On Tue, 16 Aug 2005 19:27:58 -0400, Bob Engelhardt
wrote:

Wayne Cook wrote:
... I've got a larger pulley on the 15HP motor which will speed up the
compressor some. But I'm not going to go twice the speed that I'm
running with the 7.5HP so that I'll have some head room (plus I don't
want to wear the compressor out to fast).

People occasionally comment that running a compressor more slowly is
better. That it lasts longer. But I would think that its life is
mostly a matter of the number of revolutions that it accumulates. And
it will run only as many as needed to produce the air required. If you
use 1000 cf per day, the compressor will only run the revolutions that
produce 1000 cf, fast or slow.

Running it at twice the rpm will probably create higher cylinder
temperatures while it's running, but the duty cycle will be 1/2 so the
overall effect will be lessened. There may still be some net negative
effect, but I wonder how much, really.

Well there's two effects that I can think of. One is the extra
heating of the air coming out of the compressor. The other is the
extra heat on the valves causing them to carbon up. There's also the
noise factor which can be considerable. Mine thumps pretty loudly as
it is. I can't imagine what it would sound like at 1000 rpm at which
one guy told me they run similar compressors on drilling rigs.




Wayne Cook
Shamrock, TX
http://members.dslextreme.com/users/waynecook/index.htm