Ok... I'm still mulling over the possibility of a Hilsch tube on one of my
machines as the coolant and to blow chips away from the cutter. I see many
commercial ones are made out of stainless, but that just isn't in my plans
if I make one. Stainless is beyond my easy working level.

I have some large aluminum bar stock laying around, (left over from another
project) and I was thinking I could turn one out of it. My quandry is in
this. I only ran across a few mentions of heat sinking in regards to Hilsch
tubes. One article said to heat sink the whole thing. I think they just
meant the whole heat separator/exchangers side of it. It would be counter
intuitive to heat sink the cold air outlet tube. I would think you would
want to insulate that. The thing is the physics of it is beyond me. I get
the basics of both principle said to be at work. It's the details.

I could easily turn heat sink fins on the outside. I just wonder if that
will provide a lower ouput temperature, or if somehow it might reduce the
efficiency of the design somehow?

"Bob La Londe" wrote in message
...
Ok... I'm still mulling over the possibility of a Hilsch tube on one of my
machines as the coolant and to blow chips away from the cutter. I see
many commercial ones are made out of stainless, but that just isn't in my
plans if I make one. Stainless is beyond my easy working level.

I have some large aluminum bar stock laying around, (left over from
another project) and I was thinking I could turn one out of it. My
quandry is in this. I only ran across a few mentions of heat sinking in
regards to Hilsch tubes. One article said to heat sink the whole thing.
I think they just meant the whole heat separator/exchangers side of it.
It would be counter intuitive to heat sink the cold air outlet tube. I
would think you would want to insulate that. The thing is the physics of
it is beyond me. I get the basics of both principle said to be at work.
It's the details.

I could easily turn heat sink fins on the outside. I just wonder if that
will provide a lower ouput temperature, or if somehow it might reduce the
efficiency of the design somehow?


I think one goal is to keep heat from migrating through the tube from the
hot end to the cool end. The best way to do this would be to make it from a
material with low thermal conductivity, which may be why they use stainless.
The hot air is near the outside over most of the length of the tube with the
cool air in the center, so that is why heatsinking the whole cylindrical
part of the tube might make sense. However, I agree heatsinking the cold
outlet itself does not make much sense.

Most refrigerators work more efficiently if the hot side is kept from
getting too hot. I do not know enough about the theory of these tubes to say
for sure if that is the case here, but it would certainly make sense.

I once bought one of these for an esoteric cooling problem. It was so noisy
we decided not to use it.

"anorton" wrote in message
m...

"Bob La Londe" wrote in message
...
Ok... I'm still mulling over the possibility of a Hilsch tube on one of
my machines as the coolant and to blow chips away from the cutter. I see
many commercial ones are made out of stainless, but that just isn't in my
plans if I make one. Stainless is beyond my easy working level.

I have some large aluminum bar stock laying around, (left over from
another project) and I was thinking I could turn one out of it. My
quandry is in this. I only ran across a few mentions of heat sinking in
regards to Hilsch tubes. One article said to heat sink the whole thing.
I think they just meant the whole heat separator/exchangers side of it.
It would be counter intuitive to heat sink the cold air outlet tube. I
would think you would want to insulate that. The thing is the physics of
it is beyond me. I get the basics of both principle said to be at work.
It's the details.

I could easily turn heat sink fins on the outside. I just wonder if that
will provide a lower ouput temperature, or if somehow it might reduce the
efficiency of the design somehow?


I think one goal is to keep heat from migrating through the tube from the
hot end to the cool end. The best way to do this would be to make it from
a material with low thermal conductivity, which may be why they use
stainless.

I was mulling that fine distinction over in my head as well. I think I
might have a piece of acetal plastic I could machine as a thread in cold air
tube and diaphragm for the cold end.


The hot air is near the outside over most of the length of the tube with
the cool air in the center, so that is why heatsinking the whole
cylindrical part of the tube might make sense. However, I agree
heatsinking the cold outlet itself does not make much sense.

Most refrigerators work more efficiently if the hot side is kept from
getting too hot. I do not know enough about the theory of these tubes to
say for sure if that is the case here, but it would certainly make sense.

I once bought one of these for an esoteric cooling problem. It was so
noisy we decided not to use it.

"Bob La Londe" wrote in message
...
Ok... I'm still mulling over the possibility of a Hilsch tube on one of my
machines as the coolant and to blow chips away from the cutter. I see
many commercial ones are made out of stainless, but that just isn't in my
plans if I make one. Stainless is beyond my easy working level.

I have some large aluminum bar stock laying around, (left over from
another project) and I was thinking I could turn one out of it. My
quandry is in this. I only ran across a few mentions of heat sinking in
regards to Hilsch tubes. One article said to heat sink the whole thing.
I think they just meant the whole heat separator/exchangers side of it.
It would be counter intuitive to heat sink the cold air outlet tube. I
would think you would want to insulate that. The thing is the physics of
it is beyond me. I get the basics of both principle said to be at work.
It's the details.

I could easily turn heat sink fins on the outside. I just wonder if that
will provide a lower ouput temperature, or if somehow it might reduce the
efficiency of the design somehow?

There seems to be two designs out there. One has a circular passage with
angled holes drilled into the main tube. The other has a lopsided cam lobe
shaped chamber to spin the air. Any idea which one is more efficient?

On 2012-03-13, Bob La Londe wrote:
Ok... I'm still mulling over the possibility of a Hilsch tube on one of my
machines as the coolant and to blow chips away from the cutter. I see many
commercial ones are made out of stainless, but that just isn't in my plans
if I make one. Stainless is beyond my easy working level.

I have some large aluminum bar stock laying around, (left over from another
project) and I was thinking I could turn one out of it. My quandry is in
this. I only ran across a few mentions of heat sinking in regards to Hilsch
tubes. One article said to heat sink the whole thing. I think they just
meant the whole heat separator/exchangers side of it. It would be counter
intuitive to heat sink the cold air outlet tube. I would think you would
want to insulate that. The thing is the physics of it is beyond me. I get
the basics of both principle said to be at work. It's the details.

I could easily turn heat sink fins on the outside. I just wonder if that
will provide a lower ouput temperature, or if somehow it might reduce the
efficiency of the design somehow?

The primary benefit of heat sinking the hot output side (the
only part which *I* see as benefiting from that) would be the reduction
of heat conducted to the cold side and heating the air coming through
that.

A secondary benefit would be reducing the discomfort of
accidentally contacting the hot output side with your hand when working
around it.

If you put styrofoam insulation around the cold tube, you would
reduce the heat gained by condensing water onto the tube and thus
improve the efficiency somewhat. (Note that this will consume a *lot*
of air, so I hope you have a good air compressor -- and good hearing
protection. :-)

BTW That might be a benefit of using stainless as the material too
lower thermal conductivity.

But, FWIW, I made one once (as an experiment) in which the
vortex was formed by a machined piece of brass (the only thing that I
was then sure that I could machine), the housing was made from an old
pipe union. The two output tubes were 1/2" copper tubing -- both of the
same size, but the output end of the hot side had to be pinched down to
about the diameter of the cold hole in the vortex assembly.

If I were to make one today, I think that I might make the
vortex forming assembly and the housing from Delrin -- minimize the
conduction of heat in both directions. Perhaps the same (or PVC) for
the cold tube. Copper or aluminum and heat sink fins for the hot tube.
And ideally, some kind of muffler on at least the hot side, which is
pointed out into the human space of the working environment. Make the
hot tube significantly larger than the cold tube, which also benefits
with better thermal conduction to the air, and only restrict the output
end (a few inches downstream) of the hot tube to the diameter of the
cold hole in the vortex assembly.

Good Luck,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

"Bob La Londe" fired this volley in
:


I was mulling that fine distinction over in my head as well. I think
I might have a piece of acetal plastic I could machine as a thread in
cold air tube and diaphragm for the cold end.

Some are made from acetal, Bob -- the whole assembly, not merely one or the
other end.

LLoyd

"Bob La Londe" fired this volley in news:n7y7r.13744
:

I have some large aluminum bar stock laying around,

I do, too. Two 'scraps' 4"x12"x18", 6061.

LLoyd

"Bob La Londe" wrote in message
...
"Bob La Londe" wrote in message
...
Ok... I'm still mulling over the possibility of a Hilsch tube on one of
my machines as the coolant and to blow chips away from the cutter. I see
many commercial ones are made out of stainless, but that just isn't in my
plans if I make one. Stainless is beyond my easy working level.

I have some large aluminum bar stock laying around, (left over from
another project) and I was thinking I could turn one out of it. My
quandry is in this. I only ran across a few mentions of heat sinking in
regards to Hilsch tubes. One article said to heat sink the whole thing.
I think they just meant the whole heat separator/exchangers side of it.
It would be counter intuitive to heat sink the cold air outlet tube. I
would think you would want to insulate that. The thing is the physics of
it is beyond me. I get the basics of both principle said to be at work.
It's the details.

I could easily turn heat sink fins on the outside. I just wonder if that
will provide a lower ouput temperature, or if somehow it might reduce the
efficiency of the design somehow?

There seems to be two designs out there. One has a circular passage with
angled holes drilled into the main tube. The other has a lopsided cam
lobe shaped chamber to spin the air. Any idea which one is more
efficient?


They both are terribly inefficient even if you also have a use for the hot
side

On Mar 13, 8:48*am, "PrecisionmachinisT"
wrote:
"Bob La Londe" wrote in ...





"Bob La Londe" wrote in message
...
Ok... I'm still mulling over the possibility of a Hilsch tube on one of
my machines as the coolant and to blow chips away from the cutter. *I see
many commercial ones are made out of stainless, but that just isn't in my
plans if I make one. *Stainless is beyond my easy working level.

I have some large aluminum bar stock laying around, (left over from
another project) and I was thinking I could turn one out of it. *My
quandry is in this. *I only ran across a few mentions of heat sinking in
regards to Hilsch tubes. *One article said to heat sink the whole thing.
I think they just meant the whole heat separator/exchangers side of it..
It would be counter intuitive to heat sink the cold air outlet tube. *I
would think you would want to insulate that. *The thing is the physics of
it is beyond me. *I get the basics of both principle said to be at work.
It's the details.

I could easily turn heat sink fins on the outside. *I just wonder if that
will provide a lower ouput temperature, or if somehow it might reduce the
efficiency of the design somehow?

There seems to be two designs out there. *One has a circular passage with
angled holes drilled into the main tube. *The other has a lopsided cam
lobe shaped chamber to spin the air. *Any idea which one is more
efficient?

They both are terribly inefficient even if you also have a use for the hot
side- Hide quoted text -

- Show quoted text -

Well, I have one small machine running flood coolant, but I would
really like to keep the other machine dry for other reasons. I can
build either design for starting the vortex. I had hoped somebody had
already experimented with them and knew which style produced a greater
temperature differential. I've got the plug design figured out to
make flow adjustment quick and easy, and I can use my NCT for checking
the output temps. I figured to just use a bathroom vent with auto
closing louvers to send the hot air outside and let the cold air
lightly pressurize (its not a sealed system) the cabinet.

On Mar 13, 4:49*am, "Lloyd E. Sponenburgh"
lloydspinsidemindspring.com wrote:
"Bob La Londe" fired this volley in news:n7y7r.13744
:

I have some large aluminum bar stock laying around,

I do, too. *Two 'scraps' 4"x12"x18", 6061.

LLoyd

Yeah. I have seen plenty of DIY ones on the web made out of PVC pipe
too. The one under lying thing I have seen in most of those is a
substantially lower differential than some of the commercially
designed ones claim. It could be design (pocket vs jet) or some other
factor like the material its made out of.

Bob La Londe wrote:
Well, I have one small machine running flood coolant, but I would
really like to keep the other machine dry for other reasons. I can
build either design for starting the vortex. I had hoped somebody had
(SNIP)
--Well howzabout running a Microdrop system; they're *almost* dry;
not real cheap tho..
--
"Steamboat Ed" Haas : Steel, Stainless, Titanium:
Hacking the Trailing Edge! : Guaranteed Uncertified Welding!
www.nmpproducts.com
---Decks a-wash in a sea of words---

Bob La Londe fired this volley in news:b589d4bf-
:

It could be design (pocket vs jet) or some other
factor like the material its made out of.



I think its the concentricity and smoothness of the bore. The gas has got
to get up to almost unimaginable rotations per minute inside there for the
differential to be very high. Any minor defect in the walls, or any out-
of-round condition would disturb the flow.

LLoyd

"Lloyd E. Sponenburgh" lloydspinsidemindspring.com wrote in message
. 3.70...
Bob La Londe fired this volley in
news:b589d4bf-
:

It could be design (pocket vs jet) or some other
factor like the material its made out of.



I think its the concentricity and smoothness of the bore. The gas has got
to get up to almost unimaginable rotations per minute inside there for the
differential to be very high. Any minor defect in the walls, or any out-
of-round condition would disturb the flow.


That's a condition I had not considered. It makes sense though.

I still wonder if the cam lobe shaped pocket vs the multiple angled jets has
a substantial difference. Most of the DIYers are using the multiple angled
jets method. Like I said. I can make either one. If I had more time to
play I might make both and set them up to used on the same hot and cold
tubes and compare. I don't have that kind of spare time right now though.

"Bob La Londe" wrote in message ...
On Mar 13, 8:48 am, "PrecisionmachinisT"
wrote:
"Bob La Londe" wrote in ...





"Bob La Londe" wrote in message
...
Ok... I'm still mulling over the possibility of a Hilsch tube on one of
my machines as the coolant and to blow chips away from the cutter. I see
many commercial ones are made out of stainless, but that just isn't in my
plans if I make one. Stainless is beyond my easy working level.

I have some large aluminum bar stock laying around, (left over from
another project) and I was thinking I could turn one out of it. My
quandry is in this. I only ran across a few mentions of heat sinking in
regards to Hilsch tubes. One article said to heat sink the whole thing.
I think they just meant the whole heat separator/exchangers side of it.
It would be counter intuitive to heat sink the cold air outlet tube. I
would think you would want to insulate that. The thing is the physics of
it is beyond me. I get the basics of both principle said to be at work.
It's the details.

I could easily turn heat sink fins on the outside. I just wonder if that
will provide a lower ouput temperature, or if somehow it might reduce the
efficiency of the design somehow?

There seems to be two designs out there. One has a circular passage with
angled holes drilled into the main tube. The other has a lopsided cam
lobe shaped chamber to spin the air. Any idea which one is more
efficient?

They both are terribly inefficient even if you also have a use for the hot
side- Hide quoted text -

- Show quoted text -

Well, I have one small machine running flood coolant, but I would
really like to keep the other machine dry for other reasons. I can
build either design for starting the vortex. I had hoped somebody had
already experimented with them and knew which style produced a greater
temperature differential. I've got the plug design figured out to
make flow adjustment quick and easy, and I can use my NCT for checking
the output temps. I figured to just use a bathroom vent with auto
closing louvers to send the hot air outside and let the cold air
lightly pressurize (its not a sealed system) the cabinet.

===

Feel free to dink around with it all you want but compressed air should by itself be entirely sufficient unless you are machining low melting temp materials almost exclusively and in an environment where contamination with liquids would also be unacceptable..

On 2012-03-13, Bob La Londe wrote:
"Bob La Londe" wrote in message
...
Ok... I'm still mulling over the possibility of a Hilsch tube on one of my
machines as the coolant and to blow chips away from the cutter. I see
many commercial ones are made out of stainless, but that just isn't in my
plans if I make one. Stainless is beyond my easy working level.

[ ... ]

There seems to be two designs out there. One has a circular passage with
angled holes drilled into the main tube. The other has a lopsided cam lobe
shaped chamber to spin the air. Any idea which one is more efficient?

Consider what might be easiest for you to make first. The
cam-shaped lobe sounds like it is calling for some fancy programming in
a CNC machine. (But then, you have the CNC machine, don't you?

The way I made mine was to turn a ring near (but not at) the OD
of the part to which the cold tube attaches, and then mill slots into
the ring so they ended up tangential to the ID of the ring -- then mate
that to a flat surface connected to the hot tube. This left a ring
cavity just outside that into which air was fed via a tapped hole in one
of the flats of the pipe junction.

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

On 2012-03-13, Bob La Londe wrote:
On Mar 13, 8:48*am, "PrecisionmachinisT"
wrote:
"Bob La Londe" wrote in ...





"Bob La Londe" wrote in message
...
Ok... I'm still mulling over the possibility of a Hilsch tube on one of
my machines as the coolant and to blow chips away from the cutter. *I see
many commercial ones are made out of stainless, but that just isn't in my
plans if I make one. *Stainless is beyond my easy working level.

[ ... ]

There seems to be two designs out there. *One has a circular passage with
angled holes drilled into the main tube. *The other has a lopsided cam
lobe shaped chamber to spin the air. *Any idea which one is more
efficient?

They both are terribly inefficient even if you also have a use for the hot
side- Hide quoted text -

The ones which I saw which prompted my experimentation with them
were being developed for use in a tank (tracked military vehicle, not a
container for liquids or compressed air). The cold air was piped into
holes in the top of the crew's helmets, to keep at least their brains
from overheating.

The two drawbacks of these things -- poor efficiency, and lots
of noise -- were not a problem in that environment. Given how much
power it takes to move all that forged iron and steel around, and how
much noise both the engines and the tracks make, the crew would happily
accept the benefit of cool heads. :-)

[ ... ]

Well, I have one small machine running flood coolant, but I would
really like to keep the other machine dry for other reasons. I can
build either design for starting the vortex. I had hoped somebody had
already experimented with them and knew which style produced a greater
temperature differential. I've got the plug design figured out to
make flow adjustment quick and easy, and I can use my NCT for checking
the output temps. I figured to just use a bathroom vent with auto
closing louvers to send the hot air outside and let the cold air
lightly pressurize (its not a sealed system) the cabinet.

Sounds as though you can experiment with both, and let us know
which works better. But I suspect that the cam lobe design is later,
and presumably it either works better, or was designed to get around
patent restrictions on Hilsch's designs. :-)

Enjoy,
DoN.

--
Remove oil spill source from e-mail
Email: | Voice (all times): (703) 938-4564
(too) near Washington D.C. | http://www.d-and-d.com/dnichols/DoN.html
--- Black Holes are where God is dividing by zero ---

Bob La Londe wrote:
Ok... I'm still mulling over the possibility of a Hilsch tube on one of my machines as the coolant and to blow chips
away from the cutter. I see many commercial ones are made out of stainless, but that just isn't in my plans if I make
one. Stainless is beyond my easy working level.

I'd consider a long coil of mini copper tubing inside
an ice - filled cooler before I'd consider a Hilsch tube.

--Winston

In article ,
Winston wrote:

I'd consider a long coil of mini copper tubing inside
an ice - filled cooler before I'd consider a Hilsch tube.

Or park the copper (or aluminum) tubing inside a mini (or larger) fridge
(or chest freezer, I suppose - depends on what you have handy and space
available) - enter the fridge section, and exit after a bunch in the
freezer section. Drain-leg in the fride section would help with
condensation. Quieter and far less power used than with the vortex tube.
If it comes out of the freezer at 0F under pressure, it should be quite
chilly by the time it expands at the nozzle.

--
Cats, coffee, chocolate...vices to live by
Please don't feed the trolls. Killfile and ignore them so they will go away.

On Wed, 14 Mar 2012 14:49:23 -0400, Ecnerwal
wrote:

In article ,
Winston wrote:

I'd consider a long coil of mini copper tubing inside
an ice - filled cooler before I'd consider a Hilsch tube.

Or park the copper (or aluminum) tubing inside a mini (or larger) fridge
(or chest freezer, I suppose - depends on what you have handy and space
available) - enter the fridge section, and exit after a bunch in the
freezer section. Drain-leg in the fride section would help with
condensation. Quieter and far less power used than with the vortex tube.
If it comes out of the freezer at 0F under pressure, it should be quite
chilly by the time it expands at the nozzle.

Nice out of (or in) the box solution- I bet the cost wouldn't be much
different from buying a commercial vortex tube.

A little muffin fan inside the fridge could help.

Spehro Pefhany wrote:
On Wed, 14 Mar 2012 14:49:23 -0400, Ecnerwal
wrote:

In ,
wrote:

I'd consider a long coil of mini copper tubing inside
an ice - filled cooler before I'd consider a Hilsch tube.

Or park the copper (or aluminum) tubing inside a mini (or larger) fridge
(or chest freezer, I suppose - depends on what you have handy and space
available) - enter the fridge section, and exit after a bunch in the
freezer section. Drain-leg in the fride section would help with
condensation.

Good idea!

Quieter and far less power used than with the vortex tube.
If it comes out of the freezer at 0F under pressure, it should be quite
chilly by the time it expands at the nozzle.

Nice out of (or in) the box solution- I bet the cost wouldn't be much
different from buying a commercial vortex tube.

A little muffin fan inside the fridge could help.

Or go cheaper, smaller and colder with a 'saturated - salt ice water'
slurry in your ice chest.
http://van.physics.illinois.edu/qa/listing.php?id=1722

--Winston

In article ,
Winston wrote:

Or go cheaper, smaller and colder with a 'saturated - salt ice water'
slurry in your ice chest.

Ice generally isn't "free"; salt is cheap, but also not free, and can be
corrosive to have around the shop; this is something Bob wants to run
every day (or nearly), and labor to drain the sal****er and load up the
fresh salt and ice also isn't free - so refrigeration wins, IMHO for
cheaper.

Smaller depends on the fridge you are using .vs. the cooler, ice source,
and salt storage, which can easily be larger than a small fridge.

It can also win on colder -21.1C is only -6F, and plenty of freezers can
be cranked colder than that. OF is just a typical setting.

It also wins on less messy.

If it were a one-day deal or the like, I'd agree with you, but I'd
choose refrigeration in a heartbeat for any regular use. I'm intimately
aware of the hassles of salt-ice refrigeration, and I'm quite certain
that if I were making ice cream and sorbet as a busness rather than for
myself, it would be an easy decision to spend the money for a
refrigerated mixer - for home use it's a lot of money, so I use salt and
ice.

--
Cats, coffee, chocolate...vices to live by
Please don't feed the trolls. Killfile and ignore them so they will go away.

On Mar 14, 4:54*pm, Ecnerwal
wrote:



If it were a one-day deal or the like, I'd agree with you, but I'd
choose refrigeration in a heartbeat for any regular use. I'm intimately
aware of the hassles of salt-ice refrigeration, and I'm quite certain
that if I were making ice cream and sorbet as a busness rather than for
myself, it would be an easy decision to spend the money for a
refrigerated mixer - for home use it's a lot of money, so I use salt and
ice.


Another approach would be to use a solid state cooler and a bit of
compressed air.

Peltier Junction Thermo Electric Heat Pump

Dan

Ecnerwal wrote:
In ,
wrote:

Or go cheaper, smaller and colder with a 'saturated - salt ice water'
slurry in your ice chest.

Ice generally isn't "free"; salt is cheap, but also not free, and can be
corrosive to have around the shop; this is something Bob wants to run
every day (or nearly), and labor to drain the sal****er and load up the
fresh salt and ice also isn't free - so refrigeration wins, IMHO for
cheaper.

Because refrigeration is free? Really?

(...)

It also wins on less messy.

OK, I'll give you that one.

(...)


My suggestion is just something to try for a few dollars.

If it works for the duration of the project, Bob is not
out much money. If it does not work, refrigeration is
not going to work either.

One experiment is worth years of theorizing.

--Winston

wrote:
On Mar 14, 4:54 pm, Ecnerwal
wrote:



If it were a one-day deal or the like, I'd agree with you, but I'd
choose refrigeration in a heartbeat for any regular use. I'm intimately
aware of the hassles of salt-ice refrigeration, and I'm quite certain
that if I were making ice cream and sorbet as a busness rather than for
myself, it would be an easy decision to spend the money for a
refrigerated mixer - for home use it's a lot of money, so I use salt and
ice.


Another approach would be to use a solid state cooler and a bit of
compressed air.

Peltier Junction Thermo Electric Heat Pump


One could refrigerate a jug of water for a few days
then use it as a heat sink for the copper tube.
That'd be inefficient but it might be cheaper
because it would eliminate the trip to the store
for bags of ice.

I like it.

--Winston

On Wed, 14 Mar 2012 20:25:39 -0700, Winston
wrote:

wrote:
On Mar 14, 4:54 pm, Ecnerwal
wrote:



If it were a one-day deal or the like, I'd agree with you, but I'd
choose refrigeration in a heartbeat for any regular use. I'm intimately
aware of the hassles of salt-ice refrigeration, and I'm quite certain
that if I were making ice cream and sorbet as a busness rather than for
myself, it would be an easy decision to spend the money for a
refrigerated mixer - for home use it's a lot of money, so I use salt and
ice.


Another approach would be to use a solid state cooler and a bit of
compressed air.

Peltier Junction Thermo Electric Heat Pump


One could refrigerate a jug of water for a few days
then use it as a heat sink for the copper tube.
That'd be inefficient but it might be cheaper
because it would eliminate the trip to the store
for bags of ice.

Who needs a store? I make my own ice in a little stand-up freezer. In
the summer, when I'm fishing, I make about 10 to 20 pounds of it every
couple of days.

It's a lot cheaper than running a compressor at the low efficiencies
of a Hilsch tube...or buying ice.

--
Ed Huntress


I like it.

--Winston

Ed Huntress wrote:
On Wed, 14 Mar 2012 20:25:39 -0700,
wrote:

wrote:
On Mar 14, 4:54 pm, Ecnerwal
wrote:



If it were a one-day deal or the like, I'd agree with you, but I'd
choose refrigeration in a heartbeat for any regular use. I'm intimately
aware of the hassles of salt-ice refrigeration, and I'm quite certain
that if I were making ice cream and sorbet as a busness rather than for
myself, it would be an easy decision to spend the money for a
refrigerated mixer - for home use it's a lot of money, so I use salt and
ice.


Another approach would be to use a solid state cooler and a bit of
compressed air.

Peltier Junction Thermo Electric Heat Pump


One could refrigerate a jug of water for a few days
then use it as a heat sink for the copper tube.
That'd be inefficient but it might be cheaper
because it would eliminate the trip to the store
for bags of ice.

Who needs a store? I make my own ice in a little stand-up freezer. In
the summer, when I'm fishing, I make about 10 to 20 pounds of it every
couple of days.

Like this?

http://www.compactappliance.com/Avan...ances-Freezers

Nifty! And probably a *lot* more energy efficient than the Peltier.

So, locate a square 10 gallon bucket, submerge coil, fill with water
and place it in the freezer. Figure out a pump to keep the drip leg
dry and Bob's your Uncle.

--Winston

"Ed Huntress" wrote in message
...
On Wed, 14 Mar 2012 20:25:39 -0700, Winston
wrote:

wrote:
On Mar 14, 4:54 pm, Ecnerwal
wrote:



If it were a one-day deal or the like, I'd agree with you, but I'd
choose refrigeration in a heartbeat for any regular use. I'm intimately
aware of the hassles of salt-ice refrigeration, and I'm quite certain
that if I were making ice cream and sorbet as a busness rather than for
myself, it would be an easy decision to spend the money for a
refrigerated mixer - for home use it's a lot of money, so I use salt
and
ice.


Another approach would be to use a solid state cooler and a bit of
compressed air.

Peltier Junction Thermo Electric Heat Pump


One could refrigerate a jug of water for a few days
then use it as a heat sink for the copper tube.
That'd be inefficient but it might be cheaper
because it would eliminate the trip to the store
for bags of ice.

Who needs a store? I make my own ice in a little stand-up freezer. In
the summer, when I'm fishing, I make about 10 to 20 pounds of it every
couple of days.

Yeah, I took all the shelves out of the freezer in my shop fridge and put a
great big tub under the little ice maker in there. It holds 30-40 pounds of
ice if I remember to turn the tub around so the other side fills. In the
summer when I am fishing a lot that is never a problem. LOL.

It's a lot cheaper than running a compressor at the low efficiencies
of a Hilsch tube...or buying ice.

I would consider using the freezer part of the fridge to pre-cool a coil of
air, but its on the other side of the shop. I actually considered putting
my CNC computers inside a little apartment fridge in the shop. Maybe now is
the time to get a second shop fridge. LOL.

On Wed, 14 Mar 2012 21:58:30 -0700, Winston
wrote:

Ed Huntress wrote:
On Wed, 14 Mar 2012 20:25:39 -0700,
wrote:

wrote:
On Mar 14, 4:54 pm, Ecnerwal
wrote:



If it were a one-day deal or the like, I'd agree with you, but I'd
choose refrigeration in a heartbeat for any regular use. I'm intimately
aware of the hassles of salt-ice refrigeration, and I'm quite certain
that if I were making ice cream and sorbet as a busness rather than for
myself, it would be an easy decision to spend the money for a
refrigerated mixer - for home use it's a lot of money, so I use salt and
ice.


Another approach would be to use a solid state cooler and a bit of
compressed air.

Peltier Junction Thermo Electric Heat Pump


One could refrigerate a jug of water for a few days
then use it as a heat sink for the copper tube.
That'd be inefficient but it might be cheaper
because it would eliminate the trip to the store
for bags of ice.

Who needs a store? I make my own ice in a little stand-up freezer. In
the summer, when I'm fishing, I make about 10 to 20 pounds of it every
couple of days.

Like this?

http://www.compactappliance.com/Avan...ances-Freezers

Yeah. Mine's a little bigger -- around 4 ft^3 -- but that one should
do it. BTW, mine has run without a hitch for 32 years. Sears.


Nifty! And probably a *lot* more energy efficient than the Peltier.

Probably. (Remind me to tell you about the piece of research
equipment, using semiconductor Peltier chips, that I built for Japan's
MITI back in the '80s. Bridgeport, South Bend lathe, and ancient
Walker Turner drill press, and the thing went to Japan's research
agency for OTEC. g)


So, locate a square 10 gallon bucket, submerge coil, fill with water
and place it in the freezer. Figure out a pump to keep the drip leg
dry and Bob's your Uncle.

--Winston

I'd be wary of doing it that way. The coil would develop a blanket of
water around it and the conductivity from the ice would be
problematic.

If it's enough chilling, great. Otherwise, I'd break the ice into
chunks and toss them in the bucket.

--
Ed Huntress

On Mar 15, 7:16*am, Ed Huntress wrote:




Nifty! *And probably a *lot* more energy efficient than the Peltier.

Ed Huntress

I am sure it would be more efficent than a Peltier device, but I was
thinking more about the space required.


Dan

Hey Ed.

You were going to tell me about the time you created a
Peltier-based test jig destined for Japan's Ministry
of International Trade and Industry to be used in Ocean
Thermal Energy Conversion research back in the 80's.

You used a Bridgy, a SB lathe and an ancient Walker
Turner drill press. Is that right?



--Winston --After the tsunami, they didn't need
to hide it under Yucca Mountain.

On Thu, 15 Mar 2012 11:05:08 -0700, Winston
wrote:

Hey Ed.

You were going to tell me about the time you created a
Peltier-based test jig destined for Japan's Ministry
of International Trade and Industry to be used in Ocean
Thermal Energy Conversion research back in the 80's.

You used a Bridgy, a SB lathe and an ancient Walker
Turner drill press. Is that right?

g Oh, yeah, I remember that...

Okay, a long tail...

I left AM to pursue a juicy contract with MITI (Japan's Ministry of
International Trade and Industry), to produce reports on new materials
applications. One of their big energy projects was OTEC (Ocean-Thermal
Energy Conversion). I wrote a paper on corrosion-resistant materials
for that project and then, in discussions with them, they expressed an
interest in the new semiconductor thermoelectric cells, as possible
candidates for electricity generation from
low-temperature-differential, high-volume seawater. They actually use
the Seebeck effect, but Peltier and Seebeck are like yin and yang.

Anyway, they said they wanted some of the new cells from a company in
Trenton, NJ, to test and evaluate. I drove down and bought a few dozen
for them. When I delivered them they said they wanted to get started
quickly because they had contracted with a company in Japan to build a
refrigerator-size test module and it would take a couple of months to
get it, and then another month to run tests.

I had a design in my head for a four-cell test unit that I could make
in one weekend. They said it wasn't enough cells. So I explained that
you could change cells in it in less than five minutes, and they could
easily test 20 cells in a day. They they could run some statistics,
figure the variance and standard deviations from a few day's worth of
testing, and have the results they wanted. So they threw some money at
me and said go ahead.

It was really simple. I took two 6-inch squares of 5/8" aluminum
tooling plate (2024 -- it was all I had) and cut a serpentine groove
in one side of each plate with a 1/2" end mill (mill -- I had to use a
friend's Bridgeport). Then I turned some custom barb fittings from
brass (turn). I drilled holes to clamp the two plates together,
leaving room for the Seebeck cells, and then drilled and tapped holes
for the barb fittings (drill). There were two barb fittings on each
plate, at opposite ends of the serpentine groove. Through one plate
you ran cold water. Through the other, warm water.

I placed four cells between the plates, smeared them with conductive
silicone grease, and clamped them together. Then I hooked aquarium
hose to the barb fittings. One pair of leads from each cell projected
out of the space between the plates. Ta-dah. About five hours of work,
IIRC.

You could measure the volume of water and the in-and-out temperatures
from each plate, and the electrical output of each cell. You can see
the implications -- a simple way to measure energy in/energy out at
different absolute temperatures and temperature differentials (there
was lots of insulation on the whole thing, in use) and to test the
output variance among cells. Very, very simple.

That's the story. They loved it. And they decided not to invest in
OTEC. g

--
Ed Huntress







--Winston --After the tsunami, they didn't need
to hide it under Yucca Mountain.

On Thu, 15 Mar 2012 14:40:40 -0400, Ed Huntress
wrote:

On Thu, 15 Mar 2012 11:05:08 -0700, Winston
wrote:

Hey Ed.

You were going to tell me about the time you created a
Peltier-based test jig destined for Japan's Ministry
of International Trade and Industry to be used in Ocean
Thermal Energy Conversion research back in the 80's.

You used a Bridgy, a SB lathe and an ancient Walker
Turner drill press. Is that right?

g Oh, yeah, I remember that...

Okay, a long tail...

I left AM to pursue a juicy contract with MITI (Japan's Ministry of
International Trade and Industry), to produce reports on new materials
applications. One of their big energy projects was OTEC (Ocean-Thermal
Energy Conversion). I wrote a paper on corrosion-resistant materials
for that project and then, in discussions with them, they expressed an
interest in the new semiconductor thermoelectric cells, as possible
candidates for electricity generation from
low-temperature-differential, high-volume seawater. They actually use
the Seebeck effect, but Peltier and Seebeck are like yin and yang.

Anyway, they said they wanted some of the new cells from a company in
Trenton, NJ, to test and evaluate. I drove down and bought a few dozen
for them. When I delivered them they said they wanted to get started
quickly because they had contracted with a company in Japan to build a
refrigerator-size test module and it would take a couple of months to
get it, and then another month to run tests.

I had a design in my head for a four-cell test unit that I could make
in one weekend. They said it wasn't enough cells. So I explained that
you could change cells in it in less than five minutes, and they could
easily test 20 cells in a day. They they could run some statistics,
figure the variance and standard deviations from a few day's worth of
testing, and have the results they wanted. So they threw some money at
me and said go ahead.

It was really simple. I took two 6-inch squares of 5/8" aluminum
tooling plate (2024 -- it was all I had) and cut a serpentine groove
in one side of each plate with a 1/2" end mill (mill -- I had to use a
friend's Bridgeport). Then I turned some custom barb fittings from
brass (turn). I drilled holes to clamp the two plates together,
leaving room for the Seebeck cells, and then drilled and tapped holes
for the barb fittings (drill). There were two barb fittings on each
plate, at opposite ends of the serpentine groove. Through one plate
you ran cold water. Through the other, warm water.

I placed four cells between the plates, smeared them with conductive
silicone grease, and clamped them together. Then I hooked aquarium
hose to the barb fittings. One pair of leads from each cell projected
out of the space between the plates. Ta-dah. About five hours of work,
IIRC.

You could measure the volume of water and the in-and-out temperatures
from each plate, and the electrical output of each cell. You can see
the implications -- a simple way to measure energy in/energy out at
different absolute temperatures and temperature differentials (there
was lots of insulation on the whole thing, in use) and to test the
output variance among cells. Very, very simple.

That's the story. They loved it. And they decided not to invest in
OTEC. g

Oh, I forgot the Plexiglass covers. The grooves were on the outside of
the sandwich, and I covered them with 1/8" Plexi. That way you could
see if a bubble was trapped in there that would screw up the output
readings from one cell.

--
Ed Huntress

Ed Huntress wrote:
On Thu, 15 Mar 2012 14:40:40 -0400, Ed Huntress
wrote:

On Thu, 15 Mar 2012 11:05:08 -0700,
wrote:

Hey Ed.

You were going to tell me about the time you created a
Peltier-based test jig destined for Japan's Ministry
of International Trade and Industry to be used in Ocean
Thermal Energy Conversion research back in the 80's.

You used a Bridgy, a SB lathe and an ancient Walker
Turner drill press. Is that right?

g Oh, yeah, I remember that...

Okay, a long tail...

I left AM to pursue a juicy contract with MITI (Japan's Ministry of
International Trade and Industry), to produce reports on new materials
applications. One of their big energy projects was OTEC (Ocean-Thermal
Energy Conversion). I wrote a paper on corrosion-resistant materials
for that project and then, in discussions with them, they expressed an
interest in the new semiconductor thermoelectric cells, as possible
candidates for electricity generation from
low-temperature-differential, high-volume seawater. They actually use
the Seebeck effect, but Peltier and Seebeck are like yin and yang.

Anyway, they said they wanted some of the new cells from a company in
Trenton, NJ, to test and evaluate. I drove down and bought a few dozen
for them. When I delivered them they said they wanted to get started
quickly because they had contracted with a company in Japan to build a
refrigerator-size test module and it would take a couple of months to
get it, and then another month to run tests.

I had a design in my head for a four-cell test unit that I could make
in one weekend. They said it wasn't enough cells. So I explained that
you could change cells in it in less than five minutes, and they could
easily test 20 cells in a day. They they could run some statistics,
figure the variance and standard deviations from a few day's worth of
testing, and have the results they wanted. So they threw some money at
me and said go ahead.

It was really simple. I took two 6-inch squares of 5/8" aluminum
tooling plate (2024 -- it was all I had) and cut a serpentine groove
in one side of each plate with a 1/2" end mill (mill -- I had to use a
friend's Bridgeport). Then I turned some custom barb fittings from
brass (turn). I drilled holes to clamp the two plates together,
leaving room for the Seebeck cells, and then drilled and tapped holes
for the barb fittings (drill). There were two barb fittings on each
plate, at opposite ends of the serpentine groove. Through one plate
you ran cold water. Through the other, warm water.

I placed four cells between the plates, smeared them with conductive
silicone grease, and clamped them together.

I guess your clamping pattern assured that every cell
had an equal share of hot and cold sink coupling.

That apparently is really difficult to do.
One of our own disassembled a shorted PWM control for an RC application
and found that say 30% of his SMT MOSFETs barely made contact
with the heat sink. (You could really see the problem by inspecting
the 'sil pad' that was wedged between the heatsink and devices.
Some FETS made quite a deep impression and some were not apparent
at all.)


Then I hooked aquarium
hose to the barb fittings. One pair of leads from each cell projected
out of the space between the plates. Ta-dah. About five hours of work,
IIRC.

You could measure the volume of water and the in-and-out temperatures
from each plate, and the electrical output of each cell. You can see
the implications -- a simple way to measure energy in/energy out at
different absolute temperatures and temperature differentials (there
was lots of insulation on the whole thing, in use) and to test the
output variance among cells. Very, very simple.

Sounds like Science, too. One could bolt on thermocouples for instance.

That's the story. They loved it. And they decided not to invest in
OTEC.g

Ouch! That's like deciding not to buy a car because all
you could test were Yugos.

I love the TE concept but despair over their inefficiency.

I suspect that Stirling motors would work the best in
this application, no? ('Sounds like a great purpose
for 'flare gas' at last.)

Oh, I forgot the Plexiglass covers. The grooves were on the outside of
the sandwich, and I covered them with 1/8" Plexi. That way you could
see if a bubble was trapped in there that would screw up the output
readings from one cell.

Very nifty!

That'd be a way to create a solar heat collector, too.
I expect the plexi would have to be replaced with another
aluminum sheet, though.

--Winston

On Thu, 15 Mar 2012 13:21:37 -0700, Winston
wrote:

Ed Huntress wrote:
On Thu, 15 Mar 2012 14:40:40 -0400, Ed Huntress
wrote:

On Thu, 15 Mar 2012 11:05:08 -0700,
wrote:

Hey Ed.

You were going to tell me about the time you created a
Peltier-based test jig destined for Japan's Ministry
of International Trade and Industry to be used in Ocean
Thermal Energy Conversion research back in the 80's.

You used a Bridgy, a SB lathe and an ancient Walker
Turner drill press. Is that right?

g Oh, yeah, I remember that...

Okay, a long tail...

I left AM to pursue a juicy contract with MITI (Japan's Ministry of
International Trade and Industry), to produce reports on new materials
applications. One of their big energy projects was OTEC (Ocean-Thermal
Energy Conversion). I wrote a paper on corrosion-resistant materials
for that project and then, in discussions with them, they expressed an
interest in the new semiconductor thermoelectric cells, as possible
candidates for electricity generation from
low-temperature-differential, high-volume seawater. They actually use
the Seebeck effect, but Peltier and Seebeck are like yin and yang.

Anyway, they said they wanted some of the new cells from a company in
Trenton, NJ, to test and evaluate. I drove down and bought a few dozen
for them. When I delivered them they said they wanted to get started
quickly because they had contracted with a company in Japan to build a
refrigerator-size test module and it would take a couple of months to
get it, and then another month to run tests.

I had a design in my head for a four-cell test unit that I could make
in one weekend. They said it wasn't enough cells. So I explained that
you could change cells in it in less than five minutes, and they could
easily test 20 cells in a day. They they could run some statistics,
figure the variance and standard deviations from a few day's worth of
testing, and have the results they wanted. So they threw some money at
me and said go ahead.

It was really simple. I took two 6-inch squares of 5/8" aluminum
tooling plate (2024 -- it was all I had) and cut a serpentine groove
in one side of each plate with a 1/2" end mill (mill -- I had to use a
friend's Bridgeport). Then I turned some custom barb fittings from
brass (turn). I drilled holes to clamp the two plates together,
leaving room for the Seebeck cells, and then drilled and tapped holes
for the barb fittings (drill). There were two barb fittings on each
plate, at opposite ends of the serpentine groove. Through one plate
you ran cold water. Through the other, warm water.

I placed four cells between the plates, smeared them with conductive
silicone grease, and clamped them together.

I guess your clamping pattern assured that every cell
had an equal share of hot and cold sink coupling.

It was an even pattern, and any difference would be apparent at the
plates' edges, but it also counted on the grease. In any case, it
worked. We moved one set of cells all around on the plates and the
results were pretty consistent.


That apparently is really difficult to do.
One of our own disassembled a shorted PWM control for an RC application
and found that say 30% of his SMT MOSFETs barely made contact
with the heat sink. (You could really see the problem by inspecting
the 'sil pad' that was wedged between the heatsink and devices.
Some FETS made quite a deep impression and some were not apparent
at all.)


Then I hooked aquarium
hose to the barb fittings. One pair of leads from each cell projected
out of the space between the plates. Ta-dah. About five hours of work,
IIRC.

You could measure the volume of water and the in-and-out temperatures
from each plate, and the electrical output of each cell. You can see
the implications -- a simple way to measure energy in/energy out at
different absolute temperatures and temperature differentials (there
was lots of insulation on the whole thing, in use) and to test the
output variance among cells. Very, very simple.

Sounds like Science, too. One could bolt on thermocouples for instance.

I attached 1N914 diodes for my own initial tests. They're very linear
for temperature when back-biased within a certain voltage range --
MUCH better than thermistors. But the leads have to be short. Amplify
the results with a 714 op amp and drive a small meter. +/- 1 deg. F
over quite a long range.

That was in 1981, remember. d8-)


That's the story. They loved it. And they decided not to invest in
OTEC.g

Ouch! That's like deciding not to buy a car because all
you could test were Yugos.

g Their primary tests were with steam turbines using ammonia for a
working fluid.


I love the TE concept but despair over their inefficiency.

I don't remember the values. I have a couple of them that I scrounged
from an old camping cooler. It killed the battery in my van one night
and I took it apart for revenge.


I suspect that Stirling motors would work the best in
this application, no? ('Sounds like a great purpose
for 'flare gas' at last.)

They'd likely be the most efficient energy coverter at those
temperatures. But you're dealing with very small temp. differentials.
It would take a *lot* of Stirlings to generate useful power.

--
Ed Huntress


Oh, I forgot the Plexiglass covers. The grooves were on the outside of
the sandwich, and I covered them with 1/8" Plexi. That way you could
see if a bubble was trapped in there that would screw up the output
readings from one cell.

Very nifty!

That'd be a way to create a solar heat collector, too.
I expect the plexi would have to be replaced with another
aluminum sheet, though.

--Winston

Ed Huntress wrote:
On Thu, 15 Mar 2012 13:21:37 -0700,
wrote:

Ed Huntress wrote:

(...)

I guess your clamping pattern assured that every cell
had an equal share of hot and cold sink coupling.

It was an even pattern, and any difference would be apparent at the
plates' edges, but it also counted on the grease. In any case, it
worked. We moved one set of cells all around on the plates and the
results were pretty consistent.

You didn't have variation in solder thickness, as our
friend did in his PWM MOSFETs, so that removed a
significant variable. Very cool, and warm.

(...)

Sounds like Science, too. One could bolt on thermocouples for instance.

I attached 1N914 diodes for my own initial tests. They're very linear
for temperature when back-biased within a certain voltage range --
MUCH better than thermistors. But the leads have to be short. Amplify
the results with a 714 op amp and drive a small meter. +/- 1 deg. F
over quite a long range.

That was in 1981, remember. d8-)

'Sounds like you had to 'level shift' and scale but you
didn't have to 'linearize'. -2 mV per degree?
Or is that the 'forward' and not 'reverse' tempco?

That's the story. They loved it. And they decided not to invest in
OTEC.g

Ouch! That's like deciding not to buy a car because all
you could test were Yugos.

g Their primary tests were with steam turbines using ammonia for a
working fluid.

(Gasp!) Though I am sure it was perfectly safe.

I love the TE concept but despair over their inefficiency.

I don't remember the values. I have a couple of them that I scrounged
from an old camping cooler. It killed the battery in my van one night
and I took it apart for revenge.

That fridge *needed* disassemblin'.

I suspect that Stirling motors would work the best in
this application, no? ('Sounds like a great purpose
for 'flare gas' at last.)

They'd likely be the most efficient energy coverter at those
temperatures. But you're dealing with very small temp. differentials.
It would take a *lot* of Stirlings to generate useful power.

In OTEC, Stirling 'ballast' would be a Good Thing, (at last).

--Winston

On Thu, 15 Mar 2012 15:05:48 -0700, Winston
wrote:

Ed Huntress wrote:
On Thu, 15 Mar 2012 13:21:37 -0700,
wrote:

Ed Huntress wrote:

(...)

I guess your clamping pattern assured that every cell
had an equal share of hot and cold sink coupling.

It was an even pattern, and any difference would be apparent at the
plates' edges, but it also counted on the grease. In any case, it
worked. We moved one set of cells all around on the plates and the
results were pretty consistent.

You didn't have variation in solder thickness, as our
friend did in his PWM MOSFETs, so that removed a
significant variable. Very cool, and warm.

These chips had flat-finished ceramic wafers on both sides.


(...)

Sounds like Science, too. One could bolt on thermocouples for instance.

I attached 1N914 diodes for my own initial tests. They're very linear
for temperature when back-biased within a certain voltage range --
MUCH better than thermistors. But the leads have to be short. Amplify
the results with a 714 op amp and drive a small meter. +/- 1 deg. F
over quite a long range.

That was in 1981, remember. d8-)

'Sounds like you had to 'level shift' and scale but you
didn't have to 'linearize'. -2 mV per degree?
Or is that the 'forward' and not 'reverse' tempco?

I really don't remember. I had used the same system years earlier for
a temperature-tire gauge for SCCA races. Those little things respond
in less than 2 seconds.


That's the story. They loved it. And they decided not to invest in
OTEC.g

Ouch! That's like deciding not to buy a car because all
you could test were Yugos.

g Their primary tests were with steam turbines using ammonia for a
working fluid.

(Gasp!) Though I am sure it was perfectly safe.

They were out at sea. The OTEC plants generally are old ships anchored
in warm water, over fairly deep waters that are much cooler at the
depths. I haven't heard anything about them for 20 years. The whole
thing probably was a dud.


I love the TE concept but despair over their inefficiency.

I don't remember the values. I have a couple of them that I scrounged
from an old camping cooler. It killed the battery in my van one night
and I took it apart for revenge.

That fridge *needed* disassemblin'.

I suspect that Stirling motors would work the best in
this application, no? ('Sounds like a great purpose
for 'flare gas' at last.)

They'd likely be the most efficient energy coverter at those
temperatures. But you're dealing with very small temp. differentials.
It would take a *lot* of Stirlings to generate useful power.

In OTEC, Stirling 'ballast' would be a Good Thing, (at last).

Speaking of Stirlings, have you heard anything about that
multiple-Stirling solar array that PG&E was building a couple of years
ago? I would have thought something would be reported about it by now.

--
Ed Huntress


--Winston

Ed Huntress wrote:

(...)

Speaking of Stirlings, have you heard anything about that
multiple-Stirling solar array that PG&E was building a couple of years
ago? I would have thought something would be reported about it by now.

http://thegreenwombat.com/2009/06/25...ith-nrgesolar/

I hadn't heard a thing, until you mentioned it just now.

Uh oh....
http://www.greentechmedia.com/articl...-falling-fast/
http://www.greentechmedia.com/articl...-by-aes-solar/

--Winston

Ed Huntress wrote:

Speaking of Stirlings, have you heard anything about that
multiple-Stirling solar array that PG&E was building a couple of years
ago? I would have thought something would be reported about it by now.

'Wish they'd turn off that JLG lift.
Those things are *noisy*.



http://www.youtube.com/watch?v=wEIQ2FVL_ys

--Winston

Ed Huntress wrote:

Speaking of Stirlings, have you heard anything about that
multiple-Stirling solar array that PG&E was building a couple of years
ago? I would have thought something would be reported about it by now.

These sound a *lot* better!

(I wonder how they made them sound like strings and horns?)
http://www.youtube.com/watch?v=ow0W4...eature=related

:]

--Winston

On Thu, 15 Mar 2012 16:10:23 -0700, Winston
wrote:

Ed Huntress wrote:

(...)

Speaking of Stirlings, have you heard anything about that
multiple-Stirling solar array that PG&E was building a couple of years
ago? I would have thought something would be reported about it by now.

http://thegreenwombat.com/2009/06/25...ith-nrgesolar/

I hadn't heard a thing, until you mentioned it just now.

Uh oh....
http://www.greentechmedia.com/articl...-falling-fast/
http://www.greentechmedia.com/articl...-by-aes-solar/

--Winston

Hmmm. That doesn't sound good.

Oh, well, we're going to have all the oil we could possibly want,
after the Republicans win the White House. And gas will be $2.50 a
gallon! Free, if you show your Tea Party ID card!

They'll probably drill in my back yard. I wonder who owns the mineral
rights? d8-)

--
Ed Huntress