Softening water treatment equipment knowledge

what is the softening water

In our daily life, we often see that the inner wall of the kettle will have scale formation after a long time. What is the reason for this? It turns out that the water we use contains a lot of inorganic salts, such as calcium and magnesium salts. These salts are not visible to the naked eye in water at room temperature. Once they are heated and boiled, a lot of calcium and magnesium salts precipitate as carbonates, which form scale against the walls of the pot.

We usually refer to the content of calcium and magnesium ions in water as “hardness”. One degree of hardness is equivalent to 10 milligrams of calcium oxide per liter of water. Water below 8 degrees Celsius is called soft water, water above 17 degrees Celsius is called hard water, and water between 8 and 17 degrees Celsius is called moderate hard water. Rain, snow, rivers, rivers and lakes are all soft water, while spring water, deep well water and sea water are all hard water

The difference between softened water and other water

Raw water refers to water that has not been treated. In a broad sense, the water before entering the water treatment process is also called the raw water of the water treatment. For example, the water sent to the clarifier by the source is called raw water.

Softening water refers to the water hardness (mainly refers to the water calcium, magnesium ions) remove or reduce a certain degree of water. In the process of water softening, only the hardness decreases, but the total salt content remains the same.

Debrine refers to water in which salts (mainly strong electrolytes dissolved in water) have been removed or reduced to a certain extent. Its conductivity is generally 1.0 ~ 10.0 µs /cm, resistivity (25℃) (0.1 ~ 1.0) ×106 ω •cm, salt content is 1 ~ 5mg/L.

Pure water refers to water with strong and weak electrolytes (such as SiO2, CO2, etc.) removed or reduced to a certain degree. Its electrical conductivity is generally: 1.0 ~ 0.1 µs /cm, electrical conductivity (1.01.0 ~ 10.0) ×106 ω •cm. The salt content is less than 1mg/L.

Ultrapure water refers to the conductive medium in the water is almost completely removed, while the gas, colloid and organic materials (including bacteria, etc.) are also removed to a very low degree of water. Its conductivity is generally 0.1 ~ 0.055 µs /cm, resistivity (25℃) >10×106 ω •cm, salt content <0.1 mg/L. Ideal pure water (theoretically) has an electrical conductivity of 0.05 µs /cm and an electrical resistivity of 18.3×106 ω •cm at 25℃.

What is softening water treatment?

The use of strong acid cation resin to replace the calcium and magnesium ions in the raw water, and then through the softening water equipment filter out of the boiler water is to become a very low hardness of the boiler with softened water.

Working principle

Because the hardness of water is mainly formed and expressed by calcium and magnesium, it is generally used cation exchange resin (water softener), the water Ca2+, Mg2+ (the main component of the formation of scale) replacement out, with the increase of Ca2+, Mg2+ in the resin, the resin removal of Ca2+, Mg2+ efficiency gradually reduced.

When the resin absorbs a certain amount of calcium and magnesium ions, it must be regenerated, the regeneration process is to use salt water in the salt box to wash the resin layer, the resin on the hardness of the ion in the replacement out, with the regeneration of waste liquid discharge tank, the resin will restore the softening exchange function.

Due to the hardness of water is mainly composed of calcium, magnesium, to form and said because of the hardness of water is mainly composed of calcium, magnesium and sodium said the principle of ion exchange softening is the raw water by sodium type cation exchange resin, make the hardness in the water composition Ca2 +, magnesium 2 + and Na + in the resin exchange, and adsorption Ca2 +, magnesium 2 + in the water, the water softening.