Dave:
The longevity of your nozzles is impressive. Especially if they are resting against white hot charcoal.
Please remind me of your setup.
Nozzle size: 1" ID ?
Engine displacement: 200 cc ?
Water drip: ?
Load in watts: ?
Vacuum: inches of water column ?
Charcoal size: 1/8:- 3/4" ?
What else should I be asking so that your results are reproducible?
Thank you for demonstrating the practical reliability of charcoal gasification!
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Max,
There is so much that you see and know that totally escapes me. Thanks for your patience with my questions and comments .
So your statement, âRemember, that a furious air blast has a furious sucking from the sides and behind. This âfilles upâ with return char all up to the nozzle-tip, and there you are!â applies only to horizontal nozzles?
When you say, âMake the roof or balcony full broad to spread out the return loop gases!â are you warning me that the return gasses may sweep char against my nozzle? Or is there some other problem caused by the return loop gases (oxidizing and wasting them) ?
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Hear Hear⌠Yes it is a great design. ( if not the best ever ) and not only in Sweden and i doubt if someone can find a better wayâŚ
1: Even more the value for using / making good quality input fuel⌠( high quality charcoal )
2: There is no substitute for quality
3: Having different opinions and other perspectives, improves the shared knowledge base we all benefit from.
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Hi, Bruce
24. of November
First Tomâs sketch:
Looking sharp = you can read the note saying: 1/2 â 1"
between the nozzle-tip and a horizontal marking line for char.
âŚ
Text among the upward bent arrows: Char flow
âŚ
Gas return flowing easily from below upward does not contribute
in filling a well dimesioned bell from below with char.
âŚ
In your case, where the return flow starts partly above a horizontal âlevel-lineâ
it is easier to be âowerflownâ by the the return flow than when the flow is from below.
Spreading it out sideways to get a larger flow area brings back less stuff. Main point is to avoid a buildup at the nozzles, as we have seen what a glowing âpadâ does to the nozzles.
You are always welcome with items of interrest and concern!
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Bruce ,
My nozzles are made up from a 25mm Dia Tig cup that has a 4 inch copper pipe rested on top of the threaded end of the TIG , I then place the TIG cup and pipe into a tin can and fill all around and up with a 75% alumina refractory cement , but leaving the last 25mm of the copper pipe uncovered , that last 25mm is pushed into the male fitting welded onto the side of the tank making an air tight seal , so its a sort of plug un plug type nozzle , that sits about 4 inches horizontally from the bottom of my tank
With this nozzle I can run all my engines , ranging from a very small suitcase Honda generator 49cc 750watts a dc 24volt generator thatâs around 80cc 25 amps, a B&S 9hp 295 cc running a 40 amp car alternator a few 160 cc inverter generators 3.5kva that struggle to put out more than 1.5kw , on the larger engines like the 400 cc 7kw inverter generator and the B&S 18hp twin cylinder lawn tractor both engines run like a dream .and I can good power out of the larger generator maybe 3 or 4 kw
Water drip I use about 1 drip every 2 seconds , charcoal is shredded down to around 1/8 up to 3/4 size , I donât have a vacuum gauge on my system , but I know when I need filter cleanouts and pipe cleanouts ect just from daily use I now get an idea when something is wrong .
I have not opened up my tank for over 3 months now ,so have no real idea just how much a build up I have on top of my nozzle right now , but I will take some photoâs for to see if you want the next time I open it up .
Dave
Do you run it every day?
Tried the bird house and it burned up. Tried the Kalle and you better use stainless steel and some exhaust to keep it cool enough to keep from burning the nozzle up too. The idea of blasting air downward into a bed of burning charcoal and keeping the nozzle relatively cool will absolutely work BUT⌠this is where I think a big misconception lies. You have to BLAST the air in. Most of the charcoal gasifiers we are making SUCK the air in using engine vacumn. The difference is velocity and at the low velocities caused by sucking you will not get that nice beer bottle shaped cavity surrounded by oxidizing charcoal. BLAST the air in at say 50 or more psi and you will get that cavity. Just my 2 cents worth. With that said, Iâll be glad to congratulate the first person who has good success with this system working on an engine vacuum only.
Gary in PA
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Hey Gary, did you figure out the problem on the Ford truck running on charcoal, with the computer and starting it. Just wondering, havenât seen any new posts on your Ford truck lately. Thanks
Bob
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Thank you for the drawing, Max. That gives me a much better point to start reading your previous verbal descriptions.
No âBlack Magicâ---- a misunderstanding of a description. âfurious sucking from the sides and behind. This âfills up " with return char all up to the nozzle-tip.â ---- I had this picture in my mind. Then it was said, " the fill-up is going on, but the blast beam sucks it downâ. Thus my drawing of the char being pulled " up " towards the nozzle, then " down " as drawn.
I now understand that you are talking about a funnel area that starts at the nozzle shield inverted funnel. In this area the char is being pulled down with the air blast and sides filled by the âfurious sucking from the sides and behind.â
Anyway, lets leave it at I think I now understand your description. Possibly I will modify my drawing to show correct perspective and post later. TomC
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Hi Don ,
Its hit and miss it depends on if there is enough sunshine to put some charge into my batteries , but I would guess its about 3 or 4 times a week this time of year , we are just coming into summer in 4 weeks time and so I will give it a rest and a strip down then , unless of course we keep getting these rainy dull days like we have today , , so far 3 runs since Monday this week each run is about 4 or 5 hours , just enough to top off my batteries
Dave.
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Hi, Tom!
24. of November 2016
O dear, o dear! A description of horizontal circumstancies with easy backflow of loose char cannot be applied on vertical circumstances!
A function description is always bound to the given situation, and cannot be applied in a quite different setup!
Black Magic! Does not work.
Hi Gary
How did you deduct that starting from 50 psi only a beautiful cavity-shaped bottle of beer this shape?
Thierry
Dave,
You are one lucky guy liveing down under. I wuld llove to be in the begining of summer now⌠the cold dark days are killing me
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I cut out the melted section from the aluminum nozzle and connected the two pieces with a steel close nipple. In an attempt to create a gap between the nozzle and the char, I drilled horizontal nozzle holes and rested a firebrick on top of the aluminum tube. Here is a picture looking down into the reactor and a cross section sketch:
I have also added water drip to this setup.
If weather cooperates I will fire her up tomorrow.
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It stopped raining so I fired up the gasifier with a firebrick shelf resting on top of a nozzle tube with a horizontal nozzle hole on each side of the tube . It took a long time (7 minutes instead of the usual 1 minute) to get a flare and the gas was never as powerful as the hot run I did a few days ago. Note that I did not turn on the water drip until the thermocouple passed 900 C after several minutes into the run. I even cranked up the fan to see if that would produce better gas, but the flare remained puny. Less than half the size of the previous flare and it flamed out several times.
I ran this test for 80 minutes. Pretty easy to control the temp with water drip at about 1 drip per second. I kept it running between 1000-1100 C most of the time. At one point the temp got up to 1280 because the water drip had stopped. (The flare did not improve during this high temp episode.) It cooled right down when I restarted the water drip. I could not supply enough water to pass all the way through to the other inlet without stalling the reaction.
I also placed a steel disc on top of the charcoal hoping that it would prevent bridging. I didnât want to shake the reactor. I thought shaking might cause the char to settle into the gap between nozzles and the char. I am curious to see if it descended horizontally or took a dive through the char.
Conclusion: two horizontal nozzle holes on opposite sides of the tube with a < 1" gap between the nozzle and the char could not produce good volume of gas at 4-5" water column. My previous test with two vertical nozzle holes and char directly against the holes produced a good large sustainable flare in one minute at 4" W.C⌠It is possible to run a gasifier with a pass-through double ended aluminum nozzle and vertical nozzle holes if using a water drip to control the temperature, but a failure in the drip system would result in a meltdown in about 10 minutes.
If the nozzle is still in workable condition upon inspection, I will test it without the firebrick to see if direct nozzle contact with the char is the determining factor in producing good gas.
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In reference to Maxâs drawing in post 236. Do you have to be concerned about the type of metal that is used in the inverted funnel? It is not in direct contact with the white char, but it would be subject to radiant heat. TomC
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Hi Bruce, Kind of curious why it took so long to get a flare. Could it be the fire brick acted like a big heat sink thereby keeping the charcoal too cool initially and not allowing formation of carbon monoxide? My guess is if you keep using this type of set up, the fire brick will eventually melt away at the edges were the oxygen meets the charcoal. But, you are using a fluid drip so that may keep the gas cool enough. Curious to see what happen here. What about ash clean out?
I took a ride to town in the Ford Ranger (black Friday special on some tools at Tractor Supply) and ran it on charcoal. What a great feeling!
I also hooked up the water supply to the water cooled nozzle and hope to test it tomorrow. Got to love this nozzle testing!
Gary in PA
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Great to hear you are driving the Ford on Charcoal Gary. Are there any New up dates that we should know about, you have been keeping very Quiet these days about your Ford.
Bob
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This morning I opened up the reactor to again find a melted aluminum nozzle. OK, lesson learned. I think Iâm done with using aluminum in the hot zone.
I removed the fire brick, left the aluminum nozzle tube in place and sealed up the two air inlets. I then installed a single ended 1-1/8" OD x 5/8" ID copper nozzle with a 3/32" x 4" saw slot. This new nozzle was installed through a separate existing port. (This nozzle had previously been used as a horizontal nozzle and endured a run with the saw slot using a brass pipe cap on a 1/2" pipe nipple for an end plug. The brass melted and the pipe burned off, but the copper was unaffected. This time I plugged the end with a piece cut from a high temp insulation board.)
I then fired up with the exact same setup as the aluminum test: the same charcoal, vacuum level, etc. I had a good strong flare in about 30 seconds. The temperature inside the nozzle levelled out at 1150 C. I tried a water drip for a few minutes and found that the temperature calmed down to 1050 with one drip per second. I removed the water drip and let it continue to flare at 1150 C. The copper pipe just outside the reactor was running at 250 C (just under 500F). When the cyclone exit temperature approached 100 C, I shut down the fan. The temperature rose quickly to 1350 C and leveled off there. I then closed all ports to let her cool. The elapsed time for this test was 85 minutes.
Through the inlet, I could see the saw slot glowing nicely throughout this run. The end plug of insulation stayed in place.
Conclusions: I agree with Gary that the low air speed created by engine vacuum requires direct contact between nozzle and char to create good gas. The saw slot idea is promising. Copper is good nozzle material, aluminum is bad.
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The saw slot in the copper nozzle was facing up/vertical.