Operation - Atlas Copco GA 37+ Instruction Book

4.2 Operation

General
1 Condensate inlet
2 Foam cover
3 Oleophilic filter
4 Service drains with valve
5 Air injection connection
6 OGC filter
7 Activated carbon filter
8 Condensate test outlet
9 Condensate outlet
The OSCi 3790 housing consists of 3 interconnected vessels. The oil-containing condensate is injected (1)
in discontinuous bursts at a downward angle into the first vessel which acts as expansion chamber. The
specially designed cover has a combination of pressure-relieving holes and a foam (2). Since the pressure is
relieved here, the entire OSCi device is pressure less. In the first vessel, a floating filter (3) made of special
synthetic fibres takes up most of the directly separable hydrocarbons from the condensate. The filter sinks
as it saturates with hydrocarbons and hence the lifetime progress of the filter can be measured by an
indicator that rests on the bag. A conventional sight glass is installed for visual inspection of the filter
position and the condensate level. On top of that, an electronic position sensor (8 - View of OSCi, 1 - View
of OSCi inlet) is connected to the Elektronikon® regulator of the compressor to keep track of the filter
lifetime without the need to open the compressor canopy.
The outlet of the first vessel is situated at the bottom and is connected to the upper half of the second
vessel.In the second vessel, the pre-filtered condensate is brought in contact with a filter bag (6), filled with
Oleophilic Granular Clay (OGC). Through a connection (5) at the bottom of the second vessel, air is
injected into the condensate. This airflow breaks stable emulsions by enhancing the absorption process of
oil onto the OGC. The air supply also prevents the formation of certain an aerobic bacteria. Also the cover
of the second vessel is equipped with ventilation holes to prevent pressure build up. The airflow is taken
from the aftercooler (on aircooled 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 nocompressed air is used when the compressor is not delivering air.
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Condensate flow scheme
Instruction book
9096 3321 00