Case Study: How Mobile Balancing Restored a 3-Meter Smoldering Ventilator to Full Operational Capacity

Six months of total downtime and weeks of limited operation with significant loss of performance—a single fan—intense economic pressure—and, in the end, a solution found right on site.

Some jobs stick in your memory. This one definitely does.

At the Malting Plant Bamberger Mälzerei, a central kiln fan with a diameter of 3 meters and a power output of 315 kW at 1,490 rpm failed. The bearings had seized, and the shaft and bearings had to be completely replaced.

The repair was carried out right on site—under extremely cramped conditions. But even after the repair, only limited operation was possible: high vibration levels led to a significant loss of power.

The Consequences for the Customer

• Approximately 6 months of total downtime
• Weeks of operation at reduced capacity
• Only 50% drying capacity remaining

Any further downtime would have had a direct impact on production and profitability.

Our On-Site Analysis

A vibration measurement quickly revealed that the primary cause was an imbalance in the fan. By performing mobile balancing directly on site, we were able to bring the vibration levels back within the permissible range.

The result:

• Vibration levels significantly reduced
• Full speed restored
• System back in operation

But the story wasn’t over yet. After about six weeks, the vibration levels rose dramatically again. The fan could only be operated at about 40% of its rated speed.

A repeat vibration analysis revealed the actual causes:

• Imbalance
• Misalignment and shaft deflection
• Loose mechanical components
• Fluttering belt
• Additional misalignment in the belt drive

After replacing a loose pulley, realigning the drive train, and performing another on-site balancing, the system ran stably again.

The result:

• Vibration levels within the safe range
• No shaking during ramp-up
• Back to full speed
• Fan back to stable continuous operation

The Most Important Insight

Such damage rarely occurs suddenly. In most cases, it is foreshadowed long in advance by changes in vibration readings. Continuous vibration monitoring allows critical conditions to be detected early on, thereby preventing costly downtime.

Early detection prevents downtime. Reacting too late means paying twice. That is precisely why condition-based maintenance has become a real competitive advantage today.

Do you face similar challenges at your facility?

We can assist you with vibration analysis, mobile balancing, and root cause analysis right on-site. Contact us at:

Phone: +49 6242 904 250 
Email: auswuchtservicecheck-if-spam@hofmannmaschinen.com

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