AU2012203455B2 - Method for controlling process parameters of a cone crusher - Google Patents

Abstract

A method for controlling the operation of a cone crusher having an internal cone connected to an unbalanced vibrator, and an external cone, the method comprising: utilising a measurement plane being connected to the internal cone, measuring distances between the measurement plane and a bottom of the body of the crusher, and calculating an angle of inclination of the inner cone, and controlling, based on the calculated angle of inclination of the inner cone, at least one parameter chose among: the angle of inclination of the inner cone, and the size of a discharge gap between the internal cone and the external cone 7 z Fig.1

Description

AUSTRALIA Patents Act 1990 COMPLETE SPECIFICATION Standard Patent Applicantss: Sandvik Intellectual Property AB Invention Title: METHOD FOR CONTROLLING PROCESS PARAMETERS OF A CONE CRUSHER The following statement is a full description of this invention, including the best method for performing it known to me/us: METHOD FOR CONTROLLING PROCESS PARAMETERS OF A CONE CRUSHER The present application is a divisional of Australian Patent Application No. 2008213178 incorporated by cross-reference. Technical Field The disclosure relates generally to crushing and reducing equipment, in particular to cone crushers, and can be used in the building, mining and ore-dressing industries. Background Art Modem crushing installations are machines complex and expensive in exploitation. One problem is the possibility to trace all operation parameters with a high accuracy, maintain said parameters within predetermined limits, and also predict and prevent emergency situations. When one crusher is out of order, this usually results in failure of all process sequence of the ore mining and processing enterprise, said crusher being an element of said sequence. Designs of crushers are known for a long time and described in literature. For example, the book VIBRATORY CRUSHERS by Vaisberg, L.A., et al., VSEGEI Publishers, Saint-Petersburg, 2004, contain Chapter 9 "Studies of Methods for Controlling Process Factors of Cone Inertial Crushers," pages 128 to 140. There are two cones - internal and external - in cone crushers. The process of crushing a source material takes place in a crushing chamber between the cones and is accompanied with quick wear of working surfaces of both cones. Therefore, continuous monitoring of compensation for wear of cones by adjusting a distance - a discharge gap between the cones allows stabilization of optimal process parameters, presence of a finished product of predetermined grading at the outOput, and improvement in the operation productivity of the installation. A previous patent application involving the inventor entitled "Cone Inertial Crusher" disclosed a crusher having higher reliability due to the possibility of smooth adjusting a swing amplitude of an inner crushing cone, see Patent RU 2,058,818, the priority as of April 13, 1993. It is to be understood that, if any prior art publication is referred to herein, such reference does not constitute an admission that the publication forms a part of the common 2 general knowledge in the art, in Australia or any other country. Summary In at least some embodiments there is disclosed a method for controlling the operation of a cone crusher having an internal cone connected to an unbalanced vibrator, and an external cone, the method comprising a measurement utilising a measurement plane being connected to the internal cone, measuring distances between the measurement plane and a bottom of the body of the crusher, and calculating an angle of inclination of the inner cone, and controlling, based on the calculated angle of inclination of the inner cone, at least one parameter chose among: the angle of inclination of the inner cone, and the size of a discharge gap between the internal cone and the external cone. In one form the method further comprising comparing the calculated angle of inclination of the inner cone to a predetermined angle of inclination of the inner cone, and correcting an operating parameter when the calculated angle of inclination deviates from the predetermined angle of inclination. In one form the method further comprising comparing estimating, based on the calculated angle of inclination of the inner cone, the size of the discharge gap between the internal cone and the external cone. In one form the method further comprising comparing an estimated size of the discharge gap between the internal cone and the external cone to a predetermined discharge gap, and correcting an operating parameter when the estimated size of the discharge gap deviates from the predetermined discharge gap. In one form, the correction of the operating parameter comprises turning an adjustment ring to which the external cone is connected. In one form, the method further comprising utilizing a measurement disc connected to the inner cone as the measurement plane, and measuring distances between the bottom of the body of the crusher and the measurement disc. In one form, the method further comprising measuring, in each of at least two different positions, distances from the bottom of the body of the crusher to the measurement plane and calculating the angle of inclination of the inner cone. In one form, the method further comprising controlling, based on the calculated angle of inclination of the inner cone, a compensation for wear of working surfaces of the cones. In one form the method further comprising measuring the size of a discharge gap 3 between the internal cone and the external cone when the crusher is running in idle mode, such that emergency situation is prevented. In one form the method further comprising utilizing the calculated angle of inclination of the inner core to detect changes in the crusher operation. In one form the method further comprising utilizing the measured distances between the measurement plane and the bottom of the body of the crusher for calculating a three dimensional position of the measurement plane, and utilizing said three-dimensional position for calculating the angle of inclination of the inner cone. In at least some further embodiments there is disclosed a cone crusher having an internal cone connected to an unbalanced vibrator, and an external cone, the cone crusher further comprising: a measurement plane being connected to the internal cone, a measuring device operative for measuring distances between the measurement plane and a bottom of the body of the crusher, and a computer which is operative for receiving information relating to said distances from the measuring device, calculating an angle of inclination of the inner cone based on said information, and controlling, based on the calculated angle of inclination of the inner cone, at least one parameter chose among: the angle of inclination of the inner cone, and the size of a discharge gap between the internal cone and the external cone. In one form, the measuring device is mounted on the bottom of the body of the crusher and is operative for measuring distances between the bottom of the body and a measurement disc forming the measurement plane and being connected to the internal cone. In one form, the measurement disc is perpendicular to a rotation axis of the unbalanced vibrator. In one form, the crusher comprises an adjustment ring to which the external cone is connected, the computer being operative for controlling the rotation of the adjustment ring to control the size of the discharge gap. In one form, the measuring device comprises at least two sensors, each sensor being operative for measuring a distance between the measurement plane and the bottom of the body of the crusher. All said measurements take place continuously, cyclically, in the operation mode, in the idle mode, and in the quiescent state. Additional advantages of the aforementioned embodiment of the method are as follows. The method may be implemented if the measurement disc R is fastened to an end face of a casing of a sliding bearing in the unbalanced vibrator of the cone crusher in such a 4 manner that the plane of the disc R is parallel to a plane of a base of the internal cone. Ultrasonic and/or laser sensors may be used as the distance sensors. In at least one form a cone of the crusher is mounted on a support in such a way as to rotate freely and is provided with means for measuring the rotation speed thereof about its axis functionally connected with a system for adjustment of the frequency and amplitude of the vibrations of the cup, and to a system for adjustment the position of the cone along the height relative to the cup. If the rotation speed of the cone is known, it is possible to determine a material layer thickness in a pane of discharge of crushed materials for a predetermined adjustment (a width of an annular gap in the pane of discharge of crushed materials) of the crusher, and if necessary, to change said thickness by adjusting a frequency and/or amplitude of means providing vibration of the cup, and/or a position along the height of the cone in order to obtain a crushed product having a desired grading, wherein said means allow automation of the crusher operation. For the predetermined frequency and amplitude of the means causing the cup vibration and the width of the discharge gap, evolution of the rotation speed of the cone makes it possible to detect wear of working surfaces of the cone and the cup. In one form, the rotation speed of the cone around its axis in order to determine a minimum thickness of a material on a crushed material discharge plane (level) based on a measure value of the rotation speed of the code and the width of the annular gap present in this plane between the cone and the cup when the crusher is in a quiescent state, and to adjust parameter of means causing vibrations of the cup and/or positions along the height of the cone relative to the cup for maintaining the minimum material layer thickness equals to a predetermined value. A method according to at least one form disclosed for controlling operation of a crushing installation may allow: - measurement and modification - in a continuous operation mode as quickly as possible and as fast as possible - of main process parameters directly affecting the quality and performance of machine operation; - prevention of malfunctions in operation and emergency situations with a high degree of probability; - presence of the comprehensive monitoring of the crusher state at any time, thereby making it possible to efficiently use and to extend the service life of the wording surfaces; - introduction of automated computerized control thereby excluding a human factor from the process of measurements and adjustments.

5 Further, it may have the possibility to accumulate and systematize statistical data of modifying process parameters in oration with different source materials or under different environment conditions in order to introduce the mathematical prediction of in-time substitution of the machine working assemblies. Further, the method according to at least one form may use simple and reliable apparatuses, which is beneficial as the crushers usually operate under complex field conditions of a producing open-cut mine, in ore mining and processing enterprises, under extreme north conditions, etc. One of main process parameters of a crushing installation is the amplitude of circular oscillations of an internal cone. Modification of the amplitude is a consequence of modifying a size of a discharge gap. In turn, the amplitude is affected by the size and strength of the source material, an unbalanced rotation frequency, and an unbalanced degree. Therefore, adjusting the amplitude of circular oscillations of the internal cone in both operation mode and idle mode allows control of operation of the machine as a whole. The method according to at least one form may also allow: - achievement the high accuracy of measurements limited only by the operation quality of the distance sensors; - dynamic monitoring of the size of the oscillation amplitude of the internal cone; this parameter allows better determination of the size of the discharge gap, and making a correction by comparing the resulted size to an optimum value stored in the central computer; - limitation of the correction speed only by a quickness of the hydraulic cylinder operation; - high quality of implementing the method is provided by a computer analysis of data. Brief Description of the Drawings The attached drawings show example embodiments of the invention. The particularity of those drawings and the associated description does not supersede the generality of the preceding broad description of the invention. Fig. I represents a cone inertial crusher Fig. 2 shows a scheme of the relationship between an angle & of deviation of the disc R plane from horizontal and an angle &' of deviation of the internal cone from vertical. Fig. 3 explains a mathematical principle for calculating parameters.

6 Detailed Description of the Drawings The method according to at least one embodiment may be practiced on the basis of the classic design of the cone crusher. Any sensors known from the prior art can be used as distance sensors, for example, ultrasonic sensor having a range from 30 to 300 mm and capable of being synchronized and programmed for joint operation. For example, there are US300-30GM-IUR2-V15 sensors available from PEPPERL+FUSHC (DE). Said sensors irradiate pulses in a cyclic mode. Said pulses are reflected from a surface of an object present in "the working effective zone," and a distance to the object to be monitored is determined from a rime of returning pulses back to a sensor. Let us consider an example using three measurement sensors because the inventor deems this variant the most optimal since a position of a plane in space is determined using three points. The purpose of the disc R is "a measurement plane;" said disc is rigidly secured perpendicularly to the rotation axis at the end face of the body of the sliding bearing in the unbalanced vibrator q and thus repeats all moves of the vibrator and therefore of the internal cone 2 associated therewith as well. In the present example, the sensors D 1, 2 and 3 are mounted below a level of the measurement disc, for example in the bottom of the body 6 in a housing of the crusher, in such a manner that the disk R is in the working zone of radiation of the sensors D (Fig. 2) in any time including a time of a maximum unbalance deviation from the axis X. An ultrasonic pulse (USP) sent from a working end face of any sensor should be directed upwardly along the vertical axis Z of the crusher. A monitoring sensor D 4 is mounted at any point of a circle on the flange 8 of the body top part between the flange of the body 6 and a flange of the adjustment ring 7 of the external cone 3. Operation of all sensors is synchronized and controlled by the central computer A cycle of measurements The sensors D 1, 2 and 3 simultaneously radiate USRs reflected from the disc R. Distances to three different points on the disc R are determined from a return time, and information is transmitted to the central computer that is guided by said three point to calculate a three-dimensional position of the plane of the disc R relative to the horizontal plane. An angle & of deviation of the plane of the disc R from horizontal equals to an angle &' of deviation of the internal cone from vertical plane, because they are the angle formed 7 by orthogonal lines, wherein the &' is taken equal to an oscillation amplitude of the internal cone 2, and Fig. 2 shows this relationship. Let us consider a particular example of calculating a position of the disc R plane under a condition that all sensors D 1, 2 and 3 are in the same horizontal plane; Fig. 3 shows explanatory drawings. A coordinate origin (0, 0, 0) is in the plane where the sensors D arranged, particularly at a point where it crosses with the rotation axis Z of the unbalanced vibrator I (the vertical axis of symmetry). In order to improve the angle determination accuracy, a radius of sensor arrangement, that is a distance from the vertical symmetry axis Z of the crusher to a location of a sensor, should a maximum allowable radius. A position of each sensor is defined by a pair of numbers (Xi, Yi) while a measurement result is defined by a number Z, that is, the sensors are oriented vertically. Let us find a plane equation in the form A--x + B y + Cz + D = 0 in accordance with three points, in other words, according to results of measurements and positions of sensors. Y Z, I A = Det Y2 Z 2 1 (2a) X3 Z31 Z X 1 1 B = Det Z 2

X

2 1 (2b) Z3 X 3 1 X, Y 1 C = Det X 2 Y2 1 (2c)

X

3

Y

3 1 X, Y, Z, D= Del X 2

Y

2

Z

2 (2d).

X

3

Y

3 Z3 The angle of inclining the plane relative to horizontal is found from the determined coefficients & = ArcCos[C/sqrt(A 2

+B

2 + C 2

)].

8 The found angle determines the oscillation amplitude of the internal cone 2. The size of the discharge gap 4 is calculated by the central computer in accordance with the found value of the oscillation amplitude of the internal cone 2. The obtained size of the discharge gap 4 is compared to a predetermined parameter in the central computer, and a control command is outputted as a result of comparison, said command being to: - continue the operation if the size of the gap 4 is within a standard; -or correct the parameters if the size of the gap 4 are beyond the standard; The main reason to modify the size of the gap is wear of the working surfaces of the cones. Correction of parameters The sensor D 4 continuously radiates USPs vertically towards the flange of the adjustment ring 7 and measures a distance S between the flange of the body 6 and the flange of the adjustment ring 7. Having made a decision to correct parameters, the central computer gives the control command to the hydraulic cylinders 10, and a pressure therein simultaneously drops, a tension of the stems 11 is reduced, a thread 12 is relaxed, and the adjustment ring 9 turns in the thread 12 under action of the centrifugal force applied to the external cone 3. The cone lowers, the distance S and the size of the discharge gap are decreased. Accordingly, the oscillation amplitude of the internal cone 2 is modified. As a result of the next cycle of measuring the modified oscillation amplitude of the internal cone 2 and with the proviso that amplitude parameters came within a standard, the central computer gives a control command to interrupt correction. In this case, the command arrives at the hydraulic cylinders 10, the pressure therein is elevated, the tension of the stem 11 increases, the thread 12 is tightened, the turn of the adjustment ring 9 is stopped. New distance S is fixed by the sensor D4 and memorized, in other words, is set as new parameter corresponding to an optimal size of the discharge gap. Operation of the sensor D4 serves as an additional protection against an emergency situation when the adjustment ring 9 could spontaneously turn because of relaxing the tension of the thread 12. This situation may be caused, for example, by unauthorized pressure drop in the hydraulic cylinders 10, the elevated level of vibration, or other working reasons. An advantage of the present method in at least one form, is continuity of measurements. Measurements are cyclic, the frequency and accuracy of measurements are 9 determined by the operation speed of the ultrasonic sensors D. In practice, it was established that it would be reasonable to establish an ultrasound pulse radiation frequency close to the rotation frequency of the unbalanced vibrator of the crusher. In order to determine a position of the internal cone in the quiescent state, the first cycle of measurement takes place yet before the crusher operation. The next cycle of measurements takes place immediately after bringing the crusher into the idle mode; this allows additional prevention of the emergency situation. Further, measurements are continuous during operation of the installation. The final cycle of measurement takes place after complete stoppage of the machine. The distinguishing features of the method according to at least one form of the disclosed have the additional positive benefits: * more fine and accurate correction of parameters; e safe operation at a maximum allowable size of the discharge gap; e accumulation of statistics with respect to wear of working surfaces of the cones depending upon a source material and other reasons; " prediction of service life and need of replacement of working assemblies of the machine on the basis of said statistics and using special software of the central computer. Presence of the automated computer control allows the operator to control the crusher both directly from the place where it operates and remotely from any distant point. Implementation of the method allows improvement in the crushing installation operation effectiveness at least by 30%. In the claims which follow and in the preceding description, except where the context requires otherwise due to express language or necessary implication, the word "comprise" or variations such as "comprises" or "comprising" is used in an inclusive sense, i.e., to specify the presence of the states features but not to preclude the presence or addition of further features in various embodiments of the method and apparatus.

Claims (15)

1. 2. A method according to claim 1, further comprising comparing the calculated angle of inclination of the inner cone to a predetermined angle of inclination of the inner cone, and correcting an operating parameter when the calculated angle of inclination deviates from the predetermined angle of inclination.
2. 3. A method according to claim 1, further comprising estimating, based on the calculated angle of inclination of the inner cone, the size of the discharge gap between the internal cone and the external cone.
3. 4. A method according to claim 3, further comprising comparing an estimated size of the discharge gap between the internal cone and the external cone to a predetermined discharge gap, and correcting an operating parameter when the estimated size of the discharge gap deviates from the predetermined discharge gap.
4. 5. A method according to claim 2 or 4, wherein the correction of the operating parameter comprises turning an adjustment ring to which the external cone is connected.
5. 6. A method according to claim 1, further comprising utilizing a measurement disc connected to the inner cone as the measurement plane, and measuring distances between the bottom of the body of the crusher and the measurement disc.
6. 7. A method according to claim 1, further comprising measuring, in each of at least two different positions, distances from the bottom of the body of the crusher to the S1I measurement plane and calculating the angle of inclination of the inner cone.
7. 8. A method according to claim 1, further comprising controlling, based on the calculated angle of inclination of the inner cone, a compensation for wear of working surfaces of the cones.
8. 9. A method according to claim 1, further comprising measuring the size of a discharge gap between the internal cone and the external cone when the crusher is running in idle mode, such that emergency situation is prevented.
9. 10. A method according to claim 1, further comprising utilizing the calculated angle of inclination of the inner core to detect changes in the crusher operation.
10. 11. A method according to claim 1, further comprising utilizing the measured distances between the measurement plane and the bottom of the body of the crusher for calculating a three-dimensional position of the measurement plane, and utilizing said three-dimensional position for calculating the angle of inclination of the inner cone.
11. 12. A cone crusher having an internal cone connected to an unbalanced vibrator, and an external cone, the cone crusher further comprising: a measurement plane being connected to the internal cone, a measuring device operative for measuring distances between the measurement plane and a bottom of the body of the crusher, and a computer which is operative for receiving information relating to said distances from the measuring device, calculating an angle of inclination of the inner cone based on said information, and controlling, based on the calculated angle of inclination of the inner cone, at least one parameter chose among: the angle of inclination of the inner cone, and the size of a discharge gap between the internal cone and the external cone.
12. 13. A cone crusher according to claim 12, wherein the measuring device is mounted on the bottom of the crusher of the crusher and is operative for measuring distances between the bottom of the body and a measurement disc forming the measurement plane and being connected to the internal cone. 12
13. 14. A cone crusher according to claim 13, wherein the measurement disc is perpendicular to a rotation axis of the unbalanced vibrator.
14. 15. A cone crusher according to claim 12, wherein the crusher comprises an adjustment ring to which the external cone is connected, the computer being operative for controlling the rotation of the adjustment ring to control the size of the discharge gap.
15. 16. A cone crusher according to claim 12, wherein the measuring device comprises at least two sensors, each sensor being operative for measuring a distance between the measurement plane and the bottom of the body of the crusher.