the gas up to a certain degree, until the drag gets bigger then the gas needed to keep up the power…
its all a act of finding balance…
for those who like to experiment:
take the largest bolt you can find and drill a nozzle hole in the length , screw that bolt in the corresponding sized nut, welded on your reactor, et voila, a new nozzle system is born
( i am talking about bolt and nut size >1" with hole size 1/2" or 3/4" )
I know i am a bit spoiled at the moment, having to many tools at my disposal, but still, i am getting the point…
As long as i keep my system simple and cheap, it tends to work flawless at any given time…
Having the knowhow on hand to build myself a “simple fire” gasifier, gives a peace of mind i never had before…
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Gary,
Nice nozzle collection you have there!
As l sayd before, this stile of nozzle will only work if there is enough mass to conduct the heat downward and to the air. Steel, ss, copper,… doesent matter as long as there is enough mass, read wall thickness.
Perhaps the easyest way to describe whats goeing on here is to compare this design with a WK firetube.
A WK firetube is cooled from the outside by fins and air streem, but the heat is not waisted, its recirculated back in the gasifier.
This is the same. Heat is conducted in the thick walled pipe, conducted downwards and picked up with incomeing air.
Will a WK firetube work with sheet steel material for the finned tube? Not for long. So wount this nozzle.
And, Koen is right. I encourage a thin lair of ash to fuse on the nozzle tops, not the holes them selfs thugh. Thats the reason l tend to avoid scrapeing the top off the nozzles like you did (however that rotating nozzle in the pipe idea is genious! Two in one. A shut off and a scraper)
This is where BruceSs genious tool kicks in. A slightly up bent thin poking rod that you poke each nozzle hole with from the air intake, cleaning it and leaveing the protective ash alone.
Looking in the lighting port while the gasifier is at full temp, the nozzle pipe is cool and dark. Just the holes glow down that butyfull charcoal light 
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Why cast iron (shape casting), being a eutectic it will melt at a lower temp. Higher levels of carbon?
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Once the nozzle sticks, the orifice gets smaller, the airspeed increases , temperature rises in the glowing zone, until complete shut down from the nozzle…
The crazy part is: decreasing the nozzle opening that way, will increase the power content from the gas up to a certain degree, until the drag gets bigger then the gas needed to keep up the power…
This might offer some insights.
Talks about the speed of gas through a char bed and how this effect gas quality.
http://www.drtlud.com/?resource=prs99370
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Hi Wallace,
Thanks for pointing out this Dr Tlud document, some of his data is useful. ( if you want to build a TLUD )
He should come to DOW and learn some stuff here about real gasifiers
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Paul Anderson, a.k.a. Dr TLUD has been to the Argos gathering and knows DOW. I’m glad that he posted this article by Thomas Reed on his site.
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Made a night video last night driving home from work, 15 miles mainly WOT uphill, at 2.30min you can see the inside of the nozzle pipe being cool and dark, just char light glowing down trugh the nozzles.
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