Type Selection of Burning Equipment FOR Lignite Biliers

TK229.6; The special design for the furnace and burner of boilers burning lignite is analyzed and the type selection of the pulverizing system is discussed by taking account of the lignite's characteristics of high moisture,low heating value and low ash fusion temperature.The impact of such characteristics on the type selection of burning equipment and pulverizing systems for the lignite boiler is studied.The value ranges of the furnace characteristic parameters for the lignite boiler are recommended.For the old lignite,the premix period in the burner should not be too long in order to avoid slagging and the velocity of the primary air is suggested to be between 17 m/s and 22 m/s.The direct-flow burner with tangential firing is preferred for lignite with the moisture higher than 35％.The medium-speed mill is better to be used for lignite with the moisture less than 35％,while for lignite with the moisture higher than 40％ the fan mill should be the first choice.