Compressed air theory
COMPRESSED AIR THEORY
With the cooperation and under supervision of our past president  Ir. H. Ghys
 Free air delivery: FAD m3/min
l /s
Capacity of compressor, expressed in free air volume at atmospheric conditions.
 Air delivery m3/min
l /s
Volume of air delivery at the outletcoks of the compressor, in compressed air conditions.
l/s = 1000/60 m3/min
 Normal flow m3/min Volume of air delivery at following ambient conditions: 0°C and 1.013 bar(a)(sea level)
General gas law
P x v / T = R = constant  or  P x V/T = m x R'
 Pressure Bar(a)(absolute)
 V: volume (m3)
 v: specific volume (m3/kg)
T : absolute temperature  °K
m : mole mass (Kmol)
 R : individual gas constant = 287,1 J/(Kg K)
 R' : universal gas constant = 8314 (J/(Kmol K)
 R = R'/m
Po x Vo/To = Pi x Vi/Ti
 Po, Pi : Pressure in bar(a)
 (absolute)
   To, Ti : absolute temperature in K (K = 273 + t°C)
 R = gasconstant = 287.1  J/(Kg K)
Calculation
input conditions:
Vo =   l/s Po = bar(a) to =    °C
outlet conditions:
Pi = bar(a) ti =    °C
 
air delivery Vi at outlet conditions  Vi =  l/s