Circulating water corrosion
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Could everyone help analyze this situation? The circulating water system is of the open type; the water temperature is kept below 29°C in summer, and the pH level is maintained between 8 and 9. The water used for replenishment is steam condensate. According to the test results, the water quality meets the standards. However, it causes severe corrosion to carbon steel equipment. Please provide your analysis! ! !
Electrochemical corrosion. Is it exposed to the air, which causes faster corrosion?
The tubes of the heat exchanger are severely corroded; it’s not clear what is causing this at present
Electrochemical corrosion is caused by the movement of positive and negative electrons in a material; therefore, the environment, as well as the material and its structure, are all important. Sacrificial anodes are usually installed on the heat exchange equipment in general circulating water systems. Is there no such installation where you are?
I agree with the view expressed on floor 5. It’s necessary to examine the damaged equipment due to severe corrosion to see if the corrosion occurs mainly in areas near the tube sheet, and whether there is scaling in those corroded areas. If scaling is present, it is because of the high turbidity of the open-loop cooling water, which leads to the deposition of dirt on the heat exchanger and subsequent under-scale corrosion
I’ve never heard of this setting. Could you explain it in more detail? Does this affect whether we can have a good New Year this year? :lol
Does using an excess amount of sodium hypochlorite also corrode the equipment?
It is a device that is generally installed at the end cover of the heat exchanger, and its size is determined by the corrosion rate. The principle is simple: sacrifice oneself (corrode the anode first) to protect the heat exchanger. https://timgsa.baidu.com/timg?image&quality=80&size=b9999_10000&sec=1577083680186&di=a96b7307ca8e71a9c5164d36adcb46d2&imgtype=0&src=http%3A%2F%2Fimg1.baiyewang.com%2Fimg1%2F4%2F1345%2F1330%2F11018830%2Fmsgpic%2F59eddb6170f6857342eefd7ca58d8391.jpeg
Aerobic corrosion occurs when there is an adequate supply of oxygen in the water, which accelerates the corrosion process. A common example is an iron tank filled with water and left stationary; corrosion is not severe either underwater or above water, with corrosion mainly occurring near the water surface.
Electrochemical corrosion. Is it exposed to the air, causing more corrosion?