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

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!

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......

"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.

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

On Sat, 22 Sep 2007 01:41:21 GMT, "Toller" wrote:

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.

Precisely right. I'm surprised Larry didn't catch that.

In article ,
Larry wrote:

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.

Ummm...there is quite a difference between atmospheric pressure at 40'
ASL and a (near) vacuum. Presumably the connection at the top is
airtight and made with as little air as possible entering the tubes, and
presumably also the bottoms of the tubes open and submerged in some sort
of a vented container At sea level, atmospheric pressure will only
support somewhere in the vicinity of 40 feet of water, so the top of the
tubes will be approaching a vacuum. (This is why wells water wells
deeper than 35 or so feet require a pump in the well, rather than at the
top.)

I see no reason why this wouldn't work, at least to some degree,
although I do wonder how using a still of any sort differs from
distillation. I also wonder how easy it would be to make an effective
vertical solar collector on a boat that doesn't need constant climbing
about to fiddle and adjust.

--
Andrew Erickson

"He is no fool who gives what he cannot keep to gain that which he cannot
lose." -- Jim Elliot

On Sep 21, 10:15 pm, Andrew Erickson
wrote:
In article ,



Larry wrote:
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.

Ummm...there is quite a difference between atmospheric pressure at 40'
ASL and a (near) vacuum. Presumably the connection at the top is
airtight and made with as little air as possible entering the tubes, and
presumably also the bottoms of the tubes open and submerged in some sort
of a vented container At sea level, atmospheric pressure will only
support somewhere in the vicinity of 40 feet of water, so the top of the
tubes will be approaching a vacuum. (This is why wells water wells
deeper than 35 or so feet require a pump in the well, rather than at the
top.)

I see no reason why this wouldn't work, at least to some degree,
although I do wonder how using a still of any sort differs from
distillation. I also wonder how easy it would be to make an effective
vertical solar collector on a boat that doesn't need constant climbing
about to fiddle and adjust.

--
Andrew Erickson

"He is no fool who gives what he cannot keep to gain that which he cannot
lose." -- Jim Elliot

hmmm, I wonder what the rate would be? One could assume that you do
not have to put in any heat to increase the temp so any heat input
would simply go into latent heat of water vapor. You would hav o
maybe use solar to heat the salt water side and cool the fresh water
side by immersing it in the ocean. Then the max rate would simply be
power in (whatever the heat from the sun would be in watts/m2 times
the area of your collector) which is Joules/sec which is roughly 4
calories/sec. Somebody look up the latent heat of water (I dont have
my handbook handy) and then you have grams/sec of fresh water (maximum
rate).

On Sat, 22 Sep 2007 01:21:39 +0000, Larry wrote:

[Brian]
The boiling point of water at the top of a sealed 40 ft column of
water is near ambient.

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!
...
Larry

They say if you give a fool half a chance, he will rush in.
And so he did. TWICE! Chortling, at that.

Brian W