[Gasification] V3.O: Crossdraft Gas-Can-i-Fier

[jim mason]

last night i added a crossdraft unit to the updraft and downdraft
demostration rig already built.  there are pictures of it on the
bottom of the page here:
http://www.whatiamupto.com/Gasification/quadrafier/index.html.  the
previous updraft and downdraft description and links are now on this
page too (though not very pretty yet).

i built the new cross draft from a 5 gal jerry type metal gas can, in
the absolute most simple form possible.  no attempt was made to make
it efficient.  just as absolutely simple as possible.

I did not allow myself to use the welder for this version. The only
power tool used in the making was a drill and an angle grinder with a
cut off wheel to make the fuel loading hopper. The fuel hopper doesn't
even have a hinge other than bending the metal back to fill it. It
doesn't get much easier that this. Build time: 4 hours.

the existing fuel bung was piped with 2" black pipe for the gas exit,
using some stainless steel mesh for the grate. The air inlet is
drilled in the gas can base (now side) so distance between air inlet
and grate can be varied for different load conditions (a la the
kalle). plumbing reducer couplings on the end of the air inlet allow
for easy changing of air inlet volumes.


We are running wood pellets in the pictures at the link. The first run
melted the sealtite electrical flex conduit i was testing, so i went
back to the flexible exhaust pipe and aluminum tape.  (a friend walked
in after the sealtite melted and offered, "jim, it seems you have
over-amped that wire there a bit from what i can tell . . . ")

The sealed hopper proved to be much more sensitive to fuel moisture
than either the open hopper stratified downdraft, or the updraft. On
the first real run, it started strong, but was quickly overwhelmed by
steam from the drying fuel inside the gasifier. Seeing this increased
sensitivity to fuel moisture with the sealed hopper design was very
interesting, and will be noted in future designs.

next up is a fluidized bed.  i hope to get that built in the next
couple days from screw together pluming parts.

j