Understand the role and maintenance of pure water equipment

Type, function and maintenance of pure water equipment
1, the strainer
1. What types of strainers are there?

The most common ones are sand filters, non-woven filter elements, and PP fiber filter filters. The size of the filter is different depending on the amount of filtered water. The lengths of the non-woven filter element and the PP fiber filter are most commonly used in 10 inches and 20 inches. The filter element used as a strainer is generally about 25u.

2. What is the role of the strainer?

These impurities are prevented from entering the activated carbon filter, and the function of the coarse filter is to remove suspended impurities having a large particle size in the water. Covering the surface of the activated carbon, the pore structure of the activated carbon loses the ability to adsorb impurities in the water.

3. Why should the maintenance of the strainer and how to maintain it?

The water flow is gradually decreasing. If not treated in time, the strainer increases sharply with increasing resistance to trapped solid impurities. Unable to meet the water flow requirements of the subsequent disposal process. For the sand filter, the pressure should be backwashed in time after the pressure rises to a certain level. During the backwashing, some fine sand is washed out of the filter, so the sand filter should be added with sand regularly. After repeated backwashing, the crushing level increases, and each backwashing cannot be washed 100%. The remaining sludge in the sand gradually increases, and the sand layer will appear “consolidation”. At this time, the sand layer should be replaced. For non-woven fabrics or PP fiber filter cartridges, it is generally difficult to flush the water after the filter holes are blocked. The filter cartridge must be replaced periodically.

2, activated carbon filter
1. What is the role of activated carbon filter?

The residual chlorine, cationic external active agent and the like not only poison the resin, but also the main function of the activated carbon filter is to remove macromolecular organic matter, iron oxide and residual chlorine. Organic substances, residual chlorine, and iron oxides are easily poisoned by ion exchange resins. It also destroys the membrane structure and renders the reverse osmosis membrane ineffective.

2. Why should I maintain the activated carbon filter?
The adsorption is irreversible, that is, the activated carbon has a certain saturated adsorption capacity, and the activated carbon filter utilizes the abundant capillary pores of the activated carbon to adsorb and filter the macromolecular organic matter, residual chlorine, iron oxide and the like in the water. Once the adsorption is saturated, the activated carbon loses its adsorption performance and cannot be washed away by backwashing. In addition, after the activated carbon adsorbs organic matter, it provides abundant nutrition for the bacteria, causing the bacteria to multiply in the activated carbon filter, and the microbial content in the water is increased by the activated carbon filtration.

3. How to maintain the activated carbon filter?

Backwashing is carried out periodically before the adsorption of activated carbon is saturated. In order to flush out a large number of bacteria and suspended solids on the surface of the activated carbon. After the adsorption of activated carbon is saturated, the new activated carbon should be replaced immediately, otherwise it will cause irreparable damage to the reverse osmosis membrane.

3, water softener
1. What is the role of the water softener?

The water is softened. If there is no water softener or water softener failure, the function of the water softener is to remove calcium and magnesium ions from the water. Calcium and magnesium salts form a water-soluble precipitate in the surface of the reverse osmosis membrane due to a sharp increase in concentration, which shortens the service life of the reverse osmosis membrane and blocks the pores of the reverse osmosis membrane.

2. Why should the water softener be maintained and how to maintain it?

After the resin exchange is saturated, it is regenerated with salt. After several years of use, the level of resin breakage becomes more and more serious, and the water softener for pure water generally uses a sodium type cation exchange resin. Gradually lose the ability to soften. Especially when the activated carbon passes through the iron, organic matter and residual chlorine in the raw water, it will directly enter the water softener, and the filter will be saturated and the activated carbon will not be replaced in time. The resin is poisoned, and once the resin is poisoned, it cannot be regenerated by regeneration. The resin should be replaced. When the working exchange capacity of the resin is significantly reduced. The raw water that has been pretreated and reaches the requirements of the reverse osmosis membrane is reverse osmosis, and the reverse osmosis is the core component of the pure water system.

Therefore, the maintenance of reverse osmosis is the key to ensuring the quality of pure water. The salt concentration of the membrane surface during the working process of the reverse osmosis membrane is higher than that of the main fluid, and after filtration, it becomes pure water. This phenomenon is called concentration polarization. The consequence of concentration polarization is that some salt precipitates on the outer surface of the membrane, blocks the water production channel of the reverse osmosis membrane, and reduces the water production of the membrane. Organic matter in the feed water is not washed out continuously or periodically washed off the surface of the membrane, especially some surface-charged reverse osmosis membranes that attract charged organic matter and stick to the membrane surface. The damage caused by the accumulation of organic matter on the surface of the membrane is more serious than the precipitation of salt on the surface of the membrane. Sometimes the damage is irreversible. The concentration of organic matter and various salts of the membrane is much higher than that of the main stream. The reproduction of bacteria provides a rich nutrient. A large number of microbial flora not only block the water production channel, but also because the reverse osmosis membrane itself is organic, it is decomposed by microorganisms, causing irreversible damage. Oxidizing substances such as residual chlorine in water are enriched in the membrane surface, and after enrichment to a certain level, the concentration of the membrane itself can be withdrawn, and the reverse osmosis membrane is decomposed by the oxidative decomposition.