- Shop-floor assessment of roll bearings in a steel mill
- Back to back trials show MHC-Memo detects all faults detected by VA
- MHC-Memo preferred as lower cost, easier to use & simpler to interpret
MHC Proves its 'Metal' on the Shop-Floor
British Steel invested in new mill stands at its Universal Beam Mill. These new stands could accommodate a wider product range and offered quick roll-change times allowing greater responsiveness to customer requirements. However a number of unexpected roll bearing failures threatened to dent the improvement in customer service. They needed an easy to use bearing condition monitoring instrument which could detect early stage faults in roll bearings and prevent bearing failure.
The benefits gained from the early fault detection are :
- Allows maintenance and spares holdings to be better planned
- Maximises plant availability and minimises unplanned shutdowns
- Enables product quality to kept to the highest standards
- Allows secondary damage to be averted
Three CM vibration instruments were thoroughly evaluated on the shop floor:
- MHC vibration instrument (loaned from Holroyd Instruments)
- Kurtosis based vibration instrument (already owned by British Steel)
- FFT based high frequency demodulation instrument (already owned by British Steel)
14 rolls were tested in turn with sensors were mounted directly onto the bearing rotating at 60 RPM. 6 of the rolls were identified as having possible damage. When stripped, each had extensive spalling on the inner race. When (after continued service) those rolls that showed no evidence of damage were stripped for visual inspection their bearings were found to have no signs of damage.
The MHC and the FFT based high frequency demodulation instrument gave substantially similar findings whilst the instrument measuring kurtosis was found to be a less reliable indicator. MHC was simpler to use, quicker and lower cost and on that basis was chosen as the preferred option.
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