Ingersoll-Rand EP 20 SE, Варианты руководства оператора/инструкции по эксплуатации, Страница: 25 / 70

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4.3 COOLANT SYSTEM (Continued)
There is a differential-pressure-bypass-valve set to
open in the event that the pressure drop across the
filter element rises to as high as 25 psi (1.8 BAR),
which indicates an excessively fouled element, as
well as poor maintenance practice.
4.4 COMPRESSED AIR SYSTEM
The air system is composed of:
1. Inlet air filter
2. Inlet valve
3. Rotors
4. Coolant/air separator
5. Minimum pressure/check valve
6. Aftercooler
7. Moisture separator/drain trap
Air enters the compressor, passing through the inlet
air filter and inlet valve.
Compression in the screw-type air compressor is
created by the meshing of two helical rotors (male
and female) on parallel shafts, enclosed in a heavy-
duty cast iron housing, with air inlet and outlet ports
located on opposite ends. The grooves of the female
rotor mesh with, and are driven by, the male rotor.
Tapered roller bearings at the discharge end prevent
axial movement of the rotors.
The air-coolant mixture discharges from the
compressor into the separation system. This system,
self-contained in the receiver tank, removes all but a
few PPM of the coolant from the discharge air. The
coolant is returned to the system and the air passes
to the aftercooler. The optional aftercooling system
consists of a heat exchanger, a condensate
separator, and a drain trap. By cooling the discharge
air, much of the water vapor naturally contained in
the air is condensed and eliminated from the
downstream plant-piping and equipment.
During unloaded operation, the inlet valve closes
and the blowdown solenoid valve opens, expelling
any compressed air back to the compressor inlet.
4.5 COOLANT/AIR SEPARATION SYSTEM
The coolant/air-separation-system is composed of a
receiver with specially designed internals, a two-
stage, coalescing-type separator-element, and
provision for return of the separator fluid back to the
compressor.
Operation
The coolant and air discharging from the
compressor flow into the receiver through a
tangential discharge outlet. This outlet directs the
mixture along the inner circumference of the
receiver, allowing the coolant stream to collect and
drop to the receiver sump.
Internal baffles maintain the circumferential flow of
remaining coolant droplets and air. In an almost
continuous change of direction of flow, more and
more droplets are removed from the air by inertial
action and then returned to the sump.
The air stream, now essentially a very fine mist, is
directed to the separator element.
The separator element is constructed with two
concentric, cylindrical sections of closely packed
fibers, each held in steel mesh. It is flange-mounted
at the receiver-outlet-cover.
The air stream enters the separator element radially
and the mist coalesces to form droplets. The
droplets collected on the outer first stage fall to the
receiver sump. Those collected on the inner second
stage collect near the outlet of the element, and are
drawn back to the compressor inlet through a filter-
screen and orifice fitting installed in the separator
scavenge line.
The air stream, now essentially free of coolant, flows
from the separator to the aftercooler, then to the
condensate separator, and on to the plant air
system.
4.6 ELECTRICAL SYSTEM
The electrical system of each SE compressor is built
around the microprocessor-based Intellisys
controller.
The standard electrical/electronic components,
enclosed in a readily accessible enclosure include:
1. SE Intellisys controller
2. Control transformers and fuses
3. Compressor motor starter, with auxiliary contacts
and overload relays
By use of a built-in Automatic Across-The-Line type
starter, the compressor can be started using full
voltage electric current. The starter is completely
automatic and controlled by the Intellisys controller.
Refer to the electrical schematic, Section 8.0
schematic 8.1.