Operational Improvements Help Paper Mill Avoid Costs of $130,091

When it comes to paper production, reliability and efficiency are essential to maintaining a successful operation. For one paper mill, this was expected to be the status quo on their brand-new paper machine line that debuted in 2022. However, frustrations quickly grew when, less than 18 months into operations, technical issues began to accumulate for the Falk™ V-Class™ reducers on their wet-end Nash* vacuum pumps. It was necessary for the team at Regal Rexnord to conduct a thorough root cause analysis to better understand why the challenges were occurring for this operation. By leaning on the years of experience within their engineering, reliability, and technology teams, Regal Rexnord was able to draw significant conclusions about the source of the issues and suggest ways to combat this moving forward.

* Nash is believed to be the trademark and/or trade name of Ingersoll Rand and is not owned or controlled by Regal Rexnord Corporation or its affiliates.

The Challenge

The paper mill initially encountered frequent failures of Falk V-Class reducers on their vacuum pumps. These failures were costly for the customer, leading to both downtime and the need to rebuild and buy new reducers. In one case, it even led to unplanned downtime when one of the units began to smoke while the paper machine was operating. Falk has built a strong reputation across heavy industries worldwide, making this situation highly unusual. Three units were pulled out of service and sent back to Milwaukee where multiple teardown inspections and reports highlighted the severity of the issue through unusual wear and tear, particularly on the input shaft bearings. This demonstrated the necessity for a comprehensive torque study by the Perceptiv™ Intelligent Reliability Solutions team to understand the dynamics seen in the application itself.

The Solution 

The collaborative analysis between teams of experts was instrumental in identifying and understanding the root cause of these failures. The torque study indicated that during equipment restarts following an outage period, there were massive torque spikes in the drive system that lasted up to 20 seconds. Based on conversations with the customer around procedures, it was deduced that these spikes were caused by a flooded start condition, where the pump is not drained below the centerline prior to start-up as recommended by the pump manufacturer. This creates a situation where the vacuum pump attempts to compress an incompressible fluid, creating high torque conditions that overstress bearings, gearing, and other components in the gearbox. The conclusion was drawn that the ‘hard starts’ had created the performance issues manifesting in the application. 

The collaborative effort led to several recommended procedure and component updates aimed at preventing future issues and enhancing reliability:

1. Recommended Procedure Updates:

• Ensure proper drainage of vacuum pumps to avoid flooded start conditions.
• Enhance the current set-up to include automated valving, which will allow easier management of water levels in the pumps and easier draining.

2. Recommended Component Upgrades:

• Upgrade to a Kop-Flex™ coupling style with better torque dampening characteristics to better protect the gearbox and other upstream components.
• Incorporate Perceptiv™ sensors permanently on the gearboxes for enhanced monitoring and diagnostics.

The Benefit

At Regal Rexnord, we stand firmly behind the quality and reliability of our brands. When the customer experienced repeated gearbox failure, our team took action, not only addressing the issue, but going above and beyond conducting a comprehensive root cause analysis. This proactive approach reflects our deep commitment to customer success, our technical expertise, and the collaborative spirit of our team. We don’t just deliver products – we deliver confidence, support, and long-term solutions. Total cost avoidance included:

• Perceptiv Diagnostic Service:
• September: $38,654 (6-week study)
• October: $35,954 (6-week study)
• December: $35,954 (6-week study)

• Warranty Teardown and Competitor Bearing: $10,000
• Field Services: $9,529
• Total Support Savings: $130,091

Conclusion

With newfound insights, metrics, and knowledge, the paper mill is poised to resume operations with renewed confidence, knowing the root cause of the issue at hand. Meanwhile, our team of seasoned engineers is equipped with enhanced understanding, ready to drive future innovations and improvements across the industry.