(120e) Troubleshooting Tunnel Vision: Packing Change Blamed for Premature Flooding

A process tower in a plant underwent a packing change to new 4^th generation random packing as a way to gain needed capacity. The production team also used this time to do some other small maintenance on the tower and auxiliary equipment. Upon restart the tower experienced premature flooding at well below design rates. Everyone instantly blamed the new packing for this flooding even though the author insisted conditions were well below the hydraulic capacity of the packing. The tower was unpacked and repacked several times and finally the production team put the old packing back in; but still the problem persisted.

Looking into the other things that were changed during the turnaround it was discovered that a very small change had a tremendous and unexpected impact on the process. This was eventually linked to be the cause of the issue. The packing change had masked the real cause of the issue which extended the troubleshooting effort; costing more lost production.

This paper captures the summary of the troubleshooting investigation and the unique learnings that occurred during the investigation. It also serves as a reminder that not all root causes are obvious ones.