One of our customer in the North West has a critical air handling unit application that removes hot process air from an aluminium recycling line. We recently took over the repairs from this site and as part of our reliability program are responsible for monitoring the condition of critical machinery. We knew this unit had a problem with one of the fan bearings and needed to be removed for service. Such is the demand for the product that we had to plan in a shutdown that would have as-small-as-possible impact on their productivity. That really meant it needed to be done quickly.
The 6 Tonne unit was removed and brought to our works where it was stripped down and fully assessed. It was a good job we removed it when we did, the fan bearing that was identified as being problematic had several of its rolling elements destroyed and could have catastrophically failed.
We used a CMM to measure the critical dimensions of the fan shaft and found the bearing journals to be undersize, this meant we had to manufacture a new shaft which we didn’t expect to. Being put under pressure is not something new to us so as the motor was being refurbished, a new fan shaft was manufactured in house. The fan and shaft were both balanced to G1.0 grade. New fan bearings were fitted with new bearing blocks, the unit was painted and fully refurbished within 4 days of us receiving it.