Accession Number : AD0787179

Title :   Sea Water Evaporator Scale Control.

Descriptive Note : Final rept.


Report Date : 31 JAN 1950

Pagination or Media Count : 72

Abstract : A review of the chemical and physical principles, which dominate the formation and deposition of sea water scale, is combined with scaling data obtained through operation of the experimental sea water evaporator. The concept of adherency is suggested to explain why the scale deposited upon the heated surfaces of the evaporator may be only a fraction of that which is precipitated in solution. The effect upon scale composition of variations in the composition of the sea water feed is discussed, and the specific effects upon scaling of additions of Belloid T-D and Navy boiler compound plus starch is considered. Full scale tests of the reduction in scaling which results from preliminary elimination of over half of the carbon dioxide content are discussed. The evaluation of scales of differing compositions is discussed. Recycled brine from the evaporator is shown to be an excellent additive, particularly if combined with filtration and a peptizing agent. The addition of the feed directly to such a recycling brine system, called preconcentration, is effective. Recommendations are made concerning additional investigative approaches to the understanding and reduction of sea water scaling. (Modified author abstract)

Descriptors :   *Chemical precipitation, *Sea water, *Evaporators, Chemical composition, Rates, Distillation, Flow rate, Adhesion, Deposition, Additives, Precipitates, Starches, Degasification, Carbon dioxide

Subject Categories : Industrial Chemistry and Chemical Processing
      Physical Chemistry

Distribution Statement : APPROVED FOR PUBLIC RELEASE