北京某水厂模拟管网内部腐蚀特性分析

Analysis of Internal Corrosion Characteristic of Simulated Pipe-loop Systems in a Waterworks in Beijing

以北京市某大型水厂活性炭滤后水为原水，构建了两套流量均为3m^3／h的非循环管网模拟系统（分别采用间歇运行和连续运行），考察了两系统的管网内部腐蚀特性。结果表明，当管垢层趋于稳定时，管垢中的亚铁／总铁值为30％～70％，且在相同的管径下，间歇运行的管网其管垢中的亚铁含量比连续运行的管网要高；垢层中所含的元素有Zn、Fe、Ca、S、Si，其中以Zn和Fe为主；管垢中的腐蚀产物部分是以晶体状态存在的，晶体的成分主要为α—Fe（OH）2、Fe2O3、CaCO3、CaSiO3及其络合产物；管道的腐蚀速率随水温和流速的提高而加快，间歇运行管网的管道腐蚀速率比连续运行的快。

Taking the treated water of GAC filter in a large-scale waterworks in Beijing as raw water, two non-circulating simulated pipe-loop systems with each flow rate of 3 m^3/h, operated intermittently and continuously were set up, and their internal corrosion characteristics were investigated. The results show that when the pipe scale tends to be stable, the proportion of Fe^2＋ to total Fe is between 30% and 70%. Under the condition of same diameter, the ted system is higher than that in the continuously ferrous content of pipe scale in the intermittently operaoperated system. The EDS examination indicates that the elements in pipe scale include Zn, Fe, Ca, S and Si, most of them are Zn and Fe. Some of pipe scale are crystals, and the components of crystal include goethite, magnetite, calcium carbonate, wollastonite and their complexes. Moreover, the corrosion rates of the systems rise with the water temperature and flow rate, and the corrosion rate in the intermittently operated system is faster than that in the continuously operated system.