Sullair Compressor Unit, Functional Description; Compressor Cooling And Lubrication System, Functional Description - Sullair 175 Operators Manual And Parts Lists

Model 185 185 CFM @ 100 PSIG ((6.9 bar)
Model 185H 185 CFM @ 150 PSIG (10.3 bar)
The control system can easily be adjusted for pres-
sures from 70 to 125 PSIG (4.8 to 8.6 bar) for stan-
dard machines and from 70 to 150 PSIG (4.8 to 10.3
bar) for "H" machines. The compressor unit is
driven by an industrial diesel engine designed to
provide enough horsepower for more than ade-
quate reserve at rated conditions. Refer to the En-
gine Operator's Manual for a more detailed descrip-
tion of the engine.
The engine cooling system is comprised of a radia-
tor, high capacity fan and thermostats. The high
capacity fan draws air through the radiator, keeping
the engine at the proper operating temperature.
The same fan also cools the fluid in the compressor
cooling and lubrication system. Prior to passing
through the radiator, the fan air passes through the
compressor fluid cooler (mounted in front of the ra-
diator). As air passes through the cooler, the heat of
compression is removed from the fluid.
The compressor is supplied with a large capacity
fuel tank which will keep the compressor running
through one (1) eight hour shift under normal oper-
ating conditions.
2.3 SULLAIR COMPRESSOR UNIT, FUNCTIONAL
DESCRIPTION
Sullair compressors feature the Sullair compressor
unit, a single---stage, positive displacement, flood
lubricated---type compressor. This unit provides
continuous (pulse---free) compression to meet your
needs. With a Sullair compressor, no maintenance
or inspection of the internal parts of the compressor
unit is required.
Fluid is injected into the compressor unit where it
mixes directly with the air as the rotors turn, com-
pressing the air. The fluid flow has three main func-
tions:
1. As coolant, it controls the rise of air temperature
normally associated with the heat of compres-
sion.
2. Seals the leakage paths between the rotors and
the stator and also between the rotors them-
selves.
3. Acts as a lubricating film between the rotors allow-
ing one rotor to directly drive the other.
After the air/fluid mixture is discharged from the
compressor unit, the fluid is separated from the air.
At this time, the air flows to your service line and the
fluid is cooled in preparation for reinjection.
2.4 COMPRESSOR COOLING AND LUBRICATION
SYSTEM, FUNCTIONAL DESCRIPTION
Refer to Figure 2---2. The compressor cooling and
lubrication system is designed to provide adequate
lubrication as well as maintain the proper operating
temperature of the compressor. In addition to the
fluid cooler and interconnecting piping, the sys-
tem consists also of three other components: a
fluid filter, thermal valve, and a fan which perform
the following functions:
S The fluid filter filters the fluid.
S The thermal valve functions as a temperature regu-
lator directing fluid either to the cooler or to the com-
pressor unit, bypassing the cooler as will be ex-
plained later.
S The fan draws air through the cooler removing the
heat of compression from the fluid.
The functions of the lubrication system are ex-
plained in more detail below. Fluid is used in the sys-
tem as a coolant and as a lubricant. It is housed in
the receiver/sump which, will from this time forward,
be referred to as the SUMP .
Upon start ---up, fluid flows from the sump to the fluid
thermal valve. Fluid circulation is achieved by forc-
ing the fluid from the high pressure region of the
sump to a lower pressure area in the compressor
unit. A minimum pressure valve (see Section 2.5
Compressor Discharge System) is provided to as-
sure adequate fluid flow under all conditions.
When entering the thermal valve upon start ---up, the
fluid temperature is cool and thus it is not necessary
to route it through the cooler. Hence the fluid flows
through the fluid filter and on to the compressor unit
bypassing the cooler. As the compressor continues
to operate, the temperature of the fluid rises and the
thermostatic control opens, allowing a portion of
the fluid to the cooler. When the temperature
reaches 170_F (77_C), the thermostat is fully open
allowing all fluid entering the thermal valve to be di-
rected to the cooler.
The cooler is a radiator---type that works in conjunc-
tion with the engine fan. The fan draws air through
the cooler removing the heat of compression from
the fluid. From the cooler, the fluid is then routed
back through the fluid filter. All fluid flowing to the
compressor unit passes through this filter. The fluid
leaving the filter flows to the compressor unit where
it lubricates, seals and cools the compression
chamber as well as lubricates the bearings and
gears.
2.5 COMPRESSOR DISCHARGE SYSTEM, FUNC-
TIONAL DESCRIPTION
Refer to Figures 2---3 and 2---4. The Sullair com-
pressor unit discharges compressed air/fluid mix-
ture into the sump. The sump has three functions:
1. It acts as a primary fluid separator.
2. Serves as the compressor fluid sump.
3. Houses the air/fluid separator.
The compressed air/fluid mixture enters the sump
and is directed against the bottom of separator. By
change of direction and reduction of velocity, large
Section 2
DESCRIPTION
9