Starting air system
For a starting air system, compressed air is supplied from air receivers that store a supply of compressed air. Compressed air receivers are classified by purpose. The main air receivers can supply the starting air for the main, auxiliary engines, the reduction valve station, and other needs of the ship. Auxiliary air receivers usually supply starting air via a separate line only to auxiliary diesels (usually diesel-generators).
Example of a starting air system
Compressed air is usually supplied to the
main air receivers by two air compressors. Which can be filled with compressed
air and auxiliary air receiver if required. The auxiliary air receiver can also
be supplemented with compressed air by transferring it to the main air receiver
or using an emergency air compressor. Which can replenish compressed air
through the connecting valve and main air receivers, but will do so relatively
slowly.
Each compressed air receiver is equipped
with the following fittings:
NOTE: The
auxiliary air receiver has an emergency compressor stop pressure switch. The
start and stop pressure switches of the main air compressors are installed in
the line connecting the main air receivers.
Air compressor outlets have oil / water
separators. The separators have a solenoid drain valve that is activated to
reduce the load on the compressor at start or stop. This valve opens just
before the compressor stops and closes shortly after the compressor starts and
accelerates. This allows the compressor to start or stop, reducing the load on
the motor and compressor drive.
Compressors running and on duty should be periodically changed to
allow each compressor to run the desired number of hours. These hours do not
have to be the same. They should be adjusted so that inspection and maintenance
work can be carried out in stages.