That sounds like what is happening, except I use a small battery powered
(thanks, Ole' Bob) mechanical stirrer. The vapor definitely condenses
on the lid, and then drips down all along the inside edge of the vessel
giving me more stirring - mixing downward at the outer perimeter of the
cylindrical vessel and upward where the brew is heating up in the middle
from the power drop across the water in between the electrodes. My
electrodes are normally near the center of the vessel. I was glad to
stumble onto this improvement, because it jumped up the quality of my CS
just by putting a lid on the two gallon brew vessel.
Thanks,
Vince
-----Original Message-----
From: Matthew McCann PE [mailto:[email protected]]
Sent: Saturday, November 29, 2003 10:26 AM
To: [email protected]
Subject: CS>Why the yellow CS - an hypothesis
It makes sense that a glass
lid on top of a thermally mixed
vessel would produce a
better CS.
In a cylindrical vessel heated
at its lower end, the steady-state
convection will be an updraft
vertically along the center axial
region, and a downdraft along
the periphery of the cylinder
except for cooling losses at
the top surface. A glass lid will
diminish the latter loss, thereby
increasing the convection
down the inside periphery of
the vessel. The result is more
stirring without additional heating.
Best wishes,
Matthew
