The Conveyor Cure

Conveyors are indispensable to cement production. From quarry extraction through raw milling, clinker transfer, and finally product dispatch, they provide continuous movement of bulk materials with minimal human intervention. Their efficiency and reliability directly affect plant productivity. When conveyors perform well, operations flow seamlessly. When they falter, production slows or even halts.

One of the most common and disruptive conveyor challenges is carryback. Fine particles cling to the return side of the belt after discharge. In cement environments, this problem is magnified by the nature of the material: dust-laden, abrasive, and prone to absorbing moisture. Carryback does not simply reduce housekeeping standards; it cascades into issues such as accelerated roller wear, belt mistracking, drag on drive systems, and, in some cases, emergency stoppages.

Spiral roller technology, and in particular the K-Spiromax® Cleaning and Tracking Roller, provides a combined approach to these challenges. The design integrates cleaning and tracking functions, making it suitable for demanding cement applications. Its performance in the field highlights both the technical features and the wider benefits for maintenance, safety, and sustainability.

Carryback in cement conveyors

The material properties of cement clinker and raw meal present unique cleaning challenges. Both are characterised by high calcium content and hygroscopic behaviour. When exposed to ambient moisture in transfer stations or enclosed tunnels, they quickly turn from free-flowing powders into a paste-like layer that adheres tightly to belt surfaces.

Traditional scrapers, whether rubber blades or metal edges, often lose effectiveness as this paste builds up. Instead of being removed cleanly, carryback is transferred from the belt to the rollers, forming build-up that increases friction and reduces belt life. Build-up on one side of the belt can also cause it to drift off the line. The misalignment itself generates additional spillage, setting up a cycle that becomes harder to correct without intervention.

The consequences are not limited to production losses. Carryback contributes to safety hazards, with spillage creating slip risks around walkways and obstructing pullwire access along conveyors. It also increases the frequency of manual clean-up tasks, which can expose workers to dust and confined-space conditions.

These interconnected challenges underline the importance of solutions that can simultaneously clean the belt surface and maintain tracking.

Spiral roller design and function

The K-Spiromax Cleaning and Tracking Roller takes a different approach from scraper systems. It is based on the principle of integrating cleaning and tracking within the roller itself. The unit is a standard return roller fitted with resilient polyurethane spirals arranged in a helical pattern across the roller face. The design produces two effects:

• Cleaning action. The spirals wipe against the belt surface, removing fine material before it can consolidate. Unlike rigid scrapers, the flexible polyurethane flicks residues away, preventing material build-up. Because polyurethane is non-abrasive, it avoids gouging or damaging the belt cover, extending belt life as well as the roller’s own service life.
• Tracking action. The helical geometry exerts a corrective force when the belt begins to drift. As one edge carries more load or adhesion than the other, the opposing spiral pattern nudges the belt back toward centre alignment. This process is continuous and does not depend on manual adjustment.

The dual action is significant in cement conveying, where cleaning inefficiency and mistracking are often linked. By addressing both together, spiral rollers help stabilise conveyor performance and reduce cumulative maintenance demands.

Placement and application

Where spiral rollers are placed within the system strongly influences their effectiveness. The general recommendation is to install them directly above a discharge chute or collection hopper, ensuring that removed material falls into controlled containment rather than onto the floor.

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Read the article online at: https://www.worldcement.com/special-reports/29122025/the-conveyor-cure/