The presence of some ions such as calcium and magnesium as well as the presence of divalent or multivalent cations in water will be the main causes of sedimentation as well as foam formation. The high hardness of the water will also cause many problems. Using resin hardeners is a common solution to these problems.
Problems that sedimentation and water hardness cause include:
- Creating foam is the result of a reaction between hard ions in water and detergent. This will create stains on a variety of surfaces.
- Non-solvent and sedimentary of soap materials resulting from the reaction with water high hardness. This reduces the efficiency of the detergents usage.
- In industrial applications, the sedimentary of equipment such as cooling towers, boilers, pipes in various equipment, etc., causes clogging of valves, pipes and so on. This will reduce their efficiency significantly and increase energy consumption.
With the above explanations, the necessity of water softening in both domestic and industrial applications seems to be essential. One of the most common systems for doing this is using a resin softener. In this system, water-soluble calcium and magnesium ions are separated by the ion exchange method with the help of cationic resins. In fact, hard water, which contains calcium and magnesium, is substituted with the sodium with the help of resin and the so-called soft water is produced.
One way to reduce the minerals dissolved in water is to use an ion exchange method. This method is very effective for removing some of the minerals in the water. This method uses ion exchange resins, or resin softener (water softener).
What is water hardness and water softener?
Water Hardness is actually due to the presence of divalent cations or more in the water. It should be noted that the most important divalent metals in water are calcium and magnesium. Iron, manganese and aluminum are also present in surface water at very low concentrations.
It is also worth noting that most underground water is more concentrated than surface water because of its greater contact with carbonate sources.
There are generally two types of water hardness: 1- temporary water hardness 2- permanent water hardness.
Temporary Water Hardness: Temporary water hardness is related to the presence of calcium and magnesium carbonates and bicarbonates. Because it builds up in the vicinity of heat and precipitates out of water, it is called temporary water hardness. For example, sediments attached to the kettle inside surface are of this type of hardness.
Permanent Water Hardness: Permanent water hardness is related to sulfates, chlorides and nitrates of divalent cations and above. Given that this type of hardness gets out of the water by heating it is called permanent hardness. Finally, the total hardness refers to the sum of the temporary and permanent harnesses of water. The hardness unit is ppm or CaCO3 mg / L.
Water hardening systems are often used to reduce or even eliminate water hardness, often with using resins oftener. Using a softener can significantly reduce water hardness. It should be remembered that the degree of water hardness is a factor in determining the amount of water hardness and is usually equivalent to one mg of calcium carbonate in the water.
Ion exchange resin
Ion exchange resins are of two types: cationic (positive charge) and anionic (negative charge) resins. As a result of ion exchange, the cations or anions in solution are replaced with the anions and cations present in the resin. So that both the solution and the resin remain electrically neutral. Ion-exchange resin or polymer Ion-exchange is a resin or polymer that acts as a medium for ion exchange. Resins are an insoluble matrix (or support structure) typically in small dimensions with a radius (0.25 – 0.5 mm). It is usually white or yellow and is made of organic polymer substrates. These grains are usually porous and provide a high contact surface at and inside them.
The capture of ions is accompanied by the release of other ions, hence this process is called ion exchange. There are various types of ion exchange resins. But most commercial resins are made of polystyrene sulfonate.
Ion exchange resins are widely used in separation, purification and disinfection processes. The most common examples of its use in softening water in a resin softener. In many cases ion exchange resins have been used in such processes as a more flexible alternative to the use of natural or synthetic zeolites. Ion exchange resins are also very effective in biodiesel filtration process.
How does a water softener (resin softener) works?
The resin water softener is packed with resin granules. This is why it is known as resin softener. Hard water containing calcium and magnesium flows through the resin. In the ion exchange process, the hard ions in the water are replaced by soft ions on the resin grains. The result is water that softened.
Over time, the resin granules are coated with calcium and magnesium ions in the water softener. As a result, their capacity to soften water is reduced. Through a process called resuscitation, the pressure water flows automatically through a water softener to a specified value. At this point, the resin grains exchange the soft ions from the regenerator with the hardness of the grains. Most of these systems have a water purifier and a sediment filter, so all types of impurities and sediment accumulated are discharged. The so-called “recharged” resin granules, the water softener, return to the cycle and continue working again.
Advantages of resin softener systems produced by Farab Zist Faraz Co.
- Production of Under pressure tanks in accordance with international standards.
- Working pressure 3 to 7 Bar and test pressure 10 Bar.
- Coating of all exterior surfaces with 3 layers of anti-corrosion coating including zinc rich, epoxy mio, polyurethane.
- Coating all surfaces in contact with water with a special coating of three epoxy paints (Zinc rich and Coal tar epoxy) with a thickness of 250 to 450 microns.
- Use fiberglass coating (FRP) for high corrosive waters and areas with high humidity.
- Produced in three types of manual, semi-automatic and fully automatic.
- Accurate and scientific design based on water quality.
Farb Zist Faraz Co. is active in designing and manufacturing various types of resin softener machines in different capacities of metal and FRP. Contact our experts to find out more about the resin softener price and the details of calculating the resin softener capacity.
Calculate resin softener
There are various factors to calculate the softener capacity of the resin and its efficiency. Factors such as the type of solid adsorbent surface, the amount of contact time for resuscitation, type of the exchange material, the quality of the water, the amount of resuscitation will be effective. Generally, the capacity of ion-exchange materials is in the range of 1–5 meq / g to about 1–2 kg / m۳. Their resuscitation is performed with the aid of 1–2 kg of sodium chloride per cubic meter of resin at a rate of 1 to 2% and a flow of 1 l / min-m۲.