THREE-STAGE COAL COMBUSTION METHOD BY USING PLASMA THERMOCHEMICAL TREATMENT Russian patent published in 2010 - IPC F23D1/00 

FIELD: power industry.

SUBSTANCE: effect is achieved with nitrogen oxide emission reduction method on the basis of three-stage pulverised coal combustion, which involves supply of larger part of fuel to the main burners - to the first zone - with excess air coefficient α=1.02-1.08, supply of fuel - reducing agent with excess air coefficient α=0.9-0.95 to the second zone located above the main burners, supply of the rest air to the third zone located above the second zone, which is theoretically required for this boiler; at that, to the reducing zone there added are products of plasma-coal thermochemical coal treatment with maximum content of reducing gases in their gaseous phase, and for that purpose the coal concentration in air-and-fuel mixture added to that chamber is specified within 0.25< µ <0.5 kg of coal per one kg of air.

EFFECT: reduction of nitrogen oxide emissions without using natural gas.

2 cl, 1 dwg