2920 1351 01
3
Instruction book
1 LEADING PARTICULARS
1.1 General description
The FD air dryers remove moisture from compressed air by
cooling the air to near freezing point. This causes water and
oil to condense. The condensate is automatically drained. The
air is warmed up before leaving the dryer.
On air-cooled dryers, the condenser has a cooling fan controlled
by a condenser pressure switch. Water-cooled dryers have an
automatic regulating valve in the water outlet of the condenser.
FD260 up to -700 are air-cooled, while FD260 W up to -700
W are water-cooled dryers. The suffix W is not mentioned
further in the book where the descriptions are valid for both
air- and water-cooled dryers.
1.2 Air circuit (Fig. 2)
Compressed air enters air/air heat exchanger (14) and is pre-
cooled by the outgoing, cold, dried air. Water and oil in the
incoming air start to condense. The air then flows through air/
refrigerant heat exchanger/evaporator (15) where the refrigerant
evaporates and withdraws heat from the air. This cools the air
to close to the evaporating temperature of the refrigerant. More
water and oil in the air condense. The cold air then flows
through separator (3) where all the condensate is separated from
the air. The condensate collects in condensate trap (4) and is
automatically drained. From separator (3) the cold dried air
flows through air/air heat exchanger (14), where it is warmed
up by the incoming air to approx. 10°C (18°F) below the
incoming air temperature. Reheating the dried air reduces its
relative humidity, so that condensation in the air net cannot
occur unless the air is cooled to below the pressure dewpoint
temperature indicated by gauge (1).
Fig. 1. Front view of FD450
F6837
To Next Page
Loading...
Need help?
General
