Rinse Cycle:

The rinse cycle removes remaining brine from the tank. Normally 10 minutes of Rinse flow equivalent to service flow is sufficient to rinse out excess brine.

Though synthetic softening resins normally last 5 years or so, but certain conditions can cause resin to breakdown earlier. Oxidation by chlorine is probably the most common cause of resin breakdown. When chlorine is used to oxidize iron in the water, the chlorine should be removed before ion exchange.

Secondly Iron will significantly affect the ability of resins to remove hardness ions. Ferrous iron can be oxidized during softening and precipitate out as iron oxide on the resin, and no amount of brine will remove the iron fouling. If iron oxide is formed before ion exchange unit, it can be filtered out by the resin and removed during the backwashing of the unit. Normally if the iron concentration in the source water is high, iron removal is provided ahead of the exchange unit to prevent fouling of the unit.

Turbidity, organic chemicals, and bacterial slimes resins resulting in the loss of some of the resin exchange capacity. The best solution is to remove of the suspended matter with filtration before the softening process.

ADVANTAGES OF ION-EXCHANGE SOFTENING:

Compared with lime-soda ash softening, ion-exchange has certain advantages. It is compact and has a low capital cost. The chemicals used are safer for the operator to handle and operation is much easier. It can be totally automated. Softeners also can be Automatic duplex type to ensure continuous supply of soft water in case of critical application like Boiler Feed etc. Many systems have found ion-exchange to be the most cost effective way to produce quality water for their customers.