Abstract: In this paper,the scaling trend of different ions which is tend to scale in brine was studied under the condition of different concentration ratios. The main constituents of scale inhibitors that have shown good efficiency in controlling scale formation used in present desalination plants were analyzed and their performance was studied under concentration ratio at 2.5. A set of horizontal tube filling film evaporation tests were carried out in the circumstance of low-temperature multi-effect distillation.The results showed that the concentration of calcium ion began to drop in concentration ratio at 1.5 and the loss increased with the increasing concentration ratio under temperature ranging from 40℃ to 90℃. The chance of calcareous scale's appearance increased with the improvement of temperature with temperature ranging from 40℃ to 90℃. The amount of scale was calculated to be 134mg/L with the concentration ratio to 2.5 in horizontal tube filling film evaporation tests in the temperature of 70℃. The addition of inhibitor can reduce the amount of deposition in evaporator. Furthermore,inhibitor A showed better performance in preventing calcium ion and sulfate ion from depositing in high concentration ratio compared with other inhibitors. It is also found that the amount of scale began to decrease with increasing dosage of the inhibitor. The amount of scale met the operation requirements of the present desalination plant in the condition of the dosage of 4.28mg/L for the inhibitor and the amountwas 33mg/L.

Key words: desalination, evaporation, fouling, inhibitor, high-concentration ratio

摘要： 对不同浓缩倍率下盐水中易成垢离子的变化趋势进行了实验研究，对海水淡化厂现用的性能较好的阻垢剂进行了分析，在浓缩倍率为2.5的条件下对不同阻垢剂的阻垢性能进行了研究，并模拟低温多效蒸发环境，进行了水平降膜蒸发实验。结果表明：在40~90℃的条件下，当海水浓缩倍率达到1.5倍左右时钙离子出现损失，随着浓缩倍率提高钙离子损失加大，随着温度的升高损失加剧，钙垢产生的概率变大；在70℃下模拟水平降膜蒸发实验浓缩到2.5倍时，表观结垢量约为134mg/L；阻垢剂的加入可以降低蒸发器上的表观结垢量，在高浓缩倍率下阻垢剂A显示了良好的阻钙离子和阻硫酸根离子结垢的能力；随着阻垢剂加药量的增加，表观结垢量减小，当阻垢剂A的加药量为4.28mg/L，表观结垢量为33mg/L，达到现有海水淡化厂实际运行水平。

关键词: 脱盐, 蒸发, 结垢, 阻垢剂, 高浓缩倍率