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# Help needed regardomg compressed air.

## Help needed regardomg compressed air.

(OP)
I am a mechanical engineer who invented a new pumpgeometry, I need to get some basics aboute how volume and temp varies with pressure. Here I think is a good place to also admit that english isn't my native language and I appologise for spelling errors and for not knowing the correct terms in english. Anyway, can someone be so kind to explain to me what is true.
Normal atmospheric pressure is 1013 Hpa or millibars or 1.013 bar above total vaccum. If I raise the pressure by reducing the volume, say from 100 to 50 liters. What pressure do I get? Will it be 2,026 bar over vaccum and is that what we consider 1 bar when we talk aboute pneumatics? If I then reduce the volume to 25 liters would I then get 4,052 bars above vaccum and would that be 3 bar on the manometer?
What would the temps be if we only consider the adiabatic gain of temerature?
I did testrun the first prototype today and it was very successful, the pump has a displacement of 0,1767 liters per revolution and at 3000 rpm I raised the pressure in a 50L tank to 2 bar in 11,8 seconds. I also have some other values and would appreciate help so I can evaluate the tests.
I'll be very grateful for any help.
Leffe

### RE: Help needed regardomg compressed air.

For ideal gases, pressure, volume and temperature are related by the equation

P1*V1/T1 = P2*V2/T2.

If you are talking a few bar pressure with air (say up to 10 at typical ambient temperatures, you don't need to worry about non-ideality.

So, if you take 100 litres of air at atmospheric pressure (1.013 bar above a perfect vacuum) and 1/2 its volume at the same temperature, the pressure will be doubled to 2 atmospheres absolute or 1 atmosphere gauge.

With any sort of compressor, there's also a temperature rise that needs to be taken into effect.

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