Deionizers are utilized to remove ionized impurities from the water. Deionization (or demineralization) is the process of removing up to 95% of the dissolved minerals from the water supply by way of ion exchange. Two separate resins are utilized for the deionization process. The Cation resin exchanges the positive ions for hydrogen ions (H+), while the Anion resin exchanges the negative ions for hydroxide ions (OH-). H + OH = H2O. Water (H2O) is theoretically produced as an end result in the deionization process.
The Cation resin is regenerated with acid (hydrochloric or sulfuric) and the Anion resin is regenerated with sodium hydroxide (caustic soda). Two Bed Deionizers have the cation resin and anion resin in separate vessels. They can be regenerated in series (cation followed by anion); or in parallel (cation and anion simultaneously). Anion resin must have the hardness removed from the influent water to prevent hardness fouling.
Two Bed Deionizers normally produce water quality in the range of 50,000 ohms up to 100,000 ohms resistivity. Mixed Bed Deionizers will produce up to 18 Mega ohm with proper pretreatment. Mixed Bed Deionizing systems are generally used as water polishers in high purity applications.
Ecodyne Industrial offers a complete line of Deionizer systems. They are offered in a multiport valve design or valve nest design with fiberglass or epoxy-lined steel pressure vessels and come standard with state-of-the-art PLC control.