Beijing Bosch Wall-Hung Boiler Repair Center; A Brief Discussion on Water Softening
Natural water contains impurities that some are not dissolved in water, such as mud, sand particles, and animal and plant remains; others can dissolve in water, such as mineral salts and gases. According to their particle size differences, they can be divided into three major categories: suspended substances, colloidal substances, and dissolved substances. The main dissolved impurities in natural water include cations like calcium ions Ca2+ and magnesium ions Mg2+, and anions like bicarbonate HC03-, sulfate SO4 2-, and chloride Cl-. Potassium has properties very similar to sodium and is generally included in the sodium content. In addition, there are trace amounts of iron ions and silicate, as well as carbon dioxide and oxygen. If this kind of water is directly used as boiler feedwater, it will cause harm, either directly or indirectly, to the boiler and steam quality. The simplest external chemical softening method is lime softening treatment: slaked lime is prepared into lime milk and added to natural water. The lime milk reacts with calcium and magnesium bicarbonates and other magnesium salts in the water to produce calcium carbonate and magnesium hydroxide precipitates. During lime softening treatment, the water temperature is between 15-40°C, and it is often carried out simultaneously with coagulation treatment. This softening method mainly removes temporary hardness and cannot meet the feedwater requirements for industrial boilers, so it should not be used alone.
Article Source: Beijing Bosch Wall-Hung Boiler Repair Center http://blog.tianya.cn/blogger/blog_main.asp?BlogID=3778593.