Every year, the cooling system for an industrial plant providing comfort cooling was shut down and drained for the winter months. Historically during this shutdown period, the cooling water piping and equipment would experience severe corrosion. During startup of the cooling system the next spring, iron flakes would peel off the piping, plugging strainers and heat transfer equipment. Unfortunately, corrosion problems such as this one are not isolated to one comfort cooling tower. Any tower that is shut down seasonally can be affected by this type of corrosion.
To protect against this problem at the industrial plant, U.S. Water Services, Cambridge, Minn., recommended its Cooling Tower Toads. The product provide a vapor corrosion inhibitor (VCI) protective layer that films all the metal components, keeping oxygen and water from creating corrosion cells on the surface of the metal. The corrosion inhibitor also coats recessed and inaccessible areas such as the vapor spaces of piping. Because the VCI replenishes coatings that are disturbed or depleted, the protection lasts for the entire layup season.
At the industrial plant, a box of 2.2 lb bags of the corrosion inhibitor product was added to the tower basin for every 1,000 gal of water. The basins were drained to the lowest possible operating level to reduce the amount of water that needed to be treated. A non-ionic biocide was added to sterilize the system as a routine maintenance practice prior to shutdown. According to U.S. Water Services, the system was recirculated for eight hours and then drained.
Inspection of the cooling system piping and heat-transfer equipment showed a noticeable improvement in the inhibition of rusting and corrosion, according to the company. To learn more from U.S. Water Services, visit www.uswaterservices.com.