What is the reason for the failure of the coal economizer pipe of the coal-fired boiler?

Question details (Performance):

1. The furnace wall at the coal economizer leaks water and steam with abnormal sound.

2. The water level in the boiler drops sharply, and the water supply is obviously greater than the evaporation capacity.

3. Smoke exhaust temperature and water outlet temperature rise.

Answer: Fault reason:

1. The water quality does not reach standard, and the oxygen in the water is decomposed into corroded pipe walls when the temperature rises.

2. The low feed water temperature and smoke exhaust temperature make the inner and outer wall of the coal economizer pipe produce acid corrosion, or flying ash wear the pipe wall thin.

3. The pipe is blocked by impurities, causing overheating.

4. Poor materials, defects in manufacturing, installation and maintenance.

Troubleshooting:

1. When economizer is slightly broke, it still maintains boiler operation, and the gap seems will not expand rapidly, in this case, load operation should be reduced, and start the spare boiler immediately, when standby boiler is in operation, then stop the boiler and repair.

2. When economizer is badly broken, insufficient filling water circulating pumps and pressure drops rapidly, in this case furnace should be emergent stopped, circulating water outlet flow should be reduced to keep boiler water pressure, keep the induced draft fan continues to run, stop boiler after remove furnace flue gas and steam.