The process and features of industrial boiler water softening equipment

A qualified boiler water treatment agent effectively plays the dual roles of scale inhibition and corrosion inhibition. Scale inhibition mainly refers to the inhibition of scale on the boiler body, while the objects of corrosion inhibition include the boiler body as well as the pipes through which steam passes, heat exchangers and condensate pipes.

They are the main scale-forming ions. Currently, most boilers in use on the market are equipped with ion exchangers to remove them. However, due to the concentration and evaporation of the boiler water, the concentration of some other dissolved salts in the water keeps increasing, and there is still a possibility that they will exceed their solubility and form scale. Especially in high-temperature areas such as flue pipes, due to the rapid vaporization of water, it is very likely that certain salts will crystallize and precipitate due to excessively high local concentrations. This is the reason why many boilers that use softened water still scale. Although this phenomenon can be alleviated by increasing the amount of sewage discharged, on the one hand, it wastes a large amount of energy; on the other hand, due to the increase in sewage discharge, the alkalinity of the boiler water drops, often falling below the lower limit of the national standard, which accelerates the rate of corrosion. Therefore, it is very necessary to take appropriate scale inhibition measures for the boiler water.

Dissolved oxygen in water is the main factor causing corrosion of boilers. Due to the high temperature inside the pot, the reaction rate between dissolved oxygen and iron is very fast. For boilers without deaerators, the adoption of chemical deaeration measures is indispensable. For boilers with deaerators, since the current deaerators cannot thoroughly remove oxygen, especially for some non-continuous operation boilers, thermal deaeration is almost ineffective when the boiler is just started each day. Therefore, it is also necessary to take chemical deaeration as a remedial method. Another major factor causing boiler corrosion isFe3+. Nowadays, most office buildings, hotels and other facilities adopt closed heating systems, and the reuse of condensate water can account for the boiler feed water80%If there are no necessary corrosion inhibition measures in the steam pipes, condensate pipes, heat exchangers and other parts, the iron on the surface of the pipes will dissolve into the condensate waterFe3+It has strong oxidizing properties and can significantly accelerate the corrosion rate of boilers. From the boiler feed waterCO2After entering the boiler, the gas escapes from the water due to heating and enters the heat exchanger along with the steam, where it dissolves again in the condensate water, making the water acidic. Under acidic conditions, the corrosion of iron accelerates significantly, with a large amount of iron dissolving into the condensate water. Sometimes, the condensate water has to be drained away. Due to the high temperature of the condensate water, this is bound to cause a huge waste of energy.