Safety, wear and sizing factors into a properly designed system
By Samuel Arnold
Conveyors serve as the backbone for material handling, often running continuously in harsh conditions. However, they frequently face challenges such as material spillage, excessive dust emissions, belt mistracking and premature component wear — issues that contribute to unplanned downtime and costly maintenance. These challenges can be addressed by properly sizing conveyor systems, optimizing geometry and applying effective wear mitigation and maintenance strategies in new conveyor designs, as well as with upgrades, to improve performance and reliability in existing systems.
Properly sizing any conveyor system starts with understanding the conveyed material’s key characteristics, such as bulk density, moisture content, particle size and flowability. These factors directly influence critical design choices like belt width, speed, power and component selection. Material properties affect behavior during transport. For example, wet materials may stick to the surrounding conveyor components or form clumps, affecting the flow consistency, while abrasive materials accelerate component wear. Considering these factors is essential to designing a conveyor system that handles materials efficiently, minimizes spillage and buildup, and reduces premature wear, ensuring reliable and cost-effective operation.
Component design is important to conveyor system longevity and performance. Each part must be designed to meet the application’s operational demands and environmental conditions, working together to maximize the overall system efficiency. Equally essential is the design of the drive system, which must accommodate horsepower and torque requirements that handle both typical operations and fully loaded starts. This includes addressing the increased starting torque needed for heavy loads. Variable frequency drives are increasingly used to enable soft starts, enhance energy efficiencies and improve speed control.
Improperly designed or sized components and systems can cause frequent breakdowns and operational bottlenecks that disrupt production, leading to increased downtime and higher maintenance costs. Conversely, overdesigning a conveyor system can result in overall system inefficiencies and higher upfront capital costs. Achieving the optimal balance through accurate sizing and appropriate component selections is critical to maximizing energy efficiency and extending the equipment’s service life.
Figure 1 — This slider bed with UHMW wear strips is installed in a load zone to increase belt support, providing better skirt rubber contact and sealing with the belt. (Photo: Motion)
Conveyor Geometry and Material Flow
Conveyor geometry extends beyond belt length and elevation, encompassing the entire physical layout that governs material movement. Poorly designed geometry, such as steep or uneven inclines, abrupt transitions or tight curves, can disrupt material flow. These issues often lead to spillage, belt mistracking and mechanical stress, all of which increase maintenance and costs.
The system’s overall layout, including the interaction between conveyors and other plant equipment, can also impact performance. Transfer points can be easily overlooked but are a key component to controlling material flow. Poorly designed transfer chutes increase the risk of material turbulence, spillage and dust, which result in reduced material flow efficiency and greater wear. Proper transfer and load zone design helps smooth material flow, prevents plugging and supports reliable operations.
Tools such as discrete element modeling (DEM) provide detailed simulations of bulk material behavior within conveyor transfer chutes. DEM visualizes flow patterns to identify potential issues within the transfer, such as material turbulence, buildup and velocity changes. This enables engineers to optimize chute shapes and material trajectories, minimizing spillage and wear while boosting throughput.
Minimizing Wear and Maximizing Component Life
By identifying the areas most prone to wear and addressing them effectively, engineers can improve conveyor reliability and extend the lifespan of key components. This approach involves optimizing system design, selecting suitable materials, and maintaining equipment to prevent breakdowns and reduce downtime.
High-wear areas typically include transfer chutes, skirtboards and skirt rubber, load zones, and conveyor belts, with belts particularly vulnerable due to constant material contact. Proper transfer chute design and controlled material flow reduce impact and abrasion on belts, lowering wear and extending service life. Selecting the right belt specifications that match the application, including cover compounds suited to the material properties, is critical for wear management. Additionally, impact beds installed in load zones help absorb energy from falling material, protecting belts and structures from damage.
Minimizing wear in transfer chutes starts with chute geometry. Smooth, gradual transitions and appropriately sized chutes control velocity and distribution, reducing impact and abrasion. Features such as adjustable spoons (curved deflectors guiding material flow to maintain uniform loading) and material diverters further balance flow, lessening localized wear. DEM analysis can also be key in this process by enabling engineers to visualize and analyze material behavior within these chutes, identifying areas of high impact or turbulence to optimize the chute design. This predictive capability helps ensure that transfer chute designs improve material flow, effectively minimize wear and extend component life.
Protective materials, such as abrasion-resistant (AR) steel for chute construction, or chute liners constructed from wear-resistant materials like AR steel, UHMW, rubber composites or ceramic coatings, should be strategically applied to the surfaces most vulnerable to wear. Material selection depends on the dominant wear mechanism (abrasion, impact, sliding) and complements design measures to better protect and prolong equipment life.
Regular inspection and timely maintenance of these wear-prone areas are essential to prevent failures.
After the addition of a deflector plate and spoon to better help material flow through the transfer, DEM analysis shows the end result of less turbulence, less dusting and no plugging in the chute. (Image: Motion)
Reducing Dust, Spillage and Wear at Transfer Points
A borate mine was experiencing persistent issues with excessive dust that impaired visibility and air quality. They also encountered significant product spillage, which caused material loss, trip hazards and costly cleanup. Over time, dust and spillage led to premature component failures, most notably rollers that seized due to material buildup. Return idler guard cages also exhibited material buildup, which accelerated belt wear and increased operating costs.
Motion’s engineering team conducted a site visit and delivered a report identifying these critical problems along with detailed design recommendations. Key improvements included replacing worn skirt clamp systems and skirt rubber in the load zones. The original clamps were ineffective due to wear and corrosion, and the skirt rubber had degraded so much that it could no longer be adjusted to seal against the belt. The new clamps featured
a simple single-lever mechanism, allowing for easy adjustment by one operator.
To further enhance belt sealing, Motion recommended installing UHMW slider beds under each load point, providing consistent belt support and improving contact with the skirt rubber (Figure 1). Additionally, the team found that the existing scrapers were improperly positioned around the discharge pulley, and their tensioning mechanism had worn out, preventing effective blade contact. Motion provided detailed drawings for scraper repositioning, gave field modification guidelines and supplied new scrapers.
After the recommended components were installed, the mine reported a dramatic reduction in airborne dust and product spillage. These upgrades are expected to significantly decrease premature idler failures and belt wear, resulting in lowered maintenance costs and improved system reliability and performance.
Design Considerations for Maintainability
When maintainability is overlooked during the design phase, simple servicing tasks can become time-consuming, labor-intensive and potentially hazardous.
Accessibility plays a critical role in maintainability. Incorporating features such as maintenance platforms around the drive pulleys, walkways, handrails, adequate lighting and easy-to-open inspection panels provides maintenance personnel access to conveyor components safely and efficiently. Designing systems for modularity, where idlers, scrapers and skirtboards can be quickly removed and replaced, significantly reduces downtime and enhances operational efficiency.
Emerging technologies are transforming maintenance strategies by using condition monitoring systems. Sensors continuously track key operational parameters across conveyor components, providing real-time data that enables predictive maintenance. By detecting early signs of wear, misalignment or other issues, operators can take proactive measures to prevent failures, reduce unplanned downtime and extend the service life of equipment.
Conveyor optimization is not a one-size-fits-all solution, but these core principles remain consistent:
Properly size the system and components, designing geometry to ensure smooth and controlled material flow;
Protect high-wear areas with effective engineering and mitigation strategies; and
Prioritize maintainability throughout the design.
When applied correctly, these fundamentals work together to reduce operating costs, minimize downtime and extend the overall service life of the conveyor system.
Samuel Arnold is the manager of engineering services at Motion Conveyance Solutions with more than 30 years of industry experience. For more information, visit motionind.biz/4g5Grlv.
Source: www.coalage.com
