Re: Can air be compressed without a thermal reaction?

Phil,

The reason why water condenses on the inside of the air compressor is not 
during compression of the air but rather when it is de-compressed during 
use.  If you removed the water prior to compression it will not condense 
in the tank.  You can also dry the compressed air prior to decompression, 
which is more economical as you can dry more air when it is compressed.  
The simple way to do this is to put a dessicant filter, such as silica 
gel or mol. seive, upstream of the regulator which controls discharge air 
pressure.  Try to keep this filter changed at regular intervals.  Some of 
the silica gel filters come with an indicator which changes color when 
water is present.

Trying to keep air cool during compression is not really practical.  You 
would have to have a heat exchanger present on the discharge side of the 
air compressor and prior to the storage tank.

Temperature increase during compression is one of those physical 
properties which cannot be overcome.  The ideal gas law states PV=nRT, 
where: P=pressure, V=volume, n=number of molecules, R is a constant, and T 
is temperature.  Since the volume of gas and the amount of gas both 
increase proportionally during air compression, they will cancel each 
other out proportionally.  R is a constant so it will not change.  So you 
are left with the equation P=T.  So if you increase pressure, temperature 
has to increase.  Hope this helps.

Carlin Gregory
Texas Gas Transmission