Hi Brian , from my play with downdraft i needed a lot more cooling , the filter with the stones in the bottom is a great way of cooling down the gas and help drop out any condensation as well see how you get on and just keep adding till its cool enough for the engines .
Dave
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It’s going to rain all day so very little gasifier progress but I did braze the cooler together.
I thought it would be quicker than welding it but it probably took just as long but I didn’t burn through the thin pipes.
If I attach it to the end of the outlet pipe I think I can get a slight downward slope to it. I wish I would have angled that outlet pipe down instead of straight but too late now.
I’m thinking I will tack weld the cooler on the outlet pipe and seal it with high temp silicone so I can get it back off if I need to change it. I don’t know how hot it will get but a rubber coupler probably wouldn’t do.
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I just had to know.
The lid is held on by gravity. The clean out port is stuffed with felt and a plastic bag covering it.
I forgot to put the lid on my charcoal barrel so it got a little wet from the rain so figured I’d use some for this test.
This video was taken just minutes after lighting it.
At least now I know this just MIGHT work.
I shut it down just after taking the video. Really just wanted to make sure I wasn’t wasting my time with this build.
No lemons here. Maybe a shot of lemon juice will help?
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Yaaayyy it fly’s!!!
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It’s raining again so I can’t really drag my welder out to do any more work on the gasifier.
There is a lot left to do to it so, once the charcoal goes out, I’m going to empty it back out and keep working.
What I wanted to find out from this test was if it would even produce gas. Considering I didn’t really have plans for this and was kind of guessing on the distance from the nozzle to the grate I wasn’t sure. I figured it should work but I’d hate to spend all this time only to find out it didn’t work.
Like I said before, I don’t NEED another gasifier since I have the simple fire and it does what I wanted it to do so there isn’t a big rush to finish this one. This test did encourage me to keep going.
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Yes this is what you want to hear! Thet puff when you lit the flare! Not the sluggish barely burning dry chargas flame… Thats the hidrogen, you will see the difference on your engine!
You do have a lot of moisture in the gas thugh. This will correct itself over time when the charbed establishes and the surroundolings plug with ash and dust. Now steam can bypass the glowzone. But allinall, excelent!
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I wasn’t even going to mention trying this because I didn’t expect it to work that fast and that good. I expected it to take a while before the gas would ignite but it happened quick.
That video was literally minutes after I lit it. Everything was wet and I even used soaking wet fine charcoal instead of ashes to seal it up so no doubt there was still moisture in that gas.
I didn’t fill it up really full either (a couple inches or so above the nozzle) because I knew I was going to have to empty it back out to continue work on it.
This was how the simple fire was when I first built it. The flare looked so good and started so fast that I hooked it up to the engine without even filtering it and it ran. This time I have already seen the engine run on charcoal so I wasn’t tempted to hook this one up to the engine yet.
I’m impatient to get this finished and use it but I hope to dedicate this one to the generator so I don’t want to rush the build too much.
For this test I just used the expanded metal out of the forge I built from the smaller tank that I originally wanted to use. I just threw some big chunks of charcoal on that grate and then shoveled in somewhat broken up charcoal directly from my barrel. I didn’t screen it at all ond only broke it up with the shovel.
I don’t really think all engine grade charcoal would have done any better for this short test but it should last longer with all smaller pieces.
There wasn’t any sense in throwing any wood in since I wasn’t planning on running it long enough to tell if it was making tar or converting the wood into charcoal and I do plan on emptying out the charcoal and using it in the simple fire and didn’t want raw wood mixed with it. The charcoal was damp though since it got rained on.
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I wuld be cautious with raw wood. First try to know the gasifier well runing on charcoal. The thing is, if it makes a lot of tar and the tar collects in the sistem, its hard to get rid of it and it will be picked up with the gas stream later, even if the gas is clean again wich can cause headakes.
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If you have ever watched the Project Farm youtubes, he has a number of old crap engines that he tests his various fuels on. Doesn’t care if they get screwed up in the process. Old lawn mower or other small equipment engines are usually easy to come by. I would never test out a new gasifier on an engine I expected to get good service from for the long haul.
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Been raining for days and looks like it’s going to do it again today so not getting much done with my gasifier build.
D = 1 Inches
L = 2 Inches
W = 1 Inches
C = 0.26 Inches
J = 5 Inches
F = 1 Inches
L0 = 5.1 Inches
L1 = 5.06 Inches
L2 = 5.04 Inches
L3 = 5.05 Inches
I know a cyclone filter is controversial if it is good or bad for a gasifier. I’m not sure how this down draft gasifier will work and a cyclone probably isn’t needed but I’d still like to try building one even if it doesn’t get added to this build.
I do use a bigger plastic Cyclone on a bucket for some of my wood working tools and almost nothing escapes. Obviously, charcoal dust and fine ash is way different than wood chips and shavings. The Cyclone was originally meant for a sandblast cabinet but is mostly used on a jointer or router.
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Building the paper patterns for the cyclone.
This one should be easy enough to just mark out on the metal but I wanted a paper pattern to make a model.
This was the input pipe that starts out round but transitions to rectangular.
This was enough to get me a life size model.
Not what I wanted.
This could work but kind of defeats the plan to keep the dust out of the cooling pipes.
Oh well, it’s the thought that counts. And, it was only built out of paper and tape.
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Brian, you put much effort in to that cooler and will probably want to keep it, but a cyclone like this, specialy if you weld fins on it, will probably cool the gas more thain the cooler, plus filter the gas. Just a thod.
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Kristijan, I did wonder about that. Plus, that cooler might be a nice size for use on a lawn mower with a smaller simple fire along with a smaller filter so the cooler will find a use even if it doesn’t go on this one.
Grass mowing season is over here. Supposed to be close to freezing by morning but I considered trying to put an alternator on an old lawn mower engine for battery charging.
I don’t know how much heat this down draft will make compared to the simple fire so I don’t know how much I need to cool it but I assume it will be hotter considering it won’t have as much charcoal to pass through before exiting.
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The engine on my BCS is a slow turning flathead 470cc engine and its probably similar in gas consumption to yours. Gas first contacts a water cooled surface, about 20x20cm, to “take the edge off” the heat, then straight to a oiled towel filter. If the gasifier runs good and efficiant, its gas looses heat extremely fast. Its the steam that carryes a lot of energy downstream. But a good gasifier must not make any in the first place.
This sayd, if you add fins to the cyclone l think this plus a filter shuld be plenty of cooling area.
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Somehow I missed this short thread:
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Putting fins on the cyclone filter, that is a great idea Kristijan, I think I will try that on mine. And may be the piping coming out of the gasifier to the cyclone and the piping leaving the cyclone going to the cooling rails. But keeping the heat in the lower part of the gasifier with well insulation, but is not needed once it leaves the lower part of the gasifier. Holding the heat in the gasifier and then releasing the heat, by cooling the gases down as quickly as you can to get the moisture/soot to drop out of the gases. Part of a good built gasifier and components to go with it. DOW
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I have a cyclone with fins on the Ranger. It works but does collect some water.
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I put a cover on the clean out port.
It’s made from the saw blade but I cut all the teeth off.
The hold down clamps are just bent pieces of 3/8 inch threaded rod and wing nuts.
I used high temp silicone and stove rope as the gasket and welded/siliconed the holes in the blade from the back side. The flat bar was just spot welded to the blade.
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Probably shouldn’t admit this but I tested the gasifier out again.
First I didn’t put enough charcoal back in and, combined with the lid just held down with gravity, I blew the lid open.
Wasn’t a bang, just a puff.
Then I added more charcoal, hooked up my filter without any extra cooler and got the generator to run.
Again, too much air leaking in the lid and blew the lid clean off that time.
Still not smart enough to stop, I put the lid back on and started the generator back up.
I was able to run the chop saw and the planer (not at the same time of course). It run the air compressor but wasn’t running it at full power and really loading down the generator.
I’m assuming the problem is everything is too wet and my nozzle holes might be too small but at least I know the thing works.
I ordered an assortment of springs to hopefully get the lid held down better but still allow it to poof if it needs to. They should be here today but don’t know if they are going to be what I need. I want it strong enough to seal on the stove rope gasket but weak enough to open slightly if it has another poof.
Once I had enough charcoal in it (still not full), the gasifier stayed cool. The gas outlet was pretty warm so it will need a cooler of some kind when I run it longer. I only run it for 10 minutes or so just to see if it worked. I assume it should run better once the ashes I used to seal it up are dried back out and I’m going to drill the nozzle holes a little bit bigger but it looks promising.
Another probably shouldn’t admit…
Put a few little broken up sticks in just a bit above the nozzle before adding more charcoal. They were bigger (longer) than they probably should be but I wanted to make sure I could find them again.
They started to char. The outlet pipe right out of the gasifier had some moisture and charcoal dust but didn’t look like tar. I didn’t screen the dust out of the charcoal from the last test. Just dumped it back in. The outlet pipe closest to the engine wasn’t even damp so the filter must be catching the dust and the moisture although, with such a short run, it wasn’t a real good test and there was only a few sticks added.
No water came out of the filter either but again, not surprising with the short run.
I’m still using the expanded metal grate. I was able to push a piece of rebar through the holes but I’d like to put a movable grate on it. Didn’t start working on cutting out pieces for the Cyclone yet. I need to redesign the inlet. I made it 1 inch and my outlet pipe is around 1-3/8 inches outside diameter.
This means my top pattern for the 4" round section has the cut outs drawn wrong but that is easy enough to fix without printing another pattern. The inlet will now be 1.5" x 2" so it is big enough to fit the 1-3/8" pipe.
The part I’m not sure about is what I will use as the catch jar or container.
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