Equations of heat exchange between furnace flame and both the water well and the refractory belt are derived by making further use of the concentrated parameter method contained in standard boiler thermal calculation guides,and an algebraic formula for computing the refractory belt area of coal firing boilers is subsequently established.

Some reasons of boiler coking have been found such as unreasonable laying of the ignition belt,uneven air speed at the outlet of the burner, non-standard coal fine,non-uniform air distribution and exceedingly high oxygen.

It is believed that the reasonably designed diameter of imagined tangential circle, the best layout of ignition belt onto the water-wall at side with back to fire, as well as spraying anti-corrosiion material coatings on area the high-temperature corrosion is easily to occur can effectively prevent and alleviate serious slagging an.

It is believed that the main causes are as follows:(1) undue arrangement of ignition belt on the water-wall; (2) the designed furnace structure is relatively somewhat small.

New-type layout of refractory belt in boiler with tangential firing burners;

Shimen Power Plant s 1 021t/h boiler was originally designed without a refractory belt.

Detachable ceramic heat-insulation layer and its application in coal-fired boilers;

Analysis and experiments were carried out on one case that ash deposited on the heat-insulation layer(refractory) in one boiler burning coal water slurry with high ash fusion temperatures(AFTs)(with initial deformation temperature above 1 400℃).

Almost all PC-fired boilers, burning low rank coals, have been adopting heat-insulating refractory liner on their furnace waterwalls to improve combustion.