<P> Fouling also occurs when hard deposits form on the surfaces of the heating mediums in the evaporators . In foods, proteins and polysaccharides can create such deposits that reduce the efficiency of heat transfer . Foaming can also create a problem since dealing with the excess foam can be costly in time and efficiency . Antifoam agents are to be used, but only a few can be used when food is being processed . </P> <P> Corrosion can also occur when acidic solutions such as citrus juices are concentrated . The surface damage caused can shorten the long - life of evaporators . Quality and flavor of food can also suffer during evaporation . Overall, when choosing an evaporator, the qualities of the product solution need to be taken into careful consideration . </P> <P> Large ships usually carry evaporating plants to produce fresh water, thus reducing their reliance on shore - based supplies . Steam ships must be able to produce high - quality distillate in order to maintain boiler - water levels . Diesel - engined ships often utilise waste heat as an energy source for producing fresh water . In this system, the engine - cooling water is passed through a heat exchanger, where it is cooled by concentrated seawater (brine). Because the cooling water (which is chemically treated fresh water) is at a temperature of 70--80 ° C (158--176 ° F), it would not be possible to flash off any water vapour unless the pressure in the heat exhanger vessel was dropped . </P> <P> To alleviate this problem, a brine - air ejector venturi pump is used to create a vacuum inside the vessel . Partial evaporation is achieved, and the vapour passes through a demister before reaching the condenser section . Seawater is pumped through the condenser section to cool the vapour sufficiently to precipitate it . The distillate gathers in a tray, from where it is pumped to the storage tanks . A salinometer monitors salt content and diverts the flow of distillate from the storage tanks if the salt content exceeds the alarm limit . Sterilisation is carried out after the evaporator . </P>

What is the purpose of an evaporator core