ROTORCOMP NK 31 - Starting; Switching off

3.6
[en] 02/2014
Installation and operating manual - NK 31ROTORCOMP 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 ows via the intake lter 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 ows via the ne sepa-
rator 6 and the minimum pressure valve 7 to the
compressed air outlet.
In the ne separator 6 the oil is ltered 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 backow 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 ows 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 ows 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 ow is routed directly via the oil cooler
10 or directly to the oil lter 9 by the thermostat
valve.
The oil then ows via the oil lter 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.