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

Dear Brian Whatcott:

On Sep 21, 3:35 pm, 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]

There are ship-board distiller units that use an engine to pull a
vacuum, and the engine's waste heat to boil that water, to generate
drinking water. A little shorter...

David A. Smith

dlzc wrote in news:1190415672.506271.93890
@k79g2000hse.googlegroups.com:

There are ship-board distiller units that use an engine to pull a
vacuum, and the engine's waste heat to boil that water, to generate
drinking water. A little shorter...

David A. Smith



http://en.wikipedia.org/wiki/Boiling_point

"The boiling point of water is 100 °C (212 °F) at standard pressure. On
top of Mount Everest the pressure is about 260 mbar (26 kPa) so the
boiling point of water is 69 °C. (156.2 °F)."

AT 40' ASL, the boiling point must be down to...to....211.95F!

Larry
--
Search youtube for "Depleted Uranium"
The ultimate dirty bomb......

Dear Larry:

"Larry" wrote in message
...
dlzc wrote in news:1190415672.506271.93890
@k79g2000hse.googlegroups.com:

There are ship-board distiller units that use an
engine to pull a vacuum, and the engine's
waste heat to boil that water, to generate
drinking water. A little shorter...

http://en.wikipedia.org/wiki/Boiling_point

"The boiling point of water is 100 0C (212 0F) at
standard pressure. On top of Mount Everest the
pressure is about 260 mbar (26 kPa) so the
boiling point of water is 69 0C. (156.2 0F)."

AT 40' ASL, the boiling point must be down
to...to....211.95F!

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?

David A. Smith

"N:dlzc D:aol T:com (dlzc)" wrote:

Dear Larry:

"Larry" wrote in message
...
dlzc wrote in news:1190415672.506271.93890
@k79g2000hse.googlegroups.com:

There are ship-board distiller units that use an
engine to pull a vacuum, and the engine's
waste heat to boil that water, to generate
drinking water. A little shorter...

http://en.wikipedia.org/wiki/Boiling_point

"The boiling point of water is 100 0C (212 0F) at
standard pressure. On top of Mount Everest the
pressure is about 260 mbar (26 kPa) so the
boiling point of water is 69 0C. (156.2 0F)."

AT 40' ASL, the boiling point must be down
to...to....211.95F!

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?

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




David A. Smith

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On Sat, 22 Sep 2007 10:15:40 -0500, jim wrote:


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?

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

"N:dlzc D:aol T:com \(dlzc\)" wrote in newsv_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?

David A. Smith


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.

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.)


Larry
--
Search youtube for "Depleted Uranium"
The ultimate dirty bomb......

Dear Larry:

"Larry" wrote in message
...
"N:dlzc D:aol T:com \(dlzc\)" wrote in
newsv_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

Brian Whatcott wrote in
:


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!

"Larry" wrote in message
...
Brian Whatcott wrote in
:


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!

I think he is suggesting that the two tube be connected so that they form a
vacuum at the top. It wouldn't take much to make the sal****er evaporate to
fill the vacuum and condense over on the fresh water side. Productivity
wouldn't be very high though.