Volume, Density, and Bulk Handling

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Volume and density play pivotal roles in shaping the specifications of bulk-handling systems. It is imperative to comprehend their differences, as this understanding significantly influences the efficiency and reliability of the equipment involved.

Volume pertains to the space a substance occupies, while density characterizes its mass. The significance lies in the fact that objects with identical masses can have different volumes and vice versa. A wooden block and a steel block, for instance, may share the same volume but differ in mass. Similarly, a kilogram of PVC and a kilogram of helium-filled balloons possess the same mass but occupy different volumes.

This distinction becomes crucial in material handling as it guides the configuration of bulk-handling equipment. Consider a conveyor tasked with managing 10 tons of shavings per hour. Volumetrically, it must be larger than a conveyor handling 10 tons of pellets per hour. Pellets, being denser, demand less space, allowing for a physically smaller conveyor. However, given identical inputs, such as conveyor length and elevation, the power and chain requirements remain consistent between the two machines, as the mass of each load remains the same.

While the difference between volume and density is common knowledge, experienced operations personnel often encounter challenges when there’s a change in material characteristics, such as if they were to transition a conveyor from handling dry woodchips to green ones. Green chips are denser than dry chips. This difference can potentially lead to performance issues or even conveyor failure. Conversely, a conveyor designed for green chips may run less efficiently when handling dry ones because the motor is now oversized for the application.

Efforts to compensate for changes in volume or density like increasing the conveyor’s speed bring their own problems. For example, light materials may fail to flow smoothly at elevated speeds, causing accumulation within the conveyor.

Faster conveyor speeds also accelerate component wear. Chains, paddles, side panels, and bottom panels succumb to increased stress, resulting in quicker deterioration. Chain conveyors, in particular, may encounter issues with chain skipping, where the chain and paddles ride over the material, damaging the product and increasing fines.

Belt conveyors can face challenges when belt velocity increases, too. Materials can sometimes bounce on a conveyor belt as they enter the tail instead of resting on it. This behavior can result in material accumulating in the tail and chute. It can also result in spillage and produce dust. Bouncing occurs because the material entering the conveyor lacks forward momentum, and inertia keeps it from changing direction, much like dinner plates stay on a table when you whip the tablecloth out from under them. Thus, it tumbles and bounces until it picks up enough momentum to “stick” to the belt.

Consult the conveyor manufacturer if you ever adjust materials or throughput rates. They can assess potential issues and identify modifications that may help. At BE&E, we strive to address your concerns and maintain the performance of our conveyors. Our commitment to solving problems underscores our dedication to producing top-performing equipment. Contact us with your questions, and let us help keep your conveyors running smoothly.