Coal breaking and crushing appts. - has lifter shelves positioned at set angle of incline on drum

摘要

The appts. for reducing coal and other materials, includes a hollow rotatable drum having an opening to receive feed material and wall means including screening openings to discharge material of desired size. Lifter shelves are positioned on the inner surface of the wall means for lifting and dropping material within the drum as the drum is rotated. Rotor includes a rotor shaft and shaft-mounted material impacting means positioned within at least a portion of the length of the drum for impacting material dropped from the shelves. The drum drive means is connected to the drum driving it at a speed in the range of about 70% to about 95% of critical speed. The lifter shelves are positioned on the drum at predetermined angle of inclination, ranging from 0 deg. up to 70" in a direction opposite to the direction of drum rotation. This angle causes the material to drop from the selves into contact with the impacting means at or near the crest of the orbit of the impacting means when the drum is rotated at the speed which directs the material from above one side of the rotor shaft to the other side of the rotor shaft in the direction of the down running side of the rotor shaft.