During the operation of the industrial circulating water system, the circulating water is continuously concentrated due to water evaporation and wind loss. The salt contained in the industrial circulating water exceeds the standard, the anions and cations increase, and the pH value changes significantly, which causes the water quality to deteriorate. The temperature, pH and nutrients of the circulating water are conducive to the reproduction of microorganisms, and sufficient sunlight on the cooling tower is an ideal place for algae growth. However, scale control, corrosion control, microbial control, etc., inevitably require circulating water treatment, and the main problems that occur during the operation of circulating water:
(1) Scale: As the circulating water evaporates continuously during the cooling process, the salt concentration in the water is continuously increased, and the solubility of some salts is exceeded and precipitated. The common ones are calcium carbonate, calcium, magnesium silicate and other scales. The texture of scale is relatively dense, which greatly reduces the heat transfer efficiency. A scale thickness of 0.6 mm reduces the heat transfer coefficient by 20%.
(2) Dirt: Dirt is mainly composed of organic matter in the water, microbial colonies and secretions, silt, dust, etc. The texture of the dirt is soft, which not only reduces the heat transfer efficiency but also causes the service life of the cycle equipment under the corrosion
(3) Corrosion: The corrosion of circulating water to heat exchange equipment is mainly electrochemical corrosion, which is caused by equipment manufacturing defects, sufficient oxygen in the water, corrosive ions (Cl-, Fe2+, Cu2+) in the water, and mucus secreted by microorganisms. The generated dirt and other factors have serious consequences for corrosion, even if the heat exchanger and water pipeline equipment are not controlled in a very short time.
Introduction of industrial circulating water equipment
2021 12/30