海水酸化与药剂耦合蒸馏淡化阻垢工艺研究

Scale inhibition performance of hybrid measures of acidification and chemical reagents in seawater distillation

采用水平降膜蒸发装置进行了海水蒸发浓缩实验,研究了海水酸化预处理与药剂阻垢耦合措施对钙镁离子损失的影响。酸化预处理和药剂耦合措施对垢物晶种的形成和晶体生长有明显抑制作用,在固定酸化程度的条件下,随着阻垢剂加入量的加大,钙离子损失量减少,阻垢率增加;在固定阻垢剂加入量的条件下,随着酸化程度的提高,钙离子损失量减少,阻垢率增加;而海水酸化处理与药剂阻垢耦合措施对镁离子损失量影响较小。通过海水酸化预处理与药剂阻垢耦合措施可以实现高浓缩倍率蒸馏法海水淡化的阻垢效果,在11 mg/L阻垢剂加入量、50%海水酸化或8 mg/L阻垢剂加入量、72%海水酸化条件下,海水3倍蒸发浓缩过程钙离子损失量接近目前工业蒸馏装置海水2倍浓缩实际水平。

Effect of hybrid measures of acidification and chemical reagents on calcium and magnesium ions scaling was investigated by seawater evaporation experiment with horizontal falling film evaporator. The hybrid measures of acidification and chemical reagents had obvious inhibition effect on the formation of seed crystal and the growth of crystal. Under the condition of the fixed degree of acidification, the loss of calcium ion decreased and the scale inhibition rate increased with scale inhibitor dosage increasing. At the same amount of scale inhibition dosage, the loss of calcium ion decreased and the scale inhibition rate increased with acidification agree increasing. However, the magnesium ion was barely affected by these measures. For seawater distillation of high-concentration ratio, scale inhibition can be achieved by hybrid measures of seawater acidification and chemical reagents. Under the conditions of 11 mg/L scale inhibitor dosage and 50% acidification or 8 mg/L scale inhibitor dosage and 72% acidification, the loss of calcium ion of seawater distillation at trinary concentrated process was close to that of twice concentrated process of the seawater distillation unit.