Frick RWB II 480, Установка, эксплуатация и обслуживание

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RWB II ROTARY SCREW COMPRESSOR UNITS
OPERATION
S70-200 IOM
Page 18
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 TDS
compressor serves a dual purpose. It is separated by a fixed
bulkhead into two sections. The movable slide valve (MSV)
section 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 so-
lenoid valves which are actuated when a signal from the
appropriate microprocessor output energizes the solenoid
valve.
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 SC-2 and enters
the load side of the cylinder. Simultaneously, oil contained in
the unload side of the cylinder flows out cylinder port SC-1
through valve ports A and T to compressor closed thread
port.
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 SC-1
and enters the unload side of the cylinder. Simultaneously,
oil contained in the load side of the cylinder flows out com-
pressor port SC-2 through valve ports B and T to compressor
closed thread port.
Figure 19
NOTE: High Stage Operation: An alternative piping ar-
rangement has been provided to increase slide valve
response time during high stage operation.
Higher operating pressures will slow the compressor unload-
ing response time. Unloading response time can be increased
by closing valve 1 (oil manifold pressure) and opening valve
2 to compressor suction pressure. See Figures 19 and 20.
NEVER OPEN VALVE 1
AND VALVE 2 AT THE SAME TIME
DURING COMPRESSOR OPERATION.
VOLUMIZER® VOLUME RATIO CONTROL
Vi Increase
Models 60 through 480: The volume ratio Vi is increased
when MSS solenoid YY3 is energized and oil flows from the
oil manifold through valve ports P and A to cylinder port SC-3
and enters the increase side of the cylinder. Simultaneously,
oil contained in the decrease side of the cylinder flows out
cylinder port SC-4 through valve ports B and T to compres-
sor closed thread port.
Vi Decrease
Models 60 through 480: The volume ratio Vi is decreased
when MSS solenoid YY4 is energized and oil flows from the
oil manifold through valve ports P and B to cylinder port SC-4
and enters the decrease side of the cylinder. Simultaneous-
ly, oil contained in the increase side of the cylinder flows out
cylinder port SC-3 through valve ports A and T to compres-
sor closed thread port.
MSV and MSS HYDRAULIC CYLINDER and SOLENOID VALVES
MODELS 60 – 480