Frick RWB II 496 User Manual

RWB II ROTARY SCREW COMPRESSOR UNITS
OPERATION
S70-210 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 publications 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
The information in this section of the manual provides the
logical step-by-step instructions to properly start up and
operate 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
compressor.
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
control from 100 to approximately10%.
5. VOLUMIZER
®
volume ratio control to allow infinitely vari-
able volume ratio from 2.4 to 4.5 during compressor operation
for all models.
6. A hydraulic unloader cylinder to operate the slide stop
and slide valve.
7. Bearing and casing design for 350 PSI discharge pressure.
This PSI rating applies only to the compressor and does
not reflect the design pressure of the various system
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 ratios.
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.
COMP RES SOR ROTAT IO N IS
CLOCKWISE WHEN FACING THE
COMPRESSOR DRIVE SHAFT. THE COMPRESSOR
SHOULD NEVER BE OPERATED IN REVERSE ROTA-
TION AS BEARING DAMAGE WILL RESULT WHICH CAN
CAUSE CATASTROPHIC FAILURE OF THE COMPRES-
SOR.
Figure 18 - Compressor Rotation Direction
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 prelube,
full-lube or cycling full-lube lubrication system. Additionally,
either system may contain dual oil filters and liquid injection,
water-cooled, or thermosyphon oil cooler for compressor
oil cooling.
PRELUBE OIL SYSTEM
The RWB II screw compressor unit is designed to be self-lu-
bricating. Oil being supplied to the compressor from the oil
separator is at system head pressure. Within the compressor,
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 essentially 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 operation an oil pump is not required except to
lubricate the compressor during start-up. During the period
from start-up to normal operation, the oil pressure alarm and
oil pressure cutout setpoints will vary according to formulas
built into the microprocessor control program. On start-up
the PRELUBE pump has 30 seconds to produce over five
pounds of oil pressure over registered discharge pressure or
a cutout will occur. When the compressor starts, oil pressure
will be ignored for two minutes. After 25 PSID pressure dif-
ferential has been reached between suction and discharge,
the PRELUBE pump will shut down and the lubrication oil will

Frick RWB II 496 Specifications

General

Brand	Frick
Model	RWB II 496
Category	Compressor
Language	English