Graeme's comments:
The slope is 24 degrees .The purpose
of this, plus the height of the stack (now 6
metres) is to
accelerate the velocity of the flame path. My ceramic carreer
seems to always lead me to 'breaking rules' .This
design can
embrace a range of firing cycles. It was designed by Hikaru
Shimamura of Bizen and myself. The attached drawings were
forwarded to Hikaru in Japan, and in his reply
noted that the design was near perfect: "softly lines like a woman"
.
The line of the arch was softened as indicated, with a tight arched
area to the rear of the main chamber acting like a 'damper
chamber' . The air ducts that lie under the chamber
floor
are for including other substances like water,charcoal etc
The 8
passive dampers either side of the exit flue act to influence
the
'pull' of heat from either side of the chamber. This kiln,
after
numerous firings, is easy to fire.I do not know the fuel
consumption or the cubic capacity of the interior. We use
Radiata (Pinus radiata)
or Macrocarpa (Cupressus
macrocarpa).
The firing lasts six days from startup to close
down. I really
like the destructive nature of slow reduction cooling. The method
basically is an intense over loading of the firebox and all side
stokes areas, followed by a quick mud up of every
port, then the damper
is closed and the chimney sealed. The trick is not to burn
your
eyebrows as you seal the side stoke ports, then the front
firebox, then seal the chimney. The dangerous bit is at
the
chimney sealup as the back pressure gets a little serious. |
