Low NOx firing technology of Mitsubishi Heavy Industries

This paper presents super low NO{sub x} combustion technologies successfully developed by MHI (Mitsubishi Heavy Industries, Ltd.) and its use in practice. PM (Pollution Minimum) burners directly reduce NO{sub x} from the burners themselves and MACT (Mitsubishi Advanced Combustion Technology) system, an in-furnace NO{sub x} removal system, reduces NO{sub x} generated from the main burners within the boiler. These firing systems are applicable to coal, oil, gas and also to other exotic fuels like Orimulsion or CWM (Coal Water Mixture). MRS (Mitsubishi Rotary Separator) mills minimizes unburnt carbon with its reliable ultra-fine grinding of coal and hence contribute to low NO{sub x}. These technologies have been applied in various combinations to 227 boilers for both new installation and retrofit jobs. Large 1,000 MWe oil or gas fired boilers and 700 MWe coal fired boilers have been put into commercial use, and a 1,000 MWe coal fired boiler is under commissioning. The technologies have been applied to small sized boilers for industrial use as well. All the delivered systems have been working both domestic and overseas to the customers` satisfaction.