Repeated shaft failures in a large slurry tank

An agitator shaft in a 15 m tank failed repeatedly at the joint to the gearbox flange. Replacing the shaft did not solve the problem.

The location and nature of the failures indicated that bending loads were an important factor. We investigated how the slurry flow affected shaft loading at different fill levels and operating modes, and the simulations indicated that the fill level being run produced very large bending moments on the shaft.

We are now evaluating different designs that would reduce the bending moment without losing mixing performance.