confusion based around self-acting engine

[Blitzkrieg]

I have been studying and reading about the various attempts at free energy and one things about tesla's idea of free energy extraction from ambient air confuses me a bit.
I think we've all been around air compressors or pressurized air in our life times, and do know that when air is pressurized it does in fact  become hotter and when it does expand it cools. But it's the "laws" for calculating these changes in pressure and temperature that confuse me according to amonton's pressure-temperature law if we were to compress ordinary room temp air to 250 psi it SHOULD have a temperature of around 5000k which is hot enough to most likely vaporize it's container or pressure vessel. Now I know that heat is radiated out of the container while it is pressurized and there is a substantial heat loss, but is it really that much heat that is lost during compression? Or am I just not calculating things properly?

[TinselKoala]

I think you are using the wrong formula.

The temperature after an adiabatic compression of air should be the T1 (initial temperature) in degrees K x (Compression ratio ^ 0.4.)
So your compression ratio is about 17 to 1, and if we have a starting temperature of 293 degrees K (room temperature) we wind up with a final temperature of about 910 K which is about 637 degrees C. That is, if I used the right formula!!

This neglects losses of course and assumes the compression happens fast.


http://en.wikipedia.org/wiki/Adiabatic_process

[Blitzkrieg]

Thank you so much this looks much more realistic.

[CANGAS]

Here is my cherry round here. Savor it! It aint gonna happen again.

Tesla published an invention for getting energy out of ambient air? I dont remember it.

I have discovered Tesla inventions for getting energy out of ambient ether, which he proposed was dynamic rather than static.

[tinman]

There is also Adiabatic cooling-which is the process of reducing heat through a change in air pressure caused by volume expansion. A simple demonstration of this can be seen when letting a tyre down. Many times you will see the valve nozzle freeze up when letting a car tyre down,even on hot day's.