On the corrosion protection of circulating cooling water pipelines
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Regarding the corrosion protection of circulating cooling water pipes, it brings to mind that in ships, aluminum or zinc blocks are installed on the bottom of the ship to reduce corrosion caused by seawater. Since both aluminum and zinc are more reactive than iron, they lose electrons in electrochemical corrosion before iron does. So I think it is possible to install aluminum or zinc blocks in the circulating cooling water pipes to reduce the carbon steel cooling water pipes. In chemical plants, cooling water systems often contain sodium chloride or calcium chloride. Since the reactor jacket uses steam, circulating water, and chilled brine, these three media often mix together.
What you are referring to is cathodic protection using the sacrificial anode method. It would be even better to coat the circulating water pipes with anti-corrosion material before combining this with cathodic protection, as that will yield better results.
It’s not that troublesome; it’s just a circulating water pipeline
Are there any specific requirements for the installation location?
To protect the outer wall of circulating cooling water pipes, the device is installed outside the pipes; if it is necessary to protect the inner wall of these pipes, then it should be installed on the inner side of them. Are the pipes thick enough? Using a slow-release scale and bacteriocide agent is a good solution.
It is possible to install a cathodic protection system in a circulating water system. However, the cost of the coating system increases accordingly.
Many storage tanks these days are designed this way, and this approach is feasible
The anti-corrosion of circulating water pipes is generally addressed through the treatment of the circulating water. Relying on internal anti-corrosion measures is not a good solution; using alloy materials results in high costs, while painting presents difficulties in terms of implementation.
In fact, circulating water is extremely important within the device; if there are problems with the circulating water, think about whether the device can still operate We generally need to treat the circulating water, using agents such as corrosion and scale inhibitors, biocides and algaecides, as well as sludge removers, since circulating water functions like the body’s cooling system.
Before putting circulating water pipes into use, they are generally flushed first, and then chemicals are added for pre-coating. Once in normal operation, water quality is controlled by adding chemicals based on the results of water quality tests, such as corrosion and scale inhibitors, as well as bactericidal and algaecidal agents.
Water treatment for circulating water is the only proper and fundamental solution, as the quality of circulating water affects pipelines and equipment; it is necessary to find solutions through water treatment techniques to address this issue. Hiring a professional water treatment company for long-term services is an effective approach.
At present, the most commonly used method is the addition of corrosion inhibitors. For applications with stringent requirements, we previously worked on seawater circulation cooling water pipelines in a nuclear power plant, where external current cathodic protection was employed; sacrificial anodes can also be used. However, there are two drawbacks: 1) welding them in place creates turbulence, and 2) they are difficult to replace. Whether zinc or aluminum should be used depends on the resistivity of the medium, as well as the quality of the water, as these factors directly affect the current efficiency of the anode