At 07:48 AM 7/22/2011, Jouni Valkonen wrote:
Damon, little two sec googling with cell phone gave me this link:
<http://brewery.org/library/SteInjCS1295.html>http://brewery.org/library/SteInjCS1295.html
It says that all boiling chambers produces about 98% dry steam.
Therefore wetness measurement that was 1.4-1.2% feels very reliable.
I think that wetness depens slightly on temperature difference
between heating element and water, but if this is the case,
difference is rather small.
As a Wikipedia editor, I became very sensitive to "synthesis," where
someone asserts that a source says something that it doesn't.
That source actually says this:
All boiling chambers usually produce steam that is 98% saturated
vapour and 2% water droplets, i.e. it is "wet" and "saturated". This
is important to remember. The % dry is called the steam "quality".
Notice that the source says "usually." That's because commercial
boilers, what is being described, are designed to produce good-quality steam!
Jouni, quoting the source, left out the word "usually," strongly
changing the meaning.
Further, the context is completely lost, that this isn't really "all
boiling chambers," i.e., every possible boiling chamber, but rather
normal ones. He's talking, later, about using a pressure cooker,
i.e., a large, open chamber, with a single escape opening at the top.
Design a different boiling chamber where steam must heavily mix with
water under more turbulent conditions, you can and will get higher wetness.
The "wetness measurement" would refer to certain measurements using
unknown and unstated procedures, based on readings from a relative
humidity meter. Nobody has been able to explain how to use an RH
meter for steam quality, and it appears impossible, the RH meter will
give the same readings for any saturated steam, i.e., any level of wetness.
In other places, a small elevation in temperature was used to claim
that the steam was dry, whereas the chamber was clearly nailed at
boiling, for the likely pressure, but dry steam would not be
self-regulating at that temperature. The steam, from the temperature
records, appears to be wet, wetness being unmeasured.
In some demos, temperature varies slightly, which is easily
attributed to variations in pressure produced by how the hose was
handled. It's slight.
