Overboard water cooling (main) system
The overboard water cooling system is supplied with
water by the main overboard water cooling pumps. When the overboard water
temperature is low a lower capacity pump or a smaller
number of pumps are used to supply water, and when the overboard water
temperature is high, a more powerful pump or several pumps are used at the same
time (only if the continuous operation of several of these pumps is planned at
the same time).
The main overboard water pumps pump water from a
common overboard water main pipe (in some systems, an intermediate overboard
water tank (Crossover Tank) may be used instead) into which the onboard water
enters from one or more Kingston boxes. Subsequently, the pumps supply the on-board
water to the heat exchangers (coolers) of the low-temperature cooling system
(some systems may also supply water to heat exchangers for other purposes),
which may or may not be equipped with a backwash system to remove any sludge
from the coolers. and debris in order to maintain the efficiency of the heat
exchanger. When leaking through these heat exchangers, the water is drained
overboard.
The Kingston boxes on the sides of the hull
and at the bottom of the vessel are fitted with a protective grille from the
outside. All Kingston boxes have overboard water supply valves. Behind these
valves, all Kingston boxes are fitted with mesh suction filters. Kingston boxes
are equipped with steam and air connections to destroy marine vegetation.
Each Kingston filter has a Copper Anode and an
Aluminum Cathode for the Marine Growth Prevention System (MGPS). Anode copper
protects the overboard water system from marine contamination and cathode
aluminum protects the system from corrosion. Anodes and cathodes release ions
into seawater that kill marine organisms. Ions dissolve in seawater to form a
gelatinous floc that is transported throughout the seawater circulation system.
The floc forms a thin coating on all surfaces of the seawater system that
protects against corrosion. Thus, MGPS controls the growth of marine organisms
and reduces corrosion throughout the overboard water system.
Example of an overboard water cooling (main) system