Next message: Richard Goodwin: "Re: lv-ab: Boat names"
This takes me back a lot of years, so hey, you chemists out there,
please jump in here...
Seems to me that most salts dissolve *more* in warmer water than in
cooler water. I remember making crystals when I was a kid, and we used
to heat up the solution to get it to dissolve more of whatever salt we
were trying to grow crystals of, then let it cool so it would crystalize
as the solution became supersaturated from cooling and from
evaporation. I seem to remember that most salts would dissolve more in
warmer water. But I also seem to remember that NACL worked slightly
opposite to that general rule -- dissolves more in cooler water, not
warmer. Please -- correct me if that is wrong. Been too many years and
too many beers (if there is such a thing).
So in a fresh water cooled engine there is a thermostat that regulates
the temperature fairly accurately. But in a seawater cooled engine,
there is no thermostat, at least in the one I had once. But the design
of the water pump and cooling channels in the engine acted as the
regulator in that case. It ran fine -- single cylinger volvo if I
remember right. The flow of heat from cylinder wall through the metal
engine block to the cooling channels, with water flow proportional to
the RPMs, was supposed to provide pretty good engine temp regulation.
The thing I don't remember, is -- does NACL dissolve more at higher temp
or lower? I do seem to remember that NACL works backward from most
salts in that it dissolves less at higher temps. Which means that the
observation below is correct.
Dick
Tom O'Meara wrote:
>
> At 12:09 PM 3/4/01 -0800, R Hepler wrote:
> >This is an odd fact I had not considered in my recent post.
> > Why do raw water cooled engines run cooler than heat
> >exchanger systems?
> <SNIP>
>
> Because running raw water cooled engines at over 150 deg. F in a salt water
> environment causes the salts to precipitate out and clog cooling galleries.
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