Ultrapure water equipment not only removes the conductive medium in the water almost completely, but also removes the colloidal substances, gases and organic substances that do not dissociate in the water to a very low level of water. The resistivity is greater than the limit value of 10～18.3MΩ*cm. It is a level that is difficult for ordinary pure water equipment to achieve. It usually adopts four steps of pretreatment, reverse osmosis technology, ultra-purification treatment and post-treatment, multi-stage filtration, high-performance ion exchange (polishing), ultrafiltration filter, and ultraviolet lamp. , in addition to TOC devices and other treatment methods, the resistivity can only be 18.25MΩ*cm
The technological process of preparing industrial ultrapure water is roughly divided into the following categories:
1. The traditional water treatment method using ion exchange resin to prepare ultrapure water, its basic process flow is: raw water →sand carbon filter→precision filter→cation bed→anion bed→mixed bed (compound bed) →pure water tank→pure water pump→post precision filter→water point
2. The combination of reverse osmosis water treatment equipment and ion exchange equipment is adopted. The basic process flow is: raw water→sand carbon filter→precision filter→reverse osmosis equipment→pure water tank→mixed bed ( Compound bed)→Ultrapure water tank→Ultrapure water pump→Post precision filter→Water point
3. The combination of reverse osmosis water treatment equipment and electrodeionization (EDI) equipment is used. This is the newest process for producing ultrapure water, and it is also an environmentally friendly, economical, and ultrapure water with great development potential. Preparation process, the basic process flow is: raw water→sand carbon filter→precision filter→reverse osmosis equipment→pure water tank→electrodeionization (EDI)→ultrapure water tank→ultrapure water pump →post precision filter→water point
Process comparison of industrial ultrapure water At present, there are basically the above three processes for preparing ultrapure water for the electronics industry, and the rest of the process flows are mostly derived from different combinations and matching on the basis of the above three basic process processes.
