METHOD FOR DIAGNOSING FAULTS IN SLURRY PUMP IMPELLERS

• US 20150122037A1
• Filed: 10/29/2014
• Published: 05/07/2015
• Est. Priority Date: 10/30/2013
• Status: Abandoned Application

• Current Assignee: Cityu Professional Services Ltd. (City University of Hong Kong), Syncrude Canada Limited
• Original Assignee: Cityu Professional Services Ltd. (City University of Hong Kong), Syncrude Canada Limited
• Inventors: OBAIA, KHALED, WOLFE, DAN, LANGE, STEFFEN, TSE, PETER W., LEUNG, JACKO T.
• Application Number:
  US14/526,757
• Publication Number:
  US 20150122037A1
• Time in Patent Office: Days
• US Class Current: 73/660
• CPC Class Codes: F04D 15/0088 Testing machines
• CPC Class Codes: F04D 7/04 the fluids being viscous or non-homogenous
• CPC Class Codes: G01H 1/003 of rotating machines G01H1/10 takes precedence
• CPC Class Codes: G05B 23/0283 Predictive maintenance, e.g. involving the monitoring of a system and, based on the monitoring results, taking decisions on the maintenance schedule of the monitored system; Estimating remaining useful life [RUL] preventive maintenance, i.e. planning maintenance according to the available resources without monitoring the system G06Q10/06

Abstract

A method of diagnosing the condition of a slurry pump impeller is provided, comprising collecting vibration data from at least one accelerometer mounted to or proximate the pump over a specific time period; calculating indicators from the collected vibration data, the indicators comprising energy level, crest factor, square root amplitude value, and fault growth parameter; and plotting the calculated indicators against time to generate a fault trend indicative of health or deterioration of the impeller. The method further involves predicting the remaining useful life of the impeller using vibration data-driven prognostics.

Claims

1. A method of diagnosing the condition of an impeller of a slurry pump comprising:

collecting vibration data from at least one accelerometer mounted to or proximate the pump over a specific time period;

calculating one or more indicators from the collected vibration data, the indicators including energy level, crest factor, square root amplitude value, and fault growth parameter; and

plotting the calculated indicators against time to generate a fault trend indicative of health or deterioration of the impeller.

2. The method of claim 1, further comprising converting the collected vibration data into frequency signals, and calculating the indicators from the frequency signals.

3. The method of claim 1, wherein the accelerometer is capable of detecting vibrations emitted from the pump during operation, and outputting and transmitting corresponding vibration response signals to a data logger operatively connected to the accelerometer.

4. The method of claim 3, comprising obtaining the vibration response signals from the data logger and transmitting the vibration response signals to a host computer, the computer being programmed to process and analyze the vibration response signals.

5. The method of claim 3, wherein the accelerometer detects vibrations ranging in frequency between about 5 Hz to about 60 kHz.

6. The method of claim 1, wherein the specific time period extends from an initial baseline time point to a subsequent time point.

7. The method of claim 6, wherein vibration data are collected per hour daily during the specific time period.

8. The method of claim 1, comprising dividing the vibration data into multiple percentages to calculate crest factor (20%).

9. The method of claim 1, wherein the fault trend comprises a polynomial trend or a linear trend.

10. The method of claim 9, further comprising subtracting a mean value of each indicator from each data point and plotting residual values.

11. The method of claim 10, further comprising adjusting the Y-scale to eliminate outliers.

12. The method of claim 1, further comprising activating an alert upon determination that the vibration data are indicative of deterioration of the impeller.

13. The method of claim 1, further comprising applying one or more prediction methods to the collected vibration data to predict the remaining useful life of the pump.

14. The method of claim 13, wherein the prediction methods are selected from support vector machine (SVM) classifiers, relevance vector machines (RVM) and exponential regression, a moving-average wear degradation index (MAWDI), or a sequential Monte Carlo (SMC) method.

15. The method of claim 14, wherein the prediction method comprises SVM classifiers.

16. The method of claim 15, comprising calculating kurtosis, clearance factor, shape factor, impulse indicator, variance, and absolute mean amplitude value from the collected vibration data.

17. The method of claim 16, comprising training the SVM classifiers with the calculated indicators.

18. The method of claim 17, comprising applying a frequency range filter to select vibration data having sub-band energies ranging between about 0 Hz to about 400 Hz.

19. The method of claim 18, comprising training the SVM classifiers with the filtered vibration data, wherein the SVM classifier predicts fault severity.

20. The method of claim 14, wherein the prediction method comprises RVM and exponential regression.

21. The method of claim 20, comprising selecting a frequency band covering frequencies ranging from about 33 Hz to about 60 Hz.

22. The method of claim 21, comprising calculating energy evolution and standard deviation from the collected vibration data.

23. The method of claim 22, comprising providing the calculated energy evolution and standard deviation to the RVM to obtain a fault trend.

24. The method of claim 14, wherein the prediction method comprises MAWDI and the SMC method.

25. The method of claim 24, comprising selecting a frequency band covering frequencies ranging from about 40 Hz to about 60 Hz.

26. The method of claim 25, comprising calculating energy evolution from the collected vibration data, and subsequently calculating the MAWDI.

27. The method of claim 26, comprising providing the MAWDI to the SMC method to obtain an estimation of the remaining useful life of the impeller.

28. The method of claim 1, further comprising outputting the plot to a display device.