除盐水箱聚脲防腐涂层溶出物检测及对水质的影响

Detection of dissolution of anticorrosive polyurea coating on desalted water tank and its effect on water quality

建立了以总有机碳(TOC)为特征指标的聚脲防腐涂层在除盐水中溶出速率的检测方法。选取了国内外数家有代表性的厂家的聚脲防腐涂层试片,考察了它们在除盐水中的TOC溶出规律,测定了其溶出速率并进行了对比分析。根据电厂除盐水箱供水TOC控制值,分析了各厂家聚脲防腐涂层TOC溶出对脱盐水箱供水水质的影响程度。结果表明:聚脲防腐涂层在除盐水中均有一定程度的有机物溶出,主要发生在初始溶出阶段的快速增长期(投运后1~2周),溶出速率大于10μg/(cm^(2)·d)的情况下对水箱水质有显著影响。经过了上述时期,TOC溶出速率将显著下降至小于2.0μg/(cm^(2)·d),对水箱水质影响不大。

A method for determining the dissolution rate of anticorrosive polyurea coating was established by taking TOC(total organic carbon)as the characteristic indicator.Several anticorrosive polyurea coating samples were selected from typical suppliers all over the world.The TOC dissolution features of them in desalted water were examined and their dissolution rates were determined for a comparative analysis.According to the limit of TOC in desalted water tank for power plant,the effect of dissolution of TOC from anticorrosive polyurea coatings from different suppliers on the water quality of desalted water tank was analyzed.A certain degree of TOC dissolution was found for all selected anticorrosive polyurea coatings in demineralized water,which occurred mainly during the rapid increase period in the initial dissolution stage(within 1 to 2 weeks after running).The water quality in desalted water tank was greatly affected when the dissolution rate of TOC was greater than 10μg/(cm^(2)·d).After the said period,the dissolution rate of TOC would decreased to less than 2.0μg/(cm^(2)·d),which had nearly no influence on the water quality in desalted water tank.