SAETT ATT VID ELDNING AV FASTA BRAENSLEN PAO WANDERROST Mińska UTSLAEPPEN AV SVAVEL- OCH KVAEVEOXIDER.

摘要

The invention relates to a method of reducing sulphur-oxide and nitrogen-oxide emissions when burning solid fuel admixed with lime powder in a boiler (1) provided with mobile grate, preferably a travelling grate (2). This is effected in a first step, in which sulphur dioxide remaining in the flue gas is bound by injecting (at 28) a horizontal curtain of dolomite powder or the like into the hearth above the bed (2) in a hearth zone where the temperature at maximum is about 1050-1110 DEG C or somewhat lower. In a second step flue gas is recycled to the combustion-air inlet (7, 25) beneath the grate in an amount such that the surface temperature of the bed will not substantially exceed 1100 DEG C, resulting in the binding of sulphur by the formation of calcium sulphate, and low nitrogen oxide emission.