INDUSTRIAL WATER SOFTENING

Water Treatment:

Ion Exchange Water Softening Plant:

The Ion-exchange resin contains a macro molecular organic polymer called cat-ion exchange resin. Let this be RNa where R- is the resin part and Na+ is sodium radical. When hard water is passed through this resin, the Na ion replaces Ca++/Mg++ ion in water and thus the water becomes soft.

  Ca(HCO3)2   + RNa  = NaHCO3 + RCa   (Not Balanced)

  Mg(HCO3)2  + RNa  = NaHCO3 + RMg  (Not Balanced)

  CaSO4              + RNa   = Na2SO4   + RCa   (Not Balanced)

  MgSO4            + RNa   = Na2SO4   + RMg  (Not Balanced)

When continuously water is passed through this resin, the Ca++ and Mg++ and other heavy earth metals will replace all the Na+ radical in the resin and thus the resin will become fully exhausted of Na+ ions.

Hard water does cause soap scum, clog pipes and clog boilers.

Soap scum is formed when the calcium ion binds with the soap. This causes an insoluble compound that precipitates to form the scum you see. Soap actually softens hard water by removing the Ca²⁺ ions from the water.

When hard water is heated, CaCO₃ precipitates out, which then clogs pipes and industrial boilers. This leads to malfunction or damage and is expensive to remove.

The exhausted resin can be regenerated using a concentrated solution of common salt. During this process all the unwanted Mg++ and Ca++ ions are replaced by Na+ ions and thus the resin becomes ready for next cycle of operation.       

Standard Water Quality for dyeing -

Standard for Textile Dye House Water Supply The following lists the minimum standards which a textile dye house water supply should meet. To achieve these levels it may be necessary to pre-treat the water before it is used for wet processing or dyeing.