Frick RWB II 480, Установка, эксплуатация и обслуживание

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RWB II ROTARY SCREW COMPRESSOR UNITS
OPERATION
S70-200 IOM
Page 16
OPERATION and START-UP INSTRUCTIONS
The Frick RWB II Rotary Screw Compressor Unit is an inte-
grated system consisting of six major subsystems:
1. Control Panel (See publication S90-010 O, M, & CS for
Quantum Panel and S70-200 OM for the Plus panel).
2. Compressor
3. Compressor Lubrication System
4. Compressor Oil Separation System
5. Compressor Hydraulic System
6. Compressor Oil Cooling System
7. Compressor Easy-Start System
The information in this section of the manual provides the
logical step-by-step instructions to properly start up and op-
erate the RWB II Rotary Screw Compressor Unit.
The following subsections must be read and understood
before attempting to start or operate the unit.
TDSH COMPRESSOR
The Frick RWB II rotary screw compressor utilizes mating
asymmetrical profile helical rotors to provide a continuous
flow of refrigerant vapor and is designed for both high pres-
sure and low pressure applications. The compressor incorpor-
ates the following features:
1. High capacity roller bearings to carry radial loads at both
the inlet and outlet ends of the compressor.
2. Heavy-duty, four-point angular contact ball bearings to carry
axial loads are mounted at the discharge end of compres-
sor.
3. Balance pistons located in the inlet end of the compressor
to reduce axial loads on the axial load bearings and increase
bearing life.
4. Moveable slide valve to provide infinite step capacity con-
trol from 100 to 10%.
5. VOLUMIZER® volume ratio control to allow infinitely vari-
able volume ratio from 2.2 to 5.0 during compressor opera-
tion for all models except 480 which is 2.2 to 4.2.
6. A hydraulic unloader cylinder to operate the slide stop and
slide valve.
7. Bearing and casing design for 350 PSI discharge pres-
sure. This PSI rating applies only to the compressor and
does not reflect the design pressure of the various sys-
tem components.
8. All bearing and control oil vented to closed thread in the
compressor instead of suction port to avoid performance
penalties from superheating suction gas.
9. Shaft seal design to maintain operating pressure on seal
well below discharge pressure, for increased seal life.
10. Oil injected into the rotors to maintain good volumetric
and adiabatic efficiency even at very high compression ra-
tios.
11. Shaft rotation clockwise facing compressor, suitable for
all types of drives. SEE CAUTION.
12. Dual compressor casing design for very low airborne
noise transmission.
COMPRESSOR ROTATION IS
CLOCKWISE WHEN FACING THE
COMPRESSOR DRIVE SHAFT. THE
COMPRESSOR SHOULD NEVER BE OPERATED IN RE-
VERSE ROTATION AS BEARING DAMAGE WILL RESULT.
Figure 16
COMPRESSOR LUBRICATION SYSTEM
The lubrication system on an RWB II screw compressor unit
performs several functions:
1. Provides lubrication to bearings and seal.
2. Provides a cushion between the rotors to minimize noise
and vibrations.
3. Helps keep the compressor cool and prevents overheating.
4. Provides an oil supply to hydraulically actuate the slide
valve and slide stop.
5. Provides oil pressure to the balance pistons to help in-
crease bearing life.
6. Provides an oil seal between the rotors to prevent rotor
contact or gas bypassing.
The compressor unit may be equipped with either a no pump
or a demand pump lubrication system. Additionally, either
system may contain dual oil filters and liquid injection, water-
cooled, or thermosyphon oil cooler for compressor oil cool-
ing.
NO PUMP OIL SYSTEM
The RWB II screw compressor unit is designed to be
self-lubricating. Oil being supplied to the compressor from
the oil separator is at system head pressure. Within the com-
pressor, oil porting to all parts of the compressor is vented
back to a point in the compressor’s body that is at a pressure
lower than compressor discharge pressure. The compressor’s
normal operation makes the compressor unit operate essen-
tially as its own oil pump. All oil entering the compressor is
moved by the compressor rotors out the compressor outlet
and back to the oil separator.
For normal high-stage operation an oil pump is not required.
COLD-START SYSTEM
The RWB II package is equipped with a special "cold start"
discharge check valve on the gas outlet connection of the oil
separator (see Figure 17). This valve causes the oil separa-
tor to develop oil pressure rapidly on initial start in order to
lubricate the compressor without requiring an oil pump, even
in cold ambient temperatures with all pressures equalized.
For high-stage packages, the cold-start valve is equipped