MATERIALS HANDLING
Material loss from conveyors
ABOVE: Ease of service should be a key element in any belt cleaner tensioning system
TENSIONING
Te ability to maintain the proper force required to keep the blade edge against the belt is a key factor in the performance of any cleaning system. Blade-to-belt pressure must be controlled to achieve optimal cleaning with a minimal rate of blade wear. Tere is a popular misconception that the harder the cleaner is pressing against the belt, the better it will clean. But research has shown that there is actually an optimum range of blade pressure, which will most effectively remove carryback material. Increasing tension beyond this range raises blade- to-belt friction, thus shortening blade life, increasing belt wear and increasing
power consumption – without improving cleaning performance. Operating a belt cleaner below the optimum pressure range also delivers less effective cleaning and can actually accelerate blade wear. A belt cleaner lightly touching the belt may appear to be in working order from a distance, whereas in reality, excessive amounts of carryback are being forced between the blade and the belt at high velocity. Tis passage of material between the belt and the blade creates channels of uneven wear on the face of the cleaner. As material continues to pass between the blade and the belt, these channels increase in size, rapidly wearing the blade to a jagged edge. A common source of blade wear that often goes unnoticed – even with a
properly installed and adjusted cleaner – is running the belt empty for long periods of time. Small particles embedded in the empty belt’s surface can create an effect like sand paper, increasing the wear rate of both the blade and the belt. Even though the cargo may be abrasive, it often has moisture in it that serves as a lubricant and coolant. Another potential source of wear is when the cleaner blade is wider than the material flow, causing the outside portion of the cleaning blade to hold the centre section of the blade away from the belt. As a result, carryback can flow between the belt and the worn area of the blade, accelerating wear on this centre section. Eventually, the process creates a curved wear pattern sometimes referred to as a “smiley face” or “mooning.”
As the centre of the blade wears unevenly, the outer edges create a “smiley face” or “mooning”
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