19
Nov
Screw Compressors

Compressed Air Technology

Posted on by Field Air Compressors

Composition of the atmospheric Air

Compressed air is one of the most important forms of energy of an up to date industrial and private business, besides using electrical energy. The efficient usage of compressed air technology is vital in any production process

Oxygen 21%
Nitrogen 78%
Other Gases 1%

Physical Units

Basic Units

M = Meters
S = Seconds
Kg = Kilogram
Bar = Pressure
C = Celsius (Temperature)
W = Watt (Electrical)
V = Volume (m3)

Definition of Pressure

Pressure can be defined in multiple ways, however, in general the following is valid, pressure is equal to force over area

Some conversions to remember

100.000Pa = 1bar
1000kPa = 1bar
1 MPa = 10 bar
1 hPa = 0.001 bar = 1mbar

The difference between absolute and over pressure

Absolute Pressure
Pressure measured from an absolute zero-point, absolute pressure is needed for all theoretical considerations as well as air blast and vacuum technology.

Over pressure 
Derived from atmospheric pressure and is the most used value.

The difference between Volume Flow and Effective Volume Flow

Volume Flow 

  • Volume flow is the quantity of air delivered per unit of time.
  • The indication is usually made in the form of m3/min (cubic metres per minute) or cfm (cubic feet per minute)

Effective Volume flow

  • Is the air flow available at the air outlet, which corresponds to the pressure and temperature of the suction conditions.
  • This flow is a real measurable value that applies to the standard atmospheric conditions.