EDI purified water equipment
Release date: November 27, 2019 11:54:06
1. Introduction to EDI
EDI is a new desalination process which combines electrodialysis with ion exchange. In this technology, the electro regeneration ion exchange desalination process is used to replace the traditional mixing process
Ion exchange desalination process di. High desalting effect can be achieved by ion exchange resin and selective ion membrane. The combined process of reverse osmosis and ion exchange resin can achieve high desalination effect of 10 ~ 15m Ω. EDI adopts standard component design and can be combined into different specification systems according to requirements
2. EDI working principle
The cation exchange module will be filled with cation exchange membrane between the cation exchange module and EDI module. EDI cells are separated from each other by a certain number of EDI cells. The negative / positive electrodes are arranged at both ends of the unit group. Driven by direct current, the cation and anion in the water flow through the fresh water chamber pass through the anion and cation exchange membrane and enter the concentrated water chamber to be removed in the fresh water chamber. The water passing through the concentrated water chamber will take the ions out of the system and become concentrated water. EDI equipment generally uses secondary reverse osmosis (RO) pure water as EDI feed water. The resistivity of RO pure water is generally 40-2 μ s / cm (25 ℃). The resistivity of EDI pure water can be as high as 18 m Ω· cm (25 ℃), but according to the use of deionized water and system configuration settings, EDI ultra pure water is suitable for the preparation of pure water with resistivity requirements of 1-18.2m Ω. Cm (25 ℃).
EDI technology is widely accepted by pharmaceutical industry, microelectronics industry, power generation industry and laboratory. In the surface cleaning, surface coating, electrolysis industry and chemical industry, high-purity water equipment is increasingly widely used.
(1) the quality of produced water is high (maximum 18 m Ω. Cm);
Simple and safe operation. Convenient management;
(3) no shutdown due to regeneration;
There is no need for regeneration of acid-base chemicals;
(5) low operation cost;
Small floor area