Attaching a Bin Activator To a Silo … More Than Just Nuts and Bolts
|Bin Activators are one of the most successful devices for ensuring flow of bulk material from storage. They can range in diameter from a couple of feet to 18 feet. Bin Activators can be extremely heavy, and while being subjected to vibration, must support the head load created by additional tons of material in the silo. Making a mistake in the design or material used in the hangers that support them can have catastrophic consequences.
Hangers perform two critical functions. First, they must safely carry the Activator and silo head load. Second, they must provide flexibility of movement under vibration and prevent transmission of that vibration to the stationery silo structure. Accordingly, they must be incredibly strong in tension yet free to move horizontally. Our experience has proven that forged steel hangers combined with isolator bushings provide the best uniform tensile properties and strength. At Vibra Screw we produced both with our own dies and molds.
Smaller Activators use smaller forged hangers combined with a lower durometer isolator. Larger activators use larger forged hangers and progressively higher durometer isolators. The critical calculation is to design for each specific load situation with the right choice of forging size and isolator stiffness. The correct design will maximize strength while minimizing vibration transmission. It may sound simple but for Activators to operate within optimal parameters hangers are a critical component.
When applications require even more load carrying ability, simply adding additional standard hangers is not always possible. Our R&D engineers have designed a cable hanger similar in design to the cables used on the world’s largest suspension bridges. The cable hanger provides excellent horizontal flexibility and vibration isolation, and up to 10 times the load capacity of our strongest regular hangers.
Our experience has shown the hanger designs we’ve described here are far superior to those using ordinary bar stock, threaded rod or even castings for vertical support combined with rudimentary off-the-shelf isolators.
Beyond the nuts and bolts of installing a Bin Activator, a carefully designed hanger system is essential. Vibra Screw’s 60 years of experience, from invention of the Bin Activator to development of its present design, ensures the safety and integrity of each system.