Figure 8-13.--Vent fog precipitator.
Dehumidifier
w h e n you are operating or performing
maintenance on dehumidifiers.
Many gas turbine ships now have a de-
humidifier permanently installed on each MRG.
Shaft Tachometer
The purpose of the dehumidifier is to maintain
the air within the MRG casing at less than 35 per-
Each MRG has two tachometer generators to
cent relative humidity when the MRG lube oil
provide an electrical signal for remote indication
system is secured. The dehumidifier is not
of propulsion shaft speed. The generators are
normally operated while the ship is underway.
driven off the upper inboard second-reduction
Detailed procedures for operating and main-
pinion shaft. The drive assembly consists of a
taining dehumidifiers are furnished by the
drive housing, a drive adapter, a drive ring, and
manufacturers' technical manuals, PMS, and the
a gear train with three quill shafts. The drive
EOSS. Carefully follow these written procedures
adapter and drive ring are connected to the
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