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Home > Archive > Alternative Power sources > January 2006 > Passive refigeration
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Passive refigeration
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| Gordon reeder 2005-12-27, 8:21 pm |
| In the Dec/Jan issue of MIT Technology review there is a short
piece about a refigeration device that needs no electricity.
(I know, gas refigerators. but this device is much simpler).
The device is a cylander 10cm by 20cm with a handle.
It is described as two chambers, one steel, one aluminum,
separated by an insulating ceramic disk fitted with two valves.
In use, the device's steel end is placed in a fire for 30 minutes.
A refigerant is boiled and moves as a gas to the second chamber
via a one way valve. The unit is then allowed to rest to allow
the gas to condense (doesn't say how long). Then the device is
inverted and the aluminum end is inserted into a food storage
pot. I cools by absorbing heat and moving the gas back to the
first chamber vie a valve that opens when the unit is inverted.
It claims that it can keep a 32 liter food storage pot cooled to
4 deg C for 24 hours.
Now, I know that this is not a very good description of the device,
a few details of it's opperation are missing. For instance, I
assume that a vacuume is developed in the steel end of the device
once it is allowed to cool. And that that vacuum lowers the
boiling point of the refrigerant in the other chamber. Other wise
why would inverting the device and opening a valve cause it to
cool?
Also how is the refrigerant moved to the second chamber while
on the fire? Is it simply moved as a gas and condenses in
the second chamber? Wouldn't a tube to move the refrigerent
(somthing like a coffee perculator)be more efficient?
Anyone want to try to reverse engineer this and make one
of your own?? Might be an intresting way to get cooling
from excessive solar hot water or Generator exhust.
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| WisJim 2005-12-27, 9:21 pm |
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Functionally this sounds like the old "IcyBall" that Crosley made back
in the 1930s (google IcyBall for more info), just updated with modern
materials. I'll be looking for more info in the future, maybe can
replace my old Icy Ball unit with something more efficient.
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| GeekBoy 2005-12-28, 1:21 am |
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"WisJim" <jiminwis@gmail.com> wrote in message
news:1135731185.654900.34420@g44g2000cwa.googlegroups.com...
>
> Functionally this sounds like the old "IcyBall" that Crosley made back
> in the 1930s (google IcyBall for more info), just updated with modern
> materials. I'll be looking for more info in the future, maybe can
> replace my old Icy Ball unit with something more efficient.
>
Sure can..try an Amonnia frig. Just light a little fire underneath.
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"Gordon reeder" <gonzo@alltomyself.com> wrote in message
news:Xns97399E21624EEgreederxprtnet@213.155.197.138...
>
> Now, I know that this is not a very good description of the device,
> a few details of it's opperation are missing. For instance, I
> assume that a vacuume is developed in the steel end of the device
> once it is allowed to cool. And that that vacuum lowers the
> boiling point of the refrigerant in the other chamber. Other wise
> why would inverting the device and opening a valve cause it to
> cool?
I'll try to make it as simple as I can. It's basic high school physics
really.
When a vapor is compressed into a liquid, a good deal of heat is given off.
When the pressure is released and the liquid is allowed to evaporate into a
vapor again, it "wants it's heat back," so it feels very cold as it absorbs
this heat.
Putting the steel end in the fire, merely boils the liquid out of that side
of the chamber, through the one-way valve and it collects in the aluminium
side under pressure. The aluminium side would remain quite warm until room
temperature cooled it down, and in this process, the refrigerant in the
chamber would condense to liquid.
When this room-temperature apparatus is turned over, the pressure on the
liquid is released, and it starts to boil, turning back to vapor. As stated
before, when liquid turns back to vapor, it absorbs heat, and feels cold.
This is similar to an aerosol can of deodorant, which contains a liquid as a
propellant, which boils when you press the nozzle, and feels quite cold when
it hits your skin.
> Also how is the refrigerant moved to the second chamber while
> on the fire? Is it simply moved as a gas and condenses in
> the second chamber? Wouldn't a tube to move the refrigerent
> (somthing like a coffee perculator)be more efficient?
The heat merely boils the liquid, creates more pressure in the chamber, and
it drives most of the liquid to the other, cooler side through a tube which
draws from the bottom of the reservoir.
>
> Anyone want to try to reverse engineer this and make one
> of your own?? Might be an intresting way to get cooling
> from excessive solar hot water or Generator exhust.
It could probably be done, but it would be difficult to make it efficient
and cost-effective without a lot of careful engineering. Another problem
might be finding a refrigerant which is efficient, legal and safe.
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| Gordon reeder 2005-12-28, 2:21 am |
| "WisJim" <jiminwis@gmail.com> wrote in news:1135731185.654900.34420
@g44g2000cwa.googlegroups.com:
>
> Functionally this sounds like the old "IcyBall" that Crosley made back
> in the 1930s (google IcyBall for more info), just updated with modern
> materials. I'll be looking for more info in the future, maybe can
> replace my old Icy Ball unit with something more efficient.
>
Well, well. I learned somthing new today. Thanks for the tip.
Looks like it works very much like the Icyball. Seems to be
improved by combining the hot and cold balls into a single
cylinrical unit and there is that valve that keeps the cool
process from starting untill it is inverted. I assume that
the Icyball is removed from the chest for recharging.
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| PanHandler 2005-12-28, 4:21 am |
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"JoeSP" <olegp@telus.net> wrote in message
news:8upsf.15394$m05.5087@clgrps12...
>
> "Gordon reeder" <gonzo@alltomyself.com> wrote in message
> news:Xns97399E21624EEgreederxprtnet@213.155.197.138...
>
> I'll try to make it as simple as I can. It's basic high school physics
> really.
>
> When a vapor is compressed into a liquid, a good deal of heat is given
> off. When the pressure is released and the liquid is allowed to evaporate
> into a vapor again, it "wants it's heat back," so it feels very cold as it
> absorbs this heat.
>
> Putting the steel end in the fire, merely boils the liquid out of that
> side of the chamber, through the one-way valve and it collects in the
> aluminium side under pressure. The aluminium side would remain quite warm
> until room temperature cooled it down, and in this process, the
> refrigerant in the chamber would condense to liquid.
>
> When this room-temperature apparatus is turned over, the pressure on the
> liquid is released, and it starts to boil, turning back to vapor. As
> stated before, when liquid turns back to vapor, it absorbs heat, and feels
> cold. This is similar to an aerosol can of deodorant, which contains a
> liquid as a propellant, which boils when you press the nozzle, and feels
> quite cold when it hits your skin.
>
>
> The heat merely boils the liquid, creates more pressure in the chamber,
> and it drives most of the liquid to the other, cooler side through a tube
> which draws from the bottom of the reservoir.
>
> It could probably be done, but it would be difficult to make it efficient
> and cost-effective without a lot of careful engineering. Another problem
> might be finding a refrigerant which is efficient, legal and safe.
The cost of heating has to be considered also.
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| Derek Broughton 2005-12-28, 9:21 am |
| Gordon reeder wrote:
> In the Dec/Jan issue of MIT Technology review there is a short
> piece about a refigeration device that needs no electricity.
> (I know, gas refigerators. but this device is much simpler).
What you describe sounds like what I understand my propane "absorption"
refrigerator to be doing - with a tedious manual intervention. Doesn't
sound simpler to me :-) Absorption refrigerators are pretty simple - all
they need is a heat source - what the source is doesn't matter.
>
> Anyone want to try to reverse engineer this and make one
> of your own?? Might be an intresting way to get cooling
> from excessive solar hot water or Generator exhust.
I could probably connect mine up to a solar hot water supply, too (though I
don't know if that's hot enough).
--
derek
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| Dale Farmer 2005-12-28, 12:21 pm |
|
Derek Broughton wrote:
> Gordon reeder wrote:
>
>
> What you describe sounds like what I understand my propane "absorption"
> refrigerator to be doing - with a tedious manual intervention. Doesn't
> sound simpler to me :-) Absorption refrigerators are pretty simple - all
> they need is a heat source - what the source is doesn't matter.
>
> I could probably connect mine up to a solar hot water supply, too (though I
> don't know if that's hot enough).
> --
> derek
Sounds like a handy device for a camping or post disaster type
living environment. For a fixed location, i.e., with generators and
so on, an ammonia cycle fridge would probably be more
appropriate. Of course, getting the generator exhaust heat to
the fridge hot point in a safe fashion may be more hassle than
it's worth. Perhaps if you keep a second fridge out next to
generator?
--Dale
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| meow2222@care2.com 2005-12-28, 5:21 pm |
| JoeSP wrote:
> It could probably be done, but it would be difficult to make it efficient
> and cost-effective without a lot of careful engineering. Another problem
> might be finding a refrigerant which is efficient, legal and safe.
Take 2 propane bottles and connect via high pressure pipe. Done.
NT
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| JoeSP 2005-12-29, 12:21 am |
|
<meow2222@care2.com> wrote in message
news:1135803080.872019.218730@z14g2000cwz.googlegroups.com...
> JoeSP wrote:
>
>
> Take 2 propane bottles and connect via high pressure pipe. Done.
>
> NT
>
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| JoeSP 2005-12-29, 12:21 am |
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<meow2222@care2.com> wrote in message
news:1135803080.872019.218730@z14g2000cwz.googlegroups.com...
> JoeSP wrote:
>
>
> Take 2 propane bottles and connect via high pressure pipe. Done.
>
> NT
>
Right, so...
Put one bottle in a fire, wait how long? then what?
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| andre_54005@yahoo.com 2005-12-29, 10:21 am |
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meow2222@care2.com wrote:
> JoeSP wrote:
>
>
> Take 2 propane bottles and connect via high pressure pipe. Done.
>
> NT
Would only work if one tank was very much larger then the other one.
At the start the small tank would be full of liquid propane, and the
large tank be at a vacuum. The large tank would have to be big enough
to hold all that propane as a gas at a low enough pressure that the
last bit of liquid propane will still boil at some usefully low temp.
_________
Andre' B.
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| meow2222@care2.com 2005-12-29, 3:21 pm |
| andre_54005@yahoo.com wrote:
> meow2222@care2.com wrote:
[color=darkred]
>
> Would only work if one tank was very much larger then the other one.
> At the start the small tank would be full of liquid propane, and the
> large tank be at a vacuum. The large tank would have to be big enough
> to hold all that propane as a gas at a low enough pressure that the
> last bit of liquid propane will still boil at some usefully low temp.
> _________
> Andre' B.
The bottles are the same size, and neither is anywhere near full, just
as a fridge's circuit would not be filled to the brim with liquid
refrigerant either.
The bottles should be mounted on a strip of metal/wood etc, and thin
metal pipe used to connect them.
NT
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| SQLit 2005-12-31, 10:21 pm |
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"WisJim" <jiminwis@gmail.com> wrote in message
news:1135974255.228126.79550@z14g2000cwz.googlegroups.com...
> Here are sites that shows home built 'IcyBall" type units. I know that
> there are some other websites showing homebuilt ones too.
> http://www.fridge.lionheart.net/
> http://www.ggw.org/~cac/IcyBall/Hom...Directions.html
> http://www.ggw.org/~cac/IcyBall/Hom.../HomeBuilt.html
> Maybe this will help folks understand them. This getting me interested
> in getting mine working again--I just have the cooling unit, no cabinet
> etc.
>
> Jim
Interesting ideas. I have been looking at the Robur gas fired stuff. They
have a basic 5 ton package unit. Unfittingly the heating is poor for my
application.
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"SQLit" <sqlit@qwest.net> wrote in message
news:yfGtf.18$7F2.1749@news.uswest.net...
>
> "WisJim" <jiminwis@gmail.com> wrote in message
> news:1135974255.228126.79550@z14g2000cwz.googlegroups.com...
>
> Interesting ideas. I have been looking at the Robur gas fired stuff.
> They
> have a basic 5 ton package unit. Unfittingly the heating is poor for my
> application.
A friendly warning on building anything that has ammonia in it.
Ammonia is a nasty substance, it burns, it explodes, it turns to a very
caustic substance when it hits moisture, so if the ammonia gas gets into you
eyes or lungs you have big problems, as it would be the same as having
caustic soda in them.
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| meow2222@care2.com 2006-01-02, 2:21 pm |
| RamRodSwordofBaal wrote:
> A friendly warning on building anything that has ammonia in it.
>
> Ammonia is a nasty substance, it burns, it explodes, it turns to a very
> caustic substance when it hits moisture, so if the ammonia gas gets into you
> eyes or lungs you have big problems, as it would be the same as having
> caustic soda in them.
I was slightly surprised to see them using ammonia, butane and propane
would seem more logical choices. But then again the pics showed them
operating these fridges with no insulation whatever...
NT
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<meow2222@care2.com> wrote in message
news:1136222347.907560.15280@f14g2000cwb.googlegroups.com...
> RamRodSwordofBaal wrote:
>
you[color=darkred]
>
> I was slightly surprised to see them using ammonia, butane and propane
> would seem more logical choices. But then again the pics showed them
> operating these fridges with no insulation whatever...
>
>
> NT
NH3 is used at most of the ice plants I work around. Propane and Butane are
used for super cold freezers, like minus 100 C. in my experience.
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| meow2222@care2.com 2006-01-02, 9:21 pm |
| SQLit wrote:
> <meow2222@care2.com> wrote in message
> news:1136222347.907560.15280@f14g2000cwb.googlegroups.com...
[color=darkred]
> you
[color=darkred]
[color=darkred]
> NH3 is used at most of the ice plants I work around. Propane and Butane are
> used for super cold freezers, like minus 100 C. in my experience.
I understood we were talking of homemade kit rather than maximally
efficient pro kit, so the considerations are different. The danger of
NH3 is what makes me suggest butane, and also the easy availability of
the gasses.
Butane can be used to replace CFCs in old fridges, so its quite
workable at ice temps, even if not perfect.
NT
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