污水储罐内牺牲阳极保护电位研究

Research on sacrificial anode protection potential in sewage storage tank

关键词:  污水储罐  牺牲阳极  布局  腐蚀  保护电位

Key words:  sewage storage tank  sacrificial anode  layout  corrosion  protection potential

摘要:

为研究牺牲阳极数量、布局等对污水储罐保护性能的影响,分别表征了阳极数量为0、1、12、16、20个时的阴极保护电位分布情况。结果 表明:Al-Zn-In系铝合金阳极材料第二相分布较均匀,材料较均匀溶解；储罐在污水中无阳极保护时的腐蚀电位约为-0.482 V；阳极数量为20个时,腐蚀电位约为-1.002 V,能够保护整个储罐不受腐蚀；阳极数量为16、12个时,储罐保护电位为-0.960 V、-0.786 V;阳极数量为14个时,阳极保护效果可以达到标准规定的要求；若任意一阳极出现虚焊等情况,则阳极数须不少于16个；储罐内部出现泥层加厚、水位下降等情况时,阳极会失去保护作用；阳极与罐板焊接要牢固,焊后清除焊渣；若阳极焊接高度不当、出现虚接、个别阳极消耗过度等情况可能会导致储罐部分区域保护效果不佳。 

Abstract:

In order to study the influence of the number and layout of sacrificial anodes on the protection performance of sewage storage tanks, the distribution of cathodic protection potentials when the number of anodes is 0,1, 12,16, 20 were respectively characterized. The results show that the Al-Zn-In series aluminum alloy anode material has a more even second phase distribution and dissolution; the corrosion potential of the storage tank in the sewage without anode protection is about -0.482 V; when the number of anodes is 20, the potential is about -1.02 V, which can protect the entire storage tank from corrosion; the storage tank protection potential could be -0.960 V and -0.786 V respectively when 16 and 12 anodes are applied and when the number of anodes is 14, the anode protection effect can reach the standard requirements; if any one of the anodes has a false weld, etc., the number of anodes must be not less than 16; when the mud layer thickens and the water level drops in the tank, the anode will lose its protective effect; the welding between anode and tank plate should be firm, and the welding slag should be removed after welding; improper anode welding height is improper, because false connections and excessive consumption of individual anodes may lead to poor protection of some areas of the tank.