Demineralised Water (also known as Deionised Water) has its mineral ions removed. Mineral ions such as cations of Sodium, Calcium, Iron, Copper, etc. and anions of Chloride, Sulphate, Nitrate, etc. are common ions present in water. Deionization is a physical process which uses specially manufactured ion exchange resins which provides ion exchange site for the replacement of the mineral salts in water with water forming H+ and OH- ions. Because the majority of water impurities are dissolved salts, deionization produces a high purity water that is generally similar to distilled water, and this process is quick and without scale build-up. Demineralised water systems are the main equipment used in the preparation process of high purity water and treatment water.

Degasser :

Degasser in water treatment is referred to Decarbonator where the primary importance is to remove Carbon Dioxide from the water. They play an important role when Alkalinity is present in water. Water containing alkalinity causes deposits and blocks the tubes in the boiler.

It is placed after the Cation exchanger to mechanically remove the Carbon Dioxide. Water containing Bicarbonates when passed through the Cation Exchanger is converted to Carbonic Acid. The Carbonic Acid easily breaks into Water and Carbon Dioxide.

HCO3 = H2O + CO2

This CO2 can be mechanically removed by the Degasser by blowing air counter current to the water flow.

It comprises of Tower, Tank, Blowers & Pumps. Degasser Tower is filled with PP ranching rings. Air is forced from the bottom of the tower by Centrifugal Blowers, while the water flows down through the packed bed of PP rings. The carbonic acid present in the water splits up into Carbon dioxide gas and Water. This Carbon dioxide gas is stripped off and escapes from the top of the tower. The water free from carbonic acid is collected in the Degassed Water tank and is pumped to down-stream units for usage.