In general, a dealkalizer is best applied to boilers operating below 700 psi. In order to justify installation of a dealkalizer on low pressure boilers, the alkalinity content should be above 50 ppm with the amount of make-up water exceeding 1,000 gallons per day.
Cooling water systems also benefit from reduced alkalinity. The addition of a dealkalizer to a cooling system will substantially reduce the amount of acid required to treat the same amount of water.
In addition to dealkalizing, these systems can be used to reduce nitrates and sulfates by utilizing specific anion exchange resins.
a) Reduce Blowdown: Alkalinity is a factor that most often dictates the amount of boiler blowdown. High alkalinity promotes boiler foaming and carryover and causes high amounts of boiler blowoff. When alkalinity is the limiting factor affecting the amount of blowdown, a dealkalizer will increase the cycles of concentrations, reducing blowdown and lowering operating costs.
b) Reduce Chemical Use: The reduction of blowdown by dealkalization keeps the water treatment chemicals in the boiler longer, thus minimizing the amount of chemicals required for efficient, non-corrosive operation.
c) Reduce Return Line Corrosion: Carbonate and bicarbonate alkalinities are decomposed by heat in boiler water, releasing carbon dioxide into the steam. This gas combines with the condensed steam in process equipment and return lines to form carbonic acid (H2CO3). This depresses the pH value of the condensate returns and results in corrosive attack on the equipment and piping.
d) Improve Textile Dyeing: Alkalinity may also produce non-uniform results in dyeing of textiles and other fabrics because of its effect on the pH value of the dye bath.
e) Improve Beverage Tastes: In beverage manufacturing, alkalinity often produces flat tastes or tends to destroy taste characteristics of flavoring extracts.