Figure 5-5 - Oil Coalescing Element - Gardner Denver VST110 Operating And Service Manual

OIL SEPARATION RESERVOIR / COALESCING ELEMENTS - These
devices serve multiple functions in the compressor package:
·
Air/oil centrifugal separation - The bulk of the liquid oil is separated, by centrifugal effects, away
from the compressed air and aerosol streams, which is then gravity-collected at the bottom of the
reservoir.
·
Oil degassing and holding - The reservoir has sufficient holding capacity to degas the oil mass
before it is drained off on its way to cooling, filtering and re-injection. It also serves as a storage
volume for the oil mass migrating from higher elevations (e.g., oil cooler, compressor casings, and
piping).
·
Air/oil final separation - The aerosols and compressed air streams are led to the upper portion of
the reservoir, where the coalescing elements (two used) reside. The fine droplets of oil (aerosol) are
trapped in each element media, coalesced, then gravity-drained, through a low-point connection and
associated tubing (oil return line) into a lower pressure region of the compressor.
Separation performance - The package oil separation system has been designed to yield 2ppm total oil
carryover at the discharge of the air/oil reservoir – the oil content level at the discharge of the package will
be lower and will depend on the amount of moisture rejected by the aftercooler.
This high level of performance will be affected by the following typical offset conditions:
·
Contaminated (e.g., dirt, varnish, moisture) or damaged (e.g., ruptured) coalescing element.
·
Contaminated (e.g., dirt, varnish, moisture) or inadequate oil in use.
·
High oil level in air/oil reservoir.
·
Blockage of oil return line strainer or orifice.
·
Abnormally frequent or fast depressurization cycles - leading to oil foaming.
Oil separator element life cannot be predicted; it will vary greatly depending on the conditions of
operation, the quality of the oil used and the maintenance of the oil and air filters. The condition of the
separator can be determined by pressure differential gauging or by inspection.
Oil Coalescing Element Monitoring - The AirSmart controller keeps track of the pressure differential
across the coalescing element. A pressure differential of 8 psi will trigger a service advisory to change
the element and a pressure differential of 15 psi will initiate a system shutdown.
Figure 5-5 – OIL COALESCING ELEMENT
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