070.655-IOM (FEB 22)
Page 4
SBTP Rotary Screw Compressor
Installation - Operation - Maintenance
Rotary screw compressor serial numbers are defined by
the following information:
Example: 10240A90000015Z
Plant
Decade Month
Year
Global
seq. no.
Additional
remarks
1024
0
A
9
0000015 Z
Month:
A = JAN, B = FEB, C = MAR, D = APR, E = MAY, F = JUN,
G = JUL, H = AUG, K = SEP, L = OCT, M = NOV, N = DEC
Additional remarks
R = Remanufactured
Z = Deviation from Standard Configuration
show which refrigerants are
compatible with the compressor as manufactured.
Figure 2: Refrigerant name plates
R290, R1270, NATURAL GAS
COMPRESSOR OPERATES ON AND IS
COMPATIBLE WITH THE FOLLOWING
REFRIGERANTS
Compressor
model
Rotor
diameter
mm
Rotor
L/D
Max
speed
rpm
Theoretical
displacement
ft³/rev (m³/rev)
Displacement at
3550 rpm
driver speed
ft³/rev (m³/rev)
Displacement at
2950 rpm
driver speed
ft³/rev (m³/h)
3511
355
1.1
3,600
0.82248 (0.02329)
2,929 (4,976)
2,434 (4,135)
3515
355
1.5
3,600
1.12124 (0.03175)
3,994 (6,786)
3,319 (5,639)
3519
355
1.9
3,600
1.42748 (0.04042)
5,058 (8,594)
4,203 (7,141)
3524
355
2.4
3,600
1.80329 (0.05106)
6,390 (10,857)
5,310 (9,022)
4013
408
1.3
3,600
1.41180 (0.03998)
5,012 (8,515)
4,165 (7,076)
4018
408
1.8
3,600
1.95481 (0.05535)
6,940 (11,790)
5,767 (9,798)
4021
408
2.13
3,600
2.31319 (0.06550)
8,212 (13,952)
6,824 (11,594)
Table 1: Compressor specifications
Description
Frick SBTP compressor
Frick SBTP rotary screw compressors use mating asym-
metrical profile helical rotors to provide a continuous flow
of vapor and are designed for both high-pressure and
low-pressure applications. The compressor incorporates
the following features:
• High-capacity sleeve bearings to carry radial loads at
both the inlet and outlet ends of the compressor.
• Heavy-duty, tilt-pad thrust bearings mounted at the
discharge end of the compressor to carry axial loads.
• Moveable slide valve to provide fully modulating
capacity control from 100% to approximately 15%,
condition dependent, of full load capacity.
•
Volumizer volume ratio control to allow infinitely vari
-
able volume ratio between minimum and maximum
values during compressor operation.
• A hydraulic cylinder to operate the slide stop and slide
valve.
• Housings are designed for 600 psig pressure.
• Shaft seal housing is designed to maintain operating
pressure on seal well below discharge pressure for
increased seal life.
• Oil injected into the rotors to maintain good volumetric
and adiabatic efficiency even at very high compression
ratios.
• The shaft rotation clockwise facing compressor from
the drive end, suitable for all types of drives. See the
following warning.
WARNING
Compressor rotation is clockwise when facing the
compressor drive shaft. Never operate the compres-
sor in reverse rotation because this can result in
bearing damage.
•
ANSI B16.1 Class 300 suction and discharge flanges for
all models.
• Specified #60 mesh x 0.0065 in. diameter stainless
steel wire or better strainer, to prevent damage to the
compressor from particles entering the suction area.
Compressor lubrication system
The lubrication system on an SBTP screw compressor per-
forms several functions:
• Provides lubrication to bearings and seal.
• Provides a cushion between the rotors to minimize
noise and vibrations.
• Helps keep the compressor cool and prevents over-
heating.
• Provides an oil supply to hydraulically actuate the slide
valve and slide stop.
• Provides an oil seal between the rotors to prevent ro-
tor contact or gas bypassing.
