AUTOMATIC SOFTENING PLANTS
By softening, the water content of calcium and magnesium salts - the water hardness builders - are changed for sodium salts which do not provide the inconveniences characterizing hard water. When the resin has been saturated with calcium and magnesium salts, regeneration takes place with brine, which drives out the accumulated calcium and magnesium salts to drain.
The plants are normally 2-tank plants for continuous operation with one tank operating, while the other regenerates or is in stand-by position. Single plants are, how- ever, available for water supplies which stand interruption during regeneration (about 2 hours).
THE PRINCIPLE OF METER CONTROL
A contact water meter on the outlet of the plant records the consumption of softened water and gives pulses to the control panel proportional to consumption. After consumption of water corresponding to one filter tank capacity, the control panel initiates regeneration of the tank due for regeneration. Thus the plant regenerates in accordance with water consumption. During regeneration, one filter tank is taken out of service simultaneously with the other supplying softened water. After regeneration, the filter tank automatically goes into stand-by position.