I am looking forward to Wayne’s book…I have made a gassifier that is a cross between the FEMA and Imbert but haven’t had much luck. Right now I am creating gas - I get gas out of a burn off valve, but not enough to maintain a burn. When I use wood pellets I get an internal explosion. I used a 6-inch pipe for the burn chamber as described in the FEMA info, I have also installed 3/4 inch air tubes. I also get a lot of water in my cooling pipes.
Hi Mark,
You’re on the right track with a FEMA/Imbert hybrid, as that is how Wayne started out, and drove several thousand miles. He has evolved way beyond that now, and I think once you see his design you will implement some major changes in yours, or possibly rebuild from the ground up as I did.
Keep at it!
Hi MarkD.
I have been doing some back reading on your FEMA-bert system before I would chime in.
My hope is that maybe you have been directly talking with Wayne? If so believe him and take my stuff with grain of salt.
Please believe me almost anything can be made to produce for a short time with a hand stacked finger nail sized hardwood woodchar bed from the grate up to 1-2" above the nozzles and then with 4-6" of really dry 2" x 2" soft wood chunks above that. I used to say it also took a good variable speed high temperature blower too, until I learned to use a common shop vac back side nozzle blowing with the inlet on the shop vac throttled back controlled with a strip of duct tape. This is the “make woodgas out of a piece of straight pipe” trick.
If you are a Y.Woodgas member read Greg Mannings message #43301 “Dam the FEMA”. He describes doing exactly this. Mayby direct link for you:
http://tech.dir.groups.yahoo.com/group/Woodgas/message/43301
( there you go MikeL. a Y.Woodgas plug)
MarkD much water in the output gas and poor gas quality is usually an indication of too much air getting in "combusting/burning up the gas prematurely inside the hearth. If so, this always produced metal glowing amounts of heat.
Your air nozzle(s) sound huge to me at 3/4 of an inch for any kind of small portable generator engine. Be big for even a 240 CID 20-30 kW Onan trailer set. What is your generator/engine size? Can you inset or cap neck down this/ these nozzle(s)?
Pellets as a compressed cell crushed densifed fuel operate/react completely differently than chunked up or corse chipped, gasses exchange, porous/permeable open cell whole wood fuels. Pellets can be gasified buy need a completely different system design and handling. DRY chunked woods are the easiest fuels. Save the difficult fuels for later after you actually have heard and ran your engine under a load.
Couple of good flare pictures with other “when it does’t work” diagnostics are here on Dutch John site:
www.woodgas.nl
Load an read, reread and then read again his Micro Gasifiers. The best engine grade gas flare is NOT the pretty blue flame.
Regards
Washington State Steve Unruh
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I have been doing quite a bit more studying and realize that my air nozzles are too low as I put them down near the grate. My wood burns up and doesn’t leave a charcoal reduction zone. I also used a straight pipe for my fire tube with no “throat”, so I may need to redo that whole section. Thanks for your comments. I feel like I have been doing this all alone until I found this site.
Thanks Steve; your posts and references are very informative. I havnt built a small gasifier yet bet these posts will really help get started.
Thanks, Ron L
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