For a quick try to see if it works, you could put duct tape over part of the air inlet of the fan to slow the air speed a little.
6 Likes
If you do the speed control or the duct tape , start of fast and when your ready to flare try slowing down or blocking partly off to maintain the flare
5 Likes
Well I know I haven’t been on here in a while. I have had a lot of other projects both at work and at home competing for my time, but also I probably needed a little break from my gasifier project anyway since it can get a little frustrating at times. But I am in it for the long haul, I might achieve this in spurts, but I am determined to get this thing working no matter how long or how many tries it takes.
So this is the latest progress - I just wasn’t really happy with my nozzle ring and felt it really could have been improved upon quite a bit, so I disassembled it and reused some of the components - the Ts with the nozzles all reusable, but I took out all the little 45s and opted to build bent pipe by following the video that was posted above, by which you do a little math, cut a few equally spaced wedges out of your pipe and then bend it around and weld it back together.
As you can see from my pics below - it is not my “prettiest work” ever. It did not come out quite as refined and symmetrical as I had hoped - the guy in the video made it look very easy, and in principle it is, but he was working with a much larger diameter pipe than I had to work with so that for starters made it a little more of a challenge. As you can see from one of the pics, I had a cut out paper circle that I was using as a template for what I was hoping to achieve and my ring doesn’t fit my template perfectly, but it does fit pretty good down in the reactor and I think will perform better than my first version.
This is the latest version:
Remember this was my first version:
Again this was the first version down in the reactor:
And now the newer improved nozzle ring down in the reactor:
So hopefully this improves my performance. My next task will be to add a little more cooling area to my radiator and then I’ll fire it up for another test, hopefully successful this time……
6 Likes
Looking much better! Less likely for dirty gas to slip past. Give it a few runs for the ashes to settle behind the nozzles and it’ll run even better.
2 Likes
If you want a bigger nozzle ring yet, you could finger tight the pipe plugs in backwards.
6 Likes
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.
2 Likes
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.
2 Likes
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 .
5 Likes
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?
5 Likes
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
7 Likes
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…
2 Likes
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.
2 Likes
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.
5 Likes
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.
6 Likes
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.
7 Likes
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
8 Likes
Dave, you are too humble. All the years you have been making woodgas electricity puts you well into the expert class!
6 Likes
