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1.Equipment Information

Equipment Type: Centrifugal Fan

Rated speed: variable frequency

Related measurement points in this case: motor load end 2H; motor free end 1H

2.Alarm and analysis process

Equipment alarm events:

2.1Analysis process

2.1.1Explanation of trends, indicator parameters and other evidence

The vibration of the unit has increased recently.

Grate Cooler F6/Motor Load End 2H/8k Speed Waveform (10-1000)_Equipment Multi-trend

2.1.2Explanation of evidence such as time domain, spectrum, and envelope demodulation

No obvious impact is seen in the time domain waveform.

Grate cooling fan F6/motor load end 2H/8k speed waveform (10-1000)_time domain waveform

The spectrum is dominated by 1X energy rise.

Grate cooling fan F6/motor load end 2H/8k speed waveform (10-1000)_spectrum analysis

3.Diagnostic conclusions and recommendations

3.1Diagnostic conclusion

2023-04-06 11:45 Push diagnosis conclusion: The vibration of the unit has increased and there are unbalanced characteristics. It is speculated that it is related to coupling damage. Affected by the operating conditions, there has been recent deterioration.

3.2Inspection and maintenance suggestions

The equipment is currently in a monitorable operating state, and it is recommended to arrange an inspection at an appropriate time. Check whether the unit's anchor bolts are loose, whether the coupling is damaged, and recheck the unit's alignment.

4.On-site inspection and maintenance process

2023-04-12 13:55 On-site feedback: The nylon rod was replaced and the nylon rod was worn.

5.On-site inspection and maintenance photos

Photos of the nylon rods provided on-site showed that the nylon rods were worn.

Maintenance photo_1

6.Verification after inspection and maintenance

After replacing the nylon rod on site, the velocity trend decreased significantly, no obvious impact was observed in the time domain waveform, and the 1X energy decreased. This indicates that on-site actions have improved the fault characteristics.

2H speed trend, waveform, and spectrum of the motor load end.png

7.Customer feedback form

Feedback_1

8.Monitoring fault range

Timely and effective collection of equipment operating status data (vibration, temperature) is subject to the constraints of network connectivity and data transmission time, and also needs to consider interference from factors such as the equipment's own attributes and production processes. At the same time, the analysis and diagnosis of equipment status is based on changes in vibration effects caused by rotating parts failures. Therefore, the status monitoring system cannot guarantee monitoring of all types of faults. The monitoring system is configured according to the measurement point scheme recommended by Party B, and the range of faults that can be monitored and the description are as follows:

9.Notes

1. If the client of this report cannot provide basic unit parameters (such as unit transmission chain diagram, gearbox structure diagram, gearbox teeth number, related bearing models and brands), the accuracy of analysis and diagnosis will be affected;

2. This report is the analysis, diagnosis and maintenance opinions of the unit by Rongzhi professional technicians, which is for reference only. The specific maintenance and repair measures shall be decided by the client.

3. This report shall not be used as evidence for any claims, litigation, etc.;

4. The client has the obligation to keep the analysis report confidential and shall not provide this report to a third party, print it into other promotional materials, or publish it on the Internet or other public information platforms without the written permission of the trustee.

1.Equipment Information

Equipment Type: Bucket Elevator

Rated speed: 1480 rpm

The relevant measuring points in this case are: bearing seat 7H at the input end of the head wheel and bearing seat 8H at the free end of the head wheel.

2.Alarm and analysis process

2023-07-05 11:08:17 Asked on site to evaluate the operation of the head wheel bearing.

2.1 Analysis process

2.1.1Explanation of trends, indicator parameters and other evidence

The low-frequency acceleration vibration trend of the bearing seat at the input end of the head wheel is relatively stable.

1 line kiln hoist/head wheel input end bearing seat 7H/128k acceleration waveform (2-2000)_trend analysis

2.1.2Explanation of evidence such as time domain, spectrum, and envelope demodulation

No obvious impact is observed in the low-frequency acceleration time domain waveform, nor is it observed after filtering.

1 line kiln hoist/head wheel input end bearing seat 7H/128k acceleration waveform (2-2000)_time domain waveform

4.219 Hz and its harmonics can be seen in the spectrum. This frequency is not related to the head wheel, but is the defect frequency of the outer ring of the bearing.

1 line kiln hoist/head wheel input end bearing seat 7H/128k acceleration waveform (2-2000)_spectrum analysis

3.Diagnostic conclusions and recommendations

3.1Diagnostic conclusion

The bearing at the input end of the head wheel has early and mid-term damage, mainly pitting and spalling of the outer ring, and has recently been slowly deteriorating.

3.2Inspection and maintenance suggestions

Pay attention to abnormal noise and temperature changes at the input end of the head wheel, and check the bearing raceway damage when the opportunity arises.

4.On-site inspection and maintenance process

2023-07-27 11:31 On-site feedback showed that the head wheel bearing raceway was damaged, there was obvious peeling on the inner raceway, and there was also large-scale peeling on the outer ring. It has been replaced.

5.On-site inspection and maintenance photos

On-site inspection and maintenance photos

Maintenance photo_1

From the figure below, it can be seen that there is obvious large-scale peeling on the outer ring. The defect frequency of the outer ring of the bearing is clear in the signal, and there is no obvious damage frequency of the inner ring.

Maintenance photo_2

6.Verification after inspection and maintenance

After replacing the head wheel input end bearing, there was no significant change in the low-frequency acceleration vibration trend, and the vibration value was consistent with the previous value.

1 line kiln hoist/head wheel input end bearing seat 7H/128k acceleration waveform (2-2000)_trend analysis

The time domain waveform of the low-frequency acceleration did not change significantly, and the waveform impact amplitude did not decrease significantly.

1 line kiln hoist/head wheel input end bearing seat 7H/128k acceleration waveform (2-2000)_time domain waveform

The bottom noise energy in the low-frequency band of the spectrum decreases significantly.

1 line kiln hoist/head wheel input end bearing seat 7H/128k acceleration waveform (2-2000)_spectrum

No bearing damage frequency was found in the envelope demodulation, and only the head wheel related frequency was found in the envelope spectrum.

1 line kiln hoist/head wheel input end bearing seat 7H/128k acceleration waveform (2-2000)_envelope demodulation

7.Customer feedback form

None

8.Monitoring fault range

Timely and effective collection of equipment operating status data (vibration, temperature) is subject to the constraints of network connectivity and data transmission time, and also needs to consider interference from factors such as the equipment's own attributes and production processes. At the same time, the analysis and diagnosis of equipment status is based on changes in vibration effects caused by rotating parts failures. Therefore, the status monitoring system cannot guarantee monitoring of all types of faults. The monitoring system is configured according to the measurement point scheme recommended by Party B, and the range of faults that can be monitored and the description are as follows:

9.Notes

1. If the client of this report cannot provide basic unit parameters (such as unit transmission chain diagram, gearbox structure diagram, gearbox teeth number, related bearing models and brands), the accuracy of analysis and diagnosis will be affected;

2. This report is the analysis, diagnosis and maintenance opinions of the unit by Rongzhi professional technicians, which is for reference only. The specific maintenance and repair measures shall be decided by the client.

3. This report shall not be used as evidence for any claims, litigation, etc.;

4. The client has the obligation to keep the analysis report confidential and shall not provide this report to a third party, print it into other promotional materials, or publish it on the Internet or other public information platforms without the written permission of the trustee.

1.Equipment Information

Equipment Type: Rotary Kiln

Rated speed: 1500rpm

Related measurement points in this case: reducer 2, 3 axis output end 4A

2.Alarm and analysis process

2.1Analysis process

2.1.1Explanation of trends, indicator parameters and other evidence

The acceleration amplitude trend of the 4A measuring point output of the reducer 2 and 3 axes is relatively stable.

Rotary kiln 56.011/reducer 2, 3 axis output end 4A/128k acceleration waveform (2-2000)_Equipment Multi-trend

The velocity amplitude trend is relatively stable.

Rotary kiln 56.011/reducer 2, 3 axis output end 4A/128k acceleration waveform (2-2000)_Equipment Multi-trend

2.1.2Explanation of evidence such as time domain, spectrum, and envelope demodulation

There is no obvious impact in the acceleration time domain waveform.

Rotary kiln 56.011/reducer 2, 3 axis output end 4A/128k acceleration waveform (2-2000)_time domain waveform

Envelope demodulation of acceleration in the low frequency band 100-300Hz reveals 21.602Hz and its harmonics.

Rotary kiln 56.011/reducer 2, 3 axis output end 4A/128k acceleration waveform (2-2000)_envelope demodulation

And there is a 1.563Hz sideband of the reducer's 3rd axis rotation frequency, so it can be inferred that 21.602Hz is a characteristic of bearing inner ring damage.

Rotary kiln 56.011/reducer 2, 3 axis output end 4A/128k acceleration waveform (2-2000)_spectrum analysis

In the low frequency band, 21.602 Hz and its harmonics are relatively abundant.

Rotary kiln 56.011/reducer 2, 3 axis output end 4A/128k acceleration waveform (2-2000)_spectrum analysis

After filtering at 20-280Hz, the acceleration time domain waveform shows an approximate three-axis frequency interval impact, and it is speculated that the damage characteristics of the inner ring of the bearing are caused by the three-axis frequency modulation.

Rotary kiln 56.011/reducer 2, 3 axis output end 4A/128k acceleration waveform (2-2000)_time domain waveform

3.Diagnostic conclusions and recommendations

3.1Diagnostic conclusion

2023-03-22 Physical examination from normal adjustment Note: There is pitting or slight flaking on the inner ring of the 3-axis bearing, and the deterioration is slow. (slightly more noticeable on the output side)

3.2Inspection and maintenance suggestions

During regular inspection, the damage of the 3-axis bearings needs to be checked.

4.On-site inspection and maintenance process

2023-08-10 12:21 Tracking record: Inspection of the main reducer of the second-line kiln found that the ball of the third-level shaft bearing had pitting corrosion, and the inner ring raceway of the rear feedback bearing had pitting corrosion and peeling, and maintenance photos were provided.

5.On-site inspection and maintenance photos

Photos of the three-axis bearing damage were provided on site, showing significant pitting and slight spalling on the inner ring of the bearing, and pitting on the rolling elements.

Bearing inner ring pitting and spalling_1

Rolling element pitting_2

Rolling element pitting_3

Rolling element pitting_4

Rolling element pitting_5

6.Verification after inspection and maintenance

After maintenance, the acceleration amplitude at the 4A measuring point at the output end of the reducer 2 and 3 axes dropped slightly.

image.png

After on-site maintenance, the 3-axis frequency interval modulation basically disappeared at 20-200Hz filtering.

Rotary kiln 56.011/reducer 2, 3 axis output end 4A/128k acceleration waveform (2-2000)_time domain waveform

After on-site maintenance, the damage characteristics of the inner rings of the 3-axis bearings have basically disappeared. (Note: The rotary kiln is a variable speed equipment, and the damage characteristics of the inner rings of the bearings will change with the speed and frequency)

Rotary kiln 56.011/reducer 2, 3 axis output end 4A/128k acceleration waveform (2-2000)_spectrum analysis

7.Customer feedback form

None

Feedback_1

8.Monitoring fault range

Timely and effective collection of equipment operating status data (vibration, temperature) is subject to the constraints of network connectivity and data transmission time, and also needs to consider interference from factors such as the equipment's own attributes and production processes. At the same time, the analysis and diagnosis of equipment status is based on changes in vibration effects caused by rotating parts failures. Therefore, the status monitoring system cannot guarantee monitoring of all types of faults. The monitoring system is configured according to the measurement point scheme recommended by Party B, and the range of faults that can be monitored and the description are as follows:

9.Notes

1. If the client of this report cannot provide basic unit parameters (such as unit transmission chain diagram, gearbox structure diagram, gearbox teeth number, related bearing models and brands), the accuracy of analysis and diagnosis will be affected;

2. This report is the analysis, diagnosis and maintenance opinions of the unit by Rongzhi professional technicians, which is for reference only. The specific maintenance and repair measures shall be decided by the client.

3. This report shall not be used as evidence for any claims, litigation, etc.;

4. The client has the obligation to keep the analysis report confidential and shall not provide this report to a third party, print it into other promotional materials, or publish it on the Internet or other public information platforms without the written permission of the trustee.

1.EquipmentInformation

Equipment Type: Centrifugal Fan

Rated speed: 3000rpm

Related measurement points in this case: Motor free end 1H

2.Alarm and analysis process

Equipment alarm events:

2.1Analysis process

2.1.1Explanation of trends, indicator parameters and other evidence

Recently, the acceleration vibration at both ends of the motor has suddenly increased.

Grate Cooler F3A/Motor Load End 2H/64k Acceleration Waveform (2-20000)_Equipment Multi-Trend

There is also a sudden rise in speed vibration.

Grate Cooler F3A/Motor Load End 2H/64k Acceleration Waveform (2-20000)_Equipment Multi-Trend

The temperatures at both ends of the motor rise synchronously.

Grate cooling fan F3A/motor load end 2H/64k acceleration waveform (2-20000)_equipment temperature multiple trends

2.1.2Explanation of evidence such as time domain, spectrum, and envelope demodulation

There is a frequency-interval shock in the acceleration waveform.

Grate cooling fan F3A/motor load end 2H/64k acceleration waveform (2-20000)_time domain waveform

The spectrum is rich in frequency conversion and its harmonics.

Grate cooling fan F3A/motor load end 2H/64k acceleration waveform (2-20000)_spectrum analysis

3.Diagnostic conclusions and recommendations

3.1Diagnostic conclusion

2023-12-06 16:24 Push diagnosis conclusion: The vibration at both ends of the motor suddenly increased, which is speculated to be related to the sudden running of the motor bearing or the crack of the shaft.

3.2Inspection and maintenance suggestions

Pay attention to the temperature changes of the motor bearings and check the bearing damage.

4.On-site inspection and maintenance process

1.On 2023-12-06 16:42, Mr. Qian from the site reported that the inner ring of the front end bearing of the motor was running and it was being processed.

2.2023-12-07 15:22 On-site worker Qian reported that the bearings at both ends of the motor should be replaced.

5.On-site inspection and maintenance photos

The inspection photos show that the front end bearing of the motor is running on the inner race.

Repair photos

6.Verification after inspection and maintenance

After on-site maintenance, the acceleration trend of the motor drive end decreased significantly.

Acceleration trend change of the motor drive end before and after on-site maintenance

The waveform impulse disappears and the peak energy decreases.

Changes in the acceleration waveform of the motor drive end before and after on-site maintenance

Changes in the acceleration waveform of the motor drive end before and after on-site maintenance

Changes in the acceleration spectrum of the motor drive end before and after on-site maintenance

7.Customer feedback form

None

8.Monitoring fault range

Timely and effective collection of equipment operating status data (vibration, temperature) is subject to the constraints of network connectivity and data transmission time, and also needs to consider interference from factors such as the equipment's own attributes and production processes. At the same time, the analysis and diagnosis of equipment status is based on changes in vibration effects caused by rotating parts failures. Therefore, the status monitoring system cannot guarantee monitoring of all types of faults. The monitoring system is configured according to the measurement point scheme recommended by Party B, and the range of faults that can be monitored and the description are as follows:

9.Notes

1. If the client of this report cannot provide basic unit parameters (such as unit transmission chain diagram, gearbox structure diagram, gearbox teeth number, related bearing models and brands), the accuracy of analysis and diagnosis will be affected;

2. This report is the analysis, diagnosis and maintenance opinions of the unit by Rongzhi professional technicians, which is for reference only. The specific maintenance and repair measures shall be decided by the client.

3. This report shall not be used as evidence for any claims, litigation, etc.;

4. The client has the obligation to keep the analysis report confidential and shall not provide this report to a third party, print it into other promotional materials, or publish it on the Internet or other public information platforms without the written permission of the trustee.