CA1247583A - Crusher gap setting - Google Patents
Crusher gap settingInfo
- Publication number
- CA1247583A CA1247583A CA000481971A CA481971A CA1247583A CA 1247583 A CA1247583 A CA 1247583A CA 000481971 A CA000481971 A CA 000481971A CA 481971 A CA481971 A CA 481971A CA 1247583 A CA1247583 A CA 1247583A
- Authority
- CA
- Canada
- Prior art keywords
- gap
- size
- crushing
- crusher
- predetermined
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
Landscapes
- Disintegrating Or Milling (AREA)
Abstract
ABSTRACT
The amplitude of the variations in the power drawn by a crusher motor is dependent on the crushing gap in the crusher, other parameters such as ore feed rate etc. remaining constant. In accordance with the invention, this phenomenon is used to set the crushing gap. The power drawn by the motor is monitored and the amplitude of the variations of the power drawn is used as a basis for determining whether the existing crushing gap is too great or too small.
The amplitude of the variations in the power drawn by a crusher motor is dependent on the crushing gap in the crusher, other parameters such as ore feed rate etc. remaining constant. In accordance with the invention, this phenomenon is used to set the crushing gap. The power drawn by the motor is monitored and the amplitude of the variations of the power drawn is used as a basis for determining whether the existing crushing gap is too great or too small.
Description
'7~
This invention relates to the measuring and setting of the crushing gap in crushers, such as gyrating di~c or cone cru~hers.
At present, the crushing gap is ascertained by leading. In the leadin~ process, the crusher i8 stopped, and a lead body is dropped into the gap on a string. When the crusher i5 re~tarted, the lead is deformed to a thickne~s equal to the crushing gap. If the gap so ascertained is incorrect, lt is necessary to reset it, and then to perform the leading proce~s again to check the setting. The leading proce~s may have to be performed over and over again until an acceptable gap i5 measured.
This unsophisticated, trial-and-error process has obvlou~ drawbacks. For in~tance, its implementation leads to considerable downtime and the f ~nal result may still not be accurate. Also, it is not uncommon for the operator to neglect to do his check3 at the required frequent intervals, with the re~ult that the gap i9 often too great as wear o~ the crusher takes place. Thi~ in ~ turn means tha~ the rock is not cru~hed to the required ~ize and may have to be returned for a ~urther pas~, and attendant reduced production and e~icies~cy. Even more seriou~ in th~ ca~e o~ diamond-bearin~ rock is the fact that diamonds can be lo~t if the gap i8 too great.
~xperiment~ conducted by the inventor revealed that the power drawn by a gyradi~c crusher during operation is not constant, even if other operatlng parameters, such a~ ore feed rate and ore size, are kept constant, but exhibits considerable variations.
Furthermore, it was found that ~he amplitude of the variations i8 greater if the crushing gap is small than if the crushing ~ap is larger.
It is an ob~ect of the invention to use these findings in the mea~uring and setting of the crusher's 3~ crushin~ ~ap.
Accordin~ly, one aspect of the invention provides a method of maintaining a predetermined ~lze of crushing gap in an ore crusher of the type comprisin~
,*~
,"
. . .
7~ 3 crusher means defining an ad~ustable crushin~ gap, and a driving motor for driving the crusher means, the method comprising the steps of e-~tablishing a predetermined gap ~ize, measuring noise in the power drawn by the motor during a crushing operation, which measured noise iq indicative of the size o~ the crushing gap, ~etting the crushing gap at the predetermined gap size in accordance with the measured noise, and maintaining the crushing gap at the predetermined gap size.
In a preferred form, the method includes the following steps: monitoring the power drawn by the motor, determining the actual crushing gap by analyzing the amplitude of the variation~ in the power drawn by the motor, comparing the actual crushing yap with a predetermined value, and ad~usting the crushing gap according to whether, and by how much, the actual gap differs from the predetermlned value.
Alternatively, the method may include the ~ollowing 6teps: monitoring the power drawn by the motor, comparing the actual amplitude value, and ad~u3tirlg the crushing gap in accorda~ce with whether, and by how much, the actual amplitude diP~er~ from the predetermined value.
In thi~ ca~e, i~ ~he actual amplitude is greatex than the predetermined value, the crushing ~ap will be increassd, and vice versa.
Pre~erably, the method o~ the invention i8 carried out continuously and automatically i.e. the power drawn i8 monitored continuously, and crushing gap ad~u~tments are made automatically as required.
Another aspect o~ the invention provide3 in an ore cru~her o~ the type comprising crusher means defining an ad~u~table crushing gap and a drive motor for driving the crusher means, the improvement comprising means for monitoring the power drawn by the motor during a crushin~
operation, and for measuring noise in the powsr drawn by the motor, and means for setting the crushing gap size to a predetermined gap size in accordance with the measured noise.
5~3 Pre~erred apparatus according to o~e embodiment of the invention includes means for monitorin~ the power drawn by the crusher motor, means for determining the actual crushlng gap by analyzing the amplitude of the 5varlations in the power drawn, means for comparing the actual gap with a predetermined gap, and means for adjusting the actual gap in accordance with whether, and by how much, the actual gap differs from the predetermined gap.
10Alternative apparatus may include means for monitorin~ the power drawn, means for comparing the amplitude of the variations in the power drawn with a predetermined amplitude valu~, and means for ad~usting the actual gap in accordance with whether, and by how much, 15the actual amplitude differs from the predetermined valu~.
Embodlment~ of the invention will now be described, by way o~ example, with reference to the accompanying drawings, in whlch:
Figure 1 shows graphs of the power drawn by a ~0gyradisc crusher ~or diferent crushln~ ~ap se~tings; and Figure 2 illustrates schematically how the crushing yap can be set contlnuou~ly to an optimum value.
Re~erring firstly to Figure 1, the power drawn characteristics recorder by a chart recorder in three 25di~ferent experiment~ with increasing crushing gaps are illustrated graphically. I~ each case, other operatlng parameters, such as ore ~eed rate and ore ~lze prior to crushing are kept constant. Power drawn is on the vertical a~is, and time on the horizontal axis. In these 30Qxperiments, the chart speed wa~ 60cm/H, and the graphs are at ~ull scale. In the experiment represented by graph (a), the crushing gap wa~ 5 mm, in that represented by yraph (b) it waY ~ mm, and in that represented by graph (c), it was 11 mm.
35Compariso~ of Figures la, lb and lc readily indicates that the smaller the crushing gap, the ~reater the noise. "Noi~e" is the variation in the power drawn and i~ represented by the wave amplitude of the graphs o~
,,, .~ .
~ "
FigureY la, lb and lc. Compare, for instance, graph (a) with graph (c), where it i8 seen that the amplitude of the variations ln the power drawn is markedly gxeater in the case of the smaller gap than in the case of the larger gap.
The invention contemplates usin~ thls phenomenon in the measuring oP the actual gap and the re~etting of that gap (if necessary) to an optimum value. Figure 2 illustrates schematically the basic components in one form of apparatus which could be used to achieve this end.
In Figure 2, a conventional crusher and motor combination i~ designated by the reference numeral 10.
During operation, the power drawn by the motor is monitored continuously by a measuring instrument 14. The instrument 14 analyses the incoming power drawn signals and produce~ from them a mea~ured gap signal which is indicative of the actual crushing gap and which is dependent on the amplitude of the variation~ in the power drawn by the motor. The mea~ured gap ~ignal i8 passed to a gap controller 16 which compare~ the actual measured gap with an ideal value and controls an on-line gap adJu~tment s~stem 1~ dependin~ on whether, and by how much, its compari~on reveals a dlf~erence between the actual and ideal gap value~. Preferably, the gap ad~u~tment system 18 will be capable of effec~ing continuous fine ad~u~tments to the gap ~etting, so maintalnlng the crushing gap continuously at an optimum value.
Note that the apparatus shown schema~ically in Fi~ure 2 effects its ad~ustment~ as a result of a comparison between a computed actual gap value and an ideal gap value. It would also be possible to have an apparatus which does not compute an actual gap value, but ~which performs a direct comparison between the ideal amplitude of the variations in the power drawn wlth an ideal amplitude value, and then performs lts adjusting function on the basis of that comparison.
.
This invention relates to the measuring and setting of the crushing gap in crushers, such as gyrating di~c or cone cru~hers.
At present, the crushing gap is ascertained by leading. In the leadin~ process, the crusher i8 stopped, and a lead body is dropped into the gap on a string. When the crusher i5 re~tarted, the lead is deformed to a thickne~s equal to the crushing gap. If the gap so ascertained is incorrect, lt is necessary to reset it, and then to perform the leading proce~s again to check the setting. The leading proce~s may have to be performed over and over again until an acceptable gap i5 measured.
This unsophisticated, trial-and-error process has obvlou~ drawbacks. For in~tance, its implementation leads to considerable downtime and the f ~nal result may still not be accurate. Also, it is not uncommon for the operator to neglect to do his check3 at the required frequent intervals, with the re~ult that the gap i9 often too great as wear o~ the crusher takes place. Thi~ in ~ turn means tha~ the rock is not cru~hed to the required ~ize and may have to be returned for a ~urther pas~, and attendant reduced production and e~icies~cy. Even more seriou~ in th~ ca~e o~ diamond-bearin~ rock is the fact that diamonds can be lo~t if the gap i8 too great.
~xperiment~ conducted by the inventor revealed that the power drawn by a gyradi~c crusher during operation is not constant, even if other operatlng parameters, such a~ ore feed rate and ore size, are kept constant, but exhibits considerable variations.
Furthermore, it was found that ~he amplitude of the variations i8 greater if the crushing gap is small than if the crushing ~ap is larger.
It is an ob~ect of the invention to use these findings in the mea~uring and setting of the crusher's 3~ crushin~ ~ap.
Accordin~ly, one aspect of the invention provides a method of maintaining a predetermined ~lze of crushing gap in an ore crusher of the type comprisin~
,*~
,"
. . .
7~ 3 crusher means defining an ad~ustable crushin~ gap, and a driving motor for driving the crusher means, the method comprising the steps of e-~tablishing a predetermined gap ~ize, measuring noise in the power drawn by the motor during a crushing operation, which measured noise iq indicative of the size o~ the crushing gap, ~etting the crushing gap at the predetermined gap size in accordance with the measured noise, and maintaining the crushing gap at the predetermined gap size.
In a preferred form, the method includes the following steps: monitoring the power drawn by the motor, determining the actual crushing gap by analyzing the amplitude of the variation~ in the power drawn by the motor, comparing the actual crushing yap with a predetermined value, and ad~usting the crushing gap according to whether, and by how much, the actual gap differs from the predetermlned value.
Alternatively, the method may include the ~ollowing 6teps: monitoring the power drawn by the motor, comparing the actual amplitude value, and ad~u3tirlg the crushing gap in accorda~ce with whether, and by how much, the actual amplitude diP~er~ from the predetermined value.
In thi~ ca~e, i~ ~he actual amplitude is greatex than the predetermined value, the crushing ~ap will be increassd, and vice versa.
Pre~erably, the method o~ the invention i8 carried out continuously and automatically i.e. the power drawn i8 monitored continuously, and crushing gap ad~u~tments are made automatically as required.
Another aspect o~ the invention provide3 in an ore cru~her o~ the type comprising crusher means defining an ad~u~table crushing gap and a drive motor for driving the crusher means, the improvement comprising means for monitoring the power drawn by the motor during a crushin~
operation, and for measuring noise in the powsr drawn by the motor, and means for setting the crushing gap size to a predetermined gap size in accordance with the measured noise.
5~3 Pre~erred apparatus according to o~e embodiment of the invention includes means for monitorin~ the power drawn by the crusher motor, means for determining the actual crushlng gap by analyzing the amplitude of the 5varlations in the power drawn, means for comparing the actual gap with a predetermined gap, and means for adjusting the actual gap in accordance with whether, and by how much, the actual gap differs from the predetermined gap.
10Alternative apparatus may include means for monitorin~ the power drawn, means for comparing the amplitude of the variations in the power drawn with a predetermined amplitude valu~, and means for ad~usting the actual gap in accordance with whether, and by how much, 15the actual amplitude differs from the predetermined valu~.
Embodlment~ of the invention will now be described, by way o~ example, with reference to the accompanying drawings, in whlch:
Figure 1 shows graphs of the power drawn by a ~0gyradisc crusher ~or diferent crushln~ ~ap se~tings; and Figure 2 illustrates schematically how the crushing yap can be set contlnuou~ly to an optimum value.
Re~erring firstly to Figure 1, the power drawn characteristics recorder by a chart recorder in three 25di~ferent experiment~ with increasing crushing gaps are illustrated graphically. I~ each case, other operatlng parameters, such as ore ~eed rate and ore ~lze prior to crushing are kept constant. Power drawn is on the vertical a~is, and time on the horizontal axis. In these 30Qxperiments, the chart speed wa~ 60cm/H, and the graphs are at ~ull scale. In the experiment represented by graph (a), the crushing gap wa~ 5 mm, in that represented by yraph (b) it waY ~ mm, and in that represented by graph (c), it was 11 mm.
35Compariso~ of Figures la, lb and lc readily indicates that the smaller the crushing gap, the ~reater the noise. "Noi~e" is the variation in the power drawn and i~ represented by the wave amplitude of the graphs o~
,,, .~ .
~ "
FigureY la, lb and lc. Compare, for instance, graph (a) with graph (c), where it i8 seen that the amplitude of the variations ln the power drawn is markedly gxeater in the case of the smaller gap than in the case of the larger gap.
The invention contemplates usin~ thls phenomenon in the measuring oP the actual gap and the re~etting of that gap (if necessary) to an optimum value. Figure 2 illustrates schematically the basic components in one form of apparatus which could be used to achieve this end.
In Figure 2, a conventional crusher and motor combination i~ designated by the reference numeral 10.
During operation, the power drawn by the motor is monitored continuously by a measuring instrument 14. The instrument 14 analyses the incoming power drawn signals and produce~ from them a mea~ured gap signal which is indicative of the actual crushing gap and which is dependent on the amplitude of the variation~ in the power drawn by the motor. The mea~ured gap ~ignal i8 passed to a gap controller 16 which compare~ the actual measured gap with an ideal value and controls an on-line gap adJu~tment s~stem 1~ dependin~ on whether, and by how much, its compari~on reveals a dlf~erence between the actual and ideal gap value~. Preferably, the gap ad~u~tment system 18 will be capable of effec~ing continuous fine ad~u~tments to the gap ~etting, so maintalnlng the crushing gap continuously at an optimum value.
Note that the apparatus shown schema~ically in Fi~ure 2 effects its ad~ustment~ as a result of a comparison between a computed actual gap value and an ideal gap value. It would also be possible to have an apparatus which does not compute an actual gap value, but ~which performs a direct comparison between the ideal amplitude of the variations in the power drawn wlth an ideal amplitude value, and then performs lts adjusting function on the basis of that comparison.
.
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A method of maintaining a predetermined size of crushing gap in an ore crusher of the type comprising crusher means defining an adjustable crushing gap, and a driving motor for driving said crusher means, said method comprising the steps of establishing a predetermined gap size, measuring noise in the power drawn by said motor during a crushing operation, which measured noise is indicative of the size of said crushing gap, setting said crushing gap at said predetermined gap size in accordance with said measured noise, and maintaining the crushing gap at said predetermined gap size.
2. A method of maintaining a predetermined size of crushing gap in an ore crusher of the type comprising crusher means defining an adjustable crushing gap, and a drive motor for driving said crusher means, said method comprising the steps of establishing a predetermined gap size, monitoring the power drawn by said motor during a crushing operation while keeping parameters of ore size and ore feed rate substantially constant, measuring noise in the power drawn by the motor during such operation, determining from the measured noise a measured size of said crushing gap, comparing said measured gap size with said predetermined gap size, adjusting the size of said crushing gap in accordance with a difference between said measured and predetermined gap sizes to maintain said predetermined gap size, and maintaining the crushing gap at said predetermined gap size.
3. A method of maintaining a predetermined size of crushing gap in an ore crusher of the type comprising crusher means defining an adjustable crushing gap, and a drive motor for driving said crusher means, said method comprising the steps of establishing a predetermined gap size, monitoring the power drawn by said motor during a crushing operation while keeping parameters of ore size and ore feed rate substantially constant, measuring noise in the power drawn by the motor during such operation, comparing said measured noise with a predetermined noise value corresponding to said predetermined gap size, adjusting the size of said crushing gap in accordance with a different between said measured noise and said predetermined noise value to maintain said predetermined gap size, and maintaining the crushing gap at said predetermined gap size.
4. In an ore crusher of the type comprising crusher means defining an adjustable crushing gap and a drive motor for driving said crusher means, the improvement comprising means for monitoring the power drawn by said motor during a crushing operation, and for measuring noise in the power drawn by the motor, and means for setting the crushing gap size to a predetermined gap size in accordance with the measured noise.
5. In an ore crusher of the type comprising crusher means defining an adjustable crushing gap and a drive motor for driving said crusher means, the improvement comprising means for monitoring the power drawn by said motor during a crushing operation while keeping parameters of ore size and ore feed rate substantially constant, means for measuring noise in the power drawn by the motor during such operation, means for determining from the measured noise a measured size of said crushing gap, means for comparing said measured gap size with a predetermined gap, and means for adjusting the size of said crushing gap in accordance with a difference between said measured and predetermined gap sizes to maintain said predetermined gap size.
6. In an ore crusher of the type comprising crusher means defining an adjustable crushing gap on a drive motor for driving said crusher means, the improvement comprising means for monitoring the power drawn by said motor during a crushing operation while keeping parameters of ore size and ore feed rate substantially constant, means for measuring noise in the power drawn by the motor during such operation, means for comparing the measured noise with a predetermined noise value corresponding to a predetermined gap size, and means for adjusting the size of said crushing gap in accordance with a difference between said measured noise and said predetermined noise value to maintain said predetermined gap size.
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| ZA84/3853 | 1984-05-22 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1247583A true CA1247583A (en) | 1988-12-28 |
Family
ID=209494
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA000481971A Expired CA1247583A (en) | 1984-05-22 | 1985-05-21 | Crusher gap setting |
Country Status (1)
| Country | Link |
|---|---|
| CA (1) | CA1247583A (en) |
-
1985
- 1985-05-21 CA CA000481971A patent/CA1247583A/en not_active Expired
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US4712743A (en) | Crusher gap setting | |
| US5580003A (en) | Method for controlling a gyratory crusher | |
| EP0306594B1 (en) | Gyratory crusher control | |
| RU2005106195A (en) | METHOD OF CONTROL OF THE SORTING MACHINE AND THE SORTING MACHINE | |
| EP3530161A1 (en) | Food preparation device with tool for grinding | |
| AU2005225337B2 (en) | Method and device for the control of a crusher | |
| CA1247583A (en) | Crusher gap setting | |
| US4544102A (en) | Differential rate screening | |
| DE4215455C2 (en) | Device and method for determining the level of mills | |
| US4627576A (en) | Differential rate screening | |
| US4212429A (en) | Method and an apparatus for controlling a crusher | |
| EP0094741B1 (en) | Differential rate screening | |
| BR8804881A (en) | NON-INTRUSIVE PROCESS FOR DETERMINING THE VALUE OF A PHYSICAL PROPERTY OF MATERIAL INSIDE A MILL | |
| US4544101A (en) | Differential rate screening | |
| US3697003A (en) | Grinding mill method and apparatus | |
| CN103439992B (en) | In a kind of grinding process the blanking of ore grinding storehouse be obstructed control method and apparatus | |
| SU1678454A1 (en) | Method for autmatic control of wet grinding machine with closed cycle | |
| SU679243A1 (en) | Method of automatic control of charging of ball mill | |
| RU2272673C2 (en) | Device for automatic control of grinding process | |
| SU1375338A1 (en) | Method of controlling the cycle of grinding of materials in the mill | |
| DE10031883C2 (en) | Method and arrangement for variably regulating the feed quantity of the material of fluctuating nature, which is fed to a plant consisting of several units, in particular a sand and gravel treatment plant | |
| SU1643086A1 (en) | Method and device for automatic control of crusher discharge slot size | |
| SU1304875A1 (en) | Method and apparatus for automatic monitoring of crusher output slit size | |
| Zeng et al. | Energy consumption in fine crushing and dry rod grinding | |
| SU1052262A1 (en) | Method of automatic control of crusher productivity |
Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |