Full definition
A primary belt cleaner is a critical component in conveyor belt systems, specifically designed to enhance operational efficiency by removing residual material that adheres to the belt after material discharge. Located at the discharge end of a conveyor, this scraper blade assembly is vital for maintaining a clean return strand, preventing carryback, which can lead to spillage, contamination, and additional wear on the belt system. The construction of primary belt cleaners varies, with common materials including molded polyurethane, which is favored for its self-sharpening properties and durability (75-85 Shore A hardness), tungsten carbide tips for extreme abrasion resistance in mining environments, ceramic inserts for longevity and aggressive cleaning capabilities, and stainless steel for applications requiring food-grade compliance. The choice of material directly affects the performance and lifespan of the cleaner, making it essential to select the right type based on the application requirements.
The mounting mechanisms for primary belt cleaners typically include torsion-arm or spring-loaded assemblies that ensure a consistent contact pressure between the blade and the belt surface. This design allows the blade to maintain optimal pressure as it wears down, which is crucial for effective cleaning. The angle of the blade is generally set between 0° and 15° relative to the belt surface, which can influence cleaning efficiency. Contact pressure usually ranges from 1 to 3 lbs per linear inch of belt width, and the efficiency of primary cleaners alone can achieve a carryback removal rate of 60-80%. It's important to ensure that the primary cleaner is compatible with any mechanical splices on the belt, as the blade must navigate over these splices without causing damage or interruptions in the cleaning process.
Regular maintenance is essential for primary belt cleaners to function effectively. According to guidelines set forth by CEMA 576 and Martin Engineering, inspections should be conducted weekly to assess tension and blade wear. Replacement of blades should occur when they reach the minimum length mark to ensure continued cleaning performance. Brands such as Martin, Flexco, ASGCO, Brelko, and Slic Stick are recognized for their high-quality primary belt cleaners, which are essential for optimizing conveyor system operations.