Process for preparing ultrapure water for electronics industry
Ultra pure water process flow chart
The process of preparing superwater in the electronics industry is roughly divided into the following:
1. The traditional water treatment method for preparing ultrapure water using ion exchange resin, the basic process is: raw water → sand charcoal filter → precision filter → raw water tank → positive bed → overcast bed → mixed bed (multi-bed) → pure Water tank → pure water pump → precision precision filter → water point 2. The combination of reverse osmosis water treatment equipment and ion exchange equipment, the basic process is: raw water → sand charcoal filter → precision filter → raw water tank → reverse osmosis equipment → mixed bed (double bed) → pure water tank → pure water pump → rear precision filter → water point 3. The way of using reverse osmosis water treatment equipment and electric deionization (EDI) equipment to match, this It is the latest process for preparing ultrapure water, and it is also an environmentally friendly, economical, and ultrapure water preparation process with great potential for development. The basic process is: raw water → sand charcoal filter → precision filter → raw water tank → reaction Permeation equipment → Electric deionization (EDI) → Pure water tank → Pure water pump → Rear-mounted precision filter → Water point comparison of three processes for preparing ultrapure water for the electronics industry These three are on this, rest of the process are carried out with different combinations derived on the basis of the above three basic process. Their advantages and disadvantages are listed below:
1. The first type adopts ion exchange resin, which has the advantages of less initial investment and less occupied area, but the disadvantage is that it needs to carry out ion regeneration frequently, consumes a lot of acid and alkali, and has certain damage to the environment.
2. The second type uses reverse osmosis as a pretreatment and is equipped with an ion exchange device, which is characterized by a higher initial investment than an ion exchange resin method, but the regeneration cycle of the ion device is relatively long, and the acid-base consumption is more expensive than using ions There is much less resin. But it is still destructive to the environment.
3. The third type uses reverse osmosis as pre-treatment and is equipped with an electric deionization (EDI) device. This is currently the most economical and environmentally-friendly process for preparing ultrapure water. No acid or alkali is required. Regeneration can continuously produce ultrapure water, which is not harmful to the environment. The disadvantage is that the initial investment is too expensive compared to the above two methods.