Method and control system for starting crushing in a gyratory crusher

Method for determining a start-up crushing gap width for a crushing operation in a gyratory crusher, the crusher comprising a crushing head fastened on a shaft and provided with first and second crushing shells arranged to form a crushing gap to receive material to be crushed, the width of the crushing gap being adjustable , and a driving device arranged to cause the crushing head to execute a gyratory pendulum movement, the method comprising the steps of:

• A. activating the driving device to cause the crushing head to initiate a gyratory pendulum movement, with the crushing gap set at a first start-up width;
• B. commencing a feed of material into the crushing gap to initiate crushing;
• C. measuring a load on the crusher resulting from the crushing;
• D. adjusting the width of the crushing gap to cause the load to approach a selected value, and obtaining a measure representative of the adjusted gap width;
• E. calculating a subsequent start-up width in accordance with the obtained measure of step D;
• and
• F. setting the width of the crushing gap to correspond to the calculated subsequent start-up width of step E prior to repeating step A for a subsequent crushing operation.

Method for determining a start-up crushing gap width for a crushing operation in a gyratory crusher, the crusher comprising a crushing head fastened on a shaft and provided with first and second crushing shells arranged to form a crushing gap to receive material to be crushed, the width of the crushing gap being adjustable, and a driving device arranged to cause the crushing head to execute a gyratory pendulum movement, the method comprising the steps of:

• A. activating the driving device to cause the crushing head to initiate a gyratory pendulum movement, with the crushing gap set at a first start-up width;
• B. commencing a feed of material into the crushing gap to initiate crushing, and starting a countdown of a predetermined time period at the start of the supply of material into the crushing gap;
• C. measuring a load on the crusher resulting from the crushing,
• D. adjusting the width of the crushing gap to cause the load to approach a selected value, and determining whether the width adjustment has occurred within the predetermined time period;
• and;
• E. setting a gap width for a subsequent crushing operation to be the same as the first gap width, when the width adjustment of step D occurs after the predetermined time period.

Apparatus for determining a start-up crushing gap width for a crushing operation in a gyratory crusher which comprises a crushing head fastened on a shaft and provided with first and second crushing shells arranged to form a crushing gap to receive material to be crushed, the width of the crushing gap being adjustable, and a driving device arranged to cause the crushing head to execute a gyratory pendulum movement, the apparatus comprising:

• activating means for activating the driving device to cause the crushing head to initiate a gyratory pendulum movement in a crushing operation, with the crushing gap set at a first start-up width;
• measuring means for measuring a load on the crusher resulting from the crushing;
• adjusting means for adjusting the gap width to cause the load to approach a selected value;
• obtaining means for obtaining a measure representative of the adjusted gap width;
• and
• calculating means for calculating a subsequent start-up width for a subsequent crushing operation in accordance with the obtained measure.