Why must the water for gas hot water boilers be treated? This is because the gas hot water boiler will generate scale with poor thermal conductivity during long-term operation, and corrode the boiler metal, which seriously endangers the operation of the gas hot water boiler.
Gas boiler water treatment is to remove these harmful impurities in the feed water and avoid their harm to the gas hot water boiler. First of all, we analyze the main harm to the boiler caused by the poor quality of gas hot water.
1. Scaling: The scale has extremely poor thermal conductivity, and its thermal conductivity is only about 1% of the boiler steel plate. Because the heat conduction of the boiler is seriously affected, the temperature of the furnace must be increased to ensure the evaporation, the amount of coal entering the boiler and the drum. The amount of induced air must be forced to increase, the heat loss of the flue gas increases, the fixed carbon in the coal is insufficiently burned, the boiler is in a bad combustion state, and the thermal efficiency of the boiler is greatly reduced.
2, soda water together
The soda co-bending phenomenon is caused by too high dissolved solids, grease, organics and other components in the boiler water. The main hazard is that the steam is severely polluted and even rendered unusable; bubbles appear in the water level gauge and the boiler water level cannot be displayed normally. The water level automatic control system completely fails, which is extremely harmful to the safety of the boiler.
3. Corrosion: Boiler corrosion caused by poor water quality mainly includes the following three types:
① Oxygen corrosion: It is characterized by local pitting corrosion, which has strong penetrability, which is extremely harmful to the safe operation of the boiler.
② Caustic embrittlement: It is caused by the high alkalinity of the boiler water for a long time, and its harm is to destroy the internal structure of the metal and reduce the strength of the boiler metal.
③ Under-scale corrosion (iron corrosion): Iron ions in the boiler water will form high-priced iron scales in the boiler. This scale can accelerate the corrosion of metallic iron under the scale, and generate new scale, forming a vicious cycle of iron corrosion. Therefore, the national “industrial boiler water quality” standards set clear requirements for the iron ion content in boiler feed water.
