Mitsubishi Heavy Industries Technical Review
    Vol. 52 No. 2 (2015)   Mitsubishi Hitachi Power Systems
    Technical Papers

    Development of Mill-burner System for Low-rank Coal with Super-high Moisture

    Ryuhei Takashima,
    Shinji Matsumoto,
    Kenichi Arima,
    Takuichiro Daimaru,
    Yasuhiro Takei,
    Kazushi Fukui

    Low grade coal accounts for half of all coal resources in the world, and super-high-moisture coal with a moisture content exceeding 50% is one such kind. When such super-high-moisture coal is applied to conventional USC boilers, the shortage of mill drying capacity and the decline of ignitability and combustibility caused by the decrease of oxygen concentration in burner zones and the increase of the moisture content of coal particles are the main concerns. In this research, grinding tests and combustion tests using super-high-moisture coal were carried out by Mitsubishi Hitachi Power Systems, Ltd. (MHPS), and the stable grinding conditions for preventing particle adhesion in mills under high humid atmosphere, as well as stable combustion under low oxygen concentration in primary gas, were verified. These results enabled the utilization of low grade and super-high-moisture coal in conventional USC boilers.