Alternative Power sources - Radiator questions

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Radiator questions

nicksanspam@ece.villanova.edu

2007-08-24, 1:25 pm

I'm thinking about using a recent Taurus auto radiator or a Ford or GMC
pickup radiator to heat water with hot sunspace air, but I'm concerned that
a) it's hard to find specs for radiator performance, and b) a mechanic says
an aluminum core radiator might crud up with corrosion in less than a year
with oxygenated water and no antifreeze.

How many Btu/h can an auto radiator move from 150 F air to 140 F water,
using its electric fan, with no wind? An engine that makes 200 HP at 25%
efficiency (unlikely with no motion :-) would burn 800 HP of gas. If 25%
of the heat leaves from 200 F water to 100 F air via the radiator, the air-
water thermal conductance is 0.25x800x746x3.41/(200-100) = 5100 Btu/h-F,
good compared to a 2'x2' all-copper $200 MagicAire 2347 duct heat exchanger
that moves 45K Btu/h from 125 F water to 1400 cfm of 68 F air with a 0.1
"H20 pressure drop.

Antifreeze would be expensive for a 1000 gallon heat storage tank, and
an antifreeze heat exchange loop would add to the cost and lower efficiency.
How much antifreeze do we need just to prevent corrosion? Is there some
corrosion inhibitor we can use at a low concentration?

Nick

stu

2007-08-24, 8:25 pm

<nicksanspam@ece.villanova.edu> wrote in message
news:fan5i1$jal@acadia.ece.villanova.edu...
> I'm thinking about using a recent Taurus auto radiator or a Ford or GMC
> pickup radiator to heat water with hot sunspace air, but I'm concerned
that
> a) it's hard to find specs for radiator performance, and b) a mechanic
says
> an aluminum core radiator might crud up with corrosion in less than a year
> with oxygenated water and no antifreeze.
>
> How many Btu/h can an auto radiator move from 150 F air to 140 F water,
> using its electric fan, with no wind? An engine that makes 200 HP at 25%
> efficiency (unlikely with no motion :-) would burn 800 HP of gas. If 25%
> of the heat leaves from 200 F water to 100 F air via the radiator, the
air-
> water thermal conductance is 0.25x800x746x3.41/(200-100) = 5100 Btu/h-F,
> good compared to a 2'x2' all-copper $200 MagicAire 2347 duct heat
exchanger
> that moves 45K Btu/h from 125 F water to 1400 cfm of 68 F air with a 0.1
> "H20 pressure drop.
>
> Antifreeze would be expensive for a 1000 gallon heat storage tank, and
> an antifreeze heat exchange loop would add to the cost and lower
efficiency.
> How much antifreeze do we need just to prevent corrosion? Is there some
> corrosion inhibitor we can use at a low concentration?
>
> Nick
>

Why use Aluminium? I wouldn't have thought it would be hard to find an old
copper one which will.
A. Be a little more efficient
B. Won't have the corrosion problems Aluminium may have.
As you wont be running it under pressure even a leaky one should be easy
enough to patch up.

As for Aluminium corroding, if it's the only metal in the system I don't
think you will have a problem. If I was making something like this (and
someday I'd like to) and using second hand stuff I think I'd suck it and see
what happened.
Stuart

beemerwacker

2007-08-24, 8:25 pm

On Aug 24, 7:12 pm, "stu" <nowh...@justyet.com> wrote:
> <nicksans...@ece.villanova.edu> wrote in message
>
> news:fan5i1$jal@acadia.ece.villanova.edu...
>
>
>
> that
> says
>
> air-
> exchanger
>
> efficiency.
>
>
> Why use Aluminium? I wouldn't have thought it would be hard to find an old
> copper one which will.
> A. Be a little more efficient
> B. Won't have the corrosion problems Aluminium may have.
> As you wont be running it under pressure even a leaky one should be easy
> enough to patch up.
>
> As for Aluminium corroding, if it's the only metal in the system I don't
> think you will have a problem. If I was making something like this (and
> someday I'd like to) and using second hand stuff I think I'd suck it and see
> what happened.
> Stuart

Be patient Nick, George will answer all.

Until then, consider the following. The radiator is based on the
constant flow of the water pump and the thermostat, which opens and
closes on a regular basis. If one were to take the engine, measure the
block and head temperatures, as well as the radiator fluid
temperatures, one would find the relationship between all of them.
Now, we know that a automobile engine with a failed thermostat will
malfunction in some way. If the thermostat is stuck open, the engine
will never ever warm up, thus giving us an indication that a typical
auto radiator is over designed for the application with a wide open
flow. If stuck closed, it will overheat.

Another similar way would be to take say, 200 degree water heated at
an even rate and flow it through the radiator and measure the
difference between the inlet and outlet at a given flow of fluid and
air through the radiator. I would suspect that you will need a much
lower flow than you expect to extract a given BTU without flow
regulation.

Feel free to take all of that out of context in any way you see fit.

daestrom

2007-08-25, 9:25 am

<nicksanspam@ece.villanova.edu> wrote in message
news:fan5i1$jal@acadia.ece.villanova.edu...
> I'm thinking about using a recent Taurus auto radiator or a Ford or GMC
> pickup radiator to heat water with hot sunspace air, but I'm concerned
> that
> a) it's hard to find specs for radiator performance, and b) a mechanic
> says
> an aluminum core radiator might crud up with corrosion in less than a year
> with oxygenated water and no antifreeze.
>
> How many Btu/h can an auto radiator move from 150 F air to 140 F water,
> using its electric fan, with no wind? An engine that makes 200 HP at 25%
> efficiency (unlikely with no motion :-) would burn 800 HP of gas. If 25%
> of the heat leaves from 200 F water to 100 F air via the radiator, the
> air-
> water thermal conductance is 0.25x800x746x3.41/(200-100) = 5100 Btu/h-F,
> good compared to a 2'x2' all-copper $200 MagicAire 2347 duct heat
> exchanger
> that moves 45K Btu/h from 125 F water to 1400 cfm of 68 F air with a 0.1
> "H20 pressure drop.
>
> Antifreeze would be expensive for a 1000 gallon heat storage tank, and
> an antifreeze heat exchange loop would add to the cost and lower
> efficiency.
> How much antifreeze do we need just to prevent corrosion? Is there some
> corrosion inhibitor we can use at a low concentration?
>

One quick google suggests at least 25% ethylene glycol...
http://www.lytron.com/support/anti_corrosive.htm

But that's still pretty high if you're talking about the whole storage tank
:-(

Another suggests that it isn't (corrosion) very bad if you can be sure to
use water that doesn't have any halides in it. But filling a whole storage
tank with demineralized water is probably about as expensive as doping it
with EG.

http://www.key-to-nonferrous.com/Articles/Article14.htm

A general rule to reduce corrosion is to use water that has a low electrical
conductivity and not connect dissimilar metals. So if you use an Al
radiator, you might consider using short sections of hose to connect it to
copper piping. This helps minimize forming a galvanic cell that will
corrode the metal with a more negative potential.

daestrom

Neon John

2007-08-25, 1:25 pm

On 24 Aug 2007 13:46:41 -0400, nicksanspam@ece.villanova.edu wrote:

>I'm thinking about using a recent Taurus auto radiator or a Ford or GMC
>pickup radiator to heat water with hot sunspace air, but I'm concerned that
>a) it's hard to find specs for radiator performance, and b) a mechanic says
>an aluminum core radiator might crud up with corrosion in less than a year
>with oxygenated water and no antifreeze.

Radiator performance is readily available from the manufacturers, if not in their
catalogs then from an inquiry. Have you looked at, say, Modine's website.

>Antifreeze would be expensive for a 1000 gallon heat storage tank, and
>an antifreeze heat exchange loop would add to the cost and lower efficiency.
>How much antifreeze do we need just to prevent corrosion? Is there some
>corrosion inhibitor we can use at a low concentration?

Coolant anti-corrosion/passivation chemical packages are available separate from
antifreeze. These are used to maintain the anti-corrosion protection in large volume
coolant systems where one wouldn't change many gallons of antifreeze just because the
protection package is depleted. Stationary diesels, locomotive engines, things like
that.

Additionally, the aluminum can be completely protected from corrosion by fresh water
using cathodic protection. There are many thousands of RV water heaters out there
with aluminum tanks that handle all sorts of tap water without corrosion. The reason
is the magnesium anode screwed into the tank. I would think that an RV replacement
anode could easily be fitted to an aluminum radiator.

John

--
John De Armond
See my website for my current email address
http://www.neon-john.com
http://www.johndearmond.com <-- best little blog on the net!
Tellico Plains, Occupied TN
I'm going crazy. Wanna come along?

nicksanspam@ece.villanova.edu

2007-08-27, 9:25 am

daestrom <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote:

>A general rule to reduce corrosion is to use water that has a low electrical
>conductivity and not connect dissimilar metals. So if you use an Al
>radiator, you might consider using short sections of hose to connect it to
>copper piping. This helps minimize forming a galvanic cell that will
>corrode the metal with a more negative potential.

We can do that, but mechanics say an electrically-isolated aluminum radiator
with rubber hoses and insulating brackets can still corrode (oxidize?) soon,
with nothing but water inside. My old boy scout canteen ended up heavily
pitted with white crud on the inside. I think this was oxidation vs mineral
deposits or galvanic corrosion, since there were no other metals involved.

Neon John <no@never.com> wrote:

>Coolant anti-corrosion/passivation chemical packages are available separate
>from antifreeze. These are used to maintain the anti-corrosion protection
>in large volume coolant systems where one wouldn't change many gallons of
>antifreeze just because the protection package is depleted. Stationary
>diesels, locomotive engines, things like that.

So far, I've only found Gunk anti-rust and water pump lube for car radiators,
$2 for 11 oz to protect 5 gallons or so, ie about $400 for 1000 gallons, and
a KPR VCI powder that costs about $20/lb and needs 0.25% concentration, ie
about $400 for 1000 gal. The tank will have a pressurized single-wall copper
pipe coil inside to make hot water for showers, so it would be nice to avoid
toxic tank water.

>Additionally, the aluminum can be completely protected from corrosion by
>fresh water using cathodic protection. There are many thousands of RV water
>heaters out there with aluminum tanks that handle all sorts of tap water
>without corrosion. The reason is the magnesium anode screwed into the tank.
>I would think that an RV replacement anode could easily be fitted to
>an aluminum radiator.

How long would it last? I gather it needn't be "fitted," just touching
the water and electrically connected to the aluminum. The 170 F tank water
won't change, so it won't have new minerals. It can absorb fresh oxygen,
esp since the radiator will drain down every day for freeze protection.
But it can't hold much oxygen, since it is hot. Then again, the corrosion
rate probably increases with temperature. The Farwest site mentions a 500
Wh/lb capacity for Mg rods used in pipelines, ie so many coulombs. How can
we turn that into a lifetime in a water heater with fresh O2 but no new
minerals? I've read that the oxide layer slows the corrosion rate, in air.

Nick

Steve Young

2007-08-27, 5:25 pm

<nicksanspam@ece.villanova.edu> wrote

> So far, I've only found Gunk anti-rust and water pump lube for car
> radiators, $2 for 11 oz to protect 5 gallons or so, ie about $400 for
> 1000 gallons, and a KPR VCI powder that costs about $20/lb and
> needs 0.25% concentration, ie about $400 for 1000 gal.

Nick, here's what I've been using in the heat storage system I built from your
suggestion of using old fuel oil tanks, some years ago. 2 parts to it, a rust
inhibitor, which costs about $15 a gallon and treats 300 gallons and an oxygen
scavenger, at about the same price per gallon. They have a chemical engineer
available, who may be able to answer any questions.

http://dwdavies.com/water_treatment/boilerkleen400.htm

and Stop-Rust #200 oxygen scavenger which is the very last item on the page.

http://dwdavies.com/water%5Ftreatment/

Hope you find this helpful.

Steve Young

daestrom

2007-08-27, 8:25 pm

<nicksanspam@ece.villanova.edu> wrote in message
news:faucme$k9e@acadia.ece.villanova.edu...
> daestrom <daestrom@NO_SPAM_HEREtwcny.rr.com> wrote:
>
>
> We can do that, but mechanics say an electrically-isolated aluminum
> radiator
> with rubber hoses and insulating brackets can still corrode (oxidize?)
> soon,
> with nothing but water inside. My old boy scout canteen ended up heavily
> pitted with white crud on the inside. I think this was oxidation vs
> mineral
> deposits or galvanic corrosion, since there were no other metals involved.
>

Quite right. Al forms a nice oxide layer that inhibits further corrosion,
*BUT* that oxide layer can be interrupted by several things. Physical
abrasion is an obvious one, but to a lesser extent erosion from very fast
moving fluids (sometimes called 'flow-accelerated corrosion'). But I don't
think you'll have trouble there.

The minerals in the water can have an affect too. From what I've read, any
with halogens (chlorides, flourides, bromides, etc...) will cause rapid
pitting of the surface. Carbonates (CaCO3, Mg2CO3, et.al.) are not so bad.
But this ends up being you either have 'bad water' or you don't. Oxygen
also plays a part and you're drain down system will have some problems with
that (each night the wet surfaces will be exposed to air, each morning
re-wetted).

I've also read that there are dozens of different alloys of Al with
different corrosion resistance. No idea what version a radiator would have.
It may be significant that the interior is protected by anti-freeze with
corrosion inhibitors and the outside (exposed to rain, road salt, and storm
water) is protected by paint.

daestrom

Robert Scott

2007-08-28, 1:25 pm

On Sat, 25 Aug 2007 11:49:16 -0400, Neon John <no@never.com> wrote:

>..,.the aluminum can be completely protected from corrosion by fresh water
>using cathodic protection. ...the magnesium anode screwed into the tank...

Aren't there also some active systems that do the same thing using electric
power instead of relying on cathodic action to provide the low voltage
differential? Of course they would stop working when the power went out, but
hopefully the amount of damage caused during the short power failure would not
amount to much.

Robert Scott
Ypsilanti, Michigan

nicksanspam@ece.villanova.edu

2007-08-29, 9:25 am

Steve Young <bowtieATbrightdslDOTnet> wrote:

>Nick, here's what I've been using in the heat storage system I built from your
>suggestion of using old fuel oil tanks, some years ago. 2 parts to it, a rust
>inhibitor, which costs about $15 a gallon and treats 300 gallons and an oxygen
>scavenger, at about the same price per gallon...

http://dwdavies.com/water%5Ftreatment/

>Hope you find this helpful.

Thanks. It was.

After talking with Modine and Farwest and Galvotec

http://www.farwestcorrosion.com/fws...mminco01.htm=20
http://www.galvotec.com/products.htm

this seems very empirical. A Galvotec engineer said they use about 5 mA/ft^2
(a lot) to protect steel in seawater, vs 2 in freshwater. They use more if
the water is flowing fast, as daestrom implied. The engineer didn't have
a value for aluminum.

The current can come from a sacrificial anode "battery" or a DC power supply.
The Farwest site has graphs to predict the lifetime of a pipeline-protection
anode as a function of soil conductivity. This seems to be a simple energy
calc. One of their products is 17 lb of magnesium inside conductive coke
inside bentonite clay inside a cotton bag, which disappears over time. This
can provide 1 amp for 1 year, ie about 1.7Vx1Ax8760h/17lb = 876 Wh/lb...

Galvotec said an anode wouldn't help much in this case (although there's
a 1996 patent for a radiator cap attached to a magnesium anode.) Modine
tried this unsuccessfully. Like chrome plating, it can protect the outside
of a tube, or the inside of a tank with a simple geometry, but it only
protects a few diameters into a tube. This seems to be a matter of water
conductivity and geometry. It might work if the deep insides of the radiator
tubes were directly connected to the anode and the parts closer to the water
hoses were connected via resistors with increasing values :-)

As to oxidation, an oil layer or oxygen getter may be useless if the radiator
is exposed to oxygen every day when it drains down to avoid freezing. STSS
EPDM-lined tank manufacturer Sven Tjernagel said "Don't use oil. That will
destroy the liner." He says just keep the water slightly alkaline. Modine says
their radiators should do fine if dielectrically isolated from other metals,
eg a bronze pump and a pressurized copper pipe DHW coil. The 12V radiator fan
could have an isolated DC supply. They say put a pan under the radiator and
make it inspectable and replaceable, in case it ever leaks.

Davies Chief Chemist Pat Fogerty recommends 0.5-2% of their "ACI 100" Al
corrosion inhibitor, listed in the "industrial" part of their web page.
A 5 gallon pail (0.5%) costs $41.80 + shipping and should last forever.

It's 42% sodium silicate, which may be essentially non-toxic when diluted.
It has a "2 mg/m^3" OSHA TLV (Threshold Limit Value) for human toxicity,
which seems to be a limit for the undiluted solution in a fog, vs a tank.
I wonder if it's still legal to preserve raw eggs in an undiluted solution.
Pat Fogerty says the MSDS says [the undiluted solution?] is non-toxic to
fish and has a "2,0,0" toxicity/flammability/corrosiveness safety rating...

Section P2902.5.2 of the 2006 ICC residential code for 1 and 2 family
dwellings says

Heat exchangers using an essentially toxic transfer fluid shall be
separated from the potable water by double-wall construction [unlike our
copper pipe coil.] An air gap open to the atmosphere shall be provided
between the two walls [which raises the cost and kills efficiency--
where's the GFX air gap?]

Section R202 defines an essentially toxic transfer fluid as

Soil, water, or graywater and fluids having a Gosselin rating of 2 or
more, including ethylene glycol, hydrocarbon oils, ammonia refrigerants
and hydrazine. [The scale runs from 2 (mildly-toxic, meaning 50% of 70 kg
humans would die if they drank 1 quart of it) to 6 (a few drops...)]

http://chem.sis.nlm.nih.gov/chemidp...p#_ToxicityData

If the "2" ACI rating is a Gosselin number for the undiluted solution,
the worst-case toxic dose would be 1 pint, and diluting to 1% makes
the toxic dose 100 pints, well over 1 quart, so it would be fine
with a single wall heat exchanger.

Nick

daestrom

2007-08-31, 1:25 pm

<nicksanspam@ece.villanova.edu> wrote in message
news:fb3g5v$lmm@acadia.ece.villanova.edu...
> Steve Young <bowtieATbrightdslDOTnet> wrote:
<snip>
>
> It's 42% sodium silicate, which may be essentially non-toxic when diluted.
> It has a "2 mg/m^3" OSHA TLV (Threshold Limit Value) for human toxicity,
> which seems to be a limit for the undiluted solution in a fog, vs a tank.
> I wonder if it's still legal to preserve raw eggs in an undiluted
> solution.

Gosh that takes me back :-) I worked for an older guy when I was a kid that
kept a couple of cans of 'water glass' around from the depression. Said
they used to dip eggs in it and let them dry. The eggs would last for
months if not years without refrigeration.

Otherwise, thanks for sharing your findings.

> Heat exchangers using an essentially toxic transfer fluid shall be
> separated from the potable water by double-wall construction [unlike our
> copper pipe coil.] An air gap open to the atmosphere shall be provided
> between the two walls [which raises the cost and kills efficiency--
> where's the GFX air gap?]

I can only surmise that since the tubing is wrapped around the separate
drain pipe and soldered to it, the supply tube wall and the drain pipe wall
are the 'double-wall'construction. I doubt that an 'air gap' is required in
all installations, maybe you better go read that again. Another typical
heat exchanger design is two pressurized coils (one for toxic and one for
potable) mounted in a vented tank filled with non-toxic. If either tubing
leaks, the vented tank overflows and is detected before the opposite tubing
develops a leak. If potable pressure drops while the tubing fails, you
merely syphon the non-toxic water from the tank.

In that regard, the GFX is similar in that since the grey-water is vented to
atmosphere and the potable is pressurized. Any leakage of either will be
detected before a second failure can occur (you either get potable or grey
water all over the floor).

My limited experience in sewage treatment (couple of summers while in school
many years ago) ISTR that all potable to sewage connections had to have a
positive break such that if potable pressure fails and sewage backs up,
there should be no way for sewage to be syphoned into potable.

You could still get contamination with a multiple simultaneous failure of
two walls while the potable pressure fails. But that's pretty remote if you
can be reasonably sure you'd detect a single failure soon after it began
leaking.

daestrom

daestrom

2007-08-31, 1:25 pm

"Robert Scott" <---@---> wrote in message
news:46d43001.1176015@news.provide.net...
> On Sat, 25 Aug 2007 11:49:16 -0400, Neon John <no@never.com> wrote:
>
>
> Aren't there also some active systems that do the same thing using
> electric
> power instead of relying on cathodic action to provide the low voltage
> differential? Of course they would stop working when the power went out,
> but
> hopefully the amount of damage caused during the short power failure would
> not
> amount to much.
>

Yes. Active service naval ships use cathodic protection with zinc anodes
that have to be replaced every year or two. But *inactive* ships in the
'mothball' fleet are protected by suspending separate electrodes in the
water around the ship. A small voltage impressed on these (only need about
1-2 V) will protect the hull from corrosion. It's much simpler to replace
the suspended electrodes (a single sailor can pull one up and replace it)
than to put the whole ship in drydock.

You can also find these 'active systems' in marinas for private yachts as
well. Same idea. If the power goes out for a couple hours, you don't see
any real damage. After all, the hull is designed to stand up to seawater
corrosion for many years, the 'active systems' just extend that further.

daestrom

dances_with_barkadas@yahoo.com

2007-09-03, 11:11 am

> Is there some
> corrosion inhibitor we can use at a low concentration?

purge the system of Oxygen with Nitrogen, then seal it?

if not, then go google on, and patent-search on, "deaerating feed
tanks". You probably don't have bleed steam on hand to run it with,
though.

dances_with_barkadas@yahoo.com

2007-09-03, 11:11 am

On Aug 24, 1:46 pm, nicksans...@ece.villanova.edu wrote:
> I'm thinking about using a recent Taurus auto radiator or a Ford or GMC
> pickup radiator

Is that because, as a mass-produced item, they're fairly cheap?

Maybe you're better off swapping a new radiator in, every XX years,
then installing another layer of complication.

Sell the old radiator to some junkyard. Scrap metal is worth a lot of
money nowadays.

dances_with_barkadas@yahoo.com

2007-09-03, 11:11 am

> Carbonates (CaCO3, Mg2CO3, et.al.) are not so bad.

The carbonates combine with the oxygen to form carbonic acid. At
your typical 900 F steam operation, it is a SEVERE headache. This is
why steam plants use active dearation to acheive 7 parts per billion
oxygen in the feedwater.

dances_with_barkadas@yahoo.com

2007-09-03, 11:11 am

> Yes. Active service naval ships use cathodic protection with zinc anodes
> that have to be replaced every year or two.

I'm in active service in the Dept of the Navy as a shipriding Marine
Engineer. I live in a world where we pay a lot of attention to the
things that really could end up being showstoppers or inspection-
passing obstacles; and usually don't have any time left for the
theoretical niceties. I'm not qualified to discuss the theoretical
utility of active cathodic-protection systems; I can report that I've
never seen a Chief Engineer direct an underling to pay attention to
the cathodic protection system.

Magnetic Silencing seems to fall into the same category. I guess that
will change the first time the Iranians use a torpedo against us.

dances_with_barkadas@yahoo.com

2007-09-03, 11:11 am

> a single sailor can pull one up and replace it

change "sailor" to "mariner", if you're referring to a SS, an M/V, a
USNS, or one of the command ships (USS Mount Whitney, USS Blue Ridge).

The Ready Reserve ("mothball") Fleet is in the custody of the
Maritime Administration. Red & white stripes on the stack. Many were
activated for the recent show in Iraq.

dances_with_barkadas@yahoo.com

2007-09-03, 11:11 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:11 am

daestrom

2007-09-03, 11:11 am

<dances_with_barkadas@yahoo.com> wrote in message
news:1188731775.880881.57480@k79g2000hse.googlegroups.com...
>
>
> The carbonates combine with the oxygen to form carbonic acid. At
> your typical 900 F steam operation, it is a SEVERE headache. This is
> why steam plants use active dearation to acheive 7 parts per billion
> oxygen in the feedwater.
>

I was only talking about carbonates and their affect on Al corrosion. The
link I found pointed out that dissolved halides were much worse at removing
the protective oxide layer than dissolved carbonates.

Carbonates in a boiler are bad news for several reasons and you don't need
900F to suffer. When you heat water the solubility for CaCO3, Mg2CO3 and
others drops off and they come out of solution. This is what forms scale on
heat transfer surfaces (even in home water heaters, and LP boilers). The
really bad part is that once the CaCO3 plates out, it will not re-dissolve
into the boiler water when you shutdown the boiler. You can't get the scale
back off with out 'mechanical' cleaning or 'chemical' cleaning. One way to
combat this in the old days was to add tri- and di-sodium phosphates. The
Na would combine with the CO3 to form a scale that was easier to remove.
The first trade name of such boiler-chemistry control was 'CalGon' (same as
the retail soap) which stood for 'calcium-gone'. But the large amount of
phosphates wasn't so good for the environment so phosphates have been
regulated.

In steam plants it is now common to use 'polishers' (ion-exchange resin
beds) to continuously demineralize the condensate/feed-water. Keeping total
conductivity down well below 0.1 micromhos/cm is quite common. This slows
the buildup of TDS in the boiler water.

Dissolved oxygen in boiler is also bad for Cl-stress corrosion. But modern
low-carbon steels have a problem with too-low an O2 content as well. Yes,
O2 levels are controlled with several techniques (deareating feed tanks,
contact feed-water heaters and such). We actually have to keep O2 levels
between 10 and 50 ppb for best results.

daestrom

daestrom

2007-09-03, 11:11 am

<dances_with_barkadas@yahoo.com> wrote in message
news:1188732243.957159.311130@r34g2000hsd.googlegroups.com...
>
> I'm in active service in the Dept of the Navy as a shipriding Marine
> Engineer. I live in a world where we pay a lot of attention to the
> things that really could end up being showstoppers or inspection-
> passing obstacles; and usually don't have any time left for the
> theoretical niceties. I'm not qualified to discuss the theoretical
> utility of active cathodic-protection systems; I can report that I've
> never seen a Chief Engineer direct an underling to pay attention to
> the cathodic protection system.
>

Nonsense, surely you've seen a rag-hat or someone replacing 'zincs'. The
zinc anodes put into the water-box ends of sea-water cooled items is exactly
that. And along the hull near the shafting and propellers. Their
inspected/replaced as part of every drydocking. Even the insides of ballast
tanks have a few 'zincs' welded into them in key locations.

As I said before, *active* cathodic protection is something that I've only
seen used on ships in the 'mothball' fleet while tied up four abreast in
places like Mare-Island (now closed).

> Magnetic Silencing seems to fall into the same category. I guess that
> will change the first time the Iranians use a torpedo against us.

Funny, many's the time I dragged degaussing cables around submarines in dock
to reduce their overall magnetic signature. Minesweepers were about the
only ones I knew with active systems though. Had to learn the function of
'D', 'H' and 'T' coils just for EM3&2.

daestrom
(former EMC(ss))

dances_with_barkadas@yahoo.com

2007-09-03, 11:11 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:11 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:11 am

daestrom

2007-09-03, 11:11 am

daestrom

2007-09-03, 11:11 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

daestrom

2007-09-03, 11:12 am

daestrom

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

daestrom

2007-09-03, 11:12 am

daestrom

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

daestrom

2007-09-03, 11:12 am

daestrom

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

daestrom

2007-09-03, 11:12 am

daestrom

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

daestrom

2007-09-03, 11:12 am

daestrom

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

dances_with_barkadas@yahoo.com

2007-09-03, 11:12 am

daestrom

2007-09-03, 11:12 am

daestrom

2007-09-03, 11:12 am

Jon Elson

2007-09-04, 3:25 am

nicksanspam@ece.villanova.edu wrote:
> I'm thinking about using a recent Taurus auto radiator or a Ford or GMC
> pickup radiator to heat water with hot sunspace air, but I'm concerned that
> a) it's hard to find specs for radiator performance, and b) a mechanic says
> an aluminum core radiator might crud up with corrosion in less than a year
> with oxygenated water and no antifreeze.
I'd strongly advise against an aluminum radiator. See how long
this stuff lasts in a closed car system.

You can usually find car radiator rebuild outfits that will use
nothing but a brass or similar alloy core - because they don't
want the angry returns. You can probably have them rebuild
something that is more suitable for your purposes, maybe a truck
radiator.

To avoid using corrosion inhibitor in the entire storage tank,
you could set up a water-water heat exchanger, basically two
coaxial pipes. You can get them with ribbed inner pipe for
better heat transfer. Or, you could run the radiator loop as a
coil of pipe in the storage tank.

Jon

Jon Elson

2007-09-04, 3:25 am

dances_with_barkadas@yahoo.com wrote:
> On Aug 24, 1:46 pm, nicksans...@ece.villanova.edu wrote:
>
>
>
>
> Is that because, as a mass-produced item, they're fairly cheap?
>
> Maybe you're better off swapping a new radiator in, every XX years,
> then installing another layer of complication.
No, having a flood in your attic will NOT be a good thing to
have happen! Your ceilings will fall onto all the stuff in the
room below, MAJOR MESS!

Jon

Vaughn Simon

2007-09-04, 9:25 am

"Jon Elson" <elson@pico-systems.com> wrote in message
news:O8SdnScGp9kWcEHbnZ2dnUVZ_gqdnZ2d@giganews.com...
> No, having a flood in your attic will NOT be a good thing to have happen!

Easily prevented with a drip pan connected to a suitable drain. They
install these under AC air handlers all the time for exactly the same reason.

Vaughn

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