What is a water softener?An ion exchange water softener is the most common type of equipment used in the removal of scale-forming calcium and magnesium ions (known as temporary hardness) from hard water. In many cases, a water softener can also be used to remove ferrous (soluble) iron from a supply. Typically a water softener supplied by Aquarius Water Systems has four major components which are also available separately as spares.Typical components of a water softener:

• a pressure vessel to contain the ion exchange resin
• the ion exchange resin
• a control valve (i.e. Fleck, Siata or Autotrol)
• a brine tank

The size of water softener required varies according to the flow-rate and the hardness of the feed water. Aquarius Water Systems stock a large range of commercial and industrial water softeners and can offer a bespoke plant for specific applications or requirements.

Operation.

A standard water softener works by allowing hard water to filter downwards through a bed of ion exchange resin. The ion exchange resin attracts the calcium and magnesium ions (hardness) and replaces them with sodium ions which are less problematic for water systems and will not cause scale build-up. Once the ion exchange resins are saturated with hardness, the regeneration sequence on the water softener begins.

Stage 1

The backwash cycle reverses the flow of the water to pass upwards through the ion exchange resin bed. This operation frees the beads of the ion exchange resin ready for the next step in the regeneration sequence.

Stage 2
In a water softener's regeneration sequence is to saturate the ion exchange resin with a brine solution. It is during stage 2 that the ion exchange resin releases the calcium and magnesium ions and replaces them with sodium ions. Both the calcium and magnesium ions flow along with the water and excess brine solution to drain.

Stage 3
In a water softener's regeneration cycle is a down-flow flush to drain. This removes any excess brine left on the ion exchange resin beds.

Stage 4

Dependant on the type of control valve used.Refills the brine storage tank with the correct volume of brine.
Returns the water softener back into service mode. The frequency of a water softener's regeneration cycle is usually pre-set, using a timer or a counter-signal from a water meter.

Working out what size of water softening plant you need?

As a guide, the information you will need to size your water softener is:

1.The total hardness of the incoming water supply and the required service flow rate.

2.If you need assistance regarding the sizing of a water softening plant, please contact us and we will be happy to help.

Aquarius Water Systems stock various sizes of water softening plants, including simplex water softeners, duplex water softeners and triplex water softeners - ranging from 10" diameter composite vessels to large diameter steel water softeners.

Having problems with your existing water softener plant?

If you are having a problem with an your existing water softener on a site, you can contact us at Aquarius Water Systems where we will be more than happy to give advice or arrange to send one of our service team to help.

The big question, “Can you drink softened water?”

Most water softeners use ion exchange resin which is suitable for potable use. However, the taste may be changed, and more important is that the level of sodium dissolved in the water will increase. There are recommended levels of sodium for drinking water so you should check that the level of hardness in the water, when replaced by sodium in the water softener, does not add to the base level of sodium so much that the sodium exceeds recommended limits. Usual practice is to have an untreated take-off point for drinking before the inlet to the water softener, Or alternatively install a drinking water reverse osmosis system.

How soft should the water be from my water softener?

A water softener will usually effectively reduce water hardness to zero. There will usually be a small leakage level of hardness. This can be reduced further by increasing the salt use when regenerating the water softener. Leakage will be worse if the level of dissolved solids is very high.In very bad water, there is a threshold level of salt use on the ion exchange resin, below which the water softener cannot be used.

What are maximum and minimum flow-rates you get through a water softening plant?

The maximum flow through a water softener is usually limited by the size of the pipe work and the increasing loss of pressure as you try to put more water through the softener. There are recommended limits for using ion exchange resin in a water softening application. These are typically 40 bed volumes per hour (maximum) so, for 100 litres of ion exchange resin, you can soften up to 4,000 litres per hour. How long you can do this for will depend on the hardness of the feed water. Don't try to soften water at a very low rate; it may tend to find the easiest path through the ion exchange resin and exhaust these first, leaking hard water before the whole of the ion exchange resin in the water softener is exhausted (this is often referred to as “trickle flow”). The general rule here is 8 bed volumes, so again for 100 litres of ion exchange resin, the minimum flow rate should not fall below 800 litres per hour.

Typical water softener uses include:

Boiler make up for low pressure boilers
Laundries
Brewing/soft drinks
Dyeing
Food processing
Cooling tower make-up

Manufacturing operations

The presence of hardness salts (calcium and magnesium ions) in the make-up water supplies to boilers, cooling and process waters can have a serious impact on their performance. Loss of heat transfer in boilers and poor cooling in re-circulating cooling systems results in an increase in both energy and water consumption, and an increase in operating costs. Our standard range of units provides service flow rates from 0.65m3/hour to 50 m3/hour, and configuring the units in a duplex or triplex system will provide a further increase in design flow rates. The water softeners have capacities which vary from 4.3m3 to 420m3 with a total input hardness level of 200ppm expressed as calcium carbonate. The water softeners use the well-proven "Ion Exchange" process to convert the hard water ions of calcium and magnesium to sodium ions. The resultant water to service is typically less than 4 ppm total hardness.

Aquarius Water Systems can provide several different control options for instigating automatic water softening plant regeneration:

Water meter control - regenerates after a specified volume of water by counting electrical pulses from the meter supplied with the softening plant.

Time-clock control - regenerates at regular pre-set time intervals.

The water softener vessels are of a seamless pressure vessel in GRP construction with moulded polyethylene inner and glass fibre reinforced wound outer shell for durability and long life.

The Aquarius Water Systems range of water softening plants have several options for salt/brining systems: Standard:A single brine tank is used for both salt storage and brine production.This utilises standard Granular or Tablet salt, supplied in either 25kg or 10kg bags. High Capacity: