About Mill Safety Start

The strength of steel limits the maximum feasible size of a geared grinding mill. Geared grinding mills today push these limits. Extra care therefore needs to be exercised to minimize the torque transients and shock loads these giant geared mills are subjected to. The two biggest transient events that a geared grinding mill is subjected to are torque spikes during start-up, and a dropped charge incident, also called a drop charge.

The Mill Safety Start System calculates the ore angle in real time during the start-up, and the mill is tripped if the ore is cemented, before it can drop and damage the mill bearings and structure. By recording the rotor currents at start-up, comprehensive liquid resistance starter performance analysis can be done, ensuring the early detection of liquid resistance starter problems and enabling corrective action to prevent damage to electrical motors, gearboxes, pinion gears and girth gear.