Exam Question
Write short notes on:
(a) Control air dryer - working principle with diagram, of any one type of dryer of your choice. (8)
(b) Any two types of Ballast water treatment system. (8)
Class 4 (4th Engineer)
MEKG
📅 Apr 2025
Reference Answer
### (a) Control Air Dryer - Refrigeration Type
#### 1. Introduction and Purpose
Control air systems are critical for the operation of pneumatic controllers, valves, and other automated machinery onboard a vessel. The compressed air used must be extremely dry and clean. The presence of moisture (water vapour) can lead to corrosion of components, freezing in cold climates, malfunctioning of sensitive pneumatic instruments, and washing away of lubrication from actuators.
A control air dryer's primary function is to reduce the dew point of the compressed air to a level where moisture will not condense under any operational ambient temperature.
#### 1. Introduction and Purpose
Control air systems are critical for the operation of pneumatic controllers, valves, and other automated machinery onboard a vessel. The compressed air used must be extremely dry and clean. The presence of moisture (water vapour) can lead to corrosion of components, freezing in cold climates, malfunctioning of sensitive pneumatic instruments, and washing away of lubrication from actuators.
A control air dryer's primary function is to reduce the dew point of the compressed air to a level where moisture will not condense under any operational ambient temperature.
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