On Mon, Jul 18, 2011 at 9:08 AM, Jed Rothwell <[email protected]> wrote:
> P.J van Noorden wrote: > > It is very important to notice that water boils at 100.5 C when the >> outside air pressure is 1030 mBar, which can be the case when a high >> pressure system is covering Italy . . . >> > > In the April 28 tests, Lewan reported: "we calibrated the probe by > immersing it in a pot with boiling water, and the measured value was then > 99.6 degrees centigrade." Later during the test they measured vapor at > "about 100.5 degrees centigrade." There is no doubt that was vapor, since it > is substantially hotter than the boiling water, plus you can see steam > coming out of the pipe. Only a little steam comes out of the pipe. The flat temperature indicates a mixture of steam and vapor at the bp. The reason for the elevated bp is increased pressure, either because of water depth, or the need to push a high volume of steam through a labyrinth of fillings. > I expect that backpressure is minimal with this system. > Check http://www.pipeflowcalculations.com/pressuredrop/ to change your expectations. Be sure to look at the calculator of K-factors and to set the pressure calculator for gas flow at the right conditions.
