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Ed Pawlowski Ed Pawlowski is offline
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Default boiling water with lid off?

On Sun, 04 Mar 2012 00:40:22 +1100, Krypsis >
wrote:

>On 3/03/2012 11:42 PM, Ed Pawlowski wrote:
>> On Sat, 03 Mar 2012 19:27:48 +1100, >
>> wrote:
>>
>>
>>
>>>
>>> Let's try this again...
>>>
>>> What is condensate if not steam that has been condensed? If you have
>>> condensate on the walls of your bathroom after having a shower, how did
>>> the condensate get there? Was it a "miracle"?

>>
>>
>> It sure was not from steam. To make steam, water has to be heated to
>> a minimum of 212F at sea level. Steam is invisible, a vapor. When we
>> "see" steam, it is really vapor mixed with the condensate.

>
>So pray tell how evaporative cooling works? They sure as hell don't boil
>the water in those systems yet they cool through latent heat of
>evaporation. Something's evaporating in them and it's my guess it is the
>water.


You can have evaporate cooling with no steam and no boiling.

>>>
>>> Now, let's look at fog. Fog is technically water vapour which has
>>> condensed. Been down to the river lately. Go down there on a cool
>>> morning sometime just as the sun is rising. You will see "fog" rising
>>>from the water. This fog is just condensate. It was given off from the
>>> surface of the water as steam or water vapour if you prefer.

>>
>> Half right. No steam in the river. Have you ever seen a river boil?
>>

>Latent heat of evaporation again.


But that does not mean it was steam. Water evaporates just sitting in
a bucket, or pour on the sidewalk, etc. No steam involved.



>
>Have you ever poured a little methylated spirits onto the skin of your
>hand? Noticed that your hand suddenly begins to feel cold? Do you know
>why that is?


Yes, and it sure as hell is not steam.


>
>The boiling point of methylated spirits (denatured alcohol) is very
>close to that ethanol which is 78 °C (172 °F). It has a lower boiling
>point than water but not by all that much in the general scheme of
>things. The methylated spirits you put on your hind will soon disappear.
>If you prevent runoff, it will still disappear. Where does it go? Easy,
>it evaporates. It changes state and will turn into a gas. Has it reached
>boiling point in order to do this? No!


Exactly, but it is not steam.



>Have a look at this Wikipedia entry;
>
>http://en.wikipedia.org/wiki/Latent_heat
>
>If you're feeling brave, look at this one;
>
>http://en.wikipedia.org/wiki/Enthalpy_of_vaporization


If you are brave, look up steam. There is a difference between
vaporization and steam. You seem to think they are the same, but they
are not.