Influencing factors of slagging on heating surface of boiler
(1) Ash characteristics of pulverized coal
Generally, the softening temperature ST of ash is used as the main indicator of slag formation. Coal with low ash melting point (ST<1200℃) is easy to slag. In addition, the slagging index also includes: silicon ratio, alkali-acid ratio, slagging index, limit viscosity and so on.
（2）Aerodynamic characteristics in the furnace
Improper air flow organization leads to flame center deviation, and the pulverized coal air flow flame adheres to the wall, causing local slagging of the water-cooled wall;
Improper air flow organization, forming flue gas retention vortex area and forming a reducing atmosphere (with CO), reducing the ash melting point and increasing the possibility of slagging.
Excess air coefficient: When the excess air in the furnace is too small, a reducing atmosphere may be generated, and the tendency of slagging will increase accordingly.
（3）Influence of boiler heat lo
(Question details) Specific performance:The wall thickness of several boiler tubes was significantly reduced in a large area, the remaining wall thickness was 2.0mm, and some furnace tubes were corroded and worn out. Furnace tube wall is covered with a thick layer of uneven scale, the surface of the scale is brick red and black, scale layer is loose, and it is easy to remove the inner wall of the furnace tube, after removing, the furnace tube wall covered with a layer of corrosion pits. There is a thin layer of brick red corrosion on the outer wall of boiler tube, some of which are attached with black adhesive. Answer: Fault reason:1. The boiler is seriously short of water.2. Poor water circulation and uneven combustion.3. The unqualified quality of the boiler water and undemanding chemical supervision make the inner wall of the pipe corrode and scale, causing the pipe overheat and reduction of the strength.4. Due to the presence of impurities and scale, the furnace tube is blocked ins
