Study On Corrosion And Scale Inhibitor Of Ozone In Warm-water Circulation System

It’s a common phenomenon that the scaling and corrosion exist in the circulatingcooling water system. To solve the issue, the scaling inhibitor and corrosion was added inthe system. Ozone processing method could achieve some function, such as corrosion,scale inhibitor and disinfection. The ozone processing method of dispose warm-watercirculation system was studied in this paper. Through validating the different quantity ofscale and corrosion situation by ozone, the best optimal dosing quantity was determined.The comparison was conducted between the ozone processing method and traditionalchemical addition approaches as to their advantages as well as disadvantages.Combined with living practice and practical knowledge the circulating cooling watersystem was simulated. The water in the heat exchanger through circulating pump to thewater storage tank, was cooling, then through a pump feed into heating apparatus. Theexperiment was conducted that when the water temperature varied from60to80℃. Theflow was designed100L/h. The best ozone dosing quantity through the experiments wasdetermined. The metal material of the pipe, the boiler and the heat exchanger are different.In this study, the typical cast iron and galvanized and20carbon steel were chose asstandard specimens.Sodium chloride was added in the corrosion experiment, which could speed up thecorrosion of metal specimens and shorten the test cycle. Therefore, the corrosion rate washigher than the code for design of industrial recirculating cooling water treatment GB50050-2007. After the system ran stably, four different groups of ozone were added, at thequantity of0,4.5,9,13.5mg/L. The experimental period7days. The best optimal dosingquantity was determined through the changes of corrosion situation by ozone. In scaleinhibition experiment, in order to shorten the test cycle, calcium chloride and magnesiumchloride were added, which could speed up the metal specimens of scale. When the systemoperated stably, four groups of ozone were added. The experimental cycle was7days. On the basis of the experiment, we have drawn several conclusions. It’s the bestcorrosion ability about20carbon steel and cast iron when ozone optimum dosage was4.5mg/L. The lowest corrosion rate of20carbon steel was0.228mm/a. It was reduced75%when combined with the blank test. The lowest corrosion rate of cast iron is0.282mm/a,which was better than the blank control group61.5%. When the ozone dosing quantity was9mg/L, the corrosion rate of galvanized is0.206to0.275mm/a. It was gone down38.2%when combined with the blank control group. It proved that the corrosion effect of theresearch results effectively. When the ozone dosing quantity was1mg/L, the scaleinhibition ability was stronger. It was better35.7%when combined with the blank group.Compared with the traditional chemical processing approach, the use of ozone treatment ofcirculating water system was better. Not only the economic cost was lower but alsoprotected the environment and had feasibility. It was worth the community to extensionresearth.