Artesis MCM Case Studies. March 2011

Transcription

1 Artesis MCM Case Studies March 2011

2 Case 1 Automotive Company: Automobile Manufacturer A Equipment: Pump Stator Isolation Breakdown Decreasing current unbalance level

3 Case 1 Automotive Company: Automobile Manufacturer A Equipment: Pump Stator Isolation Breakdown MCM gave alarm indicating a developing electrical fault. Thermal camera results verified MCM s warnings. The pump motor was replaced. Hot Spot on stator winding

4 Case 2 Automotive Company: Automobile Manufacturer A Equipment: Tower Fan Imbalance & Misalignment MCM first gave a warning of a problem on 16 th October 2005, and diagnosed a looseness problem. The decision was to wait for further indications. Renewed alert on 19 th November 2005 initiated an inspection and a loose attachment bolt was found on 14 th February Oct Increasing unbalance parameter level Oct Nov Feb

5 Case 2 Automotive Company: Automobile Manufacturer A Equipment: Tower Fan Imbalance & Misalignment Loose bolt correctly identified Oct 05 Nov 05 Dec 05 Jan 06 Feb 06 Mar 06 Consistent Continued Looseness Continued alarm on monitoring of indicated briefly, monitoring of foundations, imbalance and but then foundation imbalance and misalignment problem problem misalignment problem disappeared Fixed foundation problem

6 Case 3 Automotive Company: Rubber & Tire Manufacturer Equipment: Rubber Mixing Mill Rotor Bar Crack MCM identified existing transmission and unbalance faults Later, MCM began giving Rotor Fault warning also

7 Case 3 Automotive Company: Rubber & Tire Manufacturer The Rotor Fault trend showed development of the rotor fault Equipment: Rubber Mixing Mill Rotor Bar Crack Vibration measurement also verified existence of broken rotor bars, confirming the MCM predictions Increasing Trend

8 Case 4 Oil & Gas Company: Oil & Gas Company A Equipment: Diesel Fuel Pump Misalignment 3th July; Change of Oil Felt Diesel Fuel Pump Trials of Axle adjustments 4 th July; axle adjustment done This case shows that MCM can be a very useful tool for quality assurance of maintenance work, showing whether alignment has been correctly completed following a maintenance task.

9 Case 5 Aerospace Company: NATO Radar Base Equipment: Radar Antenna Gear Box Defect January , the problem starts February , the gear box changed A gear box defect is detected at a NATO radar base. Early detection of this fault helped uninterrupted operation of the radar.

10 Case 6 Water Company: Water Distribution Co. A Equipment: Pump Loose Foundation & Unbalance

11 Case 6 Water Company: Water Distribution Co. A Equipment: Pump Loose Foundation & Unbalance Before Maintenance After Maintenance Loose Foundation Problem April 29, 2008 February 19, 2009 Before Maintenance After Maintenance Unbalance Problem April 29, 2008 February 19, 2009

12 Case 7 Metals Company: Iron & Steel Company A Equipment: Reversing Cold Rolling Mill Fume Fan Dirty Filter

13 Case 7 Metals Company: Iron & Steel Company A Equipment: Reversing Cold Rolling Mill Fume Fan Dirty Filter This fan discharges dust-laden air out of the factory via a filter. Motor Current MCM started to warn the user by giving a Watch Load alarm on 15 th April Motor Status 2 Parameter Examination of the motor current trend shows that the motor current had been gradually decreasing since 17 th November This indicates that the filter blockage started on that date and had been gradually deteriorating to the point where it exceeded the MCM alarm level on 15 th April. Watch Load Level This drop off in current shows that the fan had not been extracting the desired volume of air, and hence the ventilation in the plant would be below design levels.

14 Case 7 Metals Company: Iron & Steel Company A Equipment: Reversing Cold Rolling Mill Fume Fan Dirty Filter The maintenance team attempted to clean the filter with compressed air on 25 th April 2009, but it was not fully successful. MCM started giving a Watch Load alert again after just 1 month of operation. The team changed the filter completely on 20 th August After this MCM stopped giving alert signals and the motor current reverted to its nominal value. Motor Current Maintenance This sort of fault would not have been possible to detect by Vibration analysis.

15 Case 8 Food Company: Sugar Refinery Equipment: Deep Well Pump Cavitation Just after MCM s LEARN period was completed, the MCM warned about a fault in a frequency band associated with Cavitation. The maintenance team dismantled the pump and checked for cavitation. The photos show the damage of cavitation which can be observed as small pits on pump blade, hence confirming the diagnosis. Increasing failure level After maintenance, MCM stopped warning.

16 Case 9 Automotive Company: Automobile Manufacturer B MCM indicated a transmission fault, so the engineers looked at the trending data, which pointed to a loose belt. Equipment: Exhaust Fan Increasing failure level Belt Looseness The maintenance team confirmed belt looseness. Belt tension starts to loose Belt looseness would tend to result in slippage, which in turn would mean that the motor could not transmit all the power to the fan. This was consistent with the decrease in the three phase currents. Decreasing current level

17 Case 10 Power Generation Company: Power Generation Company A Developing bearing failure Equipment: Feed Water Pump Bearing Fault One month after the MCM installation, MCM indicated a developing Bearing fault. Maintenance team verified the bearing fault and replaced the bearing of the motor. After the maintenance action MCM stopped giving alarm verifying the effectiveness of the maintenance action. MCM Alarm history Examine 1 Level

18 Case 11 Water Company: Saline Water Conversion The frequency spectrum indicates stator winding problem in both pumps at 120 Hz as shown in the figure below. Both pumps are stopped and then restarted in the same day on May 14, MCMScada long term trending data shows an increase in current balance parameters and amplitude variations in currents before and after May 14, Equipment: Pump Stator Failure May 14, 2007 S and T phase currents before May 14, 2007 Current Balance Swapped S and T phase currents

19 Case 13 Manufacturing Company: Battery Manufacturer Equipment: Compressor Bearing Fault MCM started giving intermittent warnings on September 2005, and a bearing problem was diagnosed by MCM. Deterioration was kept under review until January When carried out, maintenance and repair actions verified the diagnostic assessment of MCM. On later examination of the MCM trends, it was found that the bearing problem was detected even earlier that 13 th September2005, but the severity was not sufficient to give rise to an alert. This demonstrates the capability of MCM to indicate developing faults at a very early stage.

20 Case 13 Manufacturing Company: Battery Manufacturer Equipment: Compressor Bearing Fault Aug 05 Sept 05 Oct 05 Nov 05 Dec 05 Jan 06 No problem, other than minor Bearing problem supply issue indicated, with 3 month warning Problem fixed, Progress having of had 3 bearing months problem to monitored prepare early indication in August

21 Case 14 Metals Company: Iron & Steel Company B Equipment: Pump Coupling Coupling fault detected and remedied.

22 Case 15 Manufacturing Company: Home Appliance Man. Equipment: Phosphate Pump Bearing Defect & Bent Shaft Increase in the 10th and 12th mechanical parameters. Change of bearings Change of bearings and shaft Bearing fault detected. The same fault indication repeated again later. Further analysis indicated to an bent shaft which was causing the fault.

23 Case 16 Automotive Company: Automobile Manufacturer C Equipment: Pump Unbalance MCM started giving Unbalance warning and soon after it became nearly consistent, on 28 th May Maintenance team checked the motor and verified the imbalance.

24 Case 16 Automotive Company: Automobile Manufacturer C Equipment: Pump Unbalance Unbalance and Motor Status 2 parameters show the development of the fault. Motor Status Increasing failure trend

25 Case 17 Pharmaceutical Company: Pharmaceutical Manufacturer Equipment: Ventilation Fan Turbulence Discontinuous but frequent warnings regarding Driven Equipment Fault were detected on a Ventilation Fan, that had been monitored by MCM. After a detailed investigation, it was realized that the warning was being given while the monitored fan was running together with the other fan supplying air to the same ventilation duct. It was observed that when two motors run together they will cause turbulence in air flow.

26 Case 18 Oil & Gas Company: Oil & Gas Company B Equipment: Reciprocating Compressor Valve Leaking Baseline from June 2010 showing clear, valve related sideband energy October 2010 LNG compressors were being monitored by VA, which was not detecting problems. MCM was then fitted to the compressors. We analyzed the results and advised that there were leaking valves that should be attended to at the next overhaul. When the equipment was stripped down, the diagnosis was confirmed. Following the overhaul, the MCM was put back into learn mode to give a new PSD curve, which had a significantly different shape from the earlier one, confirming that we detected the change resulting from the overhaul. Vibration Analysis detected no change whatsoever. Baseline from October 2010 following an overhaul. It can be seen that the valve sidebands are no longer present but there is broadband noise from one of the piston baffles.

27 Case 19 Oil & Gas Company: Oil & Gas Company C Equipment: LNG Pump Shaft Deflection MCM correctly identified that the pump had no major faults No major faults all green

28 Case 19 Oil & Gas Company: Oil & Gas Company C Equipment: LNG Pump Shaft Deflection MCM trends revealed that the pump was experiencing increased rub energy when the load was too high The cause of this was slight movement in one of the shaft bearings causing wear to the shaft and shaft deflection. This was confirmed during strip down work on the pump and was related to a design problem that has since been eliminated.

29 Case 20 Water Company: Water Distribution Co. B Equipment: Pump Pump Blockage MCM began giving load alarms in September Some inherent frictionrelated faults were identified in the frequency spectrum.

30 Case 20 Water Company: Water Distribution Co. B Equipment: Pump Pump Blockage MCM began giving load alarms in September 2010 and the active power of the pump dropped drastically in December. The cause was a piece of wood blocking the pump inlet.

31 Case 21 Power Generation Company: Power Generation Company B Equipment: ID Fan Fouling Power from waste generation station. Between shutdowns the ID Fan system fouls leading to reduced efficiency. MCM identifies this point by recognising the difference in the load conditions of the motor. Load alarm as power drops off / increases!

32 Case 21 Power Generation Company: Power Generation Company B Equipment: ID Fan Fouling The trends highlight the gradual change in current between shutdowns, indicating that the system is fouling and that the fan is working harder to overcome this. Temporary, short term, changes in power can also be seen to have a large effect on the vibration response of the machine.

33 Case 22 Oil & Gas Company:Oil & Gas Company D Equipment: Pump Stator Insulation Progression Frequent alarm and trend responses indicated changes in internal motor conditions. Green, yellow and blue lines correspond to internal electrical fault

34 Case 22 Company: Oil & Gas Oil & Gas Company D Equipment: Pump Stator Insulation Progression The trending showed that there was significant phase current disproportionality in addition to the stator-related trend increases and alarms. Currents in the three phases vary in shape and separation Red line (Ir) and yellow line (Is) cross over frequently, indicating inconsistent behaviour between the phases