Water softening system is used to decrease the hardness of water, mainly to remove Calcium and Magnesium ions in the water. It do not decrease the salt content during the water softening process.
Working principle of water softening system
Water hardness is mainly formed by Calcium and Magnesium, so we usually use cation exchange resin (water softener), to displace Ca2+ and Mg2+ in the water, resin efficiency to remove Ca2+ and Mg2+ will decrease as the Ca2+ and Mg2+ in the resin increase. Resin need to regenerate after absorbing a certain amount of Magnesium ions, salt solution of salt tank washes resin layers and displace the hard ions in the resin, as the generating waste liquid is excluded from the can, resin recover its softening exchange functions. We know that the principle of sodium ions exchange softening treatment is that raw water exchanges resins through sodium ions, to exchange Ca2+ and Mg2+ with Na+ in the resin, thus absorbing Ca2+ and Mg2+, then water is softened. If RNa stands for Na resin, the exchange process is as follows:
2RNa + Ca2+ = R2Ca + 2Na+
2RNa + Mg2+ = R2Mg + 2Na+
Running process of control valve:
Run, reverse washing, salt absorbing, slow washing, tank water replenishing, washing.
