Demineralization – The Process of removing minerals and salts from water using ion exchange process. Demineralized water mostly contains of Calcium, Magnesium, Sodium, Chloride. The demineralized water is also called deionised water or Demin water.
The old methods of removing ionic impurities which has some limitations. They can remove only some of the cations or anions, whereas demineralizers can remove all of them. Nevertheless, the demineralizers continue in use,because they are economical: the chemicals added are less expensive than the acidic and caustic soda regenerants used for demineralization and their doses are smaller. Therefore in many demineralizing projects the old methods are included as pretreatment and the combination often results in the lowest operating cost. The pretreatment plant relieves the demieralizer of a considerable burden and allows it to act as finisher and refiner in the production of high quality effluent. The pretreatment methods in a demineralizer plant removes certain ionic impurities such as iron and manganese, that may foul the ion exchange resins of the demineralizers.
A demineralizer is a system, which uses ion exchange chemical process to remove dissolved ionic compounds (salts) from water. It is also known as Deionized Water System, Demineralizer or DM Plant. A typical Demineralization Plant (DM Plant) consists of two vessels. The feed water or raw water is passed through first vessel i.e. containing strong base cation resin in the form of Hydrogen (H+), whereupon all the positively charged ions (sodium, calcium, iron and copper etc.) are exchanged for Hydrogen ions; after that, the water further passed through another vessel containing strong base anion resin in the form of Hydroxyl (OH-), whereupon all the negatively charged ions (chloride, sulphate, nitrate, etc) are exchanged for hydroxide ions
Demineralized Water is Water completely free ( or almost ) of dissolved minerals as a result of one of the following processes :
Demineralized Water also known as Deionized Water, Water that has had its mineral ions removed. Mineral ions such as cations of sodium, calcium, iron, copper, etc and anions such as 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 buildup. De-mineralization technology is the proven process for treatment of Water. A DM Water System produces mineral free Water by operating on the principles of ion exchange, Degasification, and polishing. Demineralized Water System finds wide application in the field of steam, power, process, and cooling.
Raw Water is passed via two small polystyrene bead filled (ion exchange resins) beds. While the cations get exchanged with hydrogen ions in first bed, the anions are exchanged with hydroxyl ions, in the second one.
In the context of Water purification, ion-exchange is a rapid and reversible process in which impurity ions present in the Water are replaced by ions released by an ion-exchange resin. The impurity ions are taken up by the resin, which must be periodically regenerated to restore it to the original ionic form. (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).
The plant is loaded with highly efficient cation and anion exchanger.Loaded with degasification system to remove every trace of minerals from the system.The raw water called in fluent water is first passed through the Cation resin bed containing SAC. Resin in H form. Ca, Mg & Na are removed and the salts are converted to their respective acids.The corresponding acid containing anions like Cl, SO4, NO3 is removed by passing the cation effluent through Anion column containing Anion resin in Hydroxide Form.The hydrogen ion from cation neutralizes the hydroxyl ion and produces pure water.The demineralization bed is provided with strong cations and anions to produce 100% pure water.
The following ions are widely found in raw Waters :
which then combine with the hydrogen ions to form water.
Types of Demineralizers
DM Plant Regeneration
Depending upon frequency of use and DI Water output, resin becomes exhausted and does not capable to deionize; in other words, their power of removing ionic materials reduces and active ion concentration reaches a low level. The process of restoring their power or enhancing active ion concentration level is called regeneration. In this process exhausted cation and anion ions are recharged with Hydrogen (H) Hydroxyl (OH) ions.
Two Bed Demineralizer
Often called Dual Bed, Two Bed Demineralizers have the cation resin and anion resin in separate vessels. They can be regenerated is 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. The Cation resin is regenerated with acid (hydrochloric or sulfuric) and the Anion resin is regenerated with sodium hydroxide (caustic soda).
Two Bed Demineralizers normally produce water quality in the range of 50,000 ohms up to 200,000 ohms resistivity, which is between 8.5 and 2.0 ppm TDS as CaCO3. Automatic mixed deionizers utilize the same resins but mix the two resins for use. This produces a significantly higher purity than two column design, up to 18 megohm.
Mixed Bed DM Plant
Mixed Bed DM Plant is a single vessel unit, which combines Cation and Anion exchangers in a single column. When it comes to require high-purity Demineralized Water, mixed bed demineralizer is considered more efficient in many ways. It is used as polishing unit to purify water to higher levels, which is treated through Two Bed demineralizer or Reverse Osmosis Unit at earlier stage. Advanced Filtration Systems, we manufacture mixed bed demineralizer plant up 50 m3/h with manual or automatic regeneration facility as required.
Industry Specific DM Plant
Our Advanced Filtration Systems manufacture DM Plant units for industrial and commercial applications with full service installation and commissioning services throughout India and overseas at very competitive price. Designed ergonomically, these units can be constructed up to 50 m3/h or more flow rate capacities. We manufacture both dual bed dm plant and mixed bed dm plant depending upon end use of demineralized water. Manufactured by our engineering team, our DM Plants are successfully working in various industrial sectors such as pharmaceutical, textile, Thermal power Plants, laboratory, dialysis and car wash etc. These water treatment systems are custom built and constructed according to customer provided specifications with availability of wide range of options and related equipment, meeting specific application requirements and quality standards.
Boilers feed Water, Textiles, Pharmaceuticals, Chemicals, Breweries, Swimming pools, Potable Water, Hospitals, Automobile, and Battery, Fertilizers.
Ion Exchange Plants
Our company offers excellent quality Demineralization Plant manufactured through technically advanced process. Demineralization Water Treatment Plant, provided by our company, is highly demanded in various industries and municipal sectors. Today, we are regarded as one of the trusted Demineralization Water Plant Exporters.
Portable or Mini- DM Water Treatment Plant
The Water free from any mineral is called Demineralized Water (D.M.Water). Naturally occurring Water has various salts in dilute form which are called Total dissolved solids (TDS) . When the Water having such mineral is required to be free from this, it is to be treated in Ion Exchange Resins column (H form) which adsorbs the positively charge ion. Now the cations free passed through Anion Resin Column (OH form) which adsorbs the negatively charged anions and Water free from the total ions shall comes out from the system.