Softening

Softening systems for drinking and industrial water Softening process: The hardness components calcium and magnesium result in many processes to malfunctions to the following equipment. For many process waters, therefore, a water softener is required. The softening process via ion exchange process takes place. Poorly soluble calcium - magnesium - ions are replaced by more readily soluble sodium ions. The water is soft. The salinity of the water remains unchanged. When the ion exchange resin is exhausted it is regenerated with brine. The regeneration may be triggered in several ways: • Timed, consumption is unregarded • Volume controlled, does not take account for variations in raw water hardness • Quality controlled, consider consumption and hardness variations. Pretreatment: Whether and in what form, the raw water must be prepared for the water softener depends on the raw water quality. Iron, manganese block the ion exchange resin irreversible, the consequence of this is that the capacity of the plant decreases. If the limit values for iron and manganese are exceeded, an appropriate filter system must be provided. Turbidity and suspended solids may also affect the ion exchanger, particularly in countercurrent softening systems, it is necessary that the raw water is free of sediments and suspended substances. Method: There are different methods for softening and regeneration Down stream, mainly for central control valves, regeneration takes place from top to bottom, as in the operation of the plant. Remote control valves are available as time or volume - controlled execution, the central control valves carry out the following steps: 1. Backwash, loosening of the ion exchange resin, flushing out impurities. (from the bottom of the tank upwards) 2. brine intake (from the top of the tank downwards) 3. slow rinse (from the top of the tank downwards) 4. Quick Rinsing 5. (from the top of the tank downwards) operation (in from above Tank downwards) Advantages of the down stream method: no major problems with plant shut down, fluctuating quantities Disadvantages: High salt and rinse water consumption. up stream process with individual valves and microprocessor or PLC control, volume or quality control 1. brine intake (from the top of the tank downwards) 3. slow rinse (from the top of the tank downwards) 4. Rapid rinse (from the top of the tank downwards ) 5. Operation (from the bottom of the tank upwards) advantages of the current method: much lower consumption of salt and water, about 50% saving; disadvantages: problems with system downtime and strongly fluctuating quantities