On a TV program I saw maybe a couple of years ago Adam Hart Davies was
presenting called 'Science Shack'. The episode was called 'When the
oil runs out'

On it he showed a weird 'plumbing' device that took hot water in one
port and due to its position caused water to be spun in a small
cylinder. Water was drawn off from the centre at a colder temperature
than the incoming water. So it was some kind of water cooler.

Does anybody know what this item was called and have any information
on how it works?

Peter wrote:


> On it he showed a weird 'plumbing' device that took hot water in one
> port and due to its position caused water to be spun in a small
> cylinder. Water was drawn off from the centre at a colder temperature
> than the incoming water. So it was some kind of water cooler.


Water or air ?  Usually this runs on compressed air and generates hot
air (and somewhat cold air).

Try searching on "Hilsch vortex tube". They're "simple" to make, but a
swine to get working well (worse than hydraulic rams). The hand-filed
"snail" in the middle is crucial.

did he not on the same program use river water to heat a bath and if so how
"Peter"  wrote in message 
news:190ph1ps1r852nk78mbl2vogumts106l1r@4ax.com...

> On a TV program I saw maybe a couple of years ago Adam Hart Davies was
> presenting called 'Science Shack'. The episode was called 'When the
> oil runs out'
>
> On it he showed a weird 'plumbing' device that took hot water in one
> port and due to its position caused water to be spun in a small
> cylinder. Water was drawn off from the centre at a colder temperature
> than the incoming water. So it was some kind of water cooler.
>
> Does anybody know what this item was called and have any information
> on how it works? 

"hammy1967"  writes:

>did he not on the same program use river water to heat a bath and if so how
>"Peter"  wrote in message 
>news:190ph1ps1r852nk78mbl2vogumts106l1r@4ax.com...
>> On a TV program I saw maybe a couple of years ago Adam Hart Davies was
>> presenting called 'Science Shack'. The episode was called 'When the
>> oil runs out'
>>
>> On it he showed a weird 'plumbing' device that took hot water in one
>> port and due to its position caused water to be spun in a small
>> cylinder. Water was drawn off from the centre at a colder temperature
>> than the incoming water. So it was some kind of water cooler.
>>
>> Does anybody know what this item was called and have any information
>> on how it works? 


An aqueous version of a Hilsch Vortex Tube???

-- 
       "The road to Paradise is through Intercourse."
        [email me at huge [at] huge [dot] org [dot] uk]

>did he not on the same program use river water to heat a bath and if so how


I can't remember if he used this novel device to heat the bath or
chill the champagne. I suspect it was the latter as he would have had
wood to burn and heat the bath 'when the oil ran out'.

More generally I am trying to learn more about the physics of thermal
stratification in water tanks. I try and imagine a column of water in
a well insulated water and suitably baffled tank, I assume it is
initially at a constant temperature throughout. Will it stratify over
time such that the water at the top becomes hotter? Again assuming no
overall energy loss.





---------------------------------
p.3,  Thermal Stratification
http://www.vok.lth.se/~eep/files/pdf/jowin.pdf

In the 1800's scientists argued whether gases in a column would
stratify due to gravity and become hotter at the bottom than the top.
Maxwell and Boltzmann said it would not, but Loschmidt a prominent
scientist of his time [25] argued that the world would have a
never-ending supply of energy this way.  
http://www.ecology.com/archived-links/energy-science-made-simple/

On Wed, 07 Sep 2005 14:44:31 +0100, Peter  
 wrote:


> More generally I am trying to learn more about the physics of thermal
> stratification in water tanks. I try and imagine a column of water in
> a well insulated water and suitably baffled tank, I assume it is
> initially at a constant temperature throughout. Will it stratify over
> time such that the water at the top becomes hotter? Again assuming no
> overall energy loss.


There is a critical size for the tank and heat diffusion through the walls  
plays its part. Up to a point, the Atlantic fits the theory, but the model  
seems to fall apart at about 1000m. Convection can do some puzzling  
things. In the real world you will need excellent insulation (probably  
dewar) and good control of evaporative loss, which will cool the surface  
layer. The short answer is that you need two tanks connected by a pipe,  
one over the other. Even then, I suspect the job will become rather a  
WOMBAT.

John Schmitt

-- 
Using Opera's revolutionary e-mail client: http://www.opera.com/mail/

The Hilsch Vortex Tube was discussed in the Yahoo Refrigerator
Alternatives group.

I can't remember the outcome but I don't think it is a practical
alternative to a refrigerator.

If you were interested you could join and check out the archives.

On Wed, 07 Sep 2005 16:22:21 +0100, Alan  wrote:


> The Hilsch Vortex Tube was discussed in the Yahoo Refrigerator
> Alternatives group.

> I can't remember the outcome but I don't think it is a practical
> alternative to a refrigerator.


The consensus appears to be that this is the case. The thermodynamic  
efficiency is rather lower than standard refrigerators and indeed lower  
than gas-powered or Peltier-effect refrigerators. It is an interesting  
toy, but that seems to be as far as it goes.

John Schmitt

-- 
Using Opera's revolutionary e-mail client: http://www.opera.com/mail/