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

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

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

On Sep 22, 10:39 pm, OldNick wrote:
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?


Gravity.

In article ,
says...
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

SNIP

Simply put a one-way (out only) valve at the top where the two tubes
are joined. Pump water up both tubes to about 3" from the top,
displacing the air in the tubes. That will only require about
16 PSI from the pumps.

The major problem would seem to be that vigorous boiling is going
to carry over salt and contaminants from the boiling salt water unless
the tubes are large or there is some sort of debubbler on the
salt water side.

For heating and cooling, I suppose that you could use the sunny and
shady sides of a sailboat mast.

Mark Borgerson

"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......