Working Principle of EDI High-Purity Water Equipment

In EDI equipment, various ions in the feed water are removed after resin exchange, and the water is purified. The ion exchange principle is used to remove ions from the water. Since the membrane is charged on both sides, water molecules are electrolyzed into hydrogen and hydroxide ions to regenerate the resin. At the same time, ions exchanged by hydrogen ions and hydroxide ions are migrated to the concentrated water chamber and discharged under the action of the current, thereby achieving the purpose of continuous regeneration and continuous use.

EDI Workflow

  1. Water enters and is distributed among the various chambers in the EDI module; under the influence of direct current, different ions migrate to their respective electrodes.
  2. Like in a mixed bed, the various ions in the water are exchanged with ion exchange resin, and the exchanged ions are then migrated to the concentrated water through their respective ion exchange membranes.
  3. The water in the freshwater compartment flows out of the module (only ions can pass through the ion exchange membrane, and water cannot pass through) to become pure water.
  4. A small portion of the recirculating concentrate water needs to be discharged and replenished with feed water. This discharged concentrate water can be returned to the previous stage RO system for reuse.
  5. Under the action of voltage, water molecules are ionized into hydrogen ions and hydroxide ions, which migrate to the resin layer through their respective ion exchange membranes, continuously regenerating the resin.

Application Areas of Ultrapure Water

RO EDI Water Treatment Systems Applications

Ultrapure water is often used in the electronics plating industry, semiconductor chips, power generation industry, pharmaceutical industry, and laboratory water. EDI pure water can also be used in pharmaceutical distilled water, water for food and beverage production, boiler feed water for power plants, and other applications.

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