| 摘要 |
PURPOSE:To provide a stable and economical means for obtaining high purity treated water, regenerated water is passed through a desalting tower comprising a first mixed bed of combined regenerated resin free from salt type resin and a second mixed bed containing a small amount of salt type resin. CONSTITUTION:Backwashing all resin moved from the desalting tower 1 to the cation regeneration tower 2 separates cation and anion exchange resins, from which cation exchange resin is regenerated by using mineral acid. Next, anion exchange resin and resin mixed portion near the boudary face are moved to the anion regeneration tower 3, backwashed, and anion exchange resin is regenerated by caustic soda. The top layer resin 6 in the tower 2 is moved to the resin mixing bath 5, the bottom layer 7 to the resin mixing bath 4. The top layer 8 of the resin in the tower 3 is moved to the bath 4, and the bottom layer 9 is moved to the bath 5. The boundary face layer 10 at the bottom of the tower 3 is moved to the tower 2 and added to resin which is to be regenrated in the next time. The resin from the bath 5 is filled in the bottom of the tower 1 to form a mixed bed 12 containing salt type resin and the resin in the bath 4 is made a mixed bed 11. Depending on the quality of regenerated water, the operation is either NH3 cycle run using only the mixed bed 11 or the H cycle run using the entire beds. |
