Operators have many issues to consider when seeking out an appropriate conveyor belt cleaner, including how to maintain the proper tension to achieve optimum cleaning performance – without introducing related problems.
Inadequate tensioning causes carryback to cling to belts and spill along its path, piling up under conveyors and emitting excessive dust. This requires extra labor for cleanup, and it can affect air quality.
Over-tensioning leads to friction damage to the carrying side of the belt, premature blade wear and potential splice damage. Both scenarios contribute to unsafe work conditions and raise the cost of operation.
“There are two basic approaches to applying tension to the belt cleaner: linear and rotary,” says Dave Mueller, conveyor products manager at Martin Engineering. “The blade’s cleaning position and angle of approach to the belt often dictate whether a linear or rotary tensioner is used.”
The Conveyor Equipment Manufacturers Association (CEMA) defines cleaning positions as primary, secondary or tertiary. Primary cleaners typically function with a “peeling” action, while secondary and tertiary cleaners are usually scrapers. Belt cleaners mounted in the primary position generally employ a rotary-style tensioner, while most units mounted in the secondary or tertiary positions use linear-style tensioners.
In most cases, belt tensioners have to be monitored and adjusted manually so they can maintain optimum pressure and carryback removal. Estimating when blades need changing is often a guessing game that, if left too long, could lead to unnecessary complications.
While manufacturers continue to improve belt cleaner effectiveness, it is clear that no single or ideal solution for belt cleaning and tensioner selection exists. Safety of personnel and the belts themselves is the primary consideration when selecting a tensioner. Ease of inspection and maintenance is critical for belt cleaner effectiveness, so the tensioner must allow for quick and safe service.
Information provided by Martin Engineering.