For my 3rd small batch I added a section of flue pipe. The wood for that batch was some cut and split pieces of dry 2x4’s and it burned fast with almost no smoke at all. The flames out the top were almost invisible and mostly just heat waves.
This was the result from 3 batches. I dumped each batch into a bucket of water to put it out so it is wet and not a large amount but I really just wanted to test this idea before trying to build a bigger version.
Your not the first to have had that thought, but I haven’t heard of anyone actually doing it yet, one guy is making heat and CO2 for his greenhouse and biochar all at the same time. Link to mentioned discussion.
Hi Steve , yes my fire has what is called a wetback ( old English term for a boiler in the back of the fire box ) fire box size is 24w x 10d x 11H
My More modern wood burning fire has the boiler on the sides and back to steal as much heat from the fire and transfer it to my radiators around the house ,corner to corner i can get 2ft wood in just about but try and keep wood as small as i can so i make more work for my self and of course more fuel for the engines .
I have 2 ways i collect the charcoal if i have a lot of very small coals i can use a small shovel and scoop it straight into the pans from inside the fire , that also gets a fair amount of ash as well , or if its fairly large chunks i use the wife’s old kitchen tongs she kindly donated to me ,but i have to wear welding glove for that as its so damn hot inside .
I was thinking more like what Dave said he does. While the furnace is being used anyway, scoop out some of the hot coals and reload the furnace with fresh wood. Put the hot coals into something airtight and fireproof to go out leaving the charcoal for use as engine fuel.
When I say engine fuel, I’m only talking small engines (for now) like running a generator or the log splitter for a hour or so at a time. I can imagine, on a cold day, being able to collect a scoop or two each time it needs more wood added.
I don’t know if Gary still uses or builds these anymore. It looks like you would have to build it yourself. I’m just planning to swipe some coals from the existing house furnace but something purposely made to make charcoal like the Keystone stove might be an option for a workshop or garage.
Rindert, I’ve been searching for either a down draft gasifier or raw wood gasifier design that wound work with my rather small engines. Did this end up working?
Most of the charcoal designs I have seen are updraft and that is likely the simplest type but I’d like to make my next build be a down draft. I’d like it to be as small as possible but big enough to get me at least half an hour.
I was looking at a mini WK gasifier but it looks like it didn’t work or at least wasn’t finished.
hello brian, on my topics you can see some small charcoal downdraft gasifiers for my mowers, tiller, stationary unit…also kristijan has one on his walkbehind mower…
nice new active people here on the forum…!
I still think I can make it work, at least on charcoal. I now have a 2200 psi pressure washer so I can spray all the tar out of the inside. Will make makes working on it a lot easier I hope. I kind of got more busy with work for a while but should be able to get back to it now.
Rindert
Yeah dont be afraid to be creative. Consider this as the concept, I would strongly encourage you to build the unit out of something more robust than an ammo box. You dont have to build out of a square box you can use round tanks just as well.
One thing me and Rindert didn’t do is follow the dimensions 100%. It is very dimension sensitive. Also the grate is meant to be fixed. One big thing to keep in mind as well, is any gasifier that Joni has brought up require high velocity at the nozzles. You do this by making the orifice tip like a jet. Say you want a 10mm nozzle, drill out 10mm and behind it drill it out a little bigger.
I chopped it up as I was filling it using the shovel and looks like this will have a lot less wasted waiting for it to go out while continuing to smolder. No smoke getting out after closing the lid. Plus, this will be dry so should be usable as soon as it cools and gets classified and ground to engine grade size.
Brian , when you first load up that drum with glowing charcoal leave the lid loose don’t what ever you do make it air tight to start with wait till the coals stop glowing before sealing up the lid air tight ,other wise it will burn up any oxygen inside and create a vacuum and collapse the drum .
Dave
I don’t have the clamp for the barrel’s lid and it doesn’t have a gasket so it won’t seal completely air tight but good enough to keep the coals from continuing to burn.
I misjudged the angle it needs to get the charcoal to go down the screen so this ended up shorter than I intended but it separates the finer (1/2" and smaller) from the charcoal I will still need to grind. I’ll still have to screen the fine stuff once more to get the ashes and biochar out.
This is what I got just from separating the charcoal without any grinding besides breaking it up with a shovel. I’m figuring there’s 2 hours worth of generator fuel in that bucket ready to use. Probably a gallon worth of biochar. That isn’t even counting the 3 or 4 buckets of bigger charcoal that could either be ground finer or saved for forge, foundry, or BBQ use.
The better barrel to put the glowing coals into was the key to having a practical system for making my own fuel. Gotta go find a lemon now.
Brian,
If you are using a 1/4 inch (4 mesh) screen for the fines, you will be ok and reclaim more engine fuel using 1/8 inch (8 mesh) screen. That is what I use and haven’t noticed any negative issues.
The hardware cloth in the new screen is 1/2 inch and my little screen is a little over 1/8 inch. I would like to have 3/4 inch as the biggest screen but I don’t have any that size. A few bigger than 1/2" pieces got mixed in with this engine grade bucket which should be fine but I think I could recover more of the bigger pieces to mix in if I get a 3/4" screen and eliminate even more grinding.
I’m still researching and hunting through my scrap trying to decide on a down draft charcoal (or wood) gasifier but my simple fire gasifier is working good enough that I’m not in a big rush to use up my scrap until I decide exactly what I want to build.
I have a 20# propane tank sitting here just waiting for a use but it’s starting to look like a filter for the simple fire if I can figure out a good way to seal it but still be able to clean or replace whatever filter material I use. The bucket filter I have now is working but the 20# tank might work better if/when I put this on a base or cart.
Thinking something like this might an option for the 20# tank. Maybe upside down so the threaded opening could be used as a drain.
The tank will be upside down so the threaded part where the valve was will get a 3/4" pipe plug to drain any condensation or to drain it if I just wash out the filter media.
It will be raised up to access the drain but I won’t know the length of the legs until I get it together.
I want to go out of the gasifier, through the condenser, and then into the bottom of the tank (formerly the top). The gas outlet will be on the removable top section where I’ll hook up the hose to the engine. I thought about making the gas outlet at the side (and still might) but it will probably be a plastic hose so being on the removable lid shouldn’t be a problem.
I discovered a problem with my plan. My nozzle still isn’t easily replaceable but that can be fixed with Tom’s suggestion. The problem is the way I have been cleaning out the charcoal is to just flip it upside down. I won’t be able to do that if I keep adding to this or mount it on a base.
Here’s one solution.
The link in that post goes to some pictures of Giorgio’s clean out port. Large pipe fittings and pipe caps are expensive and I can’t tell for sure but it looks like Giorgio’s version isn’t threaded. Where my clean out port would go is in one of the hottest places on my gasifier. Would woodstove gasket rope and high temperature silicone handle the temperature at the bottom side of my gasifier? I’m thinking a section of square tube welded on the side unless I find something better.
