In response to a question posted to the
Gasification List regarding the smallest throat used in a gasifier, the smallest
recorded was a WW2 Imbert at 2.3", I have dug out this 1985 project that I built
with a 1" throat. For practical purposes if in serious need, 2.3" works
very well, and this is the size of the MicroLab gasifier shown earlier on this
This gasifier was to have been a
working model, and the gas making was only tested once to ensure it made
gas, before all the effort went into the gas cooling/cleaning system. At the
time it was built, our knowledge of tunability, and behaviour of the charcoal
evolution in relation to fuel size was minimal, so it cannot be claimed that
this particular gasifier could have made a tar free gas. With another 24 years
experience to assess this design, the gas it made was probably mainly pyrolysis
gas full of tar, but it could now be designed correctly in hind
As a model gasifier, I would put it into
the same category as miniature steam engines which everyone would like to own,
but never afford to purchase.
Fuel hopper and gas making hearth.
Cooling cleaning assembly.
Very over done with 3 sets of paired cyclones, 3 first stage char separators,
and condenser/gas cooler.
Sawdust filter with one
screen lifted. 12V Fan assembly removed from end of gas