Introduction to EDI
Continuous electrodeionization (EDI, Electro, deionization) is the use of mixed ion exchange resin adsorption of ions in the water, while the absorbed ion in the DC voltage under the effect of yin and Yang respectively through ion exchange membrane process was removed. In this process, the ion exchange resin is continuously regenerated by electricity, so it is not necessary to use the regeneration process. This new technology can replace the traditional ion exchange equipment to produce high quality water
Two, the characteristics of EDI
1, EDI without chemical regeneration EDI regeneration without downtime
2, to provide stable water quality low energy consumption
3, easy operation and management, low labor intensity and low operating costs
4, the use of reverse osmosis technology to remove salt, and then use the EDI technology for two times the salt can completely make the pure water manufacturing process to avoid the use of acid-base regeneration.
Three, the working principle of EDI
In the EDI device, various ions in the water are removed after being exchanged by the resin, and the water is purified. This is the use of ion exchange theory to remove ions in water. Due to the membrane voltage on both sides, the water molecules are electrolytic hydrogen ions and hydroxyl ions to regenerate resin, at the same time, by hydrogen ions and hydroxyl ions by ion exchange under the action of current, are migrated to the concentrated water chamber and discharge, so as to achieve the purpose of using the continuous continuous regeneration.
(1) the distribution of water into the EDI module;
(2) under the action of direct current, various ions migrate to the corresponding electrode;
(3) and mixed bed, all kinds of ion in water by ion exchange and ion exchange resin, were exchanged over the respective ion exchange membrane to migrate to the concentrated water. The water in the fresh water chamber is discharged into the module (only the ions can pass through the ion exchange membrane, and the water can not pass).
(4) concentrated water circulation in concentrated water. In order to improve and maintain the conductivity of the concentrated water chamber, most of the concentrated water is recycled;
(5) the concentrated water of circulation needs less discharge, which is added by water. This part of the discharge of water can be returned to the former level of the RO device reuse;
(6) the water molecules are ionized hydrogen ions and hydroxyl ions under the action of voltage, migration to the resin layer over the respective ion exchange membrane, continuous regeneration of trees