Phenomenon:
1. The steam drum water level fluctuates sharply, in serious condition, the water level is not clearly shown in the local water level gauge.
2. The saturated steam salinity increases.
3. In serious condition,  the superheated steam temperature fell sharply, the steam pipe water was impacted, and white steam emitted from the flange.

Causes:
1. The feed water and boiler water quality deteriorated.
2. Chemical reagent was improper adjusted or  necessary blowdown was not done.
3. The dosing to the boiler was too much.
4. The load increased too fast, pressure dropped suddenly.
5. Steam separator device was not good, it has been overload operated for a long time.

Processing:
1. Immediately report the monitor on-duty, to reduce the boiler load and maintain a relatively stable operation.
2. According to the situation of steam temperature, adjust the setting value or change automatically-controlling to manually-controlling. Turn down the attemperation water， if  necessary, turn on  the superheater system for draining.
3. Report to the monitor on-duty, inform the water treatment department to stop dosing, open wide the continuously draining valve, strengthen the regular drainage, improve the quality of boiler water, and open the emergency valve to drain water in order to decrease the water level to - 50 mm and strengthen water supply for exchanging water in order to prevent too low water level.
4. Rinse and comprehensive check water level gauge once.
5. After boiler water quality  is normal,  slowly increase the boiler load.
6. Before the boiler water quality was not improved, the boiler shall maintain low -load operation, it is strictly prohibited to increase the load.    （lsh）