RWF ROTARY SCREW COMPRESSOR UNITS
OPERATION
S70-600 IOM (OCT04)
Page 15
COMPRESSOR HYDRAULIC SYSTEM
The compressor hydraulic system moves the movable slide
valve (MSV) to load and unload the compressor. It also moves
the movable slide stop (MSS) to increase or decrease the
compressor’s volume ratio (Vi).
The hydraulic cylinder located at the inlet end of the SGC
compressor serves a dual purpose. It is separated by a
fixed bulkhead into two sections. The movable slide valve
(MSV) sec tion is to the left of the bulkhead and the movable
slide stop (MSS) to the right. Both sections are considered
double-acting hydraulic cylinders as oil pressure moves the
pistons in either direction.
Both sections are controlled by double-acting, four-way
solenoid valves which are actuated when a signal from the
appropriate micropro cessor output energizes the solenoid
valve.
SINGLE-ACTING MODE - High Stage
Close valve at SC2
Open valve at BP (bypass)
High stage compressor loading:
The compressor loads
when MSV solenoid YY2 is energized and oil flows from the
unload side of the cylinder out port SC1, through valve ports
A and T to compressor suction. Simultaneously, discharge
pressure loads the slide valve.
High stage compressor unloading:
The compressor
unloads when MSV solenoid YY1 is energized and oil flows
from the oil manifold through valve ports P and A to cylinder
port SC1 and enters the unload side of the cylinder. Simulta-
neously, gas on the load side of the cylinder is vented through
port SC2 and valve BP to compressor suction.
NOTE: To control the rate of loading and unloading,
throttle the needle valve at SC1 port.
DOUBLE-ACTING MODE - Booster
Open valve at SC2
Close valve at BP (bypass)
Booster Compressor Loading:
The compressor loads
when MSV solenoid YY2 is energized and oil flows from the
oil manifold through valve ports P and B to cylinder port SC2
and enters the load side of the cylinder. Simultaneously, oil
con tained in the unload side of the cylinder flows out cyl-
inder port SC1 through valve ports A and T to com pressor
suction.
Booster Compressor Unloading:
The compressor un loads
when MSV solenoid YY1 is energized and oil flows from the
oil manifold through valve ports P and A to cylinder port SC1
and enters the unload side of the cylinder. Simultaneous ly,
oil contained in the load side of the cylinder flows out of
compressor port SC2 through valve ports B and T to com-
pressor suction.
NOTE: To control the rate of loading and unloading,
throttle valves SC1 and SC2.
NOTE: To slow all valve movements - loading, unloading,
and Vi change - throttle valve 2.
NEVER open valve BP and valve
SC2 at the same time during com-
pressor operation.
Figure 15
VOLUMIZER VOLUME RATIO CONTROL
Open valve at SC3
Open valve at SC4
Compressor Vi increase:
The volume ratio Vi is increased
when MSS solenoid valve YY3 is energized and oil flows from
the oil manifold through valve ports P and A to compressor
port SC3, enters the increase side of the cylinder and over-
comes the decrease spring tension. Simultaneously, oil flows
from SC4 port through valve ports B and T to compressor
suction.
Compressor Vi decrease:
The volume ration Vi is de-
creased when MSS solenoid valve YY4 is energized and
oil flows from the oil manifold through valve ports P and B
to compressor port SC4, enters the decrease side of the
cylinder. Simultaneously, oil flows form SC3 port through
valve ports A and T to compressor suction.
TO CONTROL THE RATE OF VI CHANGE, THROTTLE THE
NEEDLE VALVE AT SC3 PORT.
SC1
SC3
SEE HYDRAULIC
SCHEMATIC
FOR FUNCTIONAL
VIEW OF VALVE
OPERATION
Figure 16
Содержание Frick RWF 100
Страница 40: ...RWF ROTARY SCREW COMPRESSOR UNITS MAINTENANCE S70 600 IOM OCT04 Page 40 P I DIAGRAM ...
Страница 43: ...RWF ROTARY SCREW COMPRESSOR UNITS MAINTENANCE S70 600 IOM OCT04 Page 43 P I DIAGRAM LIQUID INJECTION BOOSTER ...
Страница 52: ...RWF ROTARY SCREW COMPRESSOR UNITS MAINTENANCE S70 600 IOM OCT04 Page 52 OPERATING LOG SHEET ...
Страница 57: ...RWF ROTARY SCREW COMPRESSOR UNITS MAINTENANCE S70 600 IOM OCT04 Page 57 ...