Potable Water - The Third Way.
 

Dear Larry:

"Larry" wrote in message
...
"N:dlzc D:aol T:com \(dlzc\)" wrote in
news:pv_Ii.42363$L_
:

What Brian left to the reader's imagination, is that the head
space of the tubes is at a near perfect vacuum, flooded only
with
water vapor. You might recall that a perfect vacuum will lift
a
column of water about 32 feet, on a high pressure day. Or had
you not figured that out?

There's a limit to the vacuum boiling. After a certain point,
water goes from a solid straight to a gas with no liquid
state, just like CO2 does at atmospheric pressure.

It actually goes into this state at very high pressures too. But
you are talking "below" the triple point, which is 0.1degC:
http://www.sv.vt.edu/classes/MSE2094...es/triple.html
.... not much of a problem above this temperature.

You can't pull a full vacuum on it and get liquid water.
http://invsee.asu.edu/ed/phase/phasefeat.htm
(see graph this website, point t.p.)

Not a full vacuum, since water vapor does fill it. And if you
boil too fast, you lose your two columns of water. And if you
don't refresh the contents of the two columns then you start
having scaling issues.

Not a slam dunk, but not a bad idea either.

David A. Smith

Potable Water - The Third Way.
 

Larry, I think you are confusing the pressure/pull of a standing/
suspended 40 ft water column and that of a 40 ft air column.

Chris


of a On Sep 21, 6:21 pm, Larry wrote:
Brian Whatcott wrote :





You've heard all about distilling water, and you've heard all about
reverse osmosis, but you haven't heard about low-cost, low energy
stills: they are brand new.

Briefly:
Take one forty ft vertical tube filled with saline.
Take one forty ft vertical tube filled with fresh water.
Connect them with a little engineering help - at the top.

The boiling point of water at sea level pressure is about 100 deg C

The boiling point of water at the top of a sealed 40 ft column of
water is near ambient.
So, it doesn't take much heat to boil the brackish water, and have it
pass to the fresh column where it is slightly cooled to hold the near
vacuum conditions at the boiling level.

[An engineering effort of a U of Utah group I think]

Brian Whatcott Altus OK

My deepest apologies to the engineers who may be rolling under their
desks, crushing their pocket protectors. It took me a while to stop
chortling. I nearly lost my Chinese dinner!

Psst...Brian....40'? What about the lake above 40', it's 400' deep and
above 40' ASL. It hasn't boiled away in millions of years from all that
pressure and lack of pressure.

In Tehran, Iran, my apartment was about 7000' ASL. Water DID boil at a
lot lower temperature. Making a cake at 7000' altitude is simply
amazing! ONE little cake mix makes 4 cakes!.....er, ah, after you clean
out the oven from putting ALL the cake mix in the pan, filling the oven!

But, alas, even at 7000', the water in my glass didn't boil itself at
ambient temperature, even at 110F out on the lawn!

Every engineering firm across the planet is going to be a jolly place
after hearing about this on Monday...(c;

Larry
--
Sure glad it doesn't work that way! We'd all be DEAD!

Potable Water - The Third Way.
 

On Sat, 22 Sep 2007 20:48:22 GMT, (Richard
Casady) wrote:

On Fri, 21 Sep 2007 17:35:02 -0500, Brian Whatcott
wrote:

The boiling point of water at the top of a sealed 40 ft column of
water is near ambient.
So, it doesn't take much heat to boil the brackish water, and have it
pass to the fresh column where it is slightly cooled to hold the near
vacuum conditions at the boiling level.

Fraid not. It takes the same ammount of heat to boil water as at 212F.
Approximately 1175 BTU/lb. You might save a little not heating the
water all the wqy to 212.


When you contradict me, it is always better to check your facts.
I do.

Brian Whatcott Altus OK

Potable Water - The Third Way.
 

On Sat, 22 Sep 2007 10:55:52 -0500, Brian Whatcott
wrote stuff
and I replied:

But what is the cheap source of getting the vacuum? I figured there
had to be a vacuum, although it was not said. But how do you get it?

Well no, he obviously hadn't figured that out. Nor can anybody figure
out what is going to hold a column of water 40 ft high as was stated in
the original post. The tubes may be 40 feet but the column of water will
be considerably less. How much less will depend on how much energy is
heating on the hot side and how much energy is cooling on the cool side.
The total amount of energy needed is not going to be any different than
any other distilling method.
Unless you have the free or cheap sources of cooling and heating at
specific temperatures this isn't going to work any better either.

-jim



Well, at least this respondent Jim, is operating at shall we say the
7th grade level of science/engineering insight. Like so many other
products of the domestic school system, he seems to have a severe
case of self-esteem syndrome.

Still, he may be retrievable, starting with a science demonstration
he may have missed. Place a beaker of water in a bell-jar and pump
the air out.

When 99% of the air has been pumped out, the water in the beaker is
boiling vigorously, until, in the usual way, the beaker boils dry.
The beaker feels cool to the touch, naturally.

To quote him: "unless I have a cheap source of heating this won't
work..."

For the $64 prize: NOW do you get it?

Brian Whatcott Altus OK


Human bevaviour: Bestiality with a brain

Potable Water - The Third Way.
 

Dear OldNick:

"OldNick" wrote in message
...
On Sat, 22 Sep 2007 10:55:52 -0500, Brian Whatcott
wrote stuff
and I replied:

But what is the cheap source of getting the vacuum?
I figured there had to be a vacuum, although it was
not said. But how do you get it?

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...

David A. Smith

Potable Water - The Third Way.
 

On Sat, 22 Sep 2007 20:43:48 -0700, "N:dlzc D:aol T:com \(dlzc\)"
wrote stuff
and I replied:

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

Is this a continuous or pulsed process? How do you maintain stasis and
extract fresh water?

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

etc

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...

David A. Smith


Human bevaviour: Bestiality with a brain

Potable Water - The Third Way.
 

Dear Old Nick:

"OldNick" wrote in message
...
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

Potable Water - The Third Way.
 

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

Potable Water - The Third Way.
 

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

Potable Water - The Third Way.
 

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