Basic Principles - Water Control Corporation SF Series Owner's Manual

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BASIC PRINCIPLES

A water softener works via a process known as Ion Exchange. In this process, a special media bed is used to exchange undesirable hardness minerals,
including calcium, potassium, and magnesium (as well as low levels of iron and manganese) for something more desirable -- in this case, a small amount
of sodium.
A water softener uses a mechanically driven control valve. During normal operation, this valve distributes the flow of raw (hard) water evenly over the
top of the media bed. As the hard water passes down through the media, hardness minerals -- primarily calcium, which exists in solution in a calcium
bicarbonate form -- are removed from solution and affixed to the media. In place of this calcium, trace amounts of sodium ions are released. What was
calcium carbonate dissolved in the water becomes sodium bicarbonate (i.e., baking soda).
Once the resin has absorbed all the hardness minerals, and released all the sodium, that it can, regeneration is required. Regeneration is the process of
removing calcium/hardness minerals from the media and resetting it with fresh sodium ions. To achieve this, a piston in the softener control valve changes
position. The media is first backwashed, to lift and unpack the bed. Next, it is bathed in a supersaturated brine (sodium chloride) solution. This bombards
the media with sodium ions, forcing the calcium/hardness minerals off and sending them down the drain. A relatively small percentage of sodium ions
remain on the media, though the majority pass to the drain as well. After this brine cycle, the media is rinsed off, the brine tank is refilled, and the system
goes back into service.
When a single tank water softener regenerates, an internal bypass is opened in the control valve. This allows the facility to be served by hard water during
the regeneration period. Typically, this occurs in the middle of the night (2AM being the standard setting). Multi-tank systems regenerate one tank at a time,
with the non-regenerating tanks remaining online (with no periods of hard water being sent to the facility).
Many multi-tank commercial softening systems feature a Progressive Flow functionality. When building flow rates are low, only one tank is online/active.
As water usage increases, more and more units come online. Conversely, as usage decreases, tanks are progressively removed from service and put back
into standby mode. By bringing tanks on and offline, based on demand, we can maximize the softening capacity and efficiency of the media in each tank.
The electronics in the control valves keep track of usage time for each individual tank. Tanks are rotated on and offline in a manner that equalizes usage
across all tanks over the course of 24 hours.
Another common option on larger commercial softening systems is Brine Reclamation, which utilizes an electronic control system and a 3-way motorized
valve to recycle a portion of the supersaturated brine (salt) water that is normally sent down the drain during regeneration. When the recycle interval ends,
the water eventually does go to drain. This ensures fresh brine for each new regeneration. By utilizing Brine Reclamation, a facility will normally see a salt
usage reduction of around 25%-35%, without any negative effects on softener capacity, efficiency, or lifespan.
For more information on commercial water softening systems, please visit WCC's website at: watercontrolinc.com or call us at 763-427-9638.
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Water Control Corporation
7150 143rd Ave NW • Ramsey, MN 55303
Phone: 763-427-9638 • Fax: 763-427-5665
www.watercontrolinc.com
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