For heating and evaporation of the sea water in the freshwater generator, the waste heat in the jacket cooling water of the Diesel engine is used. The heat exchanger in the freshwater generator is connected to the jacket cooling water system of the Diesel engine, and is thus working as an extra cooler.
The jacket cooling water, which may reach a temperature between 60 and 90° C, is passed outside the tubes of the heat exchanger. During this passage the temperature will drop between 4 and 13° C depending on the amount of jacket cooling water used.
The controlled amount of sea feed water is led to the interior of the heat exchanger tubes, where it is heated under vacuum and evaporated by rising film evaporation, meaning that optimum conditions are achieved and scale formations minimized.
The vacuum required is obtained by means of a water ejector which automatically ensures correct conditions.
The generated vapours pass through the separator, in which the sea water drops are separated to the brine and discharged by means of a water ejector.
The saturated vapour rises to the sea water cooled condenses, and on the outside of the tubes it will condense into fresh water which is collected in a shell and discharged by the freshwater pump. - The salinity of the fresh water produced is automatically controlled by the salinometer.
The temperature of the cooling water led through the condenser tubes will rise between 6 and 16° C depending on the flow chosen.