Machinery monitoring reduces shutdowns for South African paper mill

By Control Engineering Staff June 20, 2006
Bearing failure on air fans can result in the shutdown of a recovery boiler for 6 to 8 hrs. Installation of an online vibration monitoring system from Emerson Process Management reduced unplanned shutdowns.

Austin , TX —The number of unplanned shutdowns has dropped significantly for the Mondi Business Paper’s Richards Bay Mill in South Africa, thanks to an online vibration monitoring system. Using Emerson Process Management ’s CSI 4500 Machinery Health Monitor, the mill can detect changes in fan behavior and alert operators, so that remedial response can be taken to prevent unexpected fan failures and boiler shutdown. The mill produces bleached hardwood pulp made from eucalyptus fiber and white top kraft linerboard.

In seven months, the newly installed technology has “prevented seven incidents due to fan imbalance and early bearing defects that could have shut us down,” said the mill’s Nico Groenewalk, senior mechanical technician, condition monitoring. “We estimate that the savings, in lost revenue from these incidents would have been $542,118. Not only are we more productive, but this is a safer workplace.”

Uneven build-up of deposits on the runners of fans providing air to the recovery boilers can change fan balance and lead to a number of problems. Bearing failure on air fans can result in a shutdown of the recovery boiler for 6 to 8 hrs. Downtime costs are estimated at $17,306/hr, not including repair costs.

The online monitoring program, which is a component of PlantWeb digital plant architecture, provides a continuous flow of information about fan condition. Operators are made aware of any changes in operation immediately so that a faulty fan can be shut down and cleaned or repaired before a failure occurs. System also trends fan behavior over time using Emerson’s AMS Suite: Machinery Health Manager software and allows remote monitoring.

—Control Engineering Daily News Desk

Jeanine Katzel , senior editor