Fouling in Evaporation

Boiling normally gives rise to higher rates of scaling than sensible heating 

Water-soluble scales and calcium carbonate account for many evaporator scaling problems. Calcium scales have a much greater impact on evaporator capacity and pose the more serious problem. The rate of calcium scaling is very dependent on temperature and is also directly proportional to solids content. Calcium scales can be controlled by minimizing calcium inputs and, to a great extent, through operation techniques. Special treatments are also sometimes effective. 

Water-soluble scales can generally be easily removed by water washing. Higher fluid velocity helps in controlling scale formation. 

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