The causes of slagging in two 2209 t/h boilers of the third-phase project for Huaneng Dezhou Power Plant have been analysed. 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. For these

remedial measures

such as adjusting operation

retrofitting the ignition belt

and adding remote hydraulic slag remover etc.

have been put forward. After implementation

it is helpful to free from the puzzle of slagging in boilers

and making the level of safe operation to reach the leading position among the similar units.