Boiler Slagging Hazard is very serious and dangerous. This passage will discuss the boiler slagging hazard in the following several aspects.

1. Boiler slagging will cause overhigh steam temperature. When a large area of furnace is coking, the heat absorption will be greatly reduced, and the flue gas temperature at furnace outlet will be overhigh, strengthening the heat transfer of superheater, causing overhigh superheated steam temperature, and resulting in overheat of superheater tube.

2. Disturb water circulation. After partial coking in the furnace, the heat absorption reduces, and the circulation flow rate decreases. In severe cases, the circulation will stop and cause the water wall tube blasting accident.

3. Decrease boiler thermal efficiency. After the heating surface is coking, the exhaust gas temperature will increase, and boiler thermal efficiency will decrease. After the burner outlet is coking, air flow deflects, and combustion deteriorates, which may burn the burner out.

4. Affect boiler output. After the water wall is coking, the evaporation capacity will decrease. The flue gas temperature will rise, steam temperature will rise, tube wall temperature will rise, and ventilation resistance will rise.

5. Affect the boiler operation safety. After coking, both the flue gas temperature and steam temperature at the superheater will increase, which will cause overheating of tube wall in severe cases. Slagging is usually uneven, which will increase the thermal deviation of superheater. This has an adverse effect on water circulation safety of natural circulation boiler and thermal deviation of forced circulation boiler. When coking block on upper part of furnace falls, it may damage the water wall tube of dry bottom hopper. The furnace may extinguish or the slag outlet will be blocked.

In brief, boiler slagging will greatly shorten the service life of boiler and its auxiliary equipment. The exhaust flue gas loss increases, the thermal efficiency decreases, and the power consumption of induced draft fan increases.