Overfeed Stoker and Underfeed Stoker Definition and Types EEEGUIDE
A ball mill consists of steel balls partly filled in a drum. The drum is rotated slowly. The raw coal is fed to the feeding hoppers. The coal moves to the drum through the classifiers and screw conveyors. As the drum rotates, there is a continuous impact between coal and the steel balls. Thus the coal is powdered. Hot air is passed through the ...