Since the hardness of water is mainly formed and expressed by calcium and magnesium, cation exchange resins (water softeners) are generally used to replace Ca2+ and Mg2+ (the main components that form scale) in the water. With the increase of Ca2+ and Mg2+ in the resin, The effectiveness of resin to remove Ca2+ and Mg2+ gradually decreases.
When the resin absorbs a certain amount of calcium and magnesium ions, it must be regenerated. The regeneration process is to wash the resin layer with salt water in the salt box to replace the hardness ions on the resin, and then discharge the resin out of the tank with the regeneration waste liquid. The soft exchange function has been restored.
Since the hardness of water is mainly formed by calcium and magnesium and expressed because the hardness of water is mainly formed by calcium and magnesium and the principle of sodium ion exchange softening treatment, the raw water is passed through sodium-type cation exchange resin to make the hardness components Ca2+, Mg2+ and The Na+ in the resin phase exchanges, thereby adsorbing Ca2+ and Mg2+ in the water, so that the water is softened. If RNa represents sodium resin, the exchange process is as follows:
2RNa + Ca2+ = R2Ca + 2Na+
2RNa + Mg2+ = R2Mg + 2Na+
After the water passes through the sodium ion exchanger, the Ca+ and Mg+ in the water are replaced with Na+.
The general operating process of the control valve is: running, backwashing, salt absorption, slow washing, salt tank water replenishment, and forward washing.