8.3.3. Volumes of compressed air receivers for compressors


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Fig. 8.5: Compressor and compressed air receiver
The ideal capacity of compressed air receiver for a compressor can be defined more precisely with the aid of a formula.

The formula is ideal when long idle periods are planned with intermittent operation. The volume of the pneumatic system can be considered as a part of the receiver volume.


    VR = Volume of compressed air receiver [m³]
    = FAD of compressor [m³/min]
    L    B = Required FAD [m³/min]
    Al = Allowed motor cycles /h     [1/h]
    (     see chapter 8.4.3 )
    p    max = Cut-out pressure of compressor [barop]
    p    min = Cut-in pressure of compressor [barop]
Despite taking all influencing factors into account, it is advisable to check the determined receiver size against the allowed motor cycles of the compressor.

Obviously, compressors with small receiver volumes VR switch on and off more often. This is a strain on the motor. In contrast, with a large receiver volume VR and a constant output the motor of a compressor switches on less often. This spares the motor.


Simple formulae for determining the size of the compressed air receiver


    VR = Volume of compressed air receiver [m³]
    Q = FAD of compressor [m³/min]
    15 or 5 = Constant factor
    Al = Allowed motor cycles /h     [1/h]
    (     see chapter 8.4.3 )
    Dp = Pressure differential ON/OFF