摘要 |
Process for producing fully desalted process water by the treatment of raw water with cation and anion exchangers in a separate multi-stage arrangement. The water which leaves the main cation exchanger stage or stages, has a residual sodium content of less than 0.5 mg Na/l before entering the anion exchange stage. Such water is fed through a strong acid cation exchanger stage, in which the exchanger material is present at a maximum of 50 percent as a suspended bed and the remainder as a solid bed. The exchanger material in the strong acid cation exchanger stage following the first strong acid cation exchanger stage, is present at a maximum of 25 percent as a suspended bed and the remainder as a solid bed. |