Critical Application Guidelines; Figure 2-1. Basic Single Screw Compressor System - Emerson Vilter VSG128 Installation, Operation And Service Manual

Section 2 • Theory of Operation

Critical Application Guidelines

To ensure the successful operation of the HPLD
compressor, the guidelines described below should be
followed.
1. Proper lubrication is critical to the operation of
the HPLD compressor. The compressor relies on
the injected oil to absorb and remove the heat of
compression, to seal the compression chambers
formed in the flutes of the screw, and to lubricate all
moving parts. For this reason, it is imperative that the
oil chosen be of correct viscosity, and that sufficient
oil flow be provided at all times, using an auxiliary
oil pump when necessary. The oil chosen must be
compatible with the process gas as well, to prevent
absorption of the gas into the oil, which would dilute
the oil and reduce the viscosity. Also, oil filtration to
25 micron nominal particle size is required to ensure
that only clean oil is injected into the compressor.
For assistance in choosing the correct oil for the
application and in sizing an auxiliary oil pump, consult
a Vilter representative.
TM
2. Injection oil temperature must be closely controlled
for optimum performance. Oil temperature must
be maintained a minimum of 15 - 20°F above
the gas mixture dew point at anytime to prevent
condensation or liquid knockout from occurring
within the compressor.
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Figure 2-1. Basic Single Screw Compressor System

HPLD Single Screw Compressor • Installation, Operation and Service Manual • Emerson • 35391HP
Note for CO and Heat Pump Applications
2
Because the oil system on the HPLD compressors utilizes
discharge gas pressure as the means to move the injection
oil through the system, it must be remembered that all
components of the oil system are exposed to full discharge
pressure and must be pressure rated accordingly.
3. Gas composition plays a role in the performance of the
HPLD compressor as well. While the HPLD is capable
of handling a wide variety of gases, it is required that
the concentration of H
100 PPM. If H S is present in the process gas in any
2
concentration, special oil additives are required to
protect the compressor from corrosion.
S in the process gas not exceed
2