Reduce scaling or pretreat water for a high purity water system.
About Water Demineralizers
Problems associated with hard water can be minimized by using a demineralizer. Untreated hard water can cause increased utility bills, higher operating costs, decreased equipment efficiency and life, increased use of detergents and chemicals and increased boiler blow-downs and downtime.
How strong base demineralizers work
The strong base demineralizer is a two-vessel system. Water first passes through a strong acid cation exchange vessel, where the ionizable salts in the water are converted to their respective acids. Then the water passes through the strong base anion exchange vessel, where the negative radicals of the acids are converted to hydroxyl (OH-) ions. The result is a water containing only hydrogen (H+) and hydroxyl (OH-) ions which combine to form pure water.
The strong acid cation vessel contains resin similar to the strong acid resin used in a water softener. However, it is regenerated with an acid to convert the resin to the hydrogen form, where it can readily remove cations such as calcium (Ca++), magnesium (Mg++) and sodium (Na+) from the water. Either hydrochloric (HCI) or sulfuric acid (H2SC4) may be used, with the provision that the use of sulfuric acid requires some equipment modifications to avoid a calcium sulfate precipitation during the regeneration process. Exchange capacities range from 15,000 to 30,000 grains per cubic foot depending upon the type of cations present, the effluent water quality desired, and the amount of acid/regenerant used.
The strong base anion vessel contains anion exchange resin. It is regenerated with caustic soda (sodium hydroxide NaOH) to convert the resin to the hydroxyl form, where it can readily remove anions such as chloride (Cl-), sulfate (SO 4–) and nitrate (NO 3-) from the water. The strong base resin (unlike the weak base resin) is also capable of removing the more weakly ionizable substances such as carbon dioxide (CO2) and silica (SiO 2). Capacities range from 10,000 to 20,000 grains per cubic foot, depending upon the type of anions present, the quality of water desired and the amount of caustic regenerant used.