A DM Water System produces mineral free waterby operating on the principles of ion exchange, Degasification, and polishing. Demineralized water also known as De-ionized Water, water that has had itsmineral ions removed. Mineral ions such as cations of sodium, calcium, iron,copper, etc and anions such as chloride, sulfate, nitrate, etc are common ionspresent in Water. Deionization is a physical process which usesspecially-manufactured ion exchange resins which provides ion exchange site forthe replacement of the mineral salts in water with water forming H+ and OH-ions. De-mineralization technology is the proven process for treatment of Water.
Ion exchange process is widely accepted for water treatment andpurification.(An ion is an atom or group of atoms with an electric charge.Positively-charged ions are called cations and are usually metals;negatively-charged ions are called anions and are usually non-metals).
Ion-exchange is a rapid and reversible process in which impurity ions presentin the water are replaced by ions released by an ion-exchange resin.
There aretwo basic types of resin.
Cation exchange resins will release Hydrogen(H+) ions or other positively charged ions in exchange for impurity cationspresent in the water. Anion exchange resins will release hydroxyl (OH-) ions orother negatively charged ions in exchange for impurity anions present in thewater.
There are three ways in whichion-exchange technology can be used in water treatment and purification:
1] Cation exchange resins alone can beemployed to soften water by Base Exchange;
2] Anion-exchange resins alone can be used for organic scavenging or nitrateremoval;
3] Combinations of cation and anion-exchange resins can be used to removevirtually all the ionic impurities present in the feed water, a process knownas de-ionization. Water de-ionizers purification process results in water ofexceptionally high quality.
For many laboratory and industrialapplications, high-purity Water which is essentially free from ioniccontaminants is required. Water of this quality can be produced by de-ionization.The two most common types of ionization
1. 2. Mixed bed deionization
Two Bed Deionization:
Thetwo-bed deionizer consists of two vessels - one containing a cation-exchangeresin in the hydrogen (H+) form and the other containing an anion resin in thehydroxyl (OH-) form. Water flows through the cation column, whereupon all thecations are exchanged for hydrogen ions. To keep the Water electricallybalanced, for every monovalent cation, e.g. Na+, one hydrogen ion is exchangedand for every divalent cation, e.g. Ca2+, or Mg2+, two hydrogen ions areexchanged. The same principle applies when considering anion-exchange. Thedecationised Water then flows through the anion column. This time, all thenegatively charged ions are exchanged for hydroxide ions which then combinewith the hydrogen ions to form Water (H2O).
Inmixed-bed deionizers the cation-exchange and anion-exchange resins areintimately mixed and contained in a single pressure vessel. The thoroughmixture of cation-exchangers and anion-exchangers in a single column makes amixed-bed deionizer equivalent to a lengthy series of two-bed plants. As aresult, the Water quality obtained from a mixed-bed deionizer is appreciablyhigher than that produced by a two-bed plant. Although more efficient inpurifying the incoming feed water, mixed-bed plants are more sensitive toimpurities in the Water supply and involve a more complicated regenerationprocess. Mixed-bed deionizers are normally used to â€˜polish' the Water to higherlevels of purity after it has been initially treated by either a two-beddeionizer or a reverse osmosis unit.
Our unique design ofdimineralizing plant ensures the maximum utilization of the effective surfacearea, uniform space and linear velocity across the resin bed which provideseffective contact time between water and resin bed yield soft water and preventany precipitation and scale formation on the surface of heat exchanges and anyprocess equipment where water is being used for further application.
Theimpurity ions are taken up by the resin, which must be periodically regeneratedto restore it to the original ionic form. For the purpose of regeneration resinis separated by backwash, regenerated separately with 5%HCl and 5%NaOH andmixed after washing.