Phenomenon:

1. The saltness of steam and boiler water increases. 

2.The water level of steam drum water increases sharply, in serious condition, the water level is not clearly shown in water level gauge. 

3. The superheater steam temperature decreases sharply. 

4. In serious condition, water-impact occurs inside the pipe and steam emits from the flange. 

Causes:

1. The chemical water treatment personnel cannot monitor the quality of boiler water, the feedwater quality deteriorates and the content of suspended solids or saltness is too big. 

2. Necessary blowdown has not been done in accordance with the requirements, the sewerage pipes have been blocked for long time and the blowdown rate decreases. 

3. The boiler load increases too fast or the boiler has operated in overload for long time. 

4. The water level of steam drum has operated at higher level for long time, thus making the work efficiency of steam -water separator decrease. 

5. The continuous blowdown device is blocked or has not been opened according to the requirement for a long time, thus making the boiler water quality decrease.