Abstract: A method of regenerating an ion exchanger which is used to treat a solution introduced to the ion exchanger in a downward changing direction. The ion exchanger contains a non-constrained bed of ion exchange material in the form of ion exchange granules and has a concentration profile through the ion exchange material after solution has been introduced to the ion exchanger in the charging direction. The method of regenerating comprises passing a regenerating solution upwardly through the non-constrained bed of ion exchange material in an intermittent flow manner comprising an alternating up flow of regenerating solution followed by a down flow of liquid in a direction opposite to the up flow. The duration and velocity of the up flow of regenerating solution is sufficient to lift and generate a perceptible mixing of ion exchange materials in approximately the bottom portion of the ion exchange bed, with the down flow being sufficient to seat the bed very rapidly and terminate mixing.

Abstract: The invention concerns an ion exchange process and system, particularly for the regeneration step following a softening or desalination of aqueous solutions. The regenerant solution is fed in an upward stream through the ion exchanger in a direction opposite to the charging direction, as a sequence of intermittent pulse intervals consisting of pulse flow followed by a period of no flow. During the pulse flow, there is limited hydrodynamic lifting of the ion exchange resin beds in layers, followed by subsequent sedimentation during the pause period, without mixing of the layers.