Introduced four years ago, aluminium rollers from Horizon Conveyor Equipment have proved to be a lightweight alternative to steel and an innovative solution to the problems of fire risk.
Since their launch, Horizon Conveyor Equipment’s innovative aluminium conveyor rollers have been tested in demanding conveyor installations all over the world. While offering major health and safety advantages to site operators, the unique design of the rollers is also providing an altogether new solution to a potentially explosive problem.
Horizon’s tightly sealed aluminium rollers are proving to be a superior option in hostile locations where conveyor reliability and the risk of fire are critical concerns. Specially designed to operate at stable temperatures and cut the risk of electrostatic charges, the rollers are not only lighter but also safer than conventional steel rollers in ATEX environments where any excess heat, sparks or fire could have catastrophic consequences.
The aluminium rollers were originally developed to address industry concerns about the health and safety risks of using standard heavy steel trough and return rollers, which not only weigh up to 90kg, but also require extra manpower and prolonged downtime to fit and replace safely, particularly in high or enclosed spaces. Increasingly stringent health and safety rules mean that operators also have to carefully consider the risks posed to personnel from steel rollers during regular conveyor running.
Horizon Conveyor Equipment Managing Director Alan Bowler explains aluminium rollers offer the same level of durability as their steel counterparts but boast weight advantages, noise reduction and energy saving features that have made plastic rollers popular. The high strength factor of aluminium rollers also makes them an ideal option for use on wide belts and in high impact locations.
The extra strength especially for long return rollers is absolutely critical for operators who face real health and safety issues when attempting to replace failed steel rollers.
Light and strong
Made from 6mm thick aluminium tube, the rollers contain a steel shaft and sealed bearings, with the bearing housings manufactured from electrically-conductive glass-reinforced nylon. A large stationary integral stone guard forms the outer primary labyrinth seal that prevents any spillage building up between the roller and the frame, which can jam the roller. A greased inner cupped lip seal together with a sealed bearing keeps out dust, debris and smaller contaminants.
Clive Burfoot, Materials Handling Engineer for E-ON at Kingsnorth Power Station, which has been using the rollers for the past three years mainly on 1350mm and 1800mm belts, says the weight of the rollers has been a major benefit on site. The rollers have been installed into a position of high tension, close to the pulley tail to accelerate the tests.
Horizon’s aluminium rollers offer immediate weight gains to site operators while their unique construction delivers superior performance and longevity in high risk environments. Their heavy duty seals and sealed bearings allow greater resilience in areas where fine dust from biomass pellets, wheat, sugar, flour and cement can damage standard rollers.
Following its conversion from coal-power to biomass, RWE Tilbury Power Station began trialling the aluminium rollers after their existing steel rollers began failing at an alarming rate.
Ron Pannell, Lead Maintenance Engineer at RWE Tilbury Power Station said that the reason for the failure was the extremely fine biomass dust that was getting through the seals of the steel rollers and into their open cage bearings. This caused the rollers to generate excessive heat leading to risk of fire and failure.
RWE sought a solution that would reduce the risk of fire through excess heat and roller failure; the solution also had to be light in weight for easy installation. Horizon’s aluminium roller was chosen for its robust labyrinth and bearing lip seals, and its electrically conductive bearing housing, which cuts the risk of sparks and prevents metal to metal bearing contact in case the roller should ever fail.
Horizon’s aluminium rollers went through an extensive trial, which involved running them for a period and then opening the seals. It found that there hadn’t been any ingress of biomass dust through the seals or into the sealed bearings.
The introduction of the aluminium roller range marks the latest development in nearly 30 years of research and design innovation. The design for the aluminium roller was originally conceived with health and safety in mind. However, with tighter regulations and more consideration to the manpower and downtime needed to change failed steel rollers, there is certainly a need for a lightweight alternative. The rollers are additionally capable of solving a wide variety of problems and reducing risks in some very hostile ATEX environments.