6.5 Compressor unit / quality of compressed air

The actual compressor unit begins at that point where the atmospheric air is drawn in, and it usually finishes where the prepared compressed air is fed into the distributor network.

Apart from the compressor the following components are necessary or possible:
- Suction pipe / vacuum filter / air intake silencer,
- Electrical supply unit including switching devices,
- Coolant supply and removal unit,
- Recooling plant,
- Aftercooler / condensate trap,
- Compressed-air dryer / fine filter
- Pressure tank,
- Installations for sound damping.

Compressors can be erected on a concrete foundation or without foundation.
The components of the unit can be installed “freely” in the space, or they form – as a compact unit – a closed plant for the generation of compressed air.

At any time, a low ambient temperature is to provide for the compressor (ventilation and exhaustion):
At a suction temperature of about 3°C each the useful supplied volume decreases by 1%.

Wet deposition (condensate trap) constitutes an important factor to obtain an appropriate quality of the compressed air.

An aftercooler should be therefore spaciously dimensioned.

If the consuming units require higher qualities of compressed air, then additional compressed-air dryers will have to be installed.

Refrigeration dryers and adsorption dryers are the most common versions.

If the generated compressed air contains oil then a considerable oil separation will result from moisture extraction. Additional special oil-water-separators might become necessary for allowing the oil to separate from the condensate.

Quality of compressed air

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