Charcoal Gasifier for Generator

Small Engines Charcoal Gasification
#57

Another Run

Last night, I decided to do another run of charcoal. This time, I just cut the wood into 2 foot long strips, and packed them tightly in the grease barrel.

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It was fun firing the retort at night. I could see the flames and the glow of the barrel much better.

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I could also see the gas jets shooting out from the bottom of the inner barrel better.

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The only thing I did differently this time is that about 1:15 into the burn, I removed the chimney and added some more wood to the outer fire. I was hoping to make sure everything completely charred inside. This extended the total burn time (including gas venting) to about 3 hours 15 minutes.

I was also tired, and we had to get up early for Sunrise Service this morning, so I decided to do a final test. I left the retort intact, and just blocked the main air intake hole with a piece of tin. It was not airtight by any means. I wondered if the charcoal would burn up overnight since the inner barrel was still sitting on the bricks.

I opened it this morning after Church. This is what it looked like.

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As you can see, there was some light ash on the very top (the bottom, while in the retort). However, it didn’t amount to much. Perhaps a couple of ounces of ash. The yield also appears to be somewhat greater than the first run, perhaps because the wood was more densely packed.

After I stirred the charcoal a little, and broke a few pieces to see how it felt, this is what it looked like.

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My preliminary conclusion is that this turned out to be even better charred than the first batch, and that the “long stick” method works, so there is no need to cube up the wood.

Still, there is a lot of labor involved in wood prep., and this method isn’t really practical for continuous operation. I am going to have to reduce the prep. time considerably, and increase the batch size. What I am thinking about doing is using a 55 gallon drum for the inner barrel, with a bigger surround of some kind around it. I hope to be able to put 3’ sawmill slabs directly into the 55 gallon drum without any extra processing. If that works, then I think it would be a pretty efficient system.

I also think that adding burn-wood half-way through helped. This is somewhat wasteful of wood, but makes it more likely that I won’t end up with uncharred pieces. However, if it wasn’t for the fact that I have more sawmill slabs than I could ever burn, I might lean towards the direct burn method like Gary and others use, since it is probably more wood efficient.

I now have enough charcoal to move on to crushing, screening, and building the gasifier for a test.

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#58

Hi Kyle, great results! It must be so nice to use formed lumber and get it so tight.
My only thought on going bigger with the inner retort is you risk having the outside layer of formed charcoal Insulate the inner layer of wood from getting enough heat. Might not matter you’ll just have to try it. Some people have experimented with the inner chimney for that reason bruce Southerland comes to mind.
Best regards David Baillie

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#59

Processing

I started working on my charcoal processing setup this afternoon.

I made a couple of screens.

The first screen is a fairly fine mesh (between 1/8" and 1/4" but it is flimsy. So, I backed it with a slightly larger diameter piece of expanded metal.

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I made the screens so they would stack together. The top screen is a 1/2" x 1" rabbit wire screen, because that’s what I had on hand. The third or bottom is a solid box to catch the fines. Here’s the stack.

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I am planning on making a jaw crusher to sit on top of the stack. Hopefully the vibrations from its operation will be enough to work the charcoal through the screens. The whole thing will be set on a 5 degree angle. But, if that doesn’t work, all the components can be used manually and separately.

However, on the back porch this evening, I discovered an even more important use for the home brew charcoal. :grinning:

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#60

David - Yes. It was convenient to use formed lumber. I did this because I wanted to process it with my table saw in these test batches. Fortunately, I have access to formed lumber that is rejects from the sawmill (too thick or thin, saw running in or out, etc.).

However, I don’t see this as a practical way to process wood in the longer term because it takes a long time. Also,my supply of this type of lumber is not unlimited. And, it is useful for rough construction projects (dog houses, etc.) so I hate to burn it.

That’s why I hope to be able to simply burn slabs, cut to length, in the longer term.

I see what you mean about a larger diameter barrel possibly causing me problems. I guess I will just have to try it and see what happens. I recently parted out an old gas hot water heater. It has a nice chimney up the middle, so maybe I will have to use something like that for the inner retort?

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#61

Exhaust Flex

I can get a pretty good deal on some 1 inch diameter flexible exhaust pipe. Would it be practical to use this for all of the “hose” connections in the simple fire design (gas output AND exhaust input), or do I need to go with larger diameter?

#62

I think the size would be ok, but that stuff is known to leak. I think charcoal Gary uses the super cheap sump pump hose for the gas.

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#63

Good job Kyle. I’d like to hear your ideas about a jaw crusher. Hand or motor powered?

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#64

Don - I don’t have a very sophisticated idea about a jaw crusher at this point. I am just going to build something out of lumber and plywood, and see what happens. My plan is to run it with a small electric motor with an eccentric wheel and push-rod.

If it comes anywhere close to working, then I will probably recreate it in metal.

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#65

For charcoal processing I use circular saw blades on an axle at the bottom of a hopper. Metal fingers (rods) between blades keeps charcoal from binding and controls maximum size.

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#66

I found the You Tube video that shows the inner barrel down tight against the bottom barrel with no spacers and the pressure of the gasses inside the inner barrel force out the flammable gasses to feed the process.

I’m not fond of tipping full barrells upside down though.

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#67

Good video.

Looks like his outer barrel is double walled and/or insulated.

Looks like his inner barrel doesn’t have a lid it all, but is just resting on its rim on the bottom of the outer barrel. Can’t get much simpler than that.

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#68

Jaw Crusher

OK.

I started building a jaw crusher yesterday.

My plan was to have a couple of pieces of thick plywood. One fixed, and one moving. The moving piece would be “hinged” at the bottom (really backed by a piece of steel pipe), and driven by a pushrod at the top to wag it back and forth an inch or two.

Then, I found this website that talks about real jaw crushers, and has a nice diagram.

http://www.aggdesigns.com/Jaw-Crusher-info.htm

I notice that the moving face (aka the “Pitman”) is actually has a slight up and down motion, as well as in and out. I am wondering how important this is?

Also, I like the way it is driven at the top by an offset shaft that works kind of like a cam across the entire length of the top of the Pitman.

So, I stopped where I was at until I can decide what to do.

I am thinking of a couple of chain driven bicycle sprockets on either side of the upper part of the Pitman; rotating in sync with a roller tube between them (by roller tube, I mean one of those rollers you would find at a sawmill that make up the roller deck that you push the cross-ties and lumber down). The roller tube could ride in a slightly larger tube fixed rigidly to the back of the Pitman. This would give it up and down motion as well as back and forth. The bottom could still ride on an iron pipe, but it would be free to slide up and down.

I realize that this poor description could be hard to visualize. I can elaborate if anybody has questions.

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#69

I Just called my partner in crime Brian and he has one of these jaw crushers that was used for crushing up house bricks , I shall be going over to his yard tomorrow and I shall try and take some pictures of it if we can dig it out , this machine will indeed crush charcoal down to whatever size you adjust the gap at the bottom too .

Dave

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#70

The farther you move the hinge point away from the face of the crusher the more up and down motion it will have. You could build the moving jaw more like an L instead of an I.

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#71

A drawing would probably help , in possible

“A small sketch is worth a thousand words”

Thierry

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#72

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#73

Have you tested this idea yet?
I asked because I have to reduce the size of chunks of coal COKE for blacksmithing. Years ago a guy gave me a ton of “4 X 6” coke. That means that it will drop through a 4" by 6" screen, but not through a smaller one.
Anyway, this guy had gotten 18 tons of it at an auction and had planned to run it through a gravel crusher to reduce it to “walnut” size for use in a blacksmiths forge.
It didn’t work out. The coke simply turned to powder and clogged that crusher. That’s why he wanted to get rid of it.
I tried simply hitting it with a hammer to break it up and got about the same results.
I found that I needed to CHOP it up to get it to the size I need. First, I chop the big pieces in half, then the next largest, etc… That way I get only about 2 or 3 percent fines.
I don’t know if charcoal would behave the same way the coke does, but I do know that I have to be somewhat careful with my charcoal, otherwise it gets pretty dusty when handling it.

Pete Stanaitis

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#74

I made one patterned after Gary G’s grinder that works pretty good. Cylinder is 3 inch pipe with teeth welded on that pass thru slots in a metal plate. A sloped screen underneath drops fines under 1/8 inch into one tub and another tub collects the finished charcoal.

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Making my simple fire gasifier
#75

Very nice, Don. You do good work! Mine is also patterned after Gary G’s grinder, but I crank it by hand. Your mesh screen looks like it might be 1/4", though. I’ve been collecting some plastic jars containing char less than 1/4" and greater than 1/8" and giving them to people who have backyard compost tumblers. They go crazy over it.
The “jaw crusher” is interesting. I wonder how it might handle a piece of wood that didn’t get converted to charcoal (a brand), especially with plywood crusher points. (Probably change them to steel real quick.) With the rotary grinder and teeth all made from rr spike pieces, a brand just bounces around until I fish it out. I don’t get many brands or rocks, but every once in a while it does happen. (Rocks get in when I make charcoal from grubbed out tree roots, or driftwood from my stock ponds.)

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#76

You are right Ray, it is 1/4 inch screen but it being on an angle it seems to act like an 1/8 inch screen because I don’t end up with hardly anything over 1/8" in the fines bin.

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