Blower Outboard Bearing Failure Identified through Advanced Condition Monitoring

Introduction:

Maintaining the reliability and efficiency of critical equipment is paramount. This case study highlights the value of continuous, real-time condition monitoring by describing the how a premature failure was identified and resolved in a blower unit installed at a specialty materials manufacturer. The proactive implementation of Hydro’s Centaur condition monitoring played a pivotal role in early detection, enabling swift intervention and preventing unnecessary downtime.

Background:

A large US chemical plant that creates a variety of specialty materials had ongoing troubles with the centrifugal blowers in their PVC division. The units are critical to production and do not have spare backup units. Hydro’s Centaur condition monitoring solution was deployed on these blowers to understand the nature of the failures as well provide insight into when the units needed attention. One of the blower units began exhibiting concerning signs on January 04, 2024. Vibration levels steadily increased over the subsequent weeks, reaching a critical point on February 9th, 2024. This prompted the decision to shut down the unit and perform a root cause analysis to quickly determine remedial actions and keep production downtime to a minimum.

Events and Details:

When elevated vibration amplitudes were first detected on the problematic blower, they were in the Blower Outboard Bearing in the vertical direction (BOBV). The velocity amplitude shown below crossed the warning threshold on January 06, 2024, alerting both Hydro and the end user’s site engineers that a condition was present and in blower was in the early stages of degradation. The observation was discussed during the weekly touchpoint between Hydro and the plant, where Hydro would review the health of all monitored assets and address any alarm events captured using Centaur with site stakeholders.

Figure 1: Velocity Amplitude as Several Alarm Thresholds Breached

The vibration velocity amplitudes continued to climb, and on January 25, 2024 they crossed the Alarm #1 threshold. The Alarm #2 threshold was breached on February 01, 2024. Continual touchpoint meetings highlighted the worsening conditions and provided an analysis of the suspected failure mode(s) affecting the blower mechanical condition. The below multi-spectrum chart shows the spectra at the BOBV location at various points along the trend – mapping the signature of the degradation.

Figure 2: Multi-Spectrum Chart of BOBV Location

The chart starts with the spectra during “normal” conditions, prior to the observed degradation. Peaks at 1X and several harmonics are present with an amplitude less than 0.15 ips RMS. As the problem is observed and continues to worsen, bearing fault frequencies and harmonic excitation appear and continue to get worse. The lowest spectrum in the chart shows vibration velocity amplitude during the final sample, when it is greater than 1 ips RMS – very severe. At this point, all the energy has moved to 1X or less than 1X frequencies – a common occurrence when a failure mode is in its final stages.

The following two spectra charts take a closer look at the condition, one chart showing the initial conditions prior to degradation and the other closer to the end of operation where bearing fault frequencies and harmonic excitation can be detected.

Figure 3: Initial Conditions

Figure 4: Near End of Operation

In parallel with the velocity measurement, Hydro and the plant reliability engineers reviewed the acceleration measurements at the same location. Acceleration often leads to velocity readings, particularly for bearing failure. The chart below shows the trend for acceleration with the amplitude shown in g’s.

Figure 5: Acceleration Trend

The following four charts show the spectra and waveform data for acceleration readings at two points during the degradation period. The first two charts show the early stages of failure with peak-to-peak amplitudes of ~6 g’s and harmonic excitation in the spectrum. The second two show acceleration data at a later stage of degradation with peak-to-peak amplitudes at ~30 g’s and increased discrete frequency amplitudes in the spectrum.

Figure 6: Waveform- Early Stage of Failure

Figure 7: Spectrum- Early Stages of Failure

Figure 8: Waveform- Late Stages of Degradation

Figure 9: Spectrum- Late Stages of Degradation

The observation noted throughout was that the blower outboard bearing was failing. Failure of this bearing could also translate to damage to the shaft and other blower components if not addressed in a timely manner.

Constant communication between Hydro and the plant prevented the issue from becoming an unexpected and catastrophic failure.

Root Cause Analysis & Remediation:

The data captured by Centaur during the monitoring period was instrumental in conducting a thorough root cause analysis. It provided a comprehensive overview of the conditions leading to the outboard bearing failure, enabling Hydro’s engineers to identify contributing factors, such as operating conditions, lubrication issues, resonance frequencies, and potential misalignments.

The root cause of the issue was found to be contamination. This PVC unit created a fine dust byproduct that was found in the atmosphere, with large quantities accumulating around the blower units. Over time, the fine PVC dust would penetrate the bearings, compromising the effectiveness of the lubrication and reducing the tolerance inside of the bearings. Plans for remediation included relocating the machines or redesigning the bearing and housing to eliminate the possibility of contamination. The plant ultimately decided relocation was not an option and consulted the bearing manufacturer for an improved design that included a sealed housing.

Hydro continues to monitor these units, with ongoing reviews of the oil quality, level, and possibility of contamination from moisture, metal, or other sources. In parallel, Hydro also recommended reviewing the load handled by this blower and the rated load of the specified bearings, as improper loading may contribute to premature bearing failure.

Results: Cutting Edge Tech and Real-Time Support

Centaur proved to be the first line of defense in identifying abnormalities in the blower unit’s performance. Leveraging real-time data analytics, Centaur detected escalating vibration levels and issued timely alerts based on preset alarm thresholds. This early warning system allowed the maintenance team to take proactive measures, and consult with Hydro’s engineers on the data, receiving immediate real-time support thus preventing a catastrophic failure and minimizing the impact on overall operations. The ability to pinpoint the issue before complete failure occurred significantly reduced the downtime and associated costs.

This case underscores the value of proactive maintenance strategies for rotating equipment. With a strong focus on customer needs, experience across brands and applications, and a commitment to innovation, Hydro’s capabilities and culture uniquely aligned with the customer’s goals for improving asset reliability and performance.

Learn more about Centaur and how it can help you reduce the cost of rotating equipment ownership.

Capability Spotlight: Resolve Reliability Problems

Why look backwards when you can be looking forward?

The problems you inherited with your pump and system design shouldn’t be an anchor holding you back from stable operation. Hydro’s mission to increase pump reliability extends beyond our service facilities and into the field. Hydro Reliability Services provides expert troubleshooting, advanced engineering analysis, and field mechanical and hydraulic testing for your rotating equipment.

Many pump applications experience ongoing vibration and reliability issues; aging installations are also seeing margins between operation and resonant conditions eroding and previously reliable equipment being pulled into problems. The root cause of these problems is often resonance, a condition that is often misdiagnosed and commonly goes undiagnosed, resulting in persistent high amplitude vibration issues for long periods of time. Structural resonance typically results in highly directional vibration and increased amplitudes that can be difficult to resolve without the proper engineering approach. Fortunately, technology has developed to diagnose resonance and develop effective solutions without resorting to costly trial-and-error methods.

To help our customers solve complex problems with critical pumping equipment, Hydro Reliability Services’ engineers bring an array of technology to the site. Monitoring of traditional health indicators – flow, power, vibration, and pressure – is supplemented with advanced technology, such as Operating Deflection Shape and Experimental Modal Analysis. Leveraging their expertise and advanced modeling software, Hydro’s reliability engineers analyze this data to determine design and system weaknesses and propose improvements. This assessment gives you the ammunition you need to make an informed judgment about the risk of current and future operation.

Read our recent case study in Pumps & Systems magazine to learn more about how field testing and troubleshooting helped a power plant resolve a vibration issue in a critical application.

What does more effective troubleshooting mean for you?

  • Maintaining a competitive edge in your marketplace through reduced operation and maintenance costs
  • Creating a safer workplace with much lower risk of equipment-related accidents and reduced exposure to hazardous materials
  • Contribution towards a sustainable future through more efficient operation and reduced risk of product leakage into the environment
  • Ability to focus resources on proactive strategies and process innovation instead of continuously reacting to problem equipment

VIATC 2024: Vibration Institute Annual Training Conference

Join Hydro at the Vibration Institute Annual Training Conference on August 7-9, 2024. Visit us at Booth 300 at the exposition to talk with Hydro Reliability Services’ Kyle Bowlin about strategies for troubleshooting vibration problems, new technologies, and effective approaches to system analysis.

This year’s VIATC will be held in Covington, KY. Learn more about the event here.

Navigating Resonance Challenges

A Case Study in Diagnostic Testing and Innovative Solutions

Some services are inherently difficult due to factors such as fluid quality or multiple disparate operating points.  These factors are an inherent part of the process and cannot be changed to improve reliability. Harsh applications can be a costly prospect, both in overhaul costs and in the time and labor required for frequent servicing. Many times we become caught in the perception that there is no improvement to be had for these services. A short mean-time-between-failures (MTBF) becomes routine and expected, and maintenance activities and parts procurement are built around this expectation.  

When equipment is sent out for refurbishment, the expectation is that mechanical and hydraulic performance upon reinstallation will be better than what was experienced in the worn condition. This assumption holds true in most cases; however, sometimes unexpected behavior can occur after a pump is remanufactured and reinstalled. While it is easy to jump to the conclusion that these performance changes were caused by errors made during the repair or installation of the equipment, sometimes the problem is more complex and related to latent weaknesses in the design that had lain dormant until refurbishment.

This scenario was experienced by a power utility in the Southeastern US when they ran into significant vibration increases after one of their boiler feed pumps was refurbished by a local repair shop. Concerned by the level of vibration, the utility reached out to Hydro South, who have extensive experience in this application and model. From there, Hydro Reliability Services was called on to collect data on the problematic equipment and use advanced modeling tools to understand the nature of the vibration. The field testing and analysis revealed that pump had been operating with a very small margin between a structural resonance and one of the pump forcing frequencies. Armed with this information, solutions were developed to increase this margin and return to stable operation.

Read the full case study in Pumps & Systems March 2024 edition.

Learn more about Hydro Reliability Services and how they support field testing, vibration troubleshooting, and advanced system studies.

Capability Spotlight: Centaur Condition Monitoring

Hydro’s Centaur is an IoT condition monitoring solution developed by rotating equipment experts with a specific focus on detecting equipment failure modes and providing impending warning of incipient problems. Centaur includes the necessary hardware, software, and dedicated engineering support to successfully trend equipment condition and avoid unplanned downtime.

The Problem

Industrial users have relied on analog gauges and route-based data collection methods for decades. These methods often lead to inaccurate or incomplete readings and can expose workers to elevated safety risks, especially in hazardous environments. More importantly, traditional methods do not provide the benefits that continuous monitoring does, such as early detection and warning alerts, remote support for troubleshooting and diagnostics, and improved MTBR/MTBF.

Our Solution

A complete picture of equipment health can only be revealed by capturing a continuous stream of data and using both analytical power and subject matter expertise to turn this data into actionable information. Centaur achieves this by combining digital vibration, temperature, and pressure sensors, cloud-based software, and the experience gained through 50 years of developing aftermarket solutions for rotating equipment.

A critical piece of Centaur’s ability to reduce users’ cost of asset ownership and avoid unnecessary downtime is its dedicated engineering team, who provide proactive monitoring oversight, monthly health reports, and advanced analytical support. These rotating equipment experts perform root cause analyses of concerning trends and alarm events, which include recommended action steps to remediate suspected issues long before they become costly failures.

The Difference

In contrast to traditional IOT companies, Centaur was developed with the input of rotating equipment experts. As an unbiased presence in the aftermarket, Hydro has amassed experience over a broad spectrum of manufacturers, designs, and applications.

This expertise influenced hardware and software design, ensuring that Centaur is capable of effectively detecting and identifying known equipment failure modes. Some examples include the measurement of phase data and a frequency range capable of detecting bearing fault frequencies.

How it Works

The Benefits

  • Increased accuracy: Provides more precise pressure readings, maintaining safe and efficient operations.
  • Greater data collection frequency: Allows creation of detailed pressure profiles and trends, supporting identification of anomalies that indicate potential issues.
  • Increased worker safety: Eliminates need for workers to access dangerous or hard-to-reach areas and provides earlier warning of potential safety issues.
  • Predictive maintenance: Enables condition-based maintenance by tracking performance degradation over time.
  • Cost savings: Reduces cost of equipment ownership by preventing potential issues and reducing downtime.
  • Trending efficiency: Detecting and trending performance degradation facilitates more informed decisions on equipment operation and maintenance.

Ready to learn more about Centaur? Contact us or apply for a free trial.