Copper tubing and sea water

ian wrote:
> I am thinking of using plain old copper tubing (the type you get from
> Home Depot) to cool the winding section of a a generator by wrapping a
> few turns of the copper tubing around the casing and then pumping sea
> water directly around the tubing. Can anyone advise whether this is
> going to work? Obviously I don't mind if it gets an ugly blue colour
> inside the tubing however I don't want to be loosing cooling
> efficiency with time, or worse have the tubing leak. The reason I
> don't want to use cuprous nickel is that it is much less malleable
> than standard copper tubing and I would not be able to simply wrap it
> around the casing.

No problems with copper and saltwater; however, doubt you will be able
to get good enough heat transfer between copper tubing and generator
casing to make it worth the effort.

Lew
 >> Stay informed about: Copper tubing and sea water 

On Sat, 02 Jun 2007 16:27:20 -0700, ian <ian_underdown.DeleteThis@hotmail.com>
wrote:

>I am thinking of using plain old copper tubing (the type you get from
>Home Depot) to cool the winding section of a a generator by wrapping a
>few turns of the copper tubing around the casing and then pumping sea
>water directly around the tubing. Can anyone advise whether this is
>going to work? Obviously I don't mind if it gets an ugly blue colour
>inside the tubing however I don't want to be loosing cooling
>efficiency with time, or worse have the tubing leak. The reason I
>don't want to use cuprous nickel is that it is much less malleable
>than standard copper tubing and I would not be able to simply wrap it
>around the casing.
>
>All ideas and comments appreciated.
>
>Ian

Certainly the concept is viable as some gen. set alternators are made
with water passages built in for sea water cooling and someone
advertises a cooler for a marine gear box that is simply a stainless
box that bolts against the side of the transmission and has sea water
pumped through it.

Home made marine air con heat exchangers are often made of plain
copper tubing and last quite a while, however they do corrode through
eventually. An alternate would be stainless tubing but that would
probably be difficult to wrap.

I would think that you are going to have to use at least 1/2" tubing
to absorb much heat which probably isn't going to be as easy to wrap
around the generator as perhaps you envision.

Last comment. Are you sure that you need to cool the generator?


Bruce in Bangkok
(brucepaigeatgmaildotcom)

--
Posted via a free Usenet account from http://www.teranews.com
 >> Stay informed about: Copper tubing and sea water 

On Jun 2, 4:27 pm, ian <ian_underd... RemoveThis @hotmail.com> wrote:
> I am thinking of using plain old copper tubing (the type you get from
> Home Depot) to cool the winding section of a a generator by wrapping a
> few turns of the copper tubing around the casing and then pumping sea
> water directly around the tubing. Can anyone advise whether this is
> going to work? Obviously I don't mind if it gets an ugly blue colour
> inside the tubing however I don't want to be loosing cooling
> efficiency with time, or worse have the tubing leak. The reason I
> don't want to use cuprous nickel is that it is much less malleable
> than standard copper tubing and I would not be able to simply wrap it
> around the casing.
>
> All ideas and comments appreciated.
>
> Ian

A German fellow from WW2 (NAZI) showed me a trick that worked fairly
well for me. He pinched off one end of the copper tubing and filled
the soft copper with sand. Then pinched off the other end. Did all the
bending, then cut the ends that were pinched off with a tubing cutter.
Not one kink anywhere! No flattened tubing no matter how I twisted and
bent it. Drained the dry sand back out after bending. I had to twirl
it around, but I could have just blown it out with an air hose.
Stick with me Ian, You will be wearing rocks as big as diamonds. My
Dad used to say that.
 >> Stay informed about: Copper tubing and sea water 

On Jun 2, 6:07 pm, Matt Colie <m... DeleteThis @nospam.net> wrote:
> Ian,
> BTDT, go find some cerrobend (sp?) to fill the tubing so it doesn't
> flatten when you bend it.
> I do not even vaguely remember the name of the high thermal conductivity
> epoxy that we used to stick the copper to the generator frame.
> Matt Colie
>
> ian wrote:
> > I am thinking of using plain old copper tubing (the type you get from
> > Home Depot) to cool the winding section of a a generator by wrapping a
> > few turns of the copper tubing around the casing and then pumping sea
> > water directly around the tubing. Can anyone advise whether this is
> > going to work? Obviously I don't mind if it gets an ugly blue colour
> > inside the tubing however I don't want to be loosing cooling
> > efficiency with time, or worse have the tubing leak. The reason I
> > don't want to use cuprous nickel is that it is much less malleable
> > than standard copper tubing and I would not be able to simply wrap it
> > around the casing.
>
> > All ideas and comments appreciated.
>
> > Ian

I have used dry beach sand and it works pretty good.
 >> Stay informed about: Copper tubing and sea water 

Over the years I've seen very little written about fuel economy in
boats. If anyone has good data I would like to see it. I am particularly
concerned with optimal speeds for planing hulls. Is it in the
displacement range? Or on the plane? Does it increase monotonically with
decreasing speed? Not in gallons per hour, but in miles per gallon. If
one has a twin screw boat, does fuel economy increase or decrease in
running only one prop? Is diesel always more economical than gas? And
anything else that bears on the problem.

Bob Swarts
 >> Stay informed about: Copper tubing and sea water 

On Jun 21, 7:24 am, R Swarts <ravensr....DeleteThis@olypen.com> wrote:
> Over the years I've seen very little written about fuel economy in
> boats. If anyone has good data I would like to see it. I am particularly
> concerned with optimal speeds for planing hulls. Is it in the
> displacement range? Or on the plane? Does it increase monotonically with
> decreasing speed? Not in gallons per hour, but in miles per gallon. If
> one has a twin screw boat, does fuel economy increase or decrease in
> running only one prop? Is diesel always more economical than gas? And
> anything else that bears on the problem.
>
> Bob Swarts

When I sold boats for Bayliner at Olympic Boat Center I was taught
that their hull was supposed to adjust itself to the most efficient
plane for the amount of throttle given to the prop. Sounded to me like
a bunch of sales talk.
I have crossed the Gulf of Alaska around 80 times in many types of
vessels and have found 8 knots to be the most economical speed to run.
I can monitor the day tank and measure gallons per day and nautical
miles covered.
Diesel is always more economical than gasoline all things being the
same. Load, distance, same boat etc.
Also, all the new fuel technology is for diesel engines, because
diesel engines can run on many different things. Rudolf Diesel even
tried to run coal dust, but he had too much trouble metering it and
injecting it. The diesel engine can even run on peanut oil. I haven't
tried it yet, but as soon as I buy an old diesel car I am going to try
it. You can buy vegatable oil from discount grocery stores cheaper
than Diesel fuel. I would like to see if it can be mixed! I have heard
that just adjusting the pump is the only modification required.
 >> Stay informed about: Copper tubing and sea water 

On Jun 21, 7:24 am, R Swarts <ravensr....TakeThisOut@olypen.com> wrote:
> Over the years I've seen very little written about fuel economy in
> boats. If anyone has good data I would like to see it. I am particularly
> concerned with optimal speeds for planing hulls. Is it in the
> displacement range? Or on the plane? Does it increase monotonically with
> decreasing speed? Not in gallons per hour, but in miles per gallon. If
> one has a twin screw boat, does fuel economy increase or decrease in
> running only one prop? Is diesel always more economical than gas? And
> anything else that bears on the problem.
>
> Bob Swarts

The reason we measure boats in gallons per hour and not miles per
hour? Wind and current make miles per hour impractical. With the
current against you, the engine can be running at 6000 RPM for an hour
and you have only covered two miles. I have seen that in the Inside
Passage around the Fraiser River. Too big of a veriable there. RPM's
and fuel used can be realistically monitored.
 >> Stay informed about: Copper tubing and sea water 

Tom, the trouble with using gallons per hour is that it doesn't measure
fuel economy. If I burn twice the gallons per hour, but go three times
as fast, then burning at the higher rate yields greater economy.

I will grant that if you are comparing identical boats at identical
speeds then gallons per hour would give the desired result.

BS


tomdownard wrote:

> The reason we measure boats in gallons per hour and not miles per
> hour? Wind and current make miles per hour impractical. With the
> current against you, the engine can be running at 6000 RPM for an hour
> and you have only covered two miles. I have seen that in the Inside
> Passage around the Fraiser River. Too big of a veriable there. RPM's
> and fuel used can be realistically monitored.
>
 >> Stay informed about: Copper tubing and sea water 

tomdownard wrote:

> On Jun 21, 7:24 am, R Swarts <ravensr... RemoveThis @olypen.com> wrote:
>
>>Over the years I've seen very little written about fuel economy in
>>boats. If anyone has good data I would like to see it. I am particularly
>>concerned with optimal speeds for planing hulls. Is it in the
>>displacement range? Or on the plane? Does it increase monotonically with
>>decreasing speed? Not in gallons per hour, but in miles per gallon. If
>>one has a twin screw boat, does fuel economy increase or decrease in
>>running only one prop? Is diesel always more economical than gas? And
>>anything else that bears on the problem.
>>
>>Bob Swarts
>
>
> When I sold boats for Bayliner at Olympic Boat Center I was taught
> that their hull was supposed to adjust itself to the most efficient
> plane for the amount of throttle given to the prop. Sounded to me like
> a bunch of sales talk.
> I have crossed the Gulf of Alaska around 80 times in many types of
> vessels and have found 8 knots to be the most economical speed to run.
> I can monitor the day tank and measure gallons per day and nautical
> miles covered.
> Diesel is always more economical than gasoline all things being the
> same. Load, distance, same boat etc.
> Also, all the new fuel technology is for diesel engines, because
> diesel engines can run on many different things. Rudolf Diesel even
> tried to run coal dust, but he had too much trouble metering it and
> injecting it. The diesel engine can even run on peanut oil. I haven't
> tried it yet, but as soon as I buy an old diesel car I am going to try
> it. You can buy vegatable oil from discount grocery stores cheaper
> than Diesel fuel. I would like to see if it can be mixed! I have heard
> that just adjusting the pump is the only modification required.
>

You can run a diesel on a mix of veggie and diesel. My dodge ram runs on
a mix of 70% veggie and 30% diesel in the summer.

Doesn't work well at any mix if the ambient temp is below 40 deg F.

But above that, mixes up to 70 percent work well.

I have more than 50K miles on mixes...

--
“TANSTAAFL”

____________________________________________________________________________

"A prudent man foresees the difficulties ahead and prepares for them;
The simpleton goes blindly on and suffers the consequences." - Proverbs 22:3
____________________________________________________________________________
 >> Stay informed about: Copper tubing and sea water 

The only measure that makes sense is miles per gallon, drift, tide,
wind effects excluded, your choice of units..

Calculated against dollers per hour time on vacations aboard (what
price freedom?)

I calculate time at 10 bucks an hour for me, shopping for bargains,
whatever. The guests can do as they please.

Terry K
 >> Stay informed about: Copper tubing and sea water 

Terry K wrote:
> The only measure that makes sense is miles per gallon, drift, tide,
> wind effects excluded, your choice of units..
>
> Calculated against dollers per hour time on vacations aboard (what
> price freedom?)
>
> I calculate time at 10 bucks an hour for me, shopping for bargains,
> whatever. The guests can do as they please.
>
> Terry K
>

Someone receintly said that as long as gas cost less than designer
water nobody was ging to worry about it.

Now there's a place in NYC selling water for over $50 a quart.
And people are buying it!!!

Richard
 >> Stay informed about: Copper tubing and sea water 

On Fri, 20 Jul 2007 17:12:45 +1000, peter.hendra.TakeThisOut@gmail.com wrote:

> Result - instant stoppage on that engine.
>
>It was decided to slowly motor with one engine back to our home base
>where repairs could more easily be done. We originally had more than
>sufficient fuel to get back home uinder two engines and then some. We
>ran out of fuel about two thirds of the way and had to be towed into
>port. As I said, don't understand why.

For one thing, the off center thrust will push the hull through the
water sideways, even with rudder keeping the thing headed in a
straight line. Also on plane is more effecient than going too fast at
displacement speeds.

Casady
 >> Stay informed about: Copper tubing and sea water 

On Thu, 21 Jun 2007 07:24:07 -0700, R Swarts <ravensrest.TakeThisOut@olypen.com>
wrote:

If
>one has a twin screw boat, does fuel economy increase or decrease in
>running only one prop?
>
>Bob Swarts

Hi Bob,
I sail a keeler but last year in my job I was aboard a planing hulled
launch powered by two 1250 HP turbo charged MTU diesels, each driving
its own propellor.

I don't know the physics of it, but I experienced a situation where a
single engine used far more diesel than twins.

We went at speed (about 45 to 50 knots) over a shallow patch and
somehow a stone got sucked into one of the two water intakes, smashing
the perspex (later replaced with polycarbonate) cap plate.
Unfortunately this was placed directly under the air intake for the
turbocharger which sucked the intake water directly into the starboard
engine cyclinders. Result - instant stoppage on that engine.

It was decided to slowly motor with one engine back to our home base
where repairs could more easily be done. We originally had more than
sufficient fuel to get back home uinder two engines and then some. We
ran out of fuel about two thirds of the way and had to be towed into
port. As I said, don't understand why.

For my keelboat, I normally calculate useage by the rule of thumb - a
tenth of a litre per horsepower per hour. Mine develops 37.5 HP at
full revs of about 3,000. According to the fuel usage curve in the
supplied manual, the best efficiency is at about 1800 revs which is
what I usually run it at - developing a lot less than 37 HP - probably
25 as I use about 2.5 litres per hour at those revs.

Hope this helps
Peter
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