Softening is a process where Calcium and Magnesium ions are exchanged for Sodium ions. Calcium and Magnesium ions associated with Alkalinity contribute for scale formation. These ions are also called as Total hardness. The strong acid Cation exchange resin in Sodium form is used for softening the water. When the resin is exhausted, it is regenerated with brine solution (Sodium Chloride) 10 % or 15% brine solution is normally used for the regeneration. If the brine solution is passed from the bottom of the resin and service flow is from the top, then it is called as Up flow softener. If the service and regeneration flows are from top to bottom, then it is called as down flow softeners. The softeners are run up to the Hardness slip of 5 ppm as CaCO3 in the treated water, which is called as Industrial Zero hardness.
HOW DOES A WATER SOFTENER WORK?
The idea behind a water softener is simple. The calcium and magnesium ions in the water are replaced with sodium ions. Since sodium does not precipitate out in pipes or react badly with soap, both of the problems of hard water are eliminated. To do the ion replacement, the water in the house runs through a bed of ion exchange resin. The resins are covered with sodium ions. As the water flows past the sodium ions, they swap places with the calcium and magnesium ions. Eventually, the resin contains nothing but calcium and magnesium and no sodium, and at this point they stop softening the water. It is then time to regenerate the ion exchange resin. Regeneration involves soaking the resin in a stream of sodium ions. Salt is sodium chloride, so the water softener mixes up a very strong brine solution and flushes it through the resin bed. The strong brine displaces all of the calcium and magnesium that has built up in the resin and replaces it again with sodium. The remaining brine plus all of the calcium and magnesium is flushed out through a drainpipe
Advantages of Soft Water
Additional Benefits of Soft Water