If you want a bigger nozzle ring yet, you could finger tight the pipe plugs in backwards.
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Well I sure wish I had better news to report. This weekend I figured I would try another test with the new nozzle ring in place - and you guessed it - another fail.
I still have not added on to my radiator yet, but from my output I did add several coils of pex (like 30 feet of coils before it makes it to the generator) to cool it a little more and frankly, coming directly out of the flair it really doesn’t feel all that hotter than ambient air so I am hesitant to put more time or money into something that probably won’t improve my results anyway.
I am so close, but just not getting it. I loaded it up with charcoal halfway up the hopper just to make sure I had plenty and the gas output again would ignite but not stay lit and when I tried to start the generator on it I heard a couple of times where it seemed like it wanted to “hit” but just not enough like it was too lean to start it.
I started wondering if it would make any difference if I reduced my choke restriction further, but again - is the juice worth the squeeze? I am really starting to get frustrated with this project that has been in the works since June and I am starting to see my time as a waste rather than an investment at this point. I sure wish one of you guys lived close to me I would buy one of y’all a nice dinner and stuff a couple Benjamin’s in someone’s pocket if someone could debug this thing, because I’m kind of getting to the tap out point soon.
I don’t want to give up on it, but at some point if I can’t figure this thing out I guess I will just have to cut my losses.
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A smaller restriction will help reduce any bad gas from passing through but it will also reduce how much gas in general from passing through, basically it’ll restrict your engine size you can use.
For frame of reference my little raw wood unit has a 2" restriction and I can run between 300cc and 700cc depending on the RPM.
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Good morning Derrick .
If you could run by here I would be glad to show you 90 mph on the speed o but my gasifier is completely different to yours .
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The Pex I am familiar with is 1/2" and 3/4" and is mainly used as water pipe. Are your “several coils” in series or parallel and what is their diameter? I wonder if it is delivering enough gas?
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Yep. We are all frustrated with your results too DerrickD.
Contrast here with another new DOW member who was able to get flares and even lawnmower engine run:
By design elements yours should be producing better engine grade gas than his.
As you suspect you probably have 1-2-3 minor faults going on.
For all initially using old rotary lawn mowers as “mule” woodgas provers I can say this . . . probably the most difficult engines to woodgas get running.
Too small of suction drawing. As a four stroke that suction only occurring once every two engine full revolutions.
Here is help alternative fueling with all of these.
#1 It must still run on it’s original gasoline fuel. That will eliminate most of the dumb-dumb mistakes like trying to operate it without a flywheel effect mower blade. Cracked flywheels that give maybe; maybe-not ignition spark. Dragging against flywheel stop brakes. Worn loose ignition shorting out stop contacts. Etc.
#2 For alternative fuels trialing you absolutely MUST be able to extended crank these over; and allow for a 2nd free hand for systems manipulating. Here is how:
Look specifically at 1:25 → 1:33, then at 2:37 → 3:00
Yes a big enough electric drill with a socket attachment will do it just fine.
Less well fine is using an electric or an air impact gun. These also must be big enough to quickly come out of impact rattling to free-spinning.
Once you are done with these mowers set-aside engines trialing be sure and go to dedicated electric starting engines only then. Especially on engine-generators. I was six months healing up a separated collar bone learning that one on a 6500 watt B&S generator set. Not everything can be solved by just bulling through it.
Regards
Steve unruh
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I believe Don Mannes is right. PEX is too small to move the gas through. Anyway you have components besides your reactor. You may be better off to just build a proven reactor design and reuse the peripheral components…
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Smallest I would go for any gasifier is 1" ID tubing. Just a bit bigger than the bore of a small engine. Plastic won’t really help to cool down the gas a whole lot other than from dwell time. I would try it as is with your existing metal cooler. Just keep in mind the engine has to draw all the way through that plumbing.
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First of all, Wayne, thanks for the offer. That would be a long day trip for me since I think you are about a 4 hour drive from where I am, but I might just take you up on it one of these days.
As far as the pex pipe goes - it is 1/2’ and it is one long coil. I had bought a 50’ coil for some plumbing and only used about 20’ so I had about 30’ left of it and all I did was put a couple of shark bit fittings on each end to be able to connect to my existing output and then into the carb of the generator.
I really didn’t think this would be my issue since, first, I was not relying solely on engine suction but was still running my output blower fan while trying to crank the engine so there should have been positive pressure at all times going to the carb and second, this is the same pex pipe that I use to deliver propane from a large tank to my larger generator and volume wise it seems to work just fine for that application, so I didn’t see why it would not work with woodgas since as I understand it, it is very similar in properties to propane.
So while I would not rule out that this could be a problem, and appreciate all the feed back on it, I figure that I had problems before I introduced the pex, and because of the things I mentioned above, I figured that this probably wasn’t causing any more problems than what I already had before I introduced the pex, but I could be wrong on that - if I could get a constant flare, then I wold definitely be looking more at removing the pex out of the equation.
Steve - that is a good idea about an electric drill with an impact. I have a bigger generator that this gasifier is ultimately being designed for but I am testing this on a smaller generator without an electric start. That was one of the reasons I was wondering about a smaller choke, because I am trying to test on a smaller engine - I was thinking maybe I could make a smaller “temporary” drop in restriction that could be dropped in and removed to run my bigger engine if it solves the problem but is not sufficient to run a bigger engine.
The frustrating thing is, if I could get a constant flare to stay lit or an engine crank and run then I would not worry about the other and could more accurately diagnose- in other words, if I could get the flare to stay lit but could not get the engine to crank and run, I would start worrying about things like if the engine is too small to suck or if the pex diameter is too small - but because I can’t even get a flare - to me its saying that there is something wrong with the quality of my woodgas.
Or conversely if I could get the engine to run off the woodgas, but I could not get the flare to stay lit then I would worry about the blower speed of torch construction - but because neither of these is happening it leads me to believe I am just not making good quality woodgas with my setup, and that’s what is puzzling to me, because I can’t think of anything else that should be standing in my way. Am I wrong in my assumptions about this, that I should be able to get one or the other - a flare that stays lit or an engine crank and run?
Here’s one thing you can try.
Warm up the gasifier until you can get the flare to light even for a moment, then close off the flaring area.
Fill the float bowl of the generator with gasoline, and start it up on gasoline to get a primed start to pull on the gasifier. I would try to get the air mixture close to what you think it’ll run on, that might bog the engine.
The gasoline will help make sure any tars coming in at first will be dissolved.
Also for your shutdown you should run a bit of gasoline as well to clean the valves.
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Derrick, maybe a missunderstanding from my part but the engine will never fire up on 100% woodgas. 50/50 wg/air is what we’re aiming for. We need suction only, to ashive that.
Flaring is different - the gas will mix with air from around the flame. Works best with large dia tubing.
With marble sized dry char up to the nozzles, dry wood chunks on top of that and the air mixing valve opened up just a crack, you should have the engine fire up in a couple minutes from lightup.
A contained pile of char with wood chunks on top will produce combustible gas - if lit and enough vacuum pulling from below - no matter what the vessel looks like. Hights, widths, diameters are fine tuning. Just make sure the motor gets its 50/50 mix.
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Good info/concerns post you put up DerrickD.
Not easy to lay out all of your thoughts and concerns.
Woodgas sucked/blown flowing is much less energy volume dense than flowing gaseous propane. You are having to carry through some unconverted CO2; passed through nitrogen; combustion moisture “steam”; and even some unused oxygen in the woodgas stream.
Time and time again here on the DOW a small engine runner on chargas or wood gas will identify a low produced engine power to some 1/2" valve.
So go big on your passages and piping, man. 1 1/2" ID minimum.
Another one I will be cheered for; and jeered for: . . . flaring. It distracts too much. Lies too much. Many, many daily engine running woodgassers flare not at all anymore.
Even in the old-time woodgasers filmed demonstrations if you view and re-view closely, they are actually flint spark gas testing. For an ignitability “snap”. Another cheered/jeered opinion I will put up - some very experienced woodgasers still use constant torch flames on their flare stacks. Just like many petroleum well heads do unless the well heads gas’s are captured for cleaning and market selling. So just flaring it off. I think the experienced woodgasers flame pot flarers are just trying to just not just spew out air pollution. Into their own air personal environments. Convert that spewed out CO into much safer CO2.
S.U.
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I don’t want to add more and complicate things so my 2 cents ,as Steve said large Dia pipe is a must for gas transfer minimum of say 1 inch .
Also as Jo pointed out , do not use the fan while trying to start the engine , in fat if you can by pass the fan altogether when in engine mode you will save the fan from being tarred up to destruction, also the fan is where air will get sucked into the system …
I forgot who mentioned it but on the end of your pipe where you want to flare you must mix air into the gas at the correct ratio for it to ignite and stay alight , the easiest way to do this is a soup tin with holes around the base and the gas pipe coming in the bottom in the middle of the can , then with gas coming in the middle and air around the outsides you can control the mixture some what with a rheostat try slowing the speed to where the flame really does want to stay alight .
Again that’s just the flare and it lets you know at least you have a burnable smoke and at first its fun to see but as Steve mentioned its not needed once you know your machine and the quality gas it makes , so get a cordless drill a fast speed one, NOT a impact drill , and a socket and if possible someone to hold that drill and spin the engine while you ever so slightly start opening up the air valve , honestly the amount of movement that ball valve can be so slight between running and not its impossible to see .
Doing too many changes all at the same time is no good for anyone , if you take advice from any of us here do only 1 change at a time other wise you will be forever chasing your tail .
I am no expert i only know that even the best of us can fail to make gas at one time or another , and all the above is what i have done in my trial to run my engines .
Dave
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Dave, you are too humble. All the years you have been making woodgas electricity puts you well into the expert class!
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[quote=“Dave & Brian, post:198-
, topic:6826, username:d100f”]
I forgot who mentioned it but on the end of your pipe where you want to flare you must mix air into the gas at the correct ratio for it to ignite and stay alight
[/quote]
This is how my flare air mixer terminates
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Oh i wish i could always put my finger on why its running nothing like it did last week or this or that , but i guess that’s sods mechanical law .
But to be honest Don i really am no expert when it comes to raw wood gasifiers or even downdraft for that matter , but i am learning as i guess we all do over time and being able to share thoughts and idea’s and congratulate the achievement’s and help to pin point the fails as we travel along this fantastic way of ours .
Dave
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Atmospheric conditions change Dave. The people who tune dragsters have often compensate between runs for changes in air density and humidity. What happened to Robb?
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Once yet again I have to thank you all for your input and the learning experience I am receiving here.
Yet more misconceptions of mine exposed.
I had always heard that propane and woodgas were very similar, so my flare design followed a simple propane torch design that I use at my farm to burn weeds. And also the piping that works for my propane generator - I assumed would work for woodgas as well.
Frankly the only reason I have not given up on this project yet is your patience with me and you all always give me something new to think of, where I might have gone wrong.
So now the question it raises for me is the piping to a small engine carburetor - if we are going with a large pipe - say 1 1/2 - but then the throat of the carburetor of a small engine usually being only about 1/2’- maybe 3/4’ opening - so then is there just a brief reduction as it introduces to the carb - are there any small engine guys out there that maybe have a picture of this construction?
What it sounds like if I am hearing - if I am hearing right is to keep the volume of woodgas as large as possible up until the very last moment before it is sucked in the carb. Also, Jan had mentioned a 50/50 gas mix and I had accounted for that or at least tried to - in my current configuration, right before the carburetor, I have a “T” with a ball valve plumbed in so I can introduce some air into the intake, but the YouTubers I had seen start their small engines I saw some start with pure woodgas - kind of like like starting on “choke” and then gradually introducing air through the ball valve as the engine warms - that’s why I thought it was ok to try to start it on pure woodgas, but as I keep learning there is a lot of bad info out there on YouTube.
One final question I thought of - regarding the blower - although it has a good velocity it may be restricting the woodgas airflow since input and output ports are 3/4” so if my output needs to be 1 1/2” I am already starting out with half that size due to the blower. I wonder if I would be better moving that blower to my input leading to the oxygen nozzles and make the blower a “pusher” instead of a “puller” - pushing air through the system instead of drawing it through. Can I still achieve a down draft this way? And does this seem like a good direction to move in? If not I will still have a lot of rework to consider since all my output piping begins at 3/4”. Not sure how I started in that direction, again probably something I saw on Youtube in the early stages before I discovered DOW
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Yeah and its funny you should mention that Tom , because I actually do live in the clouds and most days we have low lying cloud due to the fact we live half way up a mountain here so everything does get rather damp including the charcoal in the gasifier , i have been giving that a lot of thought since testing downdraft units , i think i may be making too much hydrogen ?? if i add a constant water drip of more than 1 drip my revs start to increase and 10 seconds later my generator motor starts to coff & pop and slow and then speed up and then stop it will start up again no problem and run till its putting out its full power and if i still have the drip going do the same again , if i stop the drip after a few mins it will settle down and run outputting full power at the lower rev range .
I think it may be time to take the head off and look at the valves as they may be needed a lapping , i also have a thinner head gasket for the clone GX390 engine my generator uses , so i might take a little off the head and help increase the compression slightly .
Dave
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