2920 1443 01 5
Instruct on book
1.2 Air drying circuit (Fig. 1.4)
Wet a r from the compressor aftercooler (2) enters the dryer
nlet, passes through nlet valve (5) and the nozzle of ejector
(11) nto a r nlet water separator (26). The a r leav ng the
aftercooler s normally saturated and has a temperature of approx.
10°C above that of the nlet cool ng water on water-cooled
compressors or above that of the amb ent temperature on a r-
cooled compressors.
In the dem ster (27), the water droplets are removed from the
a r. The a r s then led through rotor (12), wh ch adsorbs the
water vapour. The dr ed a r then flows nto a r outlet
compartment (30) and leaves the dryer through outlet valve (33).
1.2.1 Regeneration air circuit
Hot regenerat on a r s branched off from p pe (1) upstream of
the compressor aftercooler. Th s a r s unsaturated and has a
temperature of 130-190°C, depend ng on the operat ng pressure,
the cool ng water nlet temperature or amb ent temperature and
the a r nlet temperature.
The regenerat on a r passes through shut-off valve (7), throttle
valve (8) and stra ner (9) to nlet seal ng sector (10), and s
blown through the wet rotor channels. S nce the hot a r has a
lower vapour pressure than the wet rotor channels, t w ll dry,
.e. regenerate, the rotor.
The wet regenerat on a r leav ng the rotor s collected n outlet
seal ng sector (14).
The hot saturated a r s then cooled down n regenerat on a r
cooler (17) and passed to water separator (18), where the free
water s evacuated by the dra n system.
The regenerat on a r s then led to the suct on chamber (28) of
ejector (11), where t s m xed w th the wet compressed a r from
the compressor aftercooler. In the ejector the veloc ty of the
wet compressed a r s ncreased, result ng n a pressure drop n
the suct on chamber of the ejector and the ent re regenerat on
a r c rcu t up to throttle valve (8). The pressure drop prevents
regenerat on a r from enter ng the dry a r outlet compartment.
1.2.2 Rotor cooling air circuit
After regenerat on, the hot channels of the rotor are cooled by
a r from the dry a r compartment (30). The cool ng a r flow s
trapped by the regenerat on a r outlet seal ng sector (14) and
m xed w th the wet regenerat on a r.
1.3 Drain system
1.3.1 Description (Fig. 1.5)
The condensate enters the Electron c Water Dra n (EWD) v a
nlet (1) and accumulates n collector (2). A capac t ve sensor
(3) cont nuously measures the l qu d level. As soon as the
collector s f lled up to a certa n level, p lot valve (4) s act vated
and d aphragm (5) opens outlet (6), d scharg ng the condensate.
When the collector has been empt ed, the outlet closes qu ckly
w thout wast ng compressed a r.
When the controller reg sters a malfunct on, the red alarm LED
(F g. 1.7) starts flash ng and the electron c dra n valve w ll
automat cally change to the alarm mode, open ng and clos ng
the valve accord ng to a sequence as shown n (F g. 1.6). Th s
cond t on cont nues unt l the fault s remed ed. If the fault s not
remed ed automat cally, ma ntenance s requ red.
1.3.2 Testing the EWD
Functional test
Br efly press the TEST button (F g. 1.7) and check that the valve
opens for condensate d scharge.
Checking the alarm signal
- Press the test button for at least 1 m nute
- Check that the alarm LED flashes
- If an alarm dev ce s connected to the NO or NC contact
(see sect on 1.3.3), check ts operat on.
- Release the test button.
1.3.3 Electrical connections of the EWD (Fig. 1.8)
The nd cat ons on the data label must correspond to the ma ns
supply voltage and frequency. Connect the electr cal supply to
the EWD as shown n F g. 1.8. Never operate the EWD w thout
an earth conductor connected. An alarm dev ce can be connected
to the normally open or normally closed contact; see F g 1.8.
