Regeneration of mixed bed resins

Patent metadata

Field	Value
Publication number	US-10287186-B2
Application number	US-201615566652-A
Country	US
Kind code	B2
Filing date	Apr 13, 2016
Priority date	Apr 15, 2015
Publication date	May 14, 2019
Grant date	May 14, 2019

Abstract

In an ion-exchange separation system, a single regeneration column provides for separation of anion and cation resins and the regeneration of both cation and anion resins with a very low level of cross-contamination. After regeneration most of the anion layer in the column is withdrawn, and most of the cation layer is withdrawn, but a portion of each layer adjacent to the interface between the layers remains in the column, to isolate these cross-contaminated portions from the regenerated resins. The withdrawn, regenerated anion and cation resins are placed back into the working vessel.

First claim

I claim:

1. In an ion exchange water treatment system using a mixed bed separator with cation and anion resins, a method for regeneration of the cation and anion resins with minimal cross-contamination, comprising:
transporting the mixed resins from a working vessel to a separation/regeneration column,
separating the anion resins from the cation resins using an upflow of backflush water, thus to divide the bed into two well stratified cation and anion layers, with the anion layer above,
regenerating the anion resin layer by flowing a regenerating alkaline liquid down through the anion layer, and regenerating the cation resin layer by flowing a regenerating acid liquid up through the cation resin layer, while withdrawing from the column the regenerating acid and alkaline liquids essentially at an interface between the anion and cation layers,
rinsing the respective regenerated layers with water, thus resulting in two clearly differentiated layers of regenerated cation and anion resins, withdrawing most of the anion resin layer from the column, leaving a residual bottom portion of the anion resin layer remaining in the column, on top of the cation resin layer,
withdrawing most of the cation resin layer from the column, from a withdrawal level essentially at the bottom of the column, leaving a residual portion of the cation resin layer remaining in the column, below the remaining anion bottom portion,
leaving behind the residual bottom portion of the anion resin layer and the residual portion of the cation resin layer, the two portions together including cross-contamination, to remain in the separation/regeneration column, subsequently to be mixed with a bed of cation and anion resins in a succeeding cycle of resin regeneration, and
reintroducing the withdrawn, regenerated anion resins and the withdrawn, regenerated cation resins to the working vessel,
whereby the resins are regenerated with minimal cross contamination in a single separation/regeneration column.

2. The method of claim 1 , wherein the anion resin and the cation resin are transported directly back to the working vessel on being withdrawn from the column.

3. The method of claim 1 , wherein the regenerating of the anion resin layer and the regeneration of the cation resin layer are performed simultaneously.

4. The method of claim 1 , wherein fluidization water is introduced up through the bottom of the column and through the cation layer during withdrawal of the anion resin layer, helping prevent contamination of the cation resin layer.

5. The method of claim 1 , wherein fluidization water is directed from the bottom of the column up through the cation resin layer during withdrawal of the cation resin layer.

6. The method of claim 1 , wherein transport water is introduced in the column from above the anion resin layer during anion resin withdrawal.

7. The method of claim 1 , wherein the withdrawal level for the cation resin layer is about 5 cm above the bottom of the column, to allow fluidization by an upflow of fluidization water during cation resin withdrawal.

8. The method of claim 1 , wherein each of the anion and cation portions remaining in the separation/regeneration column is about 15 to 20 cm deep.

9. The method of claim 1 , including measuring withdrawal of the cation resin layer so as to leave a preselected depth of the cation layer remaining as said small portion of the cation layer.

Assignees

• Ovivo Inc

Inventors

• Dominique Gensbittel

Classifications

• C02F1/42 Primary

  by ion-exchange (ion-exchange in general B01J) · CPC title

• C02F2303/16

  Regeneration of sorbents, filters · CPC title

• B01J47/04

  Mixed-bed processes · CPC title

• C02F2001/427

  using mixed beds · CPC title

• B01J49/09

  of mixed beds · CPC title