Economy and risk of cleaning brushes for heat exchangers

摘要

Heat exchangers should work for many years satisfying and by low lifecycle costs. Equipping the tubes with brushes for cleaning inside can help to reduce corrosion and costs. But an additional risk of corrosion arises by running a heat exchanger at low velocity of water, causing brushes being blocked. The minimum velocity of water required depends on thickness, number and oversize length of the bristles, temperature of water, inside diameter, surface and on the total length of the tubes. For example in tubes of 4 m length, ID 16 mm, 480 bristles D 0.15 mm at 16 ℃, the water velocity should be minimum 0.8 m/s. Shorter tubes, thicker bristles, more bristles, lower temperature or lower water velocity are a higher risk.