Sullair TSR20, User Manual

Page: 15 / 48

SECTION 2 TSR32 USER MANUAL R00
15
2.3 COMPRESSOR COOLING
AND LUBRICATION
DESCRIPTION
Refer to Figure 2-3. The cooling and lubrication
system consists of a fan , fan motor , aftercooler/
fluid cooler , full flow fluid filter , thermal valve ,
and interconnecting tubes .
The pressure in the receiver tank starts the fluid flow
by forcing the fluid from the high pressure area of the
tank to an area of lower pressure in the compressor.
Fluid flows from the receiver tank to the thermal
valve that is fully open when the fluid temperature is
below 175°F. The fluid passes through the thermal
valve, the main filter, and directly to the compressor
where it lubricates, cools and seals the rotors, and
the compression chamber.
As the discharge temperature rises above 175°F,
due to the heat of compression, the thermal valve
begins to close and a portion of the fluid then flows
through the cooler. From the cooler the fluid flows to
the fluid filter and on to the compressor. A portion of
the fluid flow to the compressor is routed to the anti-
friction bearings which support the compressor
rotors.
The fluid filter has a replacement element and an
integral bypass valve. Refer to
Section 3.5:
Lubrication Change Recommendations and
Maintenance, Fluid Filter and Separator on page 26.
2.4 COMPRESSOR DISCHARGE
DESCRIPTION
Refer to Figure 2-3 . The compressor discharges the
compressed air/fluid mixture into the combination
receiver tank. The receiver has three basic functions:
1. It acts as an air/fluid separator.
2. Serves as the compressor fluid sump.
3. Houses the air/fluid separator elements.
The compressed air/fluid mixture enters the receiver
tank and flows through an internal baffle system that
causes most of the fluid to fall to the bottom of the
receiver tank. A small amount of fluid remaining in
the compressed air collects on the surface of the
separator elements as the air flows through the
separators.
Two return lines (or scavenge tube) lead from the
bottom of the separators dry side to a medium
pressure region in the compressor. Scavanged fluid
is returned by a pressure differential between the
receiver and compressor.
Visual sight glasses are located on the return line to
observe this flow. This return line also has an orifice
(protected by a strainer) to ensure an unobstructed
flow.
The Supervisor Controlle
pressure drop through the separator if the element
becomes dirty or plugged. (Refer to
Section 3.5:
Lubrication Change Recommendations and
Maintenance, Fluid Filter and Separator on page 26.)
It will also shut down the compressor if the discharge
temperature reaches 250°F (121°C).
A minimum pressure/check valve located
downstream from the separator maintains the
receiver pressure at approximately 50 psig (3.4 bar)
during load conditions. This pressure level is
necessary for proper air/fluid separation and
sufficient fluid circulation.
A terminal check valve is a sub-component of the
minimum pressure/check valve that prevents
compressed air in the service line from back-flowing
into the receiver on shutdown or when the
compressor is operating in an unload condition. Also,
opens if the receiver tank pressure exceeds its
rating.
Add fluid to the receiver tank through the capped
fluid filter port. There is also a sight glass that
enables the user to check the receiver tank fluid
level. See
Section 4.6: Fluid Level Check on page
34.
FUNCTIONAL DESCRIPTION
Refer to Figure 2-6. The purpose of the compressor
control system is to regulate the amount of the air
being compressed to match the amount of
compressed air being used. The Capacity Control
WARNING
Stop the compressor and relieve all internal
pressure before removing caps, plugs, and/
or other components when the compressor
is running or pressurized.