The necessity of using anti-scalants

Almost all problems associated with the use of water for cooling purposes can be attributed to one or more impurities such as hardness salts (such as calcium and magnesium, which deposit as scale in pipes and especially on heating surfaces), silica, iron, microbiological species, oil, and dissolved gases. The problem of scaling and corrosion caused by the use of natural hard water in cooling towers during recirculation poses major economic and technical problems, including reduced system efficiency and increased frequency of chemical cleaning. The nature and rate of scaling are determined by physical, chemical, and bacteriological effects. The formation of mineral deposits on heat exchangers, reverse osmosis membrane surfaces, cooling water systems, boilers, secondary oil recovery and the use of water flooding techniques, desalination plants, flue gas desulfurization systems, etc. is mainly due to the mineral composition of the cooling water system. Minerals present are not a problem as long as they remain in solution, but when they find specific spots and stick to the metal surface, they can have destructive effects. These compounds usually adhere strongly to the relatively rough surfaces present in high temperature areas and turn into hard and dense masses known as scale. These scales are mainly formed due to mineral compounds such as calcium, magnesium, silica, iron oxide, barium, etc. Common scales include calcium carbonate, calcium sulfate, magnesium hydroxide, barium sulfate, calcium phosphate, calcium oxalate, etc., of which calcium carbonate is the most common scale. In the industry, various chemical formulations have been used to treat cooling waters and reduce the problem of scale formation and corrosion. Since the main scales in cooling waters are calcium carbonate and sulfate, efforts should be directed towards the performance of inhibitors of this type of scale.