Screen deck failure analysis at a coal washing plant
Panels were lasting a third of their rated life. The panels were not the problem.
The plant had changed panel suppliers twice in eighteen months, each time because the polyurethane was failing early — cracked bridges, blown apertures, panels lifting at the corners. Both suppliers were reputable. Both sets of panels failed the same way.
Reading the failure, not the invoice
Identical failure modes across two different materials almost always means the deck, not the panel. We pulled a full deck and put a straight edge across the support rails. Three rails had bowed by more than four millimetres. Every panel spanning those rails was being flexed on every stroke, and polyurethane does not forgive repeated flex at the bridge.
The bowing itself traced back to a feed distribution problem upstream. Material was landing heavy on one side of the deck, and the rails on that side had been carrying an off-design load for years.
What was actually needed
- Replace three support rails and re-shim the deck to flat
- Fit a feed distribution plate to spread the load across the full deck width
- Return to a standard panel specification — no exotic material required
Panel life went from roughly four months to the rated eleven. The customer had been about to specify a considerably more expensive panel compound to solve a problem that was, in the end, three pieces of bent steel.
