I would avoid Generac generators.
Just a nightmare to work on and find parts for.
I think they make their money in parts and service not sales. .
Walk around a marina and see what people have in small boats.
That is a good place to start looking for a reliable motor with strong quality guts.
But sometimes you might be forced to use an auto engine if you are a budget builder on a mission.
The little Ford LIMA 4 cylinder would probably be a good motor to try.
They made a lot of these and put them in cars like the Pinto, Mustang and Ford ranger pick up.
Sometimes you get lucky and find something unloved that can be adapted.
Remove the gear box from a PTO generator and you may have something that bolts up to a converted auto engine
The space was one inch, same thickness as the roll of insulation. So I just wrapped it around, used a piece of wire to hold it, and stuffed it in the bigger barrel. It slid in with just enough friction to hold it at any position, unless I pushed down, so the sizing is important to make it easy.
All the flames go up the pipe and extra heat is soaked in around the base of the drum as well , i found that when turning really really wet or green wood into charcoal i could start the fire on floor waste and when i wanted to go indoors for a cuppa i would throw some logs on and they would last ages slowly drying the wood inside , when the fire ban is off here i shall rebuild my drum and the pit i stand my drum over i shall insulate with fire bricks to keep more heat into the drum as well . i shall see if i can find any pics , but my set up is so ugly i squint my eyes every time i walk past my set up
I have used both types: fire underneath and rocket tube. The under fire type is definitely more flexible and forgiving. If I have dry feedstock and if I use a blower to create a blast furnace in the tube, the rocket style works well. I find that it helps to have a long stainless steel expanded metal grate in the fire tube so I can push plenty of air underneath all of the fuel. BTW, blowing into the fire tube helps slightly pressurize the retort which helps to drive out the moisture.
Made a little progress today. Six inch diameter L shaped tube (1/8" wall thickness) is bolted down to 1" x 3" tube under the floor. A Saturn-ring/flange welded to the L tube holds the tube in position and also serves as a face to tighten the lid against. Fire rope (not shown) fills any space in the crack. I haven’t decided how to insulate the top yet. And does it need some kind of opening in the lid with a check valve to release pressure, or is the pipe carrying gases down to the L tube enough? I plan to seal the crack around the lower L tube hole with furnace cement. There is a ring clamp to seal the lid, but it is not shown. The L tube assembly is bolted to the barrel and can be removed and replaced without welding. I still need to complete the chimney.
Thanks for suggesting the expanded metal grate. I don’t have any stainless but I have some mild steel that I can use and I’m sure it will improve performance.
Thanks for sharing all your experience Steve. We have lots of fir trees on our property as well as some arbutus, which is a hard wood. The arbutus is generally considered ‘better’ for fireplaces, but if I understand you, the fir is better for my gasifier with a small generator because it burns faster? I plan to make the wood, whether fir or arbutus, into charcoal before going into the gasifier, to make the process more efficient.
Looking good, Greg.
This design is similar to the Anila Biomass Gasifier stove. The first one I built was inside a propane tank, and the raw wood was loaded into the tank via a hatch on the side. It worked well, and took about four hours to make a good batch of charcoal. At the base of the inside vertical tube I drilled four 1/4" holes which jetted into the burn chamber. This was a very non-linear burn that roared like a rocket engine once it got going. When it finished, the four small holes did not allow the charcoal to burn up, so all you had to do was leave it sit for several days to cool down, empty, and reload. A few times, I inserted a copper coil into a large pot on top of the stove, and pumped it into my solar water collector tank, thus using the heat coming out of the top of the stove. The water in the pot reflects the temperature of the water in the collector tank, so even though it is receiving a tremendous amount of heat, it slowly warms. https://stoves.bioenergylists.org/anila
The grate in my stove was a pyramid, and I used the little stones as recommended by the designer. Here is a YouTube video/slide show I made seven years ago: https://www.youtube.com/watch?v=gmjfXDdEU48
I used a blower from a discarded microwave oven, controlled by a ceiling fan speed control.
The hatch on this one is too small, so it takes a while to load and unload. Also, mice loved the insulation, and moved in when the stove was not in use.
It looks great! I want to see how well this works!
I am not suggesting you change your design. But i might have opted to run the gas pipe out the side then down to save space inside the retort, and maybe cool the gases off a bit.
Good morning GregC.
Arbutus is Pacific Mandrone, right?
I’ve done some 300 pound test runs on this wood. It’s fine if a bit “slow” versus most firs. Many kinds of firs. And selected portions in any single fir.
I had thought you wanted the DYI-made wood charcoal for first system pre-zones loading.
Of course any woodgasifier really is a charcoal pot/pile at it’s heart.
Using only pre-made wood charcoal as your fuel input you will probably be O.K. at low loadings in this Ben’sBook system.
I would be wary using just wood charcoal in any purpose designed woodgasifier under heavier loadings though.
System internal damaging overheating.
Raw wood inputs converting to charcoal actually internally cools the system.
The pure charcoal gasifier guys have to add back in steam and/or engine exhaust for system internal heats controlling.
Wood does this with carry-in intra/inner cell moisture’s.
Looks nice. Yes, you will need a way to vent the moisture out through the lid. Use a valve on that vent that can be shut once the escaping gas becomes rich enough to ignite.
Hi Greg , just as Bruce suggested with the pipe out the top lid to vent off moisture , always try and keep that pipe straight with no 90 deg bends as it will soon fill up with tar and gunk .
here is James Hookways design
@BillSchiller When the wood is heated from the rocket stove, the gases from the wood go down the smaller vertical tube into the rocket stove, hopefully to help the fire.
@bsoutherland It makes sense - Let it vent out through the lid when it is moisture and force it down into the rocket stove when it becomes flammable. Thanks for clarifying. I’ll be sure to build a lid vent.
@d100f I started with Hookway’s design and I’m trying to improve it. I should be able to test it in a few days if I don’t get too distracted. How high above the lid do you find is the best length for the chimney?
