REGENERATION OF CATION EXCHANGE RESIN OF MIXED BED TYPE DESALTING APPARATUS

摘要

PURPOSE:To shorten a water passing washing time by passing an acid solution through a cation exchange resin containing a very small amount of an anion exchange resin separated by utilizing specific gravity difference to regenerate the same and extruding the acid solution before washing the regenerated resin with a boric acid solution. CONSTITUTION:A mixed bed resin consisting of a strongly acidic cation exchange resin and a strongly basic anion exchange resin is transferred to a cation exchange resin regeneration tower B from a mixed bed type desalting tower A and both resins are separated by utilizing specific gravity difference. Subsequently, the anion exchange resin 2 of the upper bed is transferred to an anion exchange resin regeneration tower C and the cation exchange resin 1 containing a very small amount of the anion exchange resin is left in the regeneration tower B. Next, an acid solution such as hydrochloric acid being a regenerating agent is passed through the tower B from a chemical injection pipe 3 to discharge a waste washing solution from a drain pipe 4. Whereupon, the cation exchange resin 1 is regenerated and the exchange group of the anion exchange resin mixed in a very small amount is converted to a perfect chlorine ion type by ion exchange. After regeneration, pure water is passed through the tower B in the same amount as the acid solution from the chemical injection pipe 3 to wash the resin I and a boric acid solution is passed through the tower B from a washing water pipe 5 to wash the resin 1 and discharged from the drain pipe 4.