Water softener, Pressure : 0.2~0.6 mpa

The Water Softener offered by the company is used for boiler feed or in hot water piping, hard water will cause scale to form since most calcium and magnesium salts are less soluble at high temperature than at normal temperatures. sodium salts do not contribute to hard scale formation so water containing only sodium salts is called soft water. The convert hard water to soft waters the calcium and magnesium salts are removed or changed to sodium salts.
In the ion exchange softener, the hard water flows through the bed of strong acid cation exchanger which causes the calcium and magnesium ions in the hard water to be exchanged for sodium ions, so that the treated water turns to soft water.
The softening process may be illustrated by the following reactions
Ca (HCO3) 2 +2 Nar CaR 2 +Na HC03
Calcium Sodium Calcium Sodium
Bicarbonate Ion Exchange Ion Exchange Bicarbonate
Mg SO4
Magnesium Sodium Magnesium Sodium
Sulfate Ion Exchanger Ion Exchanger Sulfate
The letter R represents the ion exchange resin. Obviously this softening process can continue only as long as the ion exchanger can supply sodium to replace the calcium and magnesium in the raw water. Like the electric storage battery, the ion exchanger bed must be regenerated at certain intervals to replenish the sodium in the ion exchanger bed.
When the ion exchanger bed is no longer capable of softening, the sodium ion exchanger having been converted to calcium and magnesium ion exchanger, it must be returned to its original state by regeneration with dilute brine. Exhaustion of the ion exchanger bed is indicated by the gradual appearance of hardness in the effluent.
The regeneration process is indicated by the following reaction.
2 Nacl + CaR2 2 Nar + CaCl2
2NaCl MgR2 2NaR MgCl2
Sodium Calcium and Sodium Calcium
Chloride Magnesium Ion Exchanger Magnesium
(Salt, Brine) Ion Exchanger Chlorides.
The brine passes through the ion exchanger bed exchanging its sodium ions for the calcium and magnesium ions on the ion exchanger. The ion exchanger is returned to the sodium form for further use. While the spent brine containing the calcium and magnesium is rinsed from the bed and sent to drain.
Inlet Water Quality
Because the ion exchanger must be kept clean to function efficiently the water to be treated must be free of suspended matter such as oil, algae, organic matter and heavy metals such as iron, aluminum. These impurities collect on the ion exchanger particles and reduce their capacity for hardness removal. Hence some waters require coagulation and filtration prior to being fed into the softener. The ion exchanger particles can act as filters, but the softening ability and capacity will suffer and the ion exchanger bed may then require frequent cleaning or replacement.
Although the ion exchanger will remove iron, the iron will coat the ion exchanger and chemically foul it. This may result in corrosion of the internals and also requires frequent ion exchanger replacement.
Output Between Regeneration
The capacity of the ion exchanger for softening water will vary with the type of exchanger and will also depend upon the salt used for regeneration. A high capacity polystyrene based caton exchanger is used in ACSION ion exchange softeners and a suitable quantity of sodium chloride is prescribed for each regeneration.
The unit of water hardness measurement is the milligram per liter as calcium carbonate or mg/lit (as CaCo3).
The raw water hardness, which the softener has been designed to treat and the expected capacity between re-generations is specified in the Data sheet.
The capacity is roughly in inversely proportional to raw water hardness that is, if the hardness increases due to seasonal or other variations in the water, the softener will give a reduced capacity between re-generations.