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Attached are some pictures of my gas plant. Yes, it was built entirely
from junk salvaged from the tip. Took about 2 years to collect enough to do it.
The Pyroliser unit is
constructed from an old electric hot water urn boiler, the hopper is a garbage bin turned upside down (FEMA
design). The promary gas cooler is made from some thin walled tube from an old bedhead, and is a pretty blue
powder coated color, the secondary cooler is the same stuff, but a nice contrasting red. The water trap is an
old jam jar, the Primary filter is made form an old vacuum cleaner with the insides constructed to the FEMA
design. The secondary filter is constructed from an old paint tin that happened to fit a used caterpiller
bulldozer paper element filter. Most of the odd pipe fittings were from my box of "stuff" and the various pipes
were offcuts from jobs around the farm. The fan was a heater unit from a Toyota Corolla car that was dumped at
the tip.
Its all mounted on an old 6 X 6 pallet and is
reasonably moveable with the aid of the tractor.
I have also fitted a pyrometer inside the hearth to
measure the combustion temperature. This got to 750 deg celcius during my tests, so it should crack tar
OK.
In the pyroliser itself, I have allowed a secondary
air intake (capped off at present) just in case the prmary air didn't allow the temp to get hot enough to crack
tars. I also have a small inspection port. (It was originally going to be the lighting port, but I decided that
I didn't want to pull the whole thing apart just to clean it out, so I cut a hole in the side to allow internal
access and made it air tight with a silastic gasket).
The first test was spectacular. After about 10 mins
I was refueling the unit and had a backfire, so it was producing combustable gas. I connected it to a 3.5 Kva
Honda alternator set and started the generator on petrol. I turned off the petrol and shut off the drawing fan
and closed the fan valve. The engine faulted and started coughing then stopped. The mixing valve was too course
to allow adjustment, so I closed it off, restarted the generator on petrol, turned off the petrol and
controlled the air mixture by lifting up the gas pipe from the intake. This got the engine running, but only
for a few minutes at a time.
Obviously the quality of the gas was not good as I
was using wood chips that were 1/2 composted. The next test will be with good quality wood chips and I expect
better results.
The gas cooler was perfect with the pipe being
touchable only 1 meter from the gas inlet. The other 6 meters of it was cool, so the thin walled pipe works
very well. I could probably shorten it to one length, but given summers here get to 40 odd degrees, extra
cooling is probably worth it. The cooler the gas, the more oxygen available to burn, and hence, more power. So
I will probably leave it alone.
The next test will be with a larger generator. I
have a 5 Kva Suberu (Robin) generator that has a failed electronic ignition unit. I have built a transistor
ignition unit and am triggering it with a HAL effect sensor. This will allow me to vary the timing to optimise
it for syngas.
Overall, I was pretty happy with the first test,
and now have some experience with wood gas. No damage was done with the backfire, apart from singed eyebrows,
but hey, isn't that what they are for? Oh yes, don't forget to wear safety glasses, I was and that probably
saved me trip to hospital to remove bits of wood from my eyes.
If there is any one else around here (Northern NSW,
Australia) experiementing with wood gas I would like to correspond with them. My e-mail is: peterlaughton at
y7mail.com.au
Till next time,,, go go gas
!!!!!!!
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