3.6
[en] 02/2014
Installation and operating manual - NK 31
ROTORCOMP VERDICHTER
3.6.2 Starting
During start-up, the intake valve
2
already opens
at minimum vacuum in the intake chamber of the
screw compressor
4
due to the rotor rotation. The
drawn in air flows via the intake filter
1
through
the intake valve
2
directly into the compression
chamber of the screw compressor
4
. There the
intake air is compressed and oil is injected for
lubrication and cooling.
The oil-air mixture then enters the separator
tank
5
in which the majority of the oil is separated
from the air. The air then flows via the fine sepa
-
rator
6
and the minimum pressure valve
7
to the
compressed air outlet.
In the fine separator
6
the oil is filtered out down
to a residual content of < 3 mg/m
3
and then
routed back into the compressor housing via a
nozzle and a non-return valve
12
.
When the compressor is switched off, the mini
-
mum pressure valve
7
with a non-return function
prevents backflow of the compressed air out of
the system into the compression chamber in the
discharge phase.
During startup a faster pressure buildup is also
ensured, which is required for optimum lubrica
-
tion and oil separation.
When the operating air pressure is reached, the
proportional regulator
3.1
opens and the pilot
air flows under the piston of the intake valve
2
,
which begins to close. The adjustable proportion
-
al regulator
3.1
steplessly controls the pressure
under the piston of the intake valve
2
in depen-
dence on the compressed-air removal. This pres-
sure acts against the spring force and therefore
determines the valve stroke and the drawn-in
quantity of air.
The compress pilot air flows via the no-load
nozzle
2.1
of the intake valve
2
back into the
compression chamber
4
.
The heat resulting during compression is dis-
sipated via the oil-air mixture. The oil circulation
also results from the pressure difference between
the outlet and inlet pressure. The optimum oper-
ating temperature for the oil is adjusted by the oil
thermostat
8
. Depending on the oil temperature,
the oil flow is routed directly via the oil cooler
10
or directly to the oil filter
9
by the thermostat
valve.
The oil then flows via the oil filter
9
to the various
injection points in the compressor block.
3.6.3 Switching off
When switching off the system, the intake valve
2
operates, supported by spring pressure, as an in-
dependent non-return valve and closes the intake
opening oil-tight.