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Vic Smith

On Sat, 08 Sep 2007 16:20:16 +0700, wrote:

Explain that again in one syllable words for me :-)

As I understand what you are saying you mean to remove the present
water cooled exhaust manifold from the cooling system and replace it
with a heat exchanger device to heat what? Water to make steam or oil
to heat water to make steam? Or did I miss something there?

What Larry's talking about is using a liquid medium near the exhaust
that will transport the heat to the distiller, similar to what nuke
plants do, but I think they still use water for the transfer.
He mentioned trans fluid, and I'm not sure of its specific heat, but
there are "better" or more appropriate heat transfer mechanisms than
water, as seen in freon A/C.
In any case, though I'm far from an expert in this, I did operate
steam plants in the Navy and acquired but never used a Stationary
license, so I speaking with *some* experience.
As I said before, complexity and size are the impediments to what
Larry is after. Science finds nothing magical in capturing and moving
heat.
But every time I've seen it done it involved sound materials selection
and engineering, bulky heat transfer vessels, and huge amounts of
insulation.

The reason I ask is because many years ago I maintained a distillation
plant that used exhaust heat to make steam. If I remember correctly
the primary power was a Perkins 4-108 diesel and it didn't make enough
exhaust heat to boil water at sea level atmospheric pressure. The
distillation vessel was heated as hot as possible using the exhaust
and then an engine driven vacuum pump dropped the pressure in the
still to create steam at temperatures lower then 212F.

Whether this was done to increase thruput or because exhaust heat
alone was not sufficient I do not recollect.

Probably both. Since the purpose was to make water, they used a
combination that made the most water. Engine exhaust is certainly
hot enough to boil water. If the same engine was driving the vacuum
pump, that's good, because a diesel's designed purpose is to create
mechanical power. No doubt you know all this, so I hope my talking
hasn't put you to sleep.

In any event, given the cost of reverse osmosis systems using engine
heat would seem rather attractive.

It would be good to see development and competition bring the initial
cost of RO units down. I'm still interested in Larry's thoughts about
the "bacteria" issues he has seen in RO units. His thoughts on the
cruise boat ailments being related to the watermakers are very
interesting.
In the meantime, his stovetop distillers are working well for him, and
use heat in a time-tested and pretty efficient way, with almost direct
application of flame to water.

--Vic