Am 19.11.2011 23:58, schrieb Alan Fletcher:
In small bubbles or small drops, surface tension is dominant.
This is true.
There is an interesting early scientific work about water electricity
from the physicist Lenard who later got the nobel price.
He points out that evaporating water is electrically charged. Therefore
the droplet is positive charged and the vapor is negative charged. This
makes rather strong electrostatic forces in the droplet and is the
reason for negative air ions observed in nature at waterfalls.
If a droplet becomes to small the repelling electrostatic forces make it
explode.
So, in microscopic areals and with purified (nonconductive) condensed
water there can be indeed anomal behaviour of water and vapour , maybe
this is what this professor has observed. It is however not observed
with ordinary boilers.
Pressure changes, so the PVT equilibrium can be different.
I have a link somewhere for this .... I'm not sure if I put in my tube boiler
analysis.
And for the life of me, I can't remember if small drops grow or shrink in a
particular PT environment. (There's a named formula).
----- Original Message -----
If the same water is _theoretically_ supposed to boil at the same
precise temperature at a given pressure, I just don't understand how
water can _theoreticallly_ survive as a liquid drop while surrounded
by steam which is above the boiling point. In other words, the theory
that the same water always boils at the same _precise_ temperature for
a given pressure is an idealisation and an approximation.
