John Baymore on thu 12 dec 02
An inside-fitted door can easily be made to lean slightly inward,
offsetting the tendency of reduction pressure to force it outward,
while an outside-stacked door would need a slight angle to the
wall-ends to make this work well. Also, when that interior
pressure does force the door to bend slightly outward, the crack
around an inside-stacked door stays constant in width. An
outside-stacked door will have a wedge-shaped gap open up along
the wall as pressure increases.
In my experience, the pressure differential that I have measured with an
inclined tube manometer between the interior of a kikln chamber and
atmospheric is so low that I think it has little to do with causing a
bricked in door to lean outward. The mass of such a door, even an IFB on=
e,
is quite high. It would take a lot of pressure to move it the amount tha=
t
they typically move.
I think the observed phenomona is actually due to the volumetric expansio=
n
of the hot face door materials more than the cold face materials. The
inside of the door gets bigger than the outside...... and it leans out fr=
om
that....not the pressure of the gasses in the interior. The rest of the
kiln is experiencing this phenomona also.....but the structure (hopefully=
) is built such that it is not so obvious.
Best,
..............................john
John Baymore
River Bend Pottery
22 Riverbend Way
Wilton, NH 03086 USA
603-654-2752 (s)
800-900-1110 (s)
JohnBaymore.com
JBaymore@compuserve.com
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