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China EDI Water System Suppliers | High-Purity Water Equipment Factory for Advanced Water Treatment
Products Video
Products Description
EDI technology substitutes the traditional hybrid ion exchange demineralization process (DI) with an electroregenerative ion exchange demineralization process. High desalination efficiency is achieved through the combined action of ion exchange resin and selective ion membranes, complemented by reverse osmosis to produce water of ultra-high quality, reaching resistivity levels of 10~15MΩ·CM.
How EDI High-Purity Water Equipment Works
1. Electrodialysis
Under the influence of a direct current electric field, ions in water migrate toward oppositely charged electrodes and are separated by selective ion exchange membranes.
2. Ion Exchange
The EDI module is filled with ion exchange resin, which absorbs ions from water and further removes impurities.
3. Regeneration
The ion exchange resin within the EDI module undergoes continuous regeneration under the electric field, eliminating the need for chemical regenerants and enabling continuous operation.
Composition of EDI High-Purity Water Equipment
1. Pre-treatment System
Includes multi-media filters, activated carbon filters, softeners, etc., designed to remove suspended particles, organic matter, and hardness ions from water.
2. Reverse Osmosis (RO)
Acts as pre-treatment for EDI, removing most ions and organic matter from water.
3. EDI Module
The core component that utilizes electrodialysis and ion exchange technology to remove trace ions from water.
4. Post-treatment System
Incorporates UV sterilizers and precision filters to ensure the final water quality meets stringent purity standards.
Conditions of Use
| Water Source | RO water production, conductivity 1-20μs/cm, maximum conductivity ≤30μs/cm (NaCl) |
| Inlet Hardness | < 1.0ppm (CaCO3) (recommended below 0.5ppm) |
| Total CO2 | < 3ppm |
| pH Value | 7.5-9 |
| Influent Organic Matter | TOC < 0.5ppm |
| Influent Oxidizer | Cl2 (active) < 0.03ppm, O3 (ozone) < 0.02ppm |
| Influent Heavy Metal Ions | Fe, Mn, variable valence metal ions < 0.01ppm |
| Inlet Silicon | SiO2 < 0.5ppm |
| Inlet Water Particle Size | < 1μm |
| Temperature | 15℃--35℃ |
| Inlet Pressure (DIN) | 0.15-0.4MPa |
| Concentrated Water Inlet Pressure (CIN) | 0.10-0.3MPa |
| Water Production Pressure (DOUT) | 0.05-0.25MPa |
| Concentrated Water Outlet Pressure (COUT) | 0.02-0.2MPa |
Application Fields
1. Electronics Industry
For the preparation of ultra-pure water in semiconductor and integrated circuit production processes.
2. Power Industry
Used for boiler feedwater, cooling water, and other applications.
3. Pharmaceutical Industry
For injection water, cleaning water, and similar uses.
4. Chemical Industry
For the production of high-purity chemicals.
The EDI device is typically placed after an electrodialyzer or reverse osmosis system (or directly applied to low-salt-content water), replacing ion exchangers to achieve further desalination and produce higher-purity water. It finds widespread application in electronics, chemicals, pharmaceuticals, atomic energy, and power industries.
Frequently Asked Questions (FAQ)
What is EDI technology and how does it improve water quality?
EDI (Electrodeionization) technology replaces the traditional hybrid ion exchange demineralization process (DI) with an electroregenerative process. It combines ion exchange resin and selective ion membranes, working alongside reverse osmosis to produce ultra-high-quality water with resistivity levels of 10~15MΩ·CM.
What are the three core steps in the EDI working process?
The process consists of: 1) Electrodialysis, where ions migrate under a DC electric field through selective membranes; 2) Ion Exchange, where resin inside the module absorbs ions and removes impurities; and 3) Regeneration, where the resin is continuously regenerated electrically without chemicals.
What components make up a complete EDI High-Purity Water System?
A standard system includes a Pre-treatment System (filters, softeners), a Reverse Osmosis System (RO) for initial desalination, the core EDI Module for trace ion removal, and a Post-treatment System (UV sterilizers, precision filters) to ensure the final purity.
What are the key feed water requirements for EDI equipment?
The feed water should be RO product water with a conductivity of 1-20μs/cm (max ≤30μs/cm), hardness < 1.0ppm (recommended below 0.5ppm), TOC < 0.5ppm, and temperature between 15°C and 35°C.
Why is EDI preferred over traditional chemical ion exchangers?
Unlike traditional ion exchangers, the EDI module undergoes continuous electrical regeneration. This eliminates the need for hazardous chemical regenerants, allows for continuous operation, and reduces environmental impact.
Where is EDI high-purity water equipment typically applied?
It is widely used in the electronics industry (semiconductor production), power industry (boiler feedwater), pharmaceutical industry (injection and cleaning water), and the chemical industry for high-purity chemical production.