"Larry" wrote

Distilled water has none of these problems. What I can't figure out,
especially on power yachts, is why all that waste engine heat going up
the stacks isn't running engine-room-mounted distillers for fresh water
to drink.

You are spot on with this comment. When I was working at Woods Hole, in the
days before reverse osmosis, they had an engineer who knew how to tweak the
waste heat vacuum distillation units to the point that they got a gallon of
fresh water for every gallon of fuel burned; that's after the fuel had
pushed the ship or made electricity.

Take a look at the power draw for a reverse osmosis unit and then figure out
how much "fresh water" you have to carry in the form of fuel.

--
Roger Long

On Wed, 22 Aug 2007 08:06:46 -0400, "Roger Long"
wrote:


"Larry" wrote

Distilled water has none of these problems. What I can't figure out,
especially on power yachts, is why all that waste engine heat going up
the stacks isn't running engine-room-mounted distillers for fresh water
to drink.

You are spot on with this comment. When I was working at Woods Hole, in the
days before reverse osmosis, they had an engineer who knew how to tweak the
waste heat vacuum distillation units to the point that they got a gallon of
fresh water for every gallon of fuel burned; that's after the fuel had
pushed the ship or made electricity.

Take a look at the power draw for a reverse osmosis unit and then figure out
how much "fresh water" you have to carry in the form of fuel.

It a size/expense issue as much as anything else. Navy boilers
commonly used "economizers" to preheat boiler feed water, but
they were fairly massive units sitting in the stacks.
Evaporators aren't exactly mini me's either.
I think a look at the heat exchangers used to provide heated water
might give some idea on what's involved.
Heck, you already don't have space to use your engine crank.
It sure would be fun to tinker with. For a sailboat I'd probably look
at rain collectors, solar stills, and bottled water first.
I've sometimes wondered why IC engine designers haven't yet come
up with an engine that can't better utilize the BTU's in the fuel
instead of throwing it away via heat. Think of those millions of
engines out there wasting all of that energy from radiators, hoses,
heads and blocks.

--Vic

On Wed, 22 Aug 2007 07:40:38 -0500, Vic Smith
wrote:

On Wed, 22 Aug 2007 08:06:46 -0400, "Roger Long"
wrote:


"Larry" wrote

Distilled water has none of these problems. What I can't figure out,
especially on power yachts, is why all that waste engine heat going up
the stacks isn't running engine-room-mounted distillers for fresh water
to drink.

You are spot on with this comment. When I was working at Woods Hole, in the
days before reverse osmosis, they had an engineer who knew how to tweak the
waste heat vacuum distillation units to the point that they got a gallon of
fresh water for every gallon of fuel burned; that's after the fuel had
pushed the ship or made electricity.

Take a look at the power draw for a reverse osmosis unit and then figure out
how much "fresh water" you have to carry in the form of fuel.

It a size/expense issue as much as anything else. Navy boilers
commonly used "economizers" to preheat boiler feed water, but
they were fairly massive units sitting in the stacks.
Evaporators aren't exactly mini me's either.
I think a look at the heat exchangers used to provide heated water
might give some idea on what's involved.
Heck, you already don't have space to use your engine crank.
It sure would be fun to tinker with. For a sailboat I'd probably look
at rain collectors, solar stills, and bottled water first.
I've sometimes wondered why IC engine designers haven't yet come
up with an engine that can't better utilize the BTU's in the fuel
instead of throwing it away via heat. Think of those millions of
engines out there wasting all of that energy from radiators, hoses,
heads and blocks.

The only distillation unit I've seen was one that used the engine to
heat the water also used the engine to drive a vacuum pump to lower
the pressure in the distillation chamber. and I suspect that is how
you would have to do it on a smallish boat. I wasn't primarily
responsible for maintenance on the damned thing but got lumbered with
working on it as I seemed to be the only one at the site that would
admit to understanding its theory of operation. Either I was the only
smart one or the only dumb one (for admitting I understood the beast).
When I left the project water was still a problem at that site.





Bruce in Bangkok
(brucepaigeATgmailDOTcom)

That is consistent with what I observed. The units were about the size of a
25 KW generator and required a lot of understanding and tweaking to function
properly. The reason it came to my notice was everyone's amazement that the
engineer was able to get more water out than even the manufacturer
(DeLaval?) thought possible.

This wouldn't be a current option unless someone were to produce a scaled
down unit for trawler yacht size boats. Even larger craft have gone largely
to reverse osmosis because they are less troublesome to run and manage.

--
Roger Long

Larry,

You weren't wrong. He said he was looking for battery electrolyte and he
said he was looking in Louisiana. Assuming he means battery acid then he's
looking for 33.5% Sulfuric acid. I would imagine any chemical supply house
would sell Sulfuric acid and he can get distilled water at any supermarket.
JC Whitney sells battery acid over the internet so I'm surprised he can't
find it locally. Perhaps he should look for a motorcycle parts store.

Dave M.

"Roger Long" wrote in news:46cc26d5$0$18984
:

You are spot on with this comment.

My other question is why we're not turning all that waste heat going up
the stack into ELECTRIC POWER! There are many heat-to-electrical power
devices available, some now very modern and efficient, that can be used
to create almost as much electric power as the alternators running off
the fanbelts create. Why aren't we recovering this, now that fuel is so
precious and expensive?

We should be able to run quite a powerful genset off a Stirling Engine
getting its heat from the exhaust manifold. Hell, it should be PART OF
the exhaust manifold. No more lagging hot exhausts. Millions of Btus
just going to waste. How silly.

The only thing I find boaters doing with the waste heat is heating the
hot water tank from the engine cooling system....another source of
immense power that goes untapped!

We inherited a forced air diesel heater on Lionheart, an Amel Sharki 41
that homeported in San Francisco and cruised the NW. Here in SC, we
replaced it with a marine AC, more beneficial to our hot climate. I know
it's a sailboat, but why didn't this boat use HOT WATER HEATERS? What a
waste without one.

Well, just dreaming....(c;

Larry
--

"Roger Long" wrote in news:46cc4cf3$0$18928
:

Even larger craft have gone largely
to reverse osmosis because they are less troublesome to run and manage.



You can tell the Love Boat industry has gone to RO because of the number of
people who have been poisoned drinking it.



Larry
--

Vic Smith brought forth on stone tablets:
On Wed, 22 Aug 2007 08:06:46 -0400, "Roger Long"
wrote:


"Larry" wrote


Distilled water has none of these problems. What I can't figure out,
especially on power yachts, is why all that waste engine heat going up
the stacks isn't running engine-room-mounted distillers for fresh water
to drink.

You are spot on with this comment. When I was working at Woods Hole, in the
days before reverse osmosis, they had an engineer who knew how to tweak the
waste heat vacuum distillation units to the point that they got a gallon of
fresh water for every gallon of fuel burned; that's after the fuel had
pushed the ship or made electricity.

Take a look at the power draw for a reverse osmosis unit and then figure out
how much "fresh water" you have to carry in the form of fuel.


It a size/expense issue as much as anything else. Navy boilers
commonly used "economizers" to preheat boiler feed water, but
they were fairly massive units sitting in the stacks.
Evaporators aren't exactly mini me's either.
I think a look at the heat exchangers used to provide heated water
might give some idea on what's involved.
Heck, you already don't have space to use your engine crank.
It sure would be fun to tinker with. For a sailboat I'd probably look
at rain collectors, solar stills, and bottled water first.
I've sometimes wondered why IC engine designers haven't yet come
up with an engine that can't better utilize the BTU's in the fuel
instead of throwing it away via heat. Think of those millions of
engines out there wasting all of that energy from radiators, hoses,
heads and blocks.

Take a look at the Crower 6-cycle engine -

bob
s/v Eolian
Seattle

RW Salnick wrote in news:fai0c9$f20$1
@gnus01.u.washington.edu:

Crower 6-cycle engine

A GREAT idea!

What would we do with all those fans in the engine rooms??...(c;

Larry
--

On Wed, 22 Aug 2007 18:42:08 +0000, Larry wrote:

"Roger Long" wrote in news:46cc4cf3$0$18928
:

Even larger craft have gone largely
to reverse osmosis because they are less troublesome to run and manage.



You can tell the Love Boat industry has gone to RO because of the number of
people who have been poisoned drinking it.



Larry

Not necessarily so Larry, We had 3, 3,000 gal/day R.O units on oil
production barges in the Java sea for about 5 years. While I agree
that they require maintenance they were far easier to maintain then
the exhaust heater and vacuum chamber distillation plant I maintained
in Irian Jaya.

The installations we had were commercial units with detailed operation
manuals. We simply followed the schedule for back flushing and
cleaning the membranes and they produced drinkable water for the
entire period we used them. We know that as we took weekly samples
from the tanks and had them laboratory tested as part of our
contractual obligations with the client.

On the other hand, people who either don't know, or don't care what
equipment they have and how to maintain it shouldn't use it.


Bruce in Bangkok
(brucepaigeATgmailDOTcom)