Sodium softening purpose

For practical purposes, it generally makes sense to use sodium softeners for RO feed flow rates of less than about 20 gpm rather than conventional, flow-proportional control difficulties in feeding based on flow control are exacerbated at low flow rates because of limited turn down on proportioning chemical feed pumps at low flow rates. However, when Nalco Company s 3D TRASAR technology is used, antisealant can be fed to RO systems operating feed flow rates as little as 3 gpm.2... 

Polytetrafluorethylene (p.t.f.e.) This polymer does not absorb water, has no solvents and is almost completely inert to chemical attack molten alkali metals and sodium in liquid ammonia are the rare exceptions. Furthermore it does not soften below 320°C, is electrically inert and has a very low coefficient of friction. It is more expensive than general purpose plastics, requires special fabrication techniques, is degraded by high energy radiation, and has a low creep resistance. 

A natural ion-exchange material used for softening water and other purposes. Typically minerals of hydrated aluminum or sodium silicates. 

Hot Lime Zeolite-Split Stream Softening. Many raw waters softened by the first two processes would contain more sodium bicarbonate than is acceptable for boder feedwater purposes. Sodium bicarbonate will decompose in (lie boiler water to give caustic soda. Caustic soda in high concentrations is corrosive and promotes foaming. The American Boiler Manufacturers Association has adopted the standard that the alkalinity content should not exceed 20% of the total solids of the boiler water. Split stream softening provides a means for reducing the alkalinity content. 

Uses of sodium carbonate. In its various forms, more than 3 million tons of soda are used annually. Approximately one-half of this amount is used in the production of other chemicals, about one-fourth is used in the manufacture of glass, and the remainder is used for a variety of purposes including the production of pulp and paper, soap, textile products, and petroleum. Appreciable quantities of sodium carbonate are also used in water softening. 

The metaphosphates are used as water softeners (Chap. 15). Sodium hexametaphpsphate, Na PeOig, is especially effective for this purpose. 

Chem. Descrip. Monocarboxylic lauric deriv, sodium salt Uses Raw material for detergents, shampoos, dishwashers textile softeners, paint emulsifiers, all-purpose washing agents Properties Liq. 38% cone. 

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