Lining plates for ball mill have helical grooves - for return movement of balls

摘要

Ball mills are internally clad by grinding plates with grooves of uniform depth and an arcuate cross-section whose radius is similar to that of the balls or the largest balls used in the mill, with groove centre lines sepd. by 80% of the max. ball dia.. The path of at least some of the grooves is helical, with a pitch angle of 3-10 (4) deg.. These helical grooves are pref. mainly located only near the discharge end of the drum, while in the remainder of the drum they are perpendicular to the drum's longitudinal axis. - For mills where material is heavily reduced, e.g. in cement mfr. Build-up of ground material and accumulation of balls at the discharge end are prevented, with the balls returned to earlier drum zones when screw movement of the grooves is opposite to material movement.(0/3)