John King Chains

21.3 Pin and bushing DRY erosion

Pin and bushing DRY erosion


Chain bearing surfaces can be eroded when handling dry materials which act like a fluid when in contact with chain. This type of wear is often identified on elevators handling materials such as finished cement or dry gypsum, if the elevator boot is flooded with material. It has been described as dry cavitation erosion. The severity of the condition depends on the amount of material in the boot and the length of time it is flooded. The appearance of the worn surface is one of extreme irregularity and once the channels and pockets of wear are established the rate of wear tends to accelerate.
To establish the most effective deterrent it is necessary to examine the conveyor design. The position of the infeed, the consistency of delivery and the chain speed, thus the ability of the elevator to keep the boot clear and avoid flooding are paramount.