The Advantages of a Twin-Tank Water Softener

Superior Product Quality and Continuous Service at an Affordable Price

Twin Tanks Provide Continuous Soft Wate

1),Twin Tank Systems
A softening system is designed to continuously supply soft water. This is achieved in one of two ways. One option is to have a single softener resin tank, regenerating it at times when no one is using water – typically 2 a.m. In order to do this, the softener must have a reserve capacity as discussed previously. 
The optimal solution is a twin tank system which provides continuous soft water yet only regenerates when the softener capacity is fully used. In a twin tank system, one tank is online and producing soft water while the other one is regenerated and then waits offline, fully regenerated. When online tank capacity is reached, the offline tank is brought online and the depleted tank is taken offline and regenerated. Because regeneration can occur as soon as the capacity of the system is met, no reserve is required.
2)Quartz sand filter 
Quartz sand filter also namely pressure filter mainly remove the solid particles from suspension and in turn reduce the load on the biological section of the filter.It also mainly as the pretreatment of softening, desalination system.The filter material mainly refined quartz and anthracite.Body material mainly can be FRP and SS housing 
3)Activated carbon filter 
It Mainly absorb the free chlorine in water( removal rate over 90%),filtration can effectively reduce some of these organic,inorganic substance as well as chroma, and residual chlorine.It’s also can be the pretreatment equipment before softening, desalination 


Each particle/granule of carbon provides a large surface area/pore structure, allowing contaminants the maximum possible exposure to the active sites within the filter media. One pound (450 g) of activated carbon contains a surface area of approximately 100 acres (40 Hectares).
4) How a Water Softener Works
Cation exchange resin is also known as cation deionization resin or water softener resin depending on how it is chemically charged. 
Cation (Cat-Ion resin in the sodium (Na- form is used to soften water by trading calcium (ca and magnesium (mg for sodium (na .A standard whole-house water softener works on the principle of ion exchange, called “cation exchange.” It conditions, or “softens,” hard water by substituting sodium chloride (salt) for hard minerals such as calcium, magnesium, and iron.
The Ion Exchange Softening Process 
In the ion exchange water softening process, water is passed through a bed of 
sulfonated styrene-divynalbenzene spherical resin beads (about 1 mm in diameter). 
The exchange sites created on the beads by the sulfonation process are then 
saturated with sodium ions by passing a brine solution through the resin. The ion exchange “softening” process takes place when the hardness ions, Ca++ and Mg++ 
attach themselves to the resin beads causing the sodium ions on the resin beads to be 
released into the water. 
Using an Ion Exchange Column (R = Ion Exchange Resin Site) 
Ca++ (aq) + Na2R(solid) 
 
 CaR(solid) + 2Na+ (aq)


When the resin becomes saturated with calcium and magnesium, it is regenerated by 
passing an NaCl brine solution through the resin. The high concentration of sodium 
ions in the brine causes the reaction to be reversed with sodium replacing the calcium 
and magnesium ions which are then discharged into the waste water. 
2Na+ 
+ (aq.con.) + CaR (solid) 
 Na2R (solid) + Ca++ (aq) 
 
All true water softeners work on this principal. 
 
This type of scale can be prevented by an ion exchange water softener, or by a 
dealkalizer. A dealklizer is an anion exchanger which removes the carbonate CO3
= 
component, thus preventing a calcium or magnesium carbonate scale from forming. 
 
Unfortunately more serious problems arise if significant quantities of sulfate ion are 
present in the hard water (as they usually are). In this case, heating may produce a 
precipitate of calcium sulfate, which, curiously enough, is less soluble at high than at 
low temperatures: 
Ca++ (aq) + SO4
= (aq) CaSO4 (solid)
Crystals of calcium sulfate are particularly likely to form in a steam boiler in which 
water is constantly being vaporized, thereby increasing the concentrations of Ca++ 
and SO4
= ions. The calcium sulfate deposits as a hard, almost insoluble scale, which 
lowers the heat conductivity of the boiler. Eventually, the deposition of calcium sulfate 
in boiler tubes may block the flow of water and lead to rupture of the pipes. 
 
The surest way to prevent any type of hardness scale buildup is with an ion exchange 
water softener whose objective is the removal of Ca++ and Mg++ ions. 
 
Ca++ (aq) + Na2R (solid) CaR (solid) + 2 Na+
 (aq) 
 
“R” again represents the ion exchange resin. The net effect of this process is the 
replacement of Ca++ and Mg++ ions responsible for hardness with unobjectionable 
Na+ ions. Other cations, especially those with a greater ion exchange affinity, such as 
the dissolved cations of radium, barium, lead, strontium, copper, zinc, and iron will 
also be removed from the water in the ion-exchange water softening process. In the 
ion exchange process there is no precipitate to filter off since the Ca++, Mg++, and all 
other multi-valent cations are selectively removed by the resin. 

How the Twin-Tank Softener Works

Water Softening Process

Hard water enters the water softener system.  As it passes through the resin inside the tank, the hard water minerals are attached to the resin and the water is softened to service the home.

Regeneration Process

When the resin becomes saturated with hard water minerals, the water softener system goes automatically into regeneration.  This is the process that frees the resin of hard water minerals, making it ready to soften the water again.

Brine water is drawn into the tank and rinses the hard water minerals off the resin and down the drain. Once the resin is free of hard water minerals, soft water rinses the remaining brine water out of the system leaving the system ready for service.

Regeneration Process

A twin-tank system assures that there is always soft water available.  The water softener system automatically switches the flow to the fresh second tank while the first tanks is regenerating.  Thus, the system always delivers soft water without interruption.