Dear Old Nick:

"OldNick" wrote in message
news
On Sat, 22 Sep 2007 20:43:48 -0700, "N:dlzc D:aol T:com
\(dlzc\)"
wrote stuff

Fill the tubes, with a small air bubble in between.
Lift the tube at the bubble. No small feat if you
are looking to make hundreds of gallons per day,
but a one-shot expense...

and I replied:

Then how do you keep the freshwater tube so
cool? It has to be a _lot_ cooler, not so?

Likely, yes. You could use evaporative cooling (of brine) on
that side, and solar heating on the other side.

Is this a continuous or pulsed process?

I woudl assume it could be either, depending on the
sophisticatioin of your control process.

How do you maintain stasis and extract fresh water?

Ever seen a mercury barometer? The bottom end of the tube ends
in a "pan" open to atmosphere. The bottom end of both tubes can
simply be sunk... one in the ocean, and one in a wet well for a
pump station.

If you have a small air bubble, where does the
extracted fresh water go?

The air bubble expands when the vaccum is created.

etc

etc. Take your shades off, dude. It is coloring everything you
see...

It isn't the greatest thing since sliced bread. But it is
another process, and a viable one.

David A. Smith

On Sun, 23 Sep 2007 21:57:56 +0800, OldNick
wrote:
....
Then how do you keep the freshwater tube so cool? It has to be a _lot_
cooler, not so?


I'm probably going to regret responding, but I will anyway, with a
question:

What is the difference in temperature between steam and water,
both at the boiling temperature of water, whatever it may be?

Cooler means lower temperature, right?

OK you can now answer your own question.
I hope.

Brian W

Dear Brian Whatcott:

"Brian Whatcott" wrote in message
...
On Sun, 23 Sep 2007 21:57:56 +0800, OldNick

wrote:
...
Then how do you keep the freshwater tube so cool? It
has to be a _lot_ cooler, not so?

I'm probably going to regret responding, but I will
anyway, with a question:

What is the difference in temperature between
steam and water, both at the boiling temperature
of water, whatever it may be?

Cooler means lower temperature, right?

OK you can now answer your own question.
I hope.

You don't happen to like bitters, do you? ;)

David A. Smith

On Sun, 23 Sep 2007 11:29:46 -0700, "N:dlzc D:aol T:com \(dlzc\)"
wrote:

Dear Brian Whatcott:

You don't happen to like bitters, do you? ;)

David A. Smith


Angostura I can take or leave:
India Pale Ale works for me,
but not if I've gone for a Burton.

:-)

Brian W

On Sun, 23 Sep 2007 18:10:09 GMT, Brian Whatcott
wrote stuff

and I replied:

You are a rude and arrogant prick


On Sun, 23 Sep 2007 21:57:56 +0800, OldNick
wrote:
...
Then how do you keep the freshwater tube so cool? It has to be a _lot_
cooler, not so?


I'm probably going to regret responding, but I will anyway, with a
question:

What is the difference in temperature between steam and water,
both at the boiling temperature of water, whatever it may be?

Cooler means lower temperature, right?

OK you can now answer your own question.
I hope.

Brian W

Human bevaviour: Bestiality with a brain

On 2007-09-22 16:07:27 -0400, Keith Hughes said:

Actually, do a search on "triple point" and look at the phase diagram
for water. That gives a good graphical depiction of the
pressure/temperature/phase relationships.

That just shows the phase vs temperature, not the energy required to
get the substance to pass that critical temperature.

See
http://en.wikipedia.org/wiki/Thermodynamic_databases_for_pure_substances
and search for "Enthalpy change of phase transitions" for some
explanation of the heat energy required to change phases, with a
diagram for zinc. (Thanks, Brian, for reminding me of the term I
couldn't remember.)

And also think a bit: If the difference between 32 and 33 were so
easily crossed, you wouldn't see so much ice in your drink so long.

--
Jere Lull
Tanzer 28 #4 out of Tolchester, MD
Xan's new pages: http://web.mac.com/jerelull/iWeb/Xan/
Our BVI pages: http://homepage.mac.com/jerelull/BVI/

Jere Lull wrote:
On 2007-09-22 16:07:27 -0400, Keith Hughes said:

Actually, do a search on "triple point" and look at the phase diagram
for water. That gives a good graphical depiction of the
pressure/temperature/phase relationships.

That just shows the phase vs temperature, not the energy required to get
the substance to pass that critical temperature.

No, it shows the phase for temperature *versus* pressure, not the same
thing at all. And the point was to clarify the temperature/pressure
relationship.

See
http://en.wikipedia.org/wiki/Thermodynamic_databases_for_pure_substances
and search for "Enthalpy change of phase transitions" for some
explanation of the heat energy required to change phases, with a diagram
for zinc. (Thanks, Brian, for reminding me of the term I couldn't
remember.)

And also think a bit: If the difference between 32 and 33 were so easily
crossed, you wouldn't see so much ice in your drink so long.

Saying the difference between "32 and 33" is misleading (or a
misunderstanding of the process). Actually, it's the difference between
Ice at 32° and Water at 32°. All the energy (enthalpy) change is used
in the phase transition (latent heat of fusion, or evaporation in the
case of distillation), and not change in temperature. Additional heat
input will raise the temperature of the water (or steam in the case of
distillation - i.e. 100°C water [at standard pressure] evaporates to
100°C steam, at the moment of phase change, and additional heat input -
and pressure - are required to raise the steam temperature further).

Keith Hughes

On Mon, 24 Sep 2007 09:38:16 +0800, OldNick
wrote stuff
and I replied:

and snickering, snide and childish as well

You are the sort of cliqueish dolt that spoils useful NGs like this.

If you have KF'd me, you simply prove your weak, childish nature.

It's shame. You do actually seem to have a lot of knowledge. IT's a
pity you have to use it to sneer and brag rather thatn help those
"lesser" than you


On Sun, 23 Sep 2007 18:10:09 GMT, Brian Whatcott
wrote stuff

and I replied:

You are a rude and arrogant prick


On Sun, 23 Sep 2007 21:57:56 +0800, OldNick
wrote:
...
Then how do you keep the freshwater tube so cool? It has to be a _lot_
cooler, not so?


I'm probably going to regret responding, but I will anyway, with a
question:

What is the difference in temperature between steam and water,
both at the boiling temperature of water, whatever it may be?

Cooler means lower temperature, right?

OK you can now answer your own question.
I hope.

Brian W

Human bevaviour: Bestiality with a brain

Human bevaviour: Bestiality with a brain

On Sep 22, 11:12 am, "Roger Long" wrote:
There's another neat way you can demonstrate this with minimal equipment.

Take a tight fitting jar and get the water boiling vigerously in it with the
cap on loose enough to let the steam out. When it is full of dense steam
and about 1/3 boiling water, remove instantly from heat and tighten cap.

When everything is cooled to room temperature, put an ice cube against the
jar and the water will start to boil. The ice condenses the water vapor
further, reducing the pressure to the point where the water will boil at
room temperature.

I've seen it done and it looks like the ice cube is boiling the water.

My father won a science fair doing this back in the 1930's.

--
Roger Long

http://www.metacafe.com/watch/414997/boiling_using_ice/

Joe

On Sep 25, 8:54 am, OldNick wrote:
On Mon, 24 Sep 2007 09:38:16 +0800, OldNick
wrote stuff
and I replied:

and snickering, snide and childish as well

You are the sort of cliqueish dolt that spoils useful
NGs like this.

.... "Go away" ...

If you have KF'd me, you simply prove your weak,
childish nature.

.... "Stay and argue with me" ...

It's shame. You do actually seem to have a lot
of knowledge. IT's a pity you have to use it to
sneer and brag rather thatn help those
"lesser" than you

.... "I will smear **** on you, if you don't argue with me" ...

Human bevaviour: Bestiality with a brain

Human bevaviour: Bestiality with a brain

How is it that you complain about other's behavior, yet you form not
one response but *two*, that show exactly the behavior your signature
talks about.

Is that signature line a complaint, an acknowledgement, or a promise?
Be good to know. Because it seems like we have a choice.

David A. Smith