I think a liquid cooled nozzle would really only affect the tip of the nozzle helping it to last longer not sure about it affecting the gas quality that much at all , dead reliable nozzles i think is every charcoaler’s dream .
Dave
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As I’ve watched these threads develope, I’ve been wondering where liquid cooled nozzles fit on the spectrum of things. Obviously greater complexity… but;
**no exotic materials
**I probably only have 50 hours on my nozzles, but they give every indication of lasting a very long time
**you can bang one together in an hour
**??
But, there is KristijanL’s ‘flute’, various ceramics, various exotic metals, (and whoever else’s solution I’m forgetting). So many options…
Chuck from Sandy, Oregon
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Hi Chuck , as long as i have spare nozzle then yes it takes as long as it takes to tip a 55 gallon drum on its side to take out a nozzle and refit with a new one .
I have tried so many types over the years now and we seem to be at a point now where maybe 3 types ( so far ) have out lasted the hundreds of hours and thousands of miles test and i for one am looking forward to someone coming up with the ultimate holy grail of nozzles that will put what we have at the moment in the shadows as too run and wear times , but i think we will always have to treat the nozzle as a replaceable consumable item , for the USA folk that means spending $15 whole bucks on something that for me so far has lasted over 2 years with no special care taken to cool it down at all , but even so that will not stop me trying new and wonderful ideas because that’s the tinkerer in me , the old if it aint broke dont fix it method sometimes has to go out the window to make a better one for the next build .
Dave
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Hi Chuck
Good clean looking nozzle! Of all the water cooled stuff this one l like most.
I am sure it costs the gas quality a few crumbles from less efficiancy but on a expense of reliability. Looking good.
But a quote from SteveU l like most, “heat (energy) is only wasted if you waste it.”
You sparked a solution that l rolled trugh my head a some days now.
More on that later!
Edit oh, l forgot. In this application of yours it might be beneficial to use stainless steel. Lower heat conductivity, less losses. Just a thod.
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That’s a nice looking gasifier Chuck. I’d like to see some more about that. I saw a video of your forge you sell. I’m going to have to steal that idea of the fluted air feed if I ever get back to pounding steel. Very nice. I’m wondering if you have some sort of check valve on the water jacket nozzle so that the heat expanded water can only move in one direction.
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Hey Tom,
I didn’t try any kind of check valve. The thermosyphon seemed to work really well. I think if you let the hot coolant leave as vertically as possible for a foot or two with as little obstruction as possible, you will always have reliable flow. With good flow design, the hotter it gets, the better the flow.
When my five gallon coolant tank gets to boiling hot, the circulation is pretty vigorous, probably because it is making tiny bubbles of steam. But it was always stable, no steam locking or total evacuation type events.
“steel” away on the forge valve! (pun intended) 
Did you notice it is almost exactly like KristijanL’s ‘flute’ nozzle? I didn’t get it from him, but we arrived at the same place. It’s kind of a wrapped Pendrick plate I guess.
Kristijan, stainless would be a natural next step, eh? The mild steel held up so well it hasn’t been a priority to try it. Perhaps you’d gain a little efficiency AND longevity. And we’re back to cost and convenience… 
edit: my gasifier designs have evolved around the trouble spots; nozzles, doors, and filters. I took SteveU’s advice and went with six inch doors (highly recommend), Matt’s advice and used flat plate, tried to solve the nozzle problem with liquid cooling, and the filters, well, still working on that. I’ll put the gasifier in an appropriate thread.
Oh, and don’t forget about fuel production. Biggest trouble spot of all.
Chuck from Sandy, Oregon
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There is quite a bit of cross pollination between forges, blast furnaces, gasifiers, etc.
The liquid cooled side draft tuyere is/was very common:
liquid cooled forge nozzle with natural flow
liquid cooled tuyere
Liquid cooled copper tuyere for blast furnace
Chuck from Sandy, Oregon
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how much steam/water is to much? im thinking of using something similar but reverse where my nozzle sits in a bigger pipe but with a round wood divider i know some water would escape though the wood pores into the wood and perhaps around the edge of the wooden
“donut” i wanted a setup that i could switch out nozzles so i came up with a 3 inch holder that i can place different nozzles into
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Hi Ryan, I didn’t follow the first part with the wood, but I hear you on the swappable nozzles.
One way is to weld the nozzle to a pipe bushing so that it had pipe threads on the OD. Screw it in, screw it out. Maybe not the best way, but it was easy.
Chuck from Sandy, Oregon
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Ryan, I’ve been mounting the nozzles another way that is easy to change out quickly.
I’m working on a no-weld solution (like others around here 
), and I’m using a large surface area flange (1 1/2 inch) with one inch Kaowool blanket gasket. The Kaowool is fragile and needs lots of area to avoid fretting and subsequent breakdown. The rock wool collapses as you clamp it down, and squeezes the bolts so that you don’t have air leaks there
(best to use bolts with smooth shanks).
So far, so good.
It is very quick and easy to change out whatever is mounted this way. Usually you can reuse the gasket without trouble.
Chuck from Sandy, Oregon
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Hi Chuck
great manufacturing, you are not a beginner
I think your gasifiers are cross drafts?
can you explain and show us the interior? 
Thierry,Québec
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Hi Thierry, it’s a very simple updraft.
The nozzle points down a little to have the right geometry for thermosyphon flow and to make sure the clinker is always below the reaction zone.
I’m trying to follow the assertions of the PNAAV703 document (pdf pgs 79-80) PNAAV703 which suggests the hottest reaction is the most efficient. So single, low area nozzle for high velocity flow and liquid cooling for longevity.
I don’t know if maximizing reaction temp is the most efficient, but it covers a multitude of other sins (damp char, marginal char, very small engines, uneven fuel sizes, etc).
The document points out high nozzle velocity and maximized reaction temp does away with classic stratification ideas like reduction zones, which suggested I might as well go with an ultra simple updraft.
The J-shaped tube takes gas out the top of the reactor to the bottom of the filter drum.
I’ve tested several gasifiers with these attributes with good success (always on small engines, I have zero experience with ‘driving on wood’
), and now I’m laying it out to you guys who have all the real experience.I hope i made it clear I’m developing the no-weld kit as a product to sell. I don’t have any ‘secrets’ as the design is purely derivative. My ulterior motives are;
- get free advice from the best forum on the Internet
- maybe get help testing so I don’t use my customers as guinea pigs (if I can get some of you to try liquid cooled nozzles, confidence and knowledge will increase)
.
Anything useful in it (if there is any), should be considered ‘open source’.
Probably should start a new thread on the gasifier itself.
Chuck from Sandy, Oregon
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I will try for sure. Ran my first succesfull char batch last weekend. Now , while improving/ integrating charmaking, i allow myself thinking of the actual gasifier. And I can’t stand mistakes. No time for that. There will be a lot to learn/ experience anyway. So I go for the proven Simple Fire. Water cooled nozzle is nice, and quite a heat source. My goal is a small CHP, so the heat is not lost. It is coming, just to much work, no time for playing.
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GoodMorning ChuckW,
Can you show your lower ash door pictured open, Please.
I’d like to see how you settled on door-to-stand-off sealing.
ALL, realize he made a captive (no hot loose door lid kicking around) self-centering, even constant edge pressure door. Not elaborate at all considering it seems? to be made of all flat stock.
And as I’ve said many times, when you are small stationary gasifier: weight&space are just not a design/fabrication factors at all. Actually considered, yes. But the lowest priority of all.
Regards
Steve Unruh
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Hey Steve, I took your advice after fighting with too small openings forever. It’s basically a stove door but center pressure like you noted. Tried more complex shapes on the door itself, but took Matts advice and went simple and flat. If anybody else sees their ideas in there, they probably aren’t wrong. 
Simple, rugged, reliability is my design target, plus a device you don’t hate to work with.
The seal groove is 1/2 inch. I bed the seal in an abundance of cement, shrink wrap the door so it has a thin plastic layer, and then just close it on the seal as it floats in the cement. After it drys you have a good mating surface.
The spring loaded latch gives you some explosion proofing.
There are some improvement to be made but they have proven to work well.
The opening is six inches.
Chuck from Sandy, Oregon
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The barrel gasifier looks great Chuck but I’m really interested in the stainless one with all the piping you posted up the page farther. I can’t figure out everything that’s going on there. Also on the water jacket for the nozzle. Did you forge that cone shape or is it something you purchased? Quality work on everything you have posted.
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Tom,
Oh, that one, lol!
Video:
nozzle test rig
That is just a test rig (aren’t they all) with a liquid cooled nozzle and side draft.
Not this nozzle but very similar.
I’m using a garden hose to cool the nozzle. The focus is bad, but at the end you might notice the coolant is quite hot.
I learned:
**About how much coolant flow was needed at 1kw output for that nozzle.
**to hate grates because they plug or melt and are generally unnecessary for charcoal rigs.
**A tiny housing (six gallons maybe) is not enough charcoal insulation, notice the discoloration near the bottom, needed to be fatter.
There is an angled port at the top with a rubber seal that previously hosted a liquid cooled nozzle that came down from the top. Bad idea number 600, way too much surface area surrounded by hot gases.
There is a filter housing off to the left.
Edit:
I generally do the taper in the lathe. Red heat, and a roller in the tool holder. It doesn’t take too long to do it manually with the forge.
Chuck from Sandy, Oregon
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this is what i starting with i planned to make a type of insert the nozzle being smaller than the 3 inch i am thinking a donut from wood that centers the smaller pipe creating a water chamber that surrounds the pipe then a donut/pipe centering kind of like those thing seen in wells that keep the pipe centered the wood being a little porus could leach though the wood the wood would act as a consumable part i could also maybe pour an aluminum donut behind the wood if to much of the water seeped past the wood why wood because wood soaks up water and it leaches it though the pores it would swell up to make a decent seal
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I can’t help but feel like the wood would create tar or some other unwanted byproduct as its running. Or just burn away.
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