Alemite Carbon Shield, Installation, Operation And Maintenance Manual

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Oil Mist
The Carbon Shield
™
system produces a continuous
mixture of air-suspended oil particles in the 1.5 to 5
micron range. Oil is drawn from an integral reservoir
(replenished automatically or manually) into the
mist head where it is atomized into the air stream.
The air/oil mist mixture—with a smoke-like
consistency—then moves through piping at low
pressure and low velocity to designated lubrication
points on gears, chains, rolling element bearings,
sleeve bearings and other key machinery parts.
As the mist approaches a lubrication point,
reclassifiers—special oil mist fittings—collect
the small dry particles and produce larger wet
droplets ideal for the lubrication of bearing
surfaces. A unique feature of oil mist lubrication
is that carbon particles separate from the oil
droplets after they contact the moving bearing
component, forming a solid carbon layer on the
target warm bearing surfaces. This combination
of liquid and solid lubrication layers minimizes
metal to metal contact in the bearings. The result
is reduced bearing wear.
Air Pressure
Compressed instrument air from an external air
supply enters the console through a filter/regulator.
The filter/regulator:
• Separates any moisture from the air
• Adjusts to regulate the air to an operating
pressure that can be used by the system.
A Programmable Logic Controller (PLC) monitors
the pressure and relays the pressure signals to the
transducer for operational control. Additionally, a
gauge on the filter/regulator displays the pressure.
Air Temperature
The dry, instrument-quality air may be heated
by an optional air heater. Heated air can help
maintain the correct oil/air ratio in cold climates.
The PLC controls air temperature by cycling the air
heater on and off according to signals received from
the air temperature thermocouple.
Mist Pressure
Air is routed to a venturi in the mist head which
lowers the static pressure and lifts oil from the
oil reservoir. The venturi effect cools the oil
particle temperature and the high speed air
atomizes the oil into fine mist resembling smoke.
A baffle downstream from the venturi traps the
larger oil particles within the spray and returns
them to the reservoir. A transducer/regulator
and PLC control the mist pressure. The HMI and
a pressure gauge(inside the cabinet) provide visual
indication of mist pressure.
Mist Outlet
The fine oil mist particles and air stream move
through the mist outlet and distribution piping
at very low speed and pressure to various fitting
lubrication points on the destination machinery.
Mist Density
Alemite’s Carbon Shield
™
consoles (CSCs) use a
proactive approach to mist density monitoring.
Unlike current technology, changes in mist
density are predicted by CSCs long before an
actual change in mist density down the stream
can be detected. This prediction is made possible
thru the use of software in the PLC, the HMI, and
sensors onboard. These devices work together
to continuously monitor the set points (not the
limits) for all the parameters that influence the
oil mist density (a.k.a oil-to-air ratio). When
a parameter changes outside its predetermined
acceptable range around the set point, an alarm
is issued and the potential cause is displayed
thru the HMI. Therefore, there is no need for
dedicated mist density sensing devices—and
their inherent operational issues—to react to
mist density changes.
How it functions