Introduction to Reverse Osmosis Pure Water Equipment by Sections: The system generally includes pretreatment units, the reverse osmosis main unit, post-treatment units, cleaning units, and an electrical control system. Pretreatment typically consists of quartz sand filters, activated carbon filters, softening filters, and precision filters. Its main function is to reduce the pollution index, residual chlorine, and other impurities in the raw water to meet the inlet requirements of the reverse osmosis system. Detailed Classification of the Pretreatment System: 1. The primary role of the quartz sand filter is to remove suspended solids, colloids, silt, clay, organic matter, particulate matter, and other impurities from the water. It can reduce water turbidity, achieve water clarification, and protect the reverse osmosis membrane. 2. The activated carbon filter mainly utilizes the large number of functional groups such as hydroxyl groups on the surface of activated carbon to chemically adsorb various substances, removing odors, organic matter, colloids, iron, and residual chlorine from the water, while also reducing water color and turbidity and minimizing contamination of the reverse osmosis system. 3. The softener uses sodium ions on ion exchange resins to exchange with calcium and magnesium ions in the water, reducing water hardness, while regenerating the ion exchange resin with soft water salt. Soft water salt is also known as ion exchange resin regenerant. 4. In the pure water equipment system, precision filters generally use 5-micron PP melt-blown filter cartridges, primarily to remove particles larger than 5 microns that were not completely eliminated by the pre-treatment system and to trap filter media lost in the previous three filtration stages, thereby protecting the RO membrane. Whether the filter cartridge can meet normal usage conditions will affect the normal operation of the reverse osmosis membrane. It is generally recommended to replace the filter cartridge monthly. High-purity water for microelectronic product production, semiconductors, picture tubes, computer circuit boards and other integrated circuits, solar cells, and dry batteries. Cleaning of the reverse osmosis membrane: Although the feed water undergoes various pretreatment measures, deposits and scaling may still form on the membrane surface after long-term use, clogging the membrane pores and reducing water production. Therefore, regular cleaning of the contaminated membrane is necessary. However, the reverse osmosis membrane system should not wait until contamination is severe before cleaning, as this will increase the difficulty of cleaning, extend the cleaning steps, and prolong the cleaning time. It is essential to correctly grasp the timing of cleaning and clean the fouling promptly. Cleaning principles: Understand local water quality characteristics, perform chemical analysis of pollutants, and select better cleaning agents and methods based on the analysis results, providing a basis for finding the best method under specific water supply conditions. Cleaning conditions: a. Product water volume decreases by 5%-10% compared to normal. b. To ensure product water volume, the temperature-corrected feed water pressure increases by 10%-15%. c. The conductivity of the permeate water (salt content) increases by 5%-10%. d. For multi-stage RO systems, the pressure drop across different stages increases significantly. Cleaning methods: First, perform system backwashing; then conduct negative pressure cleaning; if necessary, perform mechanical cleaning; followed by chemical cleaning. Since chemical cleaning is more effective, and other methods are sometimes difficult to implement, the agents provided by various suppliers, although their names and usage methods may differ, generally follow similar principles. Cleaning steps are as follows: Cleaning a single-stage system: (1) Prepare the cleaning solution; (2) Input the cleaning solution at low flow rate; (3) Circulate; (4) Soak; (5) High-flow pump circulation; (6) Rinse; (7) Restart the system. Special contaminant cleaning includes: Cleaning salt scale, cleaning carbonate scale, cleaning iron and manganese contamination, cleaning organic matter contamination, etc. The service life of the reverse osmosis membrane in Nantong reverse osmosis ultrapure water equipment depends on the membrane's chemical stability, physical stability, feed water source, pretreatment, cleaning frequency, and operational management level.