| 1. |
- Forssberg, Eric, et al.
(författare)
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Vibrationssignalanalyse bei der Eisenerzmahlung
- 1994
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Ingår i: Aufbereitungstechnik - Mineral processing. - 0004-783X. ; 35:10, s. 505-
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Tidskriftsartikel (refereegranskat)abstract
- Vibration signal measurements were performed on a commercial scale grinding process operated at LKAB. Three channels of mechanical vibration signals from the axial, horizontal and vertical directions, and one channel of acoustic signal at the centre of the abrasion zone outside the ball mill shell, were picked up, digitised and processed using a personal computer. The feed rate, power draw, pulp temperature were recorded automatically by the process control system while material samples of mill feed and product were taken for determination of particle size distribution and pulp density during signal acquisition. The particle size distributions, time-domain waveforms and power spectra were illustrated and discussed. By multivariate data analysis, close relationships were established between grinding parameters and the pattern of vibration signals. The results show that vibration signal analysis could be used to monitor grinding parameters for industrial scale ball mills.
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| 2. |
- Zeng, Yigen, et al.
(författare)
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Application of digital signal processing and multivariate data analysis to vibration signals from ball-mill grinding
- 1993
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Ingår i: Mineral Processing and Extractive Metallurgy. - 0371-9553 .- 1743-2855. ; 102:Jan-Apr, s. 39-43
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Tidskriftsartikel (refereegranskat)abstract
- During mechanical grinding high-intensity vibration is emitted that contains information on the operating state of the mill. To study the influence of operating parameters on the vibration signature tests were performed with a laboratory ball-mill. Five operating parameters were considered: mill speed, powder filling (as a percentage of voidage), pulp density, grinding period, and pulp temperature. Vibration signals were detected by an accelerometer, amplified by a portable vibrometer and recorded with a digital audio tape recorder. A digital oscilloscope was used to convert the signals into an IBM-compatible data format.
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| 3. |
- Zeng, Yigen, et al.
(författare)
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Application of vibration signal measurement for monitoring grinding parameters
- 1994
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Ingår i: Mechanical systems and signal processing. - : Elsevier BV. - 0888-3270 .- 1096-1216. ; 8:6, s. 703-713
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Tidskriftsartikel (refereegranskat)abstract
- Vibration signal measurements are discussed for monitoring operating parameters in a laboratory-scale ball mill. The vibration signal was first picked up with an accelerometer, amplified by a vibrometer and then transmitted to a DAT recorder during the entire testing period. The signal on the DAT recorder was resampled and converted into IBM compatible personal computer readable data format using a digital oscilloscope. The vibration signal analyses included rms estimation, power spectral estimation, waterfall plot, principal component analysis and stepwise multiple regression analysis. Clear differences in the rms and the spectra are found for different grinding conditions. Three principal components described about 95% of the total variation in the spectra. Each principal component was related mainly to one to three major frequency bands. Close correlation was found between the vibration signal and grinding parameters. Therefore, an alternative method can be developed for monitoring the operating parameters in a ball mill.
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| 4. |
- Zeng, Yigen, et al.
(författare)
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Application of vibration signals to monitoring crushing parameters
- 1993
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Ingår i: Powder Technology. - 0032-5910 .- 1873-328X. ; 76:3, s. 247-252
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Tidskriftsartikel (refereegranskat)abstract
- Vibration measurements for fine crushing have been performed on a laboratory scale jaw crusher on dolomite. The original vibration signal was sensed by an accelerometer and stored on a DAT recorder during the whole testing period. The vibration signal was resampled and converted into an IBM PC compatible data format with a digital oscilloscope. The time-domain vibration signal was analyzed with the aid of a digital signal processing technique. The crushing process can be inspected by replaying the sample of the time-domain waveform. The variation of the vibration pattern was described by a few `latent' variables obtained by principal component analysis. Relations were established between the crusher setting, the product size and the latent variables by multiple regression. Measurement of the vibration signal provides a new strategy for monitoring crushing processes.
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| 5. |
- Zeng, Yigen, et al.
(författare)
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Effect of powder filling fraction on particle size and energy consumption in coarse grinding
- 1991
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Ingår i: Scandinavian journal of metallurgy. - 0371-0459 .- 1600-0692. ; 20:5, s. 300-304
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Tidskriftsartikel (refereegranskat)abstract
- Particle size distribution, power draw, and energy consumption have been compared between rod and ball mills under laboratory dry batchwise grinding conditions. A parabolic-sine equation has been used to describe the particle size distributions of ground products and it fit satisfactorily with the particle size data. Based on this equation, the effects of the powder filling fraction and other operating parameters on the product fineness have been analyzed mathematically. The power draw and the energy consumption have also been related to the operating parameters. It was found that the maximum power draw occurs when the powder filling fraction is about 0.6 and 0.5 for the rod and ball mills respectively. The specific energy consumption of the rod mill is smaller than that of the ball mill under coarse grinding conditions.
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| 6. |
- Zeng, Yigen, et al.
(författare)
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Effects of mill feed size and rod charges on grinding performance
- 1992
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Ingår i: Powder Technology. - : Elsevier BV. - 0032-5910 .- 1873-328X. ; 69:2, s. 119-123
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Tidskriftsartikel (refereegranskat)abstract
- The effects of mill feed sizes and the rod charges on ground product fineness, energy utilization and energy consumption have been investigated on a rod mill under dry batchwise grinding conditions. The effect of reducing mill feed size on product fineness decreases with grinding time, while the effects of different composition of rod charges are very small. Smaller rod diameter, coarser mill feed size and shorter grinding time will increase the energy utilization. The energy consumption in batch grinding is described by the Bond method. Using smaller rod diameter and reducing the mill feed size will optimize energy use in coarse grinding.
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| 7. |
- Zeng, Yigen, et al.
(författare)
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Effects of mill feed size on product fineness and energy consumption in coarse grinding
- 1991
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Ingår i: Minerals Engineering. - 0892-6875 .- 1872-9444. ; 4:5-6, s. 599-609
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Tidskriftsartikel (refereegranskat)abstract
- The effects of some grinding parameters on the product fineness and the energy consumption under dry batchwise coarse grinding conditions are studied on rod and ball mills. A parabolic-sine equation is suitable to describe the particle size distribution. The constants in the equation are related to the grinding parameters, which permits a mathematical analysis. A relation between energy consumption and grinding parameters is also established, and the grinding effects in the rod and ball mills are compared.
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| 8. |
- Zeng, Yigen, et al.
(författare)
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Effects of operating parameters on vibration signal under laboratory scale ball grinding conditions
- 1992
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Ingår i: International Journal of Mineral Processing. - 0301-7516 .- 1879-3525. ; 35:3, s. 273-290
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Tidskriftsartikel (refereegranskat)abstract
- Experiments were performed under batchwise wet grinding conditions with dolomite. The vibration signal was received by an accelerometer and transmitted to a vibrometer. The vibration signal was first stored on a Digital-Audio-Tape recorder in voltage format during the grinding tests. The original signal was then resampled and converted into data format for an IBM or compatible personal computer by a digital oscilloscope. The Root-Mean-Square and the power spectrum were estimated on the time-domain vibration signal. A partial correlation analysis was applied to the frequency-domain spectrums to detect the non-zero correlation between the frequency bands and the operating parameters in grinding. A stepwise regression analysis was used to locate the key frequency bands for describing the changes of a particular operating parameter. After vibration analysis, the operating parameters in grinding, e.g., the mill speed, the powder filling, the pulp density, the pulp temperature and the batchwise grinding time were found to be strongly correlated with a few frequency bands. It is therefore possible to develop an efficient method for monitoring the operating parameters in grinding based on the vibration signal.
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| 9. |
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| 10. |
- Zeng, Yigen, et al.
(författare)
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Energy consumption in fine crushing and dry rod grinding
- 1992
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Ingår i: Minerals & metallurgical processing. - 0747-9182. ; 9:2, s. 69-72
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Tidskriftsartikel (refereegranskat)abstract
- Fine crushing and rod grinding have been investigated using a laboratory-scale jaw crusher and a rod mill. The net energy consumption in both crushing and grinding was evaluated from torque measurements. An empirical relationship was established between energy consumption, particle size and operating parameters. When the mill feed size is reduced, through fine crushing, to about 80% passing 3 mm, the energy consumption will be minimized in a comminution chain of fine crushing and coarse rod grinding. The results in fine crushing were compared with a large-scale test.
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