MATERIALS HANDLING
Consigned to the scrapheap – low-grade ‘sacrificial’ belts
Despite fitting thicker, heavier belts, we continue to have to replace belts too frequently because of rip and impact damage. What is the best solution? Rob van Oijen investigates
CONVEYOR CLINIC
T
he short answer to the question concerned is that there are no simple solutions, but there are several actions
that will dramatically reduce damage, improve output and minimise costs. These fall into two categories: conveyor design and maintenance, and the conveyor belt itself.
CONVEYOR DESIGN AND MAINTENANCE A significant proportion of belt damage is caused by incorrect installation of auxiliary equipment, damaged, protruding steelwork and components vibrating loose and ultimately becoming detached. The best way to avoid such problems is regular inspection (at least
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daily) backed up by a preventive maintenance regime. This should include rapid replacement of worn or damaged components because they can cause so much collateral damage. The loading point of any conveyor
should always be a target for scrutiny because it is so often the source of damage problems as well as general wear and tear. Several key considerations include: ensuring central loading with material feeding at the same speed and direction as belt travel, repositioning or redesigning chutes to minimise the velocity of free-falling material, integrating screen bars or a ‘V’ slot in the chute to handle lumpy materials mixed with fines, utilising impact idlers or cradles to absorb impact energy, maintaining
clearance between the skirting and belt to prevent objects from becoming trapped, and ensuring smooth flow at the delivery point to prevent blockages.
IT IS NOT WHAT YOU EXPECT... The biggest single cause of catastrophic rip damage is trapped material such as large, sharp rocks or other foreign objects. If these become lodged in a chute or some other part of the conveyor mechanism, they can puncture the belt cover, penetrate the belt carcass and cut the belt lengthwise as it is pulled against the object. Even the thickest, heaviest of belts can quite easily be ripped apart over its entire length in a matter of minutes.
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