Through oxygen content regulating experiment

the reason for high combustible matter content in fly ash for NO.4 boiler in a power plant was obtained.That is

pyramid in separator of coal mill blocked because of impurities appearing in coal supply process

causing coal powder accumulation inside the inner pyramid

and deadlocking of the air lock door

which kept open

therefore

the coal particle was over coarse.Thus

to solve this problem

separator of the mill was cleared thoroughly

and the air lock valve of the recycling device for inner pyramid was handled.After these measures were taken

combustible content in fly ash reduced

and thermal efficiency of the boiler was improved by an average of 0.56%.