Panda Water Tech Pvt. Ltd.™

ISO 9001 CERTIFIED

Softening Plants & DM Panda™ Softeners are based on Ion Exchange Process. The system comprises of Mild Steel / FRP Pressure Vessel, Frontal piping wok with manual multi port valve for easy operation and control. Standard softeners are available as DOWN Flow and UP flow type. Ranges are available from 1000 LPH to 1000000 LPH. The system is supplied with necessary brine solution preparation tank for regeneration of the softeners. Softeners A water softener is a unit that is used to soften water, by removing the minerals that cause the water to be hard. When water is referred to as 'hard' this simply means, that it contains more minerals than ordinary water. These are especially the minerals calcium and magnesium. The degree of hardness of the water increases, when more calcium and magnesium dissolves. Magnesium and calcium are positively charged ions. Because of their presence, other positively charged ions will dissolve less easily in hard water than in water that does not contain calcium and magnesium. This is the cause of the fact that soap doesn't really dissolve in hard water. Water softening can prevent these negative effects. In many industrial applications, such as the drinking water preparation, in breweries and in sodas, but also for cooling- and boiler feed water the hardness of the water is very important. When water contains a significant amount of calcium and magnesium, it is called hard water. Hard water is known to clog pipes and to complicate soap and detergent dissolving in water. Water softening is a technique that serves the removal of the ions that cause the water to be hard, in most cases calcium and magnesium ions. Iron ions may also be removed during softening. The best way to soften water is to use a water softener unit and connect it directly to the water supply Hard water causes a higher risk of lime scale deposits systems. Due to this lime scale build-up, pipes are blocked and the efficiency of hot boilers and tanks is reduced. This increases the cost of water heating by about fifteen to twenty percent. Water softening means expanding the life span of machines. It also contributes to the improved working, and longer lifespan of solar heating systems, air conditioning units and many other water-based applications. Water softeners are specific ion exchangers that are designed to remove ions, which are positively charged. Softeners mainly remove calcium (Ca2+) and magnesium (Mg2+) ions. Calcium and magnesium are often referred to as 'hardness minerals'. Softeners are sometimes even applied to remove iron. The softening devices are able to remove up to five milligrams per litre (5 mg/L) of dissolved iron. Softeners can operate automatic, semi-automatic, or manual. Each type is rated on the amount of hardness it can remove before regeneration is necessary. A water softener collects hardness minerals within its conditioning tank and from time to time flushes them away to drain. Ion exchangers are often used for water softening. When an ion exchanger is applied for water softening, it will replace the calcium and magnesium ions in the water with other ions, for instance sodium or potassium. The exchanger ions are added to the ion exchanger reservoir as sodium and potassium salts (NaCl and KCl). A good water softener will last many years, and need little maintenance, besides filling them with salt occasionally. For water softening, three types of salt are generally sold: - Rock salt - Solar salt - Evaporated salt Rock salt as a mineral occurs naturally in the ground. It is obtained from underground salt deposits by traditional mining methods. It contains between ninety-eight and ninety-nine percent sodium chloride. It has a water insolubility level of about 0.5-1.5%, being mainly calcium sulphate. Its most important component is calcium sulphate. Solar salt as a natural product is obtained mainly through evaporation of seawater. It contains 85% sodium chloride. It has a water insolubility level of less than 0.03%. It is usually sold in crystal form. Sometimes it is also sold in pellets. Evaporated salt is obtained through mining underground salt deposits of dissolving salt. The moisture is then evaporated, using energy from natural gas or coal. Evaporated salt contains between 99.6 and 99.99% sodium chloride. Rock salt contains a lot of matter that is not water-soluble. As a result, the softening reservoirs have to be cleaned much more regularly, when rock salt is used. Rock salt is cheaper than evaporated salt and solar salt, but reservoir cleaning may take up a lot of your time and energy. Solar salt contains a bit more water-insoluble matter than evaporated salt. When one makes a decision about which salt to use, consideration should be given to how much salt is used, how often the softener needs cleanout, and the softener design. If salt usage is low, the products could be used alternately. If salt usage is high, insoluble salts will build up faster when using solar salt. Additionally, the reservoir will need more frequent cleaning. In that case evaporated salt is recommended. It is generally not harmful to mix salts in a water softener, but there are types of softeners that are designed for specific water softening products. When using alternative products, these softeners will not function well. Mixing evaporated salt with rock salt is not recommended, as this could clog the softening reservoir. It is recommended that you allow your unit to go empty of one type of salt before adding another to avoid the occurrence of any problems. Salt is usually added to the reservoir during regeneration of the softener. The more often a softener is regenerated, the more often salt needs to be added. Usually water softeners are checked once a month. To guarantee a satisfactory production of soft water, the salt level should be kept at least half-full at all times. Demineralization (DM) Any process used to remove minerals from water, however, commonly the term is restricted to ion exchange processes. Deionisation entails removal of electrically charged (ionised) dissolved substances by binding them to positively or negatively charged sites on a resin as the water passes through a column packed with this resin. This process is called ion exchange and can be used in different ways to produce deionised water of various qualities. Strong acid cation + Strong base anion resin systems These systems consist of two vessels - one containing a cation-exchange resin in the hydrogen (H+) form and the other containing an anion resin in the hydroxyl (OH-) form (see picture below). Water flows through the cation column, whereupon all the cations are exchanged for hydrogen ions. The decationised water then flows through the anion column. This time, all the negatively charged ions are exchanged for hydroxide ions which then combine with the hydrogen ions to form water (H2O). These systems remove all ions, including silica. In the majority of cases it is advisable to reduce the flux of ions passed to the anion exchanger by installing a CO2 removal unit between the ion exchange vessels. This reduces the CO2 content to a few mg/l and brings about a reduction of the following strong base anion resin volume and in the regeneration reagent requirements. In general the strong acid cation and strong base anion resin system is the simplest arrangement and a deionised water that may be used in a wide variety of applications can be obtained with it. Strong acid cation + weak base anion + Strong base anion resin systems This combination is a variation of the previous one. It provides the same quality of deionised water, while offering economic advantages when treating water which contains high loads of strong anions (chlorides and sulphates). The subtitle shows that the system is equipped with an extra weak base anion exchanger before the final strong base anion exchanger. The optional CO2 removal unit may be installed either after the cation exchanger, or between the two anion exchangers (see picture below). The regeneration of the anion exchangers takes place with caustic soda (NaOH) solution first passing through the strong base resin and then through the weak base resin. This method requires less caustic soda than the method described before because the remaining regeneration solution after the strong base anion exchanger is usually sufficient to regenerate the weak base resin completely. Moreover, when raw water contains a high proportion of organic matter, the weak base resin protects the strong base resin. Mixed-bed Deionisation In mixed-bed deionisers the cation-exchange and anion-exchange resins are intimately mixed and contained in a single pressure vessel. The two resins are mixed by agitation with compressed air, so that the hole bed can be regard as an infinite number of anion and cation exchangers in series (mixed bed resin). To carry out regeneration, the two resins are separated hydraulically during the loosening phase. As the anion resin is lighter than the cation resin it rises to the top, while the cation resin falls to the bottom. After the separation step the regeneration is carried out with caustic soda and a strong acid. Any excess regenerant is removed by rinsing each bed separately. The advantages of mixed bed systems are as follows: - the water obtained is of very high purity and its quality remains constant throughout the cycle, - pH is almost neutral, - rinse water requirements are very low. The disadvantages of mixed bed systems are a lower exchange capacity and a more complicated operating procedure because of separation and remixing steps which have to be carried out.