Leading Particulars; General Description - Atlas Copco XRXS 567 Cd Instruction Manual

Leading particulars

GENERAL DESCRIPTION

The XRYS 557 Cd - XRYS 1220 CD7 is a silenced,
two-stage, oil-injected screw compressor, built for a
nominal effective working pressure of 35 bar (510
psi).
The XRXS 567 Cd - XRXS 1240 CD7 and XRXS 607
Cd - XRXS 1275 CD7 are silenced, two-stage, oil-
injected screw compressors, built for a nominal
effective working pressure of 30 bar (435 psi).
The XRVS 617 Cd - XRVS 1300 CD7 and XRVS 647
Cd - XRVS 1350 CD7 are silenced, two-stage, oil-
injected screw compressors, built for a nominal
effective working pressure of 25 bar (365 psi).
Engine
The compressors are driven by a 6 cilinder in-line
liquid-cooled diesel engine.
The engine's power is transmitted to the compressor
element through a heavy-duty coupling.
Compressor
The compressor casing houses two screw-type rotors,
mounted on ball and roller bearings. The male rotor,
driven by the engine, drives the female rotor. The
compressor delivers pulsation-free air.
Injected oil is used for sealing, cooling and
lubricating purposes.
The XRXS and XRVS type compressors can be
equipped with two different gears, resulting in
different FAD (Free Air Delivery).
- 14 -
Compressor oil system
The oil is boosted by air pressure. The system has no
oil pump.
The oil is removed from the air, in the air/oil vessel at
first by centrifugal force, secondly through the oil
separator element.
The vessel is provided with an oil level indicator.
Regulation
The compressor is provided with a single or dual
pressure pneumatic regulating system and a blow-off
valve which is integrated in the unloader assembly.
The valve is closed during operation by air receiver
pressure and opens by air receiver pressure via the
compressor element when the compressor is stopped.
When the air consumption increases, the air receiver
pressure will decrease and vice versa.
This receiver pressure variation is sensed by the
regulating valve which, by means of control air to the
unloader and an electronic engine speed regulator,
matches the air output to the air consumption. The air
receiver pressure is maintained between the pre-
selected working pressure and the corresponding
unloading pressure.