Atlas Copco GA 75+ Instruction Book page 126

condensate. This airflow breaks stable emulsions by enhancing the sorption process of oil onto the OGC. The
air supply also prevents the formation of certain anaerobic bacteria. Also the cover of the second vessel is
equipped with ventilation holes to prevent pressure buildup. The airflow is taken from the aftercooler (on air
cooled units) or from the water separator (WSD) (on water cooled units). An integrated nozzle with strainer
limits the airflow (approximately 450 l/h at reference conditions), while a solenoid valve makes sure no
compressed air is used when the compressor is not delivering air.
A level switch (7 - View of OSCi), connected to the Elektronikon® Graphic controller of the compressor
monitors the condensate level in the second vessel. During normal operation this switch is in the closed
position, so that any abnormality (a too high condensate level) opens the electric circuit and triggers the alarm,
which is made visible on the Elektronikon® display (see section Warnings).
The condensate further flows to the third vessel, through a pipe connecting both lower halves of the vessels.
An activated carbon filter (7) cleans the condensate further, and the clean condensate flows out of connection
(9). A test outlet (8) is positioned below the normal outlet. Both outlets are connected to the compressor drain
plate by their corresponding tubes.
At the bottom of the vessels, drain tubes with valves (4) are provided for easy servicing.
In this setup, the cleaning process can be understood by splitting it up per vessel:
• First vessel: pre-separation and sorption of most of the free, directly separable oil
• Second vessel: emulsion separation and oil sorption
• Third vessel: sorption of the remaining oil
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Instruction book
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