I. Overview
High purity water equipment. As a device for producing high purity water, EDI high purity water equipment, as a secondary desalination device after reverse osmosis equipment, can produce up to 10 - 18.2MΩ.CM. Therefore, it is widely used in microelectronics industry, semiconductor industry, power generation industry, pharmaceutical industry and laboratories. It can also be used as pharmaceutical distilled water, production water for food and beverage, make-up water for boilers in power plants, and other applications of high purity water.

II. Introduction to EDI
Continuous electro-deionization (EDI, Electro deionization or CDI, continuous electrode ionization) is a process in which mixed ion exchange resins are used to adsorb positive and negative ions in feed water, and at the same time, these adsorbed ions are removed by passing through positive and negative ion exchange membranes respectively under the action of direct current voltage. In this process, the ion exchange resin is continuously regenerated electrically, so there is no need to use acid and alkali to regenerate it. This new technology can replace traditional ion exchange devices and produce ultrapure water up to 18M-CM. It can be described more clearly as follows: EDI uses anion and cation membranes, which are symmetrically stacked. Anion and cation resins are sandwiched between anion and cation membranes. Under the action of direct current voltage, anion and cation exchange is carried out respectively. At the same time, under the action of voltage gradient, water will electrolyze to produce a large amount of H+ and OH-. These H+ and OH- continuously regenerate the anions and cations in the middle of the ion membrane. Due to the continuous exchange and regeneration of EDI, the purity of pure water is getting higher and higher, so high-purity high purity water is easily produced.
EDI high purity water equipment is a professional tool for preparing ultrapure water formed by combining reverse osmosis technology and ion exchange technology. It adopts a microcomputer intelligent program control system, which can automatically detect and display water quality; while obtaining high-quality produced water, it ensures water output.

III. General process flow of high purity water equipment:
Since high purity water equipment has higher requirements for influent water, and the influent water quality requires conductivity <10μs/cm, generally double-stage reverse osmosis or single-stage reverse osmosis is used as pretreatment. The general process flow is as follows:
Single-stage reverse osmosis equipment + EDI:
Raw water tank → raw water pump → quartz sand filter → activated carbon filter → scale inhibitor dosing device (or softened water equipment) → precision filter → high-pressure pump → reverse osmosis membrane unit → pure water tank → booster pump → EDI device → high purity water tank
Double-stage reverse osmosis + EDI:
Raw water tank → raw water pump → quartz sand filter → activated carbon filter → scale inhibitor dosing device (or softened water equipment) → precision filter → first-stage high-pressure pump → first-stage reverse osmosis membrane unit → second-stage high-pressure pump → second-stage reverse osmosis membrane unit → pure water tank → booster pump → EDI device → high purity water tank

IV. Performance advantages

1. It can continuously and stably produce high-quality pure water without shutdown due to resin regeneration;

2. There is no pollutant discharge, which is environmentally friendly and saves the investment in waste liquid treatment;

3. The equipment has a compact structure, small floor area, saves space, and also has energy-saving advantages;

4. The device debugging is completed at the factory, with small on-site workload and easy on-the-job training;

5. Daily maintenance is simple and labor intensity is low.

6. The desalination rate is greater than 99.9%, and the efficiency is much higher than that of two-stage reverse osmosis and simple ion exchange.

V. Application fields

1. Chemical water treatment in power plants

2. Ultrapure water for electronics, semiconductor, and precision machinery industries

3. Water for fine chemical and cutting-edge disciplines.