Engineering Solutions for Reducing Wear in Bulk Material Conveyors

The movement of bulk materials through conveyors can present a number of design challenges. Bulk materials are usually hard, often harder than the surfaces of the conveyance. The nature of the materials can increase wear on components, leading to expensive repairs, premature replacement of equipment or costly downtime.

As such, the design of the equipment should address these problems in advance. By understanding the issues inherent to bulk material conveyance, engineers can develop design solutions to reduce the likelihood of damage and maintain efficiency in production.

Problems Common to Bulk Material Conveyance

For any design to be useful, it must address the common problems inherent to the process. In the case of bulk material conveyance, engineers must contend with high-impact zones, damage caused by constant friction during production, component wear over time and unanticipated equipment downtime.

High-Impact Zones

The conveyor may have certain high-impact zones that require additional evaluation in the design phase. Simply put, the bulk material usually strikes the conveyor material in specific places. These high-impact zones are more vulnerable to wear, scratching or failure. Understanding where the material is likely to hit can help engineers change the flow of the material or increase the durability of the components used in high-impact zones.

Friction

When two materials come in contact with each other, the impact can create friction that could cause damage. The bulk material touches the components of the conveyance and triggers an abrasion as the grains or metals move down the production cycle. Signs of friction are common in high-impact zones, like pneumatic elbows.

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Friction is more likely to become an issue when the surface of the conveyor equipment is not as hard as the bulk material being moved. Evaluating the friction coefficient, based on dense phase or dilute phase design, can help engineers determine whether the conveyor components need additional protection from friction.

Component Wear

A high degree of impact and friction contributes to wear on certain components. Surfaces that are more likely to scratch due to friction may be more difficult to clean. Over time, surface scratches and dents can compromise the material, increasing the likelihood of buckling or warping. Damage may contribute to material contamination or lower efficiency in production. Eventually, component wear requires repair or replacement.

Equipment Downtime

Many manufacturing facilities maintain a narrow margin between costs and revenue, highlighting the importance of equipment uptime. The general cost of equipment means that manufacturers may not have more than one of any system.

When a conveyor fails due to excessive wear on components, production may stop entirely. As engineers design conveyor parts, they should evaluate potential solutions that will minimize downtime due to wear from bulk materials.

Design Phase Solutions

With a thorough understanding of the common problems that manufacturers face when processing bulk materials, it is reasonable to shift focus to the design phase. Implementing technologies such as discrete element method modeling, along with preventive components like ceramic-composite materials, rock boxes, impact rollers and abrasion-resistant coatings, engineers can design effective and damage-resistant grain storage solutions.

DEM Modeling

To determine where the materials are most likely to hit, discrete-element method modeling can be a useful tactic. DEM modeling involves using numerical methods to evaluate where the materials will move along a conveyor.

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In essence, the movement of each particle is assessed individually, instead of trying to determine how the material will move in bulk. With the model, engineers can evaluate the hardness and other aspects of the bulk material to determine the likelihood of wear.

Ceramic-Composite Materials

Ceramic is a popular material for extreme environments like high heat, but alone, it may not be strong enough to handle the worst presented by bulk material processing. The use of ceramic-composite or ceramic matrix materials can gain many of the benefits of ceramic without its brittleness. 

Typically, the composite combines ceramic with another material, such as silicon carbide. The result is notably resistant to high temperatures, but also very hard and less likely to sustain damage from high impact in the bulk material conveyance.

Rock Boxes

The use of surge pockets or rock boxes are key elements of a robust bulk material conveyor design. Surge pockets create a space in the conveyance that allows the material to accumulate, but not to an excessive degree.

The rock box spreads the material, usually in a grid or honeycomb pattern, so that it is more likely to collide with itself than the interior material or liner of the container. The device usually requires an alert system to notify users in the event that the material backs up enough to stop production.

Impact Rollers

Many conveyors rely on rollers and belts to transport material, which can be a common source of impact, damage and system downtime. Impact rollers can help to reduce the potential for damage.

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Specifically, impact rollers use materials with a high hardness to reduce denting or scratching, even for bulk material processing at high velocity. The rollers are positioned at high-impact points, such as loading and transfer zones, with multiple slopes to allow the material to strike the surface and move along the belt with minimal disruption.

Abrasion-Resistant Coatings and Liners

The coating on the material of the conveyor may be the last defense against damage. Manufacturers often rely on abrasion-resistant coatings on metal or ceramic components to decrease the negative effects of impact and friction.

Abrasion-resistant liners are also an option to reduce damage in areas where the material itself cannot mitigate the risk. Liners are fairly simple to replace and usually cost less than replacing the component.

Since manufacturers rely heavily on the use of bulk materials, they require processing facilities that can withstand the weight, friction, velocity and impact of the materials on equipment. Conveyors with poor design elements are more likely to contribute to unexpected wear, repair, and downtime.

By integrating sound design principles, like DEM modeling and surge pockets, engineers can provide a system that meets requirements and minimizes the potential for damage presented by the bulk material.