Paper Mill Bearing Failure Because of Thermal Shock
Rapid thermal expansion from quickly restarting a paper machine can damage bearings. Gradual reintroduction of steam prevents thermal shock and unplanned shutdowns.
What happens when you steam-up your paper machine too fast?
Paper machines operate at high temperatures, but during shutdowns they cool off.
When restarting operations, it's critical to bring the system up to temperature gradually. If high temperatures are reintroduced too quickly, it will lead to a rapid thermal expansion it causes rapid thermal expansion leading to bearing damage.
At a Canadian paper mill, the bottom pocket roll bearing in the dryer section of a paper machine was severely damaged due to thermal shock.
This bearing failure was found with the SDT340 during the next ultrasound survey. The crest factor of this bearing was far above baseline indicating a new fault had developed. And further inspection revealed the bearing had completely split.
To prevent future thermal shock, steam must be reintroduced gradually. This ensures the components expand evenly, reducing the risk of damage and unplanned shutdowns.
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