High-vibration incidents at the Proserpine, Victoria and Plane Creek shredders – actions and response planning

During the 2018 crushing season, Victoria Mill’s B side Shredder developed reoccurring high levels of vibration with variability in the phase angle following the processing of low-quality cane. Over a course of weeks, the vibration levels trended upward until reaching unacceptable levels (>10 mm/s). Vibration analysis trends indicated an out-of-balance phase angle shift. This followed evidence of a phase-angle shift at the Proserpine Mill when the disc pack was found to be loose. With 10 weeks until the end of crush, attempts were made to reduce the vibrations at Victoria Mill to acceptable levels and manage the operational capacity of the shredder to the end of season by the reduction of load and speed to mitigate the risk of an extended stoppage. Multiple corrective strategies were undertaken over 4 weeks and were unsuccessful. Failed corrective attempts ultimately led to equipment shutdown with a focus on emergency repair. A decision was made to remove the rotor, transport it to the Burdekin and conduct repairs at the Pioneer Mill’s Integrated Work Management (IWM) utilising its workforce and skill base. Operations recommenced 8 days following initial equipment shutdown and isolation, 2 days ahead of initially planned. This paper maps the response plan that was adopted to optimize the corrective actions to minimize the operational impact to the business. Learnings saw the creation of a Shredder Response Plan that was implemented during a similar incident at the Plane Creek Mill. Key words Shredder, high vibration, phase angle, response plan