How often is it normal to clean the copper tubes of the cooling units in an open-type cooling tower? (The equipment has been in use for 4.5 years.)

It mainly depends on the degree of scaling in your system; determine it based on the actual usage requirements. Is that so?

The system uses pure water, so scaling is minimal; there are bacteria inside the copper pipes

You just need to add a biocide; when scaling is minimal, use a smaller amount of a descaling agent with low corrosion rate, and run it online. It’s not a big problem if it’s not cleaned

The circulating water on-site is open-type circulating water, and the system allows dust, sediment, fungi, algae, as well as deposits of such organisms to enter at the cooling tower. If the system does not perform proper water replenishment and drainage on a regular basis, sediment within the system will gradually accumulate. If the amount of wastewater removed from the system is insufficient, the sludge accumulated there can eventually cause blockages in the pipes and other issues ； Therefore, open-loop circulating water requires chemical treatment for maintenance; the system needs to have scale and corrosion inhibitors added, as well as disinfectants applied on a regular basis ； Adding pure water only prolongs the time before the system gets clogged; it does not resolve the sludge problem fundamentally. If proper daily maintenance is carried out, the system will basically not get clogged. Additionally, open-systems do not require the addition of pure water, as this is too costly, and it does not solve the problem at its root. Regular tap water, combined with chemical treatment, is sufficient to solve the problem.

I’m not sure about your specific situation, but generally speaking, it’s quite extravagant to use an open-system design in order to avoid scale problems while still using pure water

Physical scale removal, sterilization, and algae suppression. To show you the scale

Once a year, a solution is added to wash out the calcium