Compressor Cooling And Lubrication System, Functional Description; Compressor Discharge System, Functional Description - Sullair 3007 Operators Manual & Parts Lists

2.4 COMPRESSOR COOLING AND
LUBRICATION SYSTEM,
FUNCTIONAL DESCRIPTION
Refer to Figure 2-3 or Figure 2-4. The Cooling and
Lubrication System (air-cooled version) consists of a fan,
fan motor, radiator-type aftercooler/fluid cooler, full flow
fluid filter, thermal valve, and interconnecting hoses. For
water-cooled models, two shell and tube heat exchangers
are substituted for the radiator-type cooler listed above.
The pressure in the receiver tank causes fluid flow by
forcing the fluid from the high pressure area of the receiver
tank to an area of lower pressure in the compressor unit.
Fluid flows from the bottom of the receiver tank to the
thermal valve. The thermal valve is fully open when the
fluid temperature is below 185˚F (85˚C) [200˚F (93˚C) for
24KT] and pressures are rated above 150 psig. The fluid
passes through the thermal valve, the main filter and
directly to the compressor unit where it lubricates, cools
and seals the rotors and the compression chamber.
As the discharge temperature rises above 185˚F (85˚C),
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
then on to the compressor unit.
A portion of the fluid flowing to the compressor is routed to
the anti-friction bearings which support the rotors inside
the compressor unit.
The fluid filter has a replacement element and an integral
pressure bypass valve. Refer to
Lubrication Change Recommendations and
Maintenance, Fluid Filter and Separator on page 21.
Water-cooled models have a water pressure switch to
prevent operation with inadequate water pressure.
2.5 COMPRESSOR DISCHARGE
SYSTEM, FUNCTIONAL
DESCRIPTION
Refer to Figure 2-3 or Figure 2-4. The compressor unit
discharges the compressed air/fluid mixture into the
combination receiver tank.
The receiver has three basic functions:
1. It acts as a primary fluid separator.
2. Serves as the compressor fluid sump.
3. Houses the final fluid separator.
SULL AIR
® ®
3000-4500 Operator's Manual and Parts List
The compressed air/fluid mixture enters the receiver tank
and flows through an internal baffle system. The direction
of movement is changed and its velocity significantly
reduced, thus causing large droplets of fluid to form and
fall to the bottom of the receiver tank. The fractional
percentage of fluid remaining in the compressed air
collects on the surface of the separator element as the
compressed air flows through the separator. A return line
(or scavenge tube) leads from the bottom of the separator
element to a medium pressure region of the compressor
unit. Fluid collecting on the bottom of the separator is
returned to the compressor by a pressure differential
between the receiver and the compressor. A visual sight
glass is located on the return line to observe this fluid flow.
There is also an orifice in this return line (protected by a
strainer) to assure proper flow. The separator system
reduces the fluid carry-over to less than 1 ppm (parts per
million). A message on the WS Controller indicates if
abnormal pressure drop through the separator develops.
Refer to
Lubrication Change Recommendations and
Maintenance, Fluid Filter and Separator on page 21.
A minimum pressure/check valve, located downstream
from the separator, assures a minimum receiver pressure
of 50 psig (3.4 bar) during loaded conditions. This
pressure is necessary for proper air/fluid separation and
proper fluid circulation.
A terminal check valve is incorporated into the minimum
pressure/check valve to prevent compressed air in the
service line from bleeding back into the receiver on
shutdown and during operation of the compressor in an
unloaded condition.
A pressure relief valve (located on the wet side of the
separator) is set to open if the receiver tank pressure
exceeds the receiver tank rating. The WS Controller will
shut down the compressor if the discharge temperature
reaches 235˚F (113˚C).
WARNING
DO NOT remove caps, plugs, and/or
other components when compressor
is running or pressurized.
Stop compressor and relieve all
internal pressure before doing so.
Fluid is added to the receiver tank via a capped fluid filler
opening, placed low on the tank to prevent overfilling of the
receiver tank. A sight glass enables the operator to visually
monitor the receiver tank fluid level.
DESCRIPTION
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