	US 7,360,726 B2
	Method and control system for starting crushing in a gyratory crusher
Kent Nilsson, Mamlö (Sweden); and Mattias Nilsson, Sjöbo (Sweden)
Assigned to Sandvik Intellectual Property AB, Sandviken (Sweden)
Appl. No. 10/544,572 PCT Filed Feb. 06, 2004, PCT No. PCT/SE2004/000152 § 371(c)(1), (2), (4) Date Jan. 09, 2006, PCT Pub. No. WO2004/069415, PCT Pub. Date Aug. 19, 2004.
Claims priority of application No. 0300328 (SE), filed on Feb. 10, 2003.
Prior Publication US 2006/0231650 A1, Oct. 19, 2006
Int. Cl. B02C 25/00 (2006.01)

U.S. Cl. 241—30 [241/37; 241/207]

9 Claims

1. 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;

wherein step B includes starting a countdown of a predetermined time period beginning with the start of the supply of material into the crushing gap; step D including determining whether the width adjustment has occurred within the predetermined time period; and step E being performed only if the width adjustment has occurred within the predetermined time period.